Taal te 
Neale Hsieeve diet 
srt veg © 


ro 


seta hio tity hat erhyest hats 4 
Sted shee thes sheds me et ep on 

4 oh lel wie Sipe 
Tenens gts 


<4 

thest 
ibid vorhad 
tad nee 


pest 
fet 
hnerin fear f 


4 a 
Bebat oy erh 
Riera as | 


§Orp pee dhe 
eiahiae! 


jules 
(oubge! 


eve 
dae 
tire 


erararehes 
TE PES, 
ov ac ita prone 
Aerie Fal ww 


aie: 
aWelet tens idat 
ad Fel dee stuns 


Sa Tiefas Roast 


TER: 
St peat Lm lashe bstiae, 
roa tilted s 
rye 


theme 
ree 9h 


Betprroieas 
pete byies) 


‘2 sia 
hot Hag ni otet aren 
pr betyes 
Mad sina cantina piae 
talb ) vf ohetad ce stdveaee iat 
we whew be tsa duaves 
gis tateee epee 


bots 
bs i Sistine is 


Fi wt 
on ms nner 


a 

re etict 

erst ihe 5 
bab oe eve 

artes ss 

: 


ia hustaie rs 


Sessks ty rides 
Bloat isesieayt ttl 


byes 


ye 
fet 


Ppele nia rd et USES 8 wi 
tet gies Te 


preety 


yoreshyer p08 momen 


Sse 
Sal aig ten 
Tyiateas ea ay 


i 
el ye he! 
eiet aya itenee we 

Beye pip cee reer) etry 
Sete Moped ys 


mth 
sad pues 


foes wi guante seed ty 
tedhten deine 
gn ait a4 ae: ese y isi 


a 
Weecesy pistes 
els 


est bai te 
Sai eisueite 
bebrataly 


Lye teve renege 
ad srenatieg? 
Leah haredrt est 
Sas 
li shened si 
¥ 
TT 


as ne 
Byceeayt: 

5 ; 

Seeley eta 


Tet slenel Cy 
~ - TS eiedera wae 


pra 
i 


Bt ptedietny 


Rar} 
aatat 


ca 
x 


f 
uy eis 
Va Haas “4 +e feria Whe popdvols 
Oi iestda tere | : rhe rebates pli 
abet 


pe tesretast 
soa 
leanne 


is 
rs 
frat 
Hehirsyh epson 
saa 2 
4a tables Meats 94) 
SERRE Crete 
Srarhscsreion peeiot ht 
Nene esha ob ltt 
Wie 4ed on hel yate 44 Chalanae st nee ae . 
okeh tite 
bas ste 
pay totais at ait Be 


fais a ots 

asi pe ren heh Se 
Je Aaa ia 
Da reset Behr 


t ran 
Sd reshcinint oo 

Tie oes t 
i 


at 


nal 


' pee re bpplats 
prenprss ; BI 
iseeahere a 7 Per onibarhseehs 

i i wstatatae 


: 

au 
ti aiteas 
2 


sees 
aa ad anda th 
Spiers) 


athe 


Sir aol atavene stele at hay 
sree Non teshatat« 
ieee Me 


Coren 
a) 


ea 


fr 


a 
sak done 
aS ielS 
eet 
ig 
ot 


bi} 


etre 
bot aati) 


ii 
bapa 
#96 


ee 


at 
s 
eases Te 


iy 


oat 


ede ” 
aiiek seitan oat gre 
ga rennenationt 
4 Oe ¥en 
Tis! ake 
peat Grats Te 
ceptseayiotp! 


te v iy Ratt 


bok 
eee 


) oe 
aaa arte 


pavaperey 
Bap os vo need 
eo in 
3 
porter 
sivlatsies 
a sidiete 
fiighert 


iSite i Vek} 

asbtod bid oexpaatebs fy het 

is Siriaas sitar 
Fr 


rpesre 
Tiaras, 


1 
pio 
Wace 


ae 


poet 


Sh sea 


hee ity 


Frenphiniey, 
Tati a 


bbara 
ces ae ae 
eiahae oy 


o 


i 


al 

preie's phe: 
eaait 
PRhLeh 


Mes taerye 
a, eng? oUaioes 
Hit iota 

rsestee Heatly 


f f btithie at 
At npran hppa piaheh:?. 


Tt 
lel gatas 


Bede teats 


peice 
se 


bopalaanres 
ais 
bts 
$ Nae 


do en 


ert 
poet 
fate 


a 
4 


2.4 
pes 
2 


Perey s 
jeabee ss ov sheer 
erate 


. st pate 
Abhetrset rh 


ae ied pitten yo 
seipenecraitt 
ease atrt ecves: 


bol 
Miatereteliret 
asitigs 


etre 


Dhanaets 
sheradsy 


2 

ph 3d ees 

Reh 
Ais 


shiek 


ere 


hits apse 
Seca sntes 


: istatetet teat, 
x “ 
sieduonest sarees 


bore 


ite 
pha 
ite 


one hy de bat 


wa 


iohesel oF 
Sol raphpeulsrsty! SS 
ae panes 
is 


pecirer ert 
rT 


tas sigs 
oe ee 


Ani ee yee 


eens res 
Tex Nr eeatcs treay erent 
etl ee epee dome 
Ae! ee 


errr 


snnyih ire 3s 


+) ot (retshedeoens 
oe 


BP lee wi sereate nce 


: = 
BS eee opens “oe 


oes Harte 
Represent 


ropegtebekyiysp 


pebacotgs paste or 


icin o.deraed 
ilges sea 


we) 


Ipisherertaaes 
aol ne she Feng ne) 


ia Beene 
ee he 


dora preh 
Sates 1 =6ee 
eee 


+2 ee 


Digitized by the Internet Archive 
in 2010 with funding from 
University of Toronto 


http://www.archive.org/details/memoirs42harv | 


MEMOIRS 


OF THE 


MUSEUM OF COMPARATIVE ZOOLOGY 


HARVARD COLLEGE. 


VOL. XLII. 


CAMBRIDGE, MASS., U.S. A. 
PRINTED FOR THE MUSEUM. 
1915. 


~ li fy vy As % 


7 ee ae 
Tue Cosmos Press: 


Epwarp W. Wuee.er, Campriner, U. S. A. 


Memoirs of the Museum of Comparative Zodlogy 
AT HARVARD COLLEGE. 


Von. Sul: 


REPORTS ON THE SCIENTIFIC RESULTS OF THE EXPEDITION TO THE 
EASTERN TROPICAL PACIFIC, IN CHARGE OF ALEXANDER AGASSIZ, 
BY THE U. S. FISH COMMISSION STEAMER “ALBATROSS,” FROM 
OCTOBER, 1904, TO MARCH, 1905, LIEUT. COMMANDER L. M. GARRETT, 
U. S. N., COMMANDING, AND OF OTHER EXPEDITIONS OF THE “ALBA- 
TROSS,” 1891-1899. 


DO. SIS 


THE SPONGES. 
3. HEXACTINELLIDA. 


By ROBERT VON LENDENFELD. 


WITH ONE HUNDRED AND NINE PLATES. 


TEXT. 


{Published by permission of Huca M. Smrra, U. 8. Commissioner of Fish and Fisheries]. 


CAMBRIDGE, U.S. A.: 
Printed for the Museum. 


JUNE, 1915. 


CONTENTS. 


REPORTS on the Scientific Results of the Expedition to the Eastern Tropical Pacific, 
in charge of ALEXANDER AGassiz, by the U. 5. Fish Commission Steamer “ Albatross,” 
from October, 1904, to March, 1905, Lieut. Commander L. M. Garrett, U. S. N., 
Commanding, and of other expeditions of the “ Albatross,” 1891-1899. XXIX. THE 
Sponges. 3. Hexactinellida. By Ropert von LeNDENFELD. 397 pp. 109 Plates. 


June, 1915. 


TABLE OF CONTENTS. 


I. INTRODUCTION 
Il. METHODS 
Soft parts 
Skeleton 
Spicules 
Graphic Tepreséntation 
Measuring . 
Biometry 
Nomenclature of the pprewtee 
LUNN EG DESCRIPTION OF THE SPECIES COLLECTED BY THE ALBATROSS 
HEXACTINELLIDA 
HEXASTEROPHORA 
EUPLECTELLIDAE 
EUPLECTELLINAE 
Ho.ascus : : ; ; : F 
H. edwardsii (Plate 18, ae 15-26; Plate 19, figs. 1-24; Plate 20, figs. 1-20) 
HoLascELLA 
H. taraxacum (Plate 21, ee. 1- 13; Plate 22, foe eas Plate 23, fot 1-3) 
H. ancorata (Plate 23, figs. 4-25; Plate 24, figs. 1-9) : , ; 
H. euonyx (Plate 24, — 10-17; Plate 25, — 1-24) 
CAULOPHACIDAE ; : ‘ 
CaAULOPHACUS : P ; : : : 5 : 
C. schulzei (Plate Ue fe 20-31; "Plate 8, figs. 1-29; Plate 9, figs. 1-33; 
Plate 10, figs. 1-29; Plate 11, ieee 1-17) : 


NS oe Go tO 


CAULOPHACELLA 
C. tenuis (Plate 12, foe 1- 19) 
CaLycosILvA 
C. cantharellus helix (Plate 1, Boa 1 a 20-24; Plate 2, fi, 3, 7-13, 15; 
Plate 3, figs. 1-5, 8-30; Plate 4, figs. 23, 24; Plate 5, 
figs. 1, 2, 4, 5, 7-9, 11-15, 18-20; Plate 6, figs. 5-21, 24— 
34; Plate 7, figs. 1-10, 12-14, 16, 17) 
C. canthareilus ane (Plate 1, figs. 9-19, 25-29; Plate 2, figs. 1, 2, 4+ 6, 14, 
; Plate 3, figs. 6, 7; Plate 4, figs. 21, 22; Plate 5, figs. 
6, 10, 16, 17; Plate 6, i 1-4, 22, 23; Plate 7 ie 
figs. 11, 15, 18) : : E 
C. cantharellus megonychia (Plate 4, figs. 1-20; Selate By fie. 21; Plate 7, 


fig. 19) 
Doubtful caulophacid (Plate 32, 10-12) 
RoOssELLIDAE ‘ ; ; F 
ROSSELLINAB 
BaTHyDORUS 
B. laevis A ; 
B. laevis spinosissimus (Plate 14, Ree 1-32; Plate 155 face He 22 » Plate 16, 
figs. 1-24) : : : : : 3 
LANUGINELLINAE : p 


LANUGONYCHIA . 
L. flabellum (Plate 12, es. 20-34: Pi: RS 13, fics! 1-28) 
ACANTHASCINAE : : . : ; 


PaGe. 


11 
11 
11 
12 
12 
13 
13 
16 
17 
19 
19 
19 
20 
20 
20 
21 
29 
29 
37 
44 
47 
47 


48 
64 
64 
67 


67 


68 


68 
92 
93 
93 
94 
94 


94 
103 
103 
103 
112 


CO 


CONTENTS. 


STAUROCALYPTUS ; 
S. hamatus (Plate 16, ge 25-43; Splote Nef, Gas 1-25; Plate 18, eg ne 14) 


EURETIDAE 
FARREA ‘ : : : ; 3 
F. occa Saree (Plate 25, eg. 25-29: Pl Her 26, figs. 1-21; Plate 27, figs. 
1-17) ; , 
F. sp.? (Plate 32, figs. 1-3) . 
F. sp.? : ‘ 
EURETE 


E. erectum (Pl: ite 30, a5, 1- 17; Plate 31, figs. 1-28) 
E. erectum A-D . ; : ; 
E. spinosum (Plate 29, figs. i 26) ‘ : : 
Euretid from Station 4641 (Plate 106, figs. 1-3) 
Euretid (?) from Station 4651 (Plate 32, figs. 4-6) 
Wuretid (?) from Station 4685 
Euretid (?) from Station 4695 
CoscINOPORIDAE 
CHONELASMA : : 
C. sp. (Plate 32, figs. 7-9) 
TRETOCALYCIDAE ; : 
HEXACTINELLA 
H. monticularis (Pl ate 28, peel 1-28) 
H. sp. indet. (Plate 32, figs. 18-15) 
AMPHIDISCOPHORA : : ‘ : 
HYALONEMATIDAE 
HYALONEMA 
HyYALONEMA - : : ; : : : : 
H. obtusum che (Pl ae 33, ie. 1-24; Plate 34, figs. 1-19; Plate 35, figs. 
1-37; Plate 36, figs. 1-45; Plate 37, figs. 1-22; Plate 
38, figs. 1-8; Plate 39, figs. 1-10 
H. obtusum robusta (Plate 39, figs. 11-41; Plate 40, figs. 1-22) 
H. agassizi (Plate 41, figs. 1-14; Plate 42, figs. 1-59; Plate 48, figs. 1- 7; 
Plate 44, figs. 1-30; Plate 45, figs. 1-64; Plate 46, figs. 
1-16; Plate 47, figs. 1-13) : : 
H. polycaulum (Plate 53, figs. 1-17; Plate 54, figs. 1-45) 
H. placuna (Plate 68, figs. 29-51; Plate 64, figs. 1-19; Plate 65, figs. i 23: 
Plate 66, figs. 1-5) 
H. sp. from Station 4656 (Plate 68, figs. 26-33; Plate 69, fies! 1-5) 
H. tenuifusum (Plate 67, figs. 1-26; Plate 68, figs. 1-25) 
H. tylostylum (Plate 69, figs. 6-25; Plate 70, figs. 1-10) 
H. grandancora (Plate 78, figs. 16-45; Plate 79, figs. 1-26) 
H. sp. from Station 3684 (Plate 80, figs. 1-16) 
LrPTroNEMA : 2 
H. campanula (Plate 81, Ben, 1- 26) 
PRIONEMA : 
H. agujanum dont A (Plate 72, foe 17-21, 23- 25, 27; Plate 73, Ae. 1-6; 
Plate 74, figs. 1-5, 8; Plate 75, figs. 1-13, 15, 17, 19-27, 
29-37; Plate 76, figs. 1-7, 11, 12, 15-36) 
H. agujanum tenuis B (Plate 72, figs. 16, 22, 26; Plate 73, fig. 7; Plate 74, 
figs. 6, 7,9; Plate 75, figs. 14, 16, 18, 28; Plate 76, figs. 
8-10, 138, 14) ; : 
. agujanum lata (Plate 77, figs. 1-10; Plate 78, de fe 15) é 
. azuerone (Plate 56, fig. 1; Plate 57, figs. 1-23; Plate 58, figs. 1-22) 
. spinosum (Plate 48, figs. 131; Plate 49, figs. 1-23; Plate 50, figs. 1-5) 
. crassum (Plate 106, figs. 4-37; Plate 107, figs. 1-20; Plate 108, figs. 1-17) 
. pinulifusum (Plate 70, figs. 11-24; Plate 71, figs. 1-11; Plate 72, figs. 
1—1'5) : 
H. fimbriatum (Plate 59, figs. 1-6; Plate 60, aa 134; Plate 61, He 1 uu: 
Plate 62, figs. 1-45; Plate 63, figs. 1-28) 


Pesca op 


PaGeE. 
112 
112 
119 
119 


119 
125 
125 
126 
126 
135 
135 
139 
140 
141 
141 
142 
142 
142 
143 
143 
144 
149 
150 
150 
150 
152 


153 
153 


172 
201 


207 
220 
222 
229 
235 
243 
245 
245 
250 


251 


251 
251 
266 
273 
278 


284 


294 


CONTENTS. 


OoNEMA ‘ . : : ; : : F 
H. bi: mreboraturs Hag ities (Plate 82, figs. 1-34; Plate 83, figs. 1-68; Plate 
84, figs. 1-32; Plate 85, figs. 1-8) ; 
H. henshawi (Plate 97, figs. 1-36; Plate 98, figs. 1-7) : 
H. crassipinulum (Plate 92, figs. 1-23; Plate 93, figs. 1-10; Plate 94, aes, 
1-33) 
H. densum (Plate 94, figs. 34-42; Plate 95, fies, 1-20; Plate 96, figs. 1-14) 
H. sequoia (Plate 85, figs. 9-21; Plate 86, figs. 1-36; Plate 87, figs. 1-7; 
Plate 88, figs. 1-13; Plate 89, figs. 1-36; Plate 90, figs. 
1-10; Plate 91, figs. 1-6) ; ; : P 
PHIALONEMA : 
H. brevancora (Pl: As 55, aes, 1-37) ; 
H. pateriferum (Plate 50, figs. 6-15; Plate 51, figs. ‘1-28: Plate 52 Sarat 1-29) 
SKIANEMA 


He Reanatonale (Plate 99, aoe 1- 37; Plate 100, Hel ie 12; “Pls Me 101, figs. 

1-3) : 3 

H. umbraculum (Plate 101, figs. 4-17; “Plate 102, figs. 18: “Plate 103, figs. 
1-36) ‘ ; : 5 : : : 

THALLONEMA : : : : : ; ‘ 

H. geminatum (Plate 103, es, 374 62 poplate 104, figs. 1-14; Plate 105, figs. 

1-14) : : : ; ; : : : 


IV. LIST OF STATIONS 


HEXACTINELLIDA. 


I. INTRODUCTION. 


In this Report the Hexactinellida collected during the ALBATROSS cruises 
of 1899-1900 and 1904-1905 in the Tropical Pacific under the direction of 
Alexander Agassiz are described. 

Mr. Agassiz’s liberality has enabled me to employ methods of research and 
graphic representation not hitherto used and to describe the material very 
fully. 


Il. METHODS. 


1. THE SOFT PARTS. 


The deep-sea Hexactinellida which come into the hands of specialists are 
generally in such a condition that very little can be made out, by the ordinary 
methods of sectioning and staining, of their very tender soft parts. This is 
due to their mixing with the deep-sea ooze during the passage of the dredge 
over the bottom and to the pull and pressure acting on them in the long haul 
to the surface. After many experiments I finally found the following method 
best suited to this kind of material: —a piece of the specimen, 3 to 1 em. in 
diameter, with intact surface is imbedded in paraffin and cut into thick radial 
sections. These are not stuck on the slide but placed free, first in xylol, then in 
alcohol, where much of the deep-sea ooze, which has got into the sponge during 
capture, and many of the fragments of spicules splintered in cutting fall out of 


the section, so that it becomes fairly clean. These loose sections are then 


12 METHODS. 


passed into absolute alcohol, in which magenta or another aniline dye soluble 
in alcohol is dissolved. In this solution the sections very rapidly become well 
stained. They are not washed after this, but immediately transferred into 
xylol, in which the magenta, azur, etc., are insoluble, and then mounted in 
balsam. By this method the canals and the flagellate chambers can be made 


out in many a perfectly hopeless looking specimen. 


2. THE SKELETON. 


For the study of the arrangement of the spicules, and of the skeleton in 
general, thick radial sections made in the manner described above, but not 
stained, gave the best results. Such sections even of hard forms with a con- 


tinuous skeleton-net, like the Euretidae, can be cut without difficulty. 


3. THE SPICULES. 


My method of fractional sedimentation with final centrifugation has 
also been employed in the examination of the Hexactinellida. On account of 
the great amount of foreign siliceous material (skeletons of Radiolaria, etc.) 
in many of the specimens these spicule-preparations are, however, often not 
so clean as one would wish. To obtain clean preparations of the larger spicules 
I made a heap of spicules of sediment (I) by boiling a piece of the sponge in nitric 
acid, allowing it to settle a short time and drying in the usual manner. From 
this I, or rather my wife, who in time grew exceedingly expert, picked out under 
the microscope the spicules wanted. A fine needle, the point of which was 
rendered sticky with Schellibaum’s mixture of collodion and clove-oil, was used 
in this work. These spicules were then regularly arranged on a slide, also 
covered with a thin layer of Schellibaum’s mixture. To this they adhere, and 
can be immersed in balsam and covered with a cover-glass without becoming 
disarranged. 

The preparations of the smaller spicules of sediment (II), etc., and the cen- 
trifugated ones were heated till all the chloroform used for dissolving the balsam 
had evaporated and only the previously boiled balsam, which is quite hard at 
ordinary temperatures, was left. They were then, whilst cooling, pressed between 
the leaves of a book. In this way preparations are obtained which are much 
clearer than unpressed ones, and which can be examined with the highest powers 


much more conveniently. 


METHODS. 13 


4. GRAPHIC REPRESENTATION. 


All the figures on the plates in this Report are photographs. These photo- 
graphs were taken partly with ordinary, and partly with ultraviolet (wave 
length 280 yu) light; with the same apparatus and in the same way as those illus- 
trating my Report on the Geodidae (Mem. M. C. Z., 1910, 41, p. 12 ff.) where 
the photographic methods employed are described. I found it very difficult 
to obtain good photographs of floricomes and other small microhexaster-forms; 
chiefly because it is hardly possible to get good clean preparations of intact 
spicules of this kind, either in balsam (for photography with ordinary light), 
or in chloral-hydrate glycerine (for photography with ultraviolet light). My 
hexaster-photographs are consequently not nearly so attractive as the drawings 
of them in the papers by other authors — but they accurately represent what 
one actually sees. 

To facilitate comparison the figures representing the systematically most 
important spicules of the same kind in the different species are given in the same 
magnification throughout. To these commensurate figures others, in other mag- 
nifications, are added where necessary. The uniform magnifications selected 
for the commensurate figures are such that the smallest forms observed come 
out just large enough to allow their main characters to be distinctly made out. 
They are: —for the pinules 300; for the microhexactines, the hexasters and 
their derivates, and the amphidises 500. The photographs of parts of the 
spicules and of whole small spicules showing minute details were all taken with 


ultraviolet light and are magnified 2000. 


5. MEASURING. 


Every exact description must be based on measured dimensions. The 
dimensions of organisms and their parts are inconstant and vary in various ways. 
To obtain dimensional data sufficient for use as premises for a systematic or 
any other biological conclusion it is therefore necessary to ascertain the range 
and biometrical character of the variation in the extension in space of the parts. 
In the case of such organisms as the Hexactinellida the smaller spicules at 
least should be studied biometrically. They can be most easily and accurately 
measured and are considered by all authors as the most important part from a 


systematic (phylogenetic) point of view. It would have been quite impossible, 


14 METHODS. 


within a reasonable space of time, to take the many thousand measurements 
necessary for this by means of the methods hitherto employed. 

I therefore cast about for a better method and finally worked out a new 
micromeasuring apparatus, which Mr. Agassiz’s liberality enabled me to set 
up. The plan of this apparatus (Fig. 1) has proved most useful. The greater 
part of it is also represented on Plate 109. The light of a powerful, self-regulat- 
ing constant-current arc-light (Fig. la) passes a system of lenses and cooler 
(Fig. 1b) and enters a microscope (Fig. le) with the optical axis placed horizon- 
tally. A movable mirror 1.5 x 1.5 m. in size (Fig. 1d) is so placed in front 
of the microscope that the image produced is reflected on to a vertical glass- 
plate (Fig. le) frosted on the side turned towards the mirror, and measuring 
2>%2m. Lamp and microscope are so placed that the latter stands at the 
side of and close to the frosted glass-plate. The observer sitting in front of 
the latter can comfortably work both the screws moving the slide to right 
and left and up and down (Fig. 1g), and that focussing the microscope (Fig. th). 
The horizontal optical axis of the microscope is oblique (not vertical) both to 
the mirror and the frosted glass. The mirror, however, is placed so that the 
axis of the cone of light reflected from it abuts vertically on the frosted glass- 
plate. This arrangement insures the image, thrown on to and visible on the 
frosted glass, being perfectly true, and not in any way distorted. By means 
of the screws moving the slide, everything on it can easily be passed in review. 
When a spicule, or anything else that is to be measured, comes into view, it 
is focussed and measured. 

When working with this apparatus, I placed lamp, microscope, mirror, and 
frosted glass always in the same position; and every time I commenced I tested 
the correctness of the position of the parts by projecting and measuring the 
micrometer-slide. For each combination of objectives and eyepieces used I 
made a special scale which was drawn on a ribbon of tracing-cloth. These 
ribbons (tapes) were fixed to canes, like strings to bows (Fig. 2). It is easy 
with these bow-string tapes to measure rapidly the distance between any two 
points in a plane vertical to the optical axis of the microscope. 

The observer dictates the dimensions thus measured, and anything else 
notable he may observe. His assistant sits behind him at a table (Fig. 11) 
with a shaded (Fig. 1k) light (Fig. 11). It is possible, if the preparation is a 
good one, to write down the dimensions at the rate of six to ten per minute. 

This method is not only convenient and rapid, but also exceedingly accurate. 


The measurements taken with it when using high powers are exact to 0.1 xu. 


Fig. 1 


Fig, 2 


PAVE 


Figs. 1, 2— Projection measuring apparatus. 


16 METHODS. 


The exactness of these measurements is indeed so great, that I detected, in 
working with this apparatus, certain slight errors in the micrometers employed, 
which had been obtained from a firm of excellent standing. These errors this 


firm itself found after having, at my request, reexamined the micrometers. 


6. BIoMETRY. 


To utilize the measurements taken biometrically, all those of the same 
dimension in different individuals must be arranged in groups of suitable extent. 
In each group all the measurements lying between certain limits are placed, 
and the number of dimensions lying between these limits ascertained. These 
numbers are then plotted on equidistant ordinates in a graph and the points 
thus obtained connected by a line. This line is the biometrical frequency-curve 
of the dimension studied. 

In the method generally employed the groups of dimensions represented 
by the ordinates of the graph are equal in range. That is to say, the mean 
dimensions of the groups to which the ordinates correspond form an arithmetrical 
progression like 1, 2,3, 4,....n. This method involves a systematic error which 
makes the resulting biometrical curve wrong and misleading. When a dimen- 
sion examined varies between limits small in comparison to itself, that error 
is slight and generally overlooked. When, however, as is the case in the amphi- 
dises of the Hexactinellida for instance, the dimensions examined vary so much 
that the largest may be twenty-five times as great as the smallest, the error 
leads to results so glaringly wrong that it is noticed at once. This error is caused 
by the equality of the extent of the successive groups and by their mean dimen- 
sions, which are represented by the ordinates of the graph, forming an arith- 
metrical progression. For it is obvious that a difference, say of 10 u, in the length 
of objects only 10-20 » long must be of far greater biological importance than 
the same difference of 10 » in the length of objects 500-510 » long. To avoid 
this error I divide the measurements taken into groups of uniformly increasing 
range. The increment selected is such that the extent of each successive group 
is 10 % greater than the extent of the preceding group, so that the ordinates, 
which are also placed by me at equal distances in the graph, represent a series 
of mean-dimensions of groups which form the geometrical progression 1.1, 1.1, 
1 a ree Talis 

The biometrical curves obtained in this manner express identically the 
character of dimensional variation of all the individuals compared, however 


METHODS. 17 


large or small they may be, and are therefore biometrically much more correct 
than those obtained by the method generally in use. In this Report such fre- 
quency-curves, which are biologically more correct, are extensively made use of. 


7. NOMENCLATURE OF THE SPICULES. 


I use the same names for the spicules as those employed by F. E. Schulze 
and other authors. The few new names given are explained where they first 
occur. I find F. E. Schulze’s division of the amphidises into the three groups 
macramphidiscs, mesamphidiscs, and micramphidises by no means universally 
applicable and have divided the different kinds of amphidises found in each 
species according to their morphological and biometrical characters, independ- 
ently of and without regard to the arrangements of them in other species. I 
have, however, retained Schulze’s names, because only a very small fraction 
indeed of the Amphidiscophora actually growing on the sea-bottom are 
known, and it would be premature to propose a new general arrangement of 
these spicules, and to replace Schulze’s names by others. 


= A= =a > === ieee ee 


=" “s Pe 08 orld dee Aes 


=e cy & IZ 


ley) AEF 3. Sate 


tS Wye 0" OP Des salted 


> ofan 
A wile ij, meal ands on 


+5666 gabe a 


III. DESCRIPTION OF THE SPECIES COLLECTED IN THE PACIFIC 
OCEAN BY THE ALBATROSS. 


HEXACTINELLIDA O. Scumiprt. 


Siliceous sponges with hexactine (triaxon) spicules, and derivates of such. 

The Albatross collection of Pacific hexactinellids comprises, besides a 
number of small, quite irrecognizable fragments and isolated hyalonematid 
stalk-spicules, from Stations 3684 (A.A. 17), 3685 (A.A. 25), 3689 (A.A. 134), 4630, 
4631, 4649, 4651, 4656, 4685, 4709, 4711, 4721, 4732, 4736, 4742, which are not 
further referred to in this Report, 124 more or less complete specimens and 130 
fragments sufficiently large for study and at least approximate identification. 

The examination of this material has corroborated the correctness of F. E. 
Schulze’s ' division of the order Hexactinellida into the two suborders Hexas- 
terophora and Amphidiscophora. 


The collection contains representatives of both suborders. 


Hexasterophora F. E. Scuuuzn. 


Hexactinellids generally (or always) with hexasters, always without amphi- 
discs. The spicules are either all free, or some of them are joined by 
secondarily deposited silica to form a firm supporting skeleton-net. 

The collection comprises sixty-seven more or less complete specimens and 
124 fragments of Hexasterophora. 

The examination of these sponges does not make necessary any alteration 
in F. E. Schulze’s most recent arrangement of the Hexasterophora in ten fami- 
lies;” all of them find a place in these families. 

1 Ff. EH. Schulze. Revision des systemes der Hyalonematiden. Sitzungsb. Akad. Berlin, 1893, no. 


30, p. 541; Amerikanische Hexactinelliden, 1899, p. 93. 
2 F. EH. Schulze. Hexactinellida. Ergeb. Deutsch. tiefsee-exped., 1904, 4, p. 172. 


20 HOLASCUS. 


The collection contains representatives of the following families: — Euplec- 
tellidae, Caulophacidae, Rossellidae, Euretidae, Coscinoporidae, and Treto- 
calycidae. 


EUPLECTELLIDAE (Gray) Isma. 


Tubular, cup-shaped or massive Hexasterophora attached by a stalk or a 
tuft of basal spicules or sedent. Generally with numerous separate oscules. 
The dermal skeleton is composed of hexactines, the proximal ray of which is the 
longest. Without hypodermal pentactines. 

The collection comprises four more or less complete specimens and six frag- 
ments of specimens of Euplectellidae. 

Ijima ' and F. E. Schulze? distinguish two subfamilies, Euplectellinae and 
Corbitellinae. The collection contains representatives of the former. 


Euplectellinae Isima. 


Euplectellidae which are attached by a tuft of basal spicules. 

The collection comprises four more or less complete specimens and six 
fragments of Euplectellinae. These belong to the two genera, Holascus and 
Holascella. The latter is new. 


HOLASCUS F. E. Scuuuze. 


Tubular Euplectellidae (Euplectellinae) with terminal sieve-plate, with 
root-tuft, and without parietal apertures in the body-wall. The chief support 
of the body-wall is a network composed of large tetractines, pentactines, or 
hexactines, held together by slender comitals. Oxyhexasters and graphiocomes 
are always present. Discohexasters and floricomes are absent. Hexactines 
with equal rays, calicocomes, and sigms occur in some species and are absent in 
others. The hypodermals are hexactines with short and thick, spiny distal ray, 
to which slender comital rhabds are attached. The anchoring spicules of the 
root-tuft are diactine rhabds with oblique backwardly directed spines and a 
distal tyle, from which anchor teeth-like spines arise. The morphological 
centre (axial cross) of these spicules is situated a considerable distance above 
their terminal anchor-tyle. 

The collection contains two more or less complete specimens and two 
fragments of this genus. All belong to the same species, which is new. 


17, Ijima. Studies on the Hexactinellida. III. Journ. Coll. sci. Tokyo, 1903, 18, p. 26, 27. 
2 FE. Schulze. Loc. cit., p. 178. 


HOLASCUS EDWARDSII. 2] 


Holascus edwardsii, sp. nov. 


Plate 18, figs. 15-26; Plate 19, figs. 1-24; Plate 20, figs. 1-20. 


Two somewhat fragmentary specimens and two separate root-tufts of this 
species were trawled in the Milne Edwards Deep, off the coast of central Peru, 
at Station 4672, on 21 November, 1904; Palominos Light House, N. E., 163 km. 
(88 miles); 13° 11.6’S., 78° 18.3’ W.; depth 5203 m. (2845 f.); they grew on fine, 
green clay; the bottom-temperature was 35.2°. 

Shape and size. One of the two specimens is fairly large, the other small. 
The large specimen (Plate 20, fig. 4) appears as a fairly straight, somewhat conic 
tube about 180 mm. in length. Originally this tube probably had a circular 
transverse section. Now it is flattened, one side touching the other. The tube 
is about 90 mm. in circumference at the upper end, and attenuated below to a 
circumference of about 50 mm. Its upper margin has a lacerated appearance, 
and is not to be considered as the true termination, but as a line of fracture 
along which the upper end of the sponge has been torn off. Below, this tube 
gradually passes into the root-tuft, the upper part of which appears as a compact 
stalk, circular in transverse section and 15 mm. in diameter. This root-tuft is 
about 100 mm. long, considerably and uniformly curved, slightly attenuated in 
the middle, and spread out distally to form a somewhat irregular spicular mass. 

The wall of the tube is 4-5 mm. thick. Its outer dermal face (Plate 20, 
fig. 4) is very rough and irregular, an appearance probably due, to some extent 
at least, to the indifferent state of preservation of the sponge. The inner, gastral 
face (Plate 20, fig. 3) is perforated by numerous more or less circular apertures. 
Two kinds of such apertures, large and small ones, can be distinguished. The 
large apertures are 1.5—2.3 mm. wide in the central part, half way up the tube. 
Toward both the upper and the lower ends of the tube they become smaller. 
These apertures are very regularly arranged in one spiral line, or in a succession of 
ring-shaped transverse rows. Within the spiral (the rings) they are close to- 
gether, separated by walls of tissue, usually only 0.5-1.5 mm. broad. The spiral 
turns (rings) themselves are farther apart, separated from each other by zones 
3-4.5 mm. broad. The small apertures are mostly circular, 0.3-0.4 mm. in 
diameter, and scattered in considerable numbers between the large ones. 

The small specimen is similar but only 42 mm. long, and also destitute of 
the upper end. Its tubular part is not collapsed, circular in transverse section, 
and 6 mm. in diameter, The root-tuft is bent quite round so as to form a semi- 
circle, 


22 HOLASCUS. EDWARDSII. 


The larger of the two separate root-tufts is rectangularly bent near the 
middle of its length. One limb, which evidently formed the stalk of the sponge, 
is 60 mm. long, cylindrical, straight, and throughout about 14 mm. thick. The 
other limb, which formed the root, is 70 mm. long, conic, and attenuated to a 
fine point. The smaller separate root-tuft is similar but more uniformly curved. 

The colour of the sponge-body proper, that is the tube, is, in spirit, nearly 
dark brown. The root-tufts are colourless. 

The skeleton. A network with rectangular meshes composed of large, stout- 
rayed pentactines, held together by slender-rayed comitals, forms the main 
support of the tubular sponge-body. The large pentactines have a short apical 
and four long lateral rays; two of the latter, the two opposite ones, are usually 
markedly longer than the other two. These pentactines lie side by side in a 
single layer in the choanosome of the tube-wall; their apical rays are directed 
radially outwards; their lateral rays extend paratangentially, the longer ones 
longitudinally, the shorter ones transversely. The distances between the centres 
of these pentactines are much smaller than the length of their lateral rays, 
which consequently cross each other repeatedly. Slender-rayed diactine to 
hexactine comitals accompany these pentactines in large numbers. As the 
rays of these spicules closely adhere to the rays of the pentactines, and as dif- 
ferent rays of the same comital are often attached to rays of different pen- 
tactines, the latter are firmly held together and in position by the former. 

Small hexactine megascleres, rhabds, microscleres, and siliceous skeletons 
of foreign organisms also occur in the choanosome. 

The small choanosomal hexactine megascleres appear to be much more 
abundant in the lower than in the upper parts of the tube-wall. Quite low down, 
in the region where the tubular body passes into the root-tuft, they form dense 
masses. 

Of choanosomal rhabds other than the diactine comitals of the large 
pentactines I have observed two kinds, centrotyles and exceedingly slender, 
thread-like rods. The centrotyles are of varying size, and the large ones usually 
accompanied by smaller ones arranged round them comital-fashion. The 
slender thread-like rhabds were found only in the choanosome of the small 
specimen. 

The microscleres are oxyhexasters, hemioxyhexasters, microoxyhexasters, 
graphiocomes and (?) ring-shaped sigms. Of the three first named, which must 
be considered as different varieties of the same kind of spicule, the oxyhexasters 


are by far the most numerous; the hemioxyhexasters are rather, the micro- 


HOLASCUS EDWARDSII. 23 


oxyhexasters very scarce. The graphiocomes are also rather rare and nearly 
always destitute of end-rays. The ring-shaped sigms are very numerous, both 
in the centrifuge spicule-preparations and in the sections, but in spite of this I 
am not at all sure that they are proper spicules of the sponge. They may, 
like the masses of other siliceous skeletal structures found in the sponge, be 
altogether foreign to it. 

Below the outer surface of the tube-wall hypodermal hexactines with two 
radially situated, differentiated rays occur. The distal, differentiated, some- 
what protruding ray is short, stout, and spined. It raises the dermal membrane 
conule-fashion. The four not differentiated (lateral) rays extend paratangen- 
tially. The proximal ray is elongated. To the distal rays of these hexactines 
slender, simple or centrotyle, comital diactines are attached, which, when 
numerous, form a sort of mantle around it. Below the inner surface similar, 
hypogastral, hexactines are situated. The distal rays of these spicules are, how- 
ever, more slender and destitute of comitals. 

The root-tuft consists chiefly of very long diactine anchor-spicules. A few 
spined styles and tylostyles, with the blunt end situated distally, are also found 
in it; these may, however, be foreign to the sponge. 

The choanosomal centrotyle rhabds (Plate 19, figs. 22-24) are 290 u-1.7 mm. 
long and, near the middle, 5-47 » thick. The small ones, under 400 u in length, 
are fairly numerous, the larger ones’rare. The tyle is usually more (Plate 19, 
fig. 23) or less (Plate 19, fig. 22) toward one end, more rarely situated centrally 
(Plate 19, fig. 24). It consists of four ray-rudiments, which are, however, 
so small in some, particularly the large centrotyle rhabds, that they can hardly 
be individually distinguished. The tyle measures 14-60 u» in transverse diame- 
ter. In the small centrotyle rhabds it is relatively large, the proportion between 
the tyle-diameter and the thickness of the adjacent parts of the spicule being 
here 2:1 to 3.5:1. In the large centrotyle rhabds the tyle is relatively small, 
this proportion being here 1.27: 1 to 1.5:1. The two rays are conic or cylindric 
and sharp-pointed or, more frequently, blunt. The largest centrotyle rhabds 
appear to be quite smooth. The small ones are spiny, particularly near their 
ends. The degree of spinulation is on the whole in inverse proportion to the 
length of the rhabd. 

The slender, thread-like rhabds observed in the small specimen are under 1 u 
thick and relatively very long. 

The rhabd comitals of the distal rays of the hypodermal pentactines are straight 
or slightly curved, simple or centrotyle, and generally 200-400 u long and 2-2.5 
thick, 


24 HOLASCUS EDWARDSII. 


The rare styles and tylostyles of the root-tuft, which, as above stated, may 
be foreign to the sponge, are covered with spines, and near the distal, rounded 
end 12-17 » thick. The distal end itself is either simply rounded off or, more 
frequently, thickened to a terminal tyle, with a maximum transverse diameter 
of 32 Me 

The anchoring spicules (Plate 20, figs. 5-20) are anisoactine rhabds. I 
did not observe any long intact ones. The longest fragments observed were 
45 mm. in length. The morphological centre, the position of which is clearly 
marked by a well-developed axial cross (Plate 20, figs. 5-8a) is only 137-200 u 
distant from the distal end of the spicule. Thus, whilst the proximal ray may 
attain a length of over 40 mm., the distal ray is usually less than 0.2 mm. long. 
Proximally the spicule is gradually attenuated to a fine point. Distally it 
thickens, and it attains its maximum thickness some distance beyond the middle 
of its length, long before the morphological centre (axial cross) is reached. 
Beyond, it again becomes thinner, and near the distal end, at the thinnest point 
between the morphological centre and the terminal anchor, is 7-11 » thick, 
about two thirds to three quarters of what it measures in the middle. At the 
distal end the spicule is thickened to a terminal tyle. 

The proximal part of the spicule (Plate 20, fig. 11) is perfectly smooth. 
Somewhere about the middle of its oblique length, backwardly directed spines 
begin to make their appearance; these usually enclose an angle of 20-30° with 
the axis of the spicule. At first (Plate 20, fig. 12) these spines are very small 
and far between. Farther on (Plate 20, figs. 13, 14) they become larger and 
more numerous, and they continue to increase in number and size quite up to 
the morphological centre (axial cross). On the distal ray the spicule has four 
to seven spines every 100 » (Plate 20, figs. 5-10, 15-20). In the middle of the 
spicule the spines are uniformly scattered and not arranged in groups (Plate 20, 
figs. 18, 14). Towards the distal end they tend to form verticillate clusters 
(Plate 20, figs. 5-8, 15-20), two of which are particularly pronounced, one situ- 
ated at the morphological centre (axial cross) (Plate 20, figs. 5-8a), the other 
at the end. Together with the terminal tyle this second cluster of spines forms 
the anchor. 

The large spines of the distal part of the spicule are 10-30 u long and 4-7 yu 
thick at the base. The terminal ones, which form the anchor-teeth, are similar 
to the others, but somewhat stouter. 

The anchor appears as a conspicuous terminal thickening with an outline 
closely resembling an inverted gothic arch. From the proximal side of this 


HOLASCUS EDWARDSII. 25 


thickening arise backwardly directed teeth usually six to eight in number. The 
anchor-teeth of the same anchor being more or less unequal in size, shape, and 
position, the anchors themselves appear more (Plate 20, figs. 5, 6, 16, 18) or less 
(Plate 20, figs. 7, 8, 19, 20) irregular. The anchor, that is the terminal style to- 
gether with its teeth, is 45-72 » long and 32-50 u broad. 

The axial thread of these spicules extends quite to the end of the terminal 
anchor-tyle. Within this tyle it is thickened in a spindle-shaped manner and 
here measures 2.5—4 » In maximum transverse diameter (Plate 20, figs. 5-10). 
This terminal thickened part of the axial thread is granular, and irregular in 
outline. From it arise a number of branchlets, up to 1» long, usually very 
oblique, strongly inclined towards the end of the anchor. According to F. E. 
Schulze’s figures! in other species of Holascus the axial thread of the anchoring 
spicules in the terminal anchor-tyle is not thicker than elsewhere. In deserib- 
ing H. tenuis this author, however, says” ‘‘Der Achsenkanal durchsetzt den 
Kolben” (that is, the terminal anchor-tyle) ‘‘bis dicht an seine untere Spitze 
und erfahrt hier zuweilen eine kleine terminale Verbreiterung oder Zerteilung 
in ein schmales Biischel mehrerer Endausliufer.”’ 

The thickening of the distal end of the spicule and of its axial thread 
in the anchor-spicules of Holascus edwardsii is doubtlessly correlated to the 
shortening of the distal ray. I think that the influence which prevented the 
distal ray from obtaining a length commensurate with the length of the proximal 
ray, also caused the thickening of the ends of the distal ray and its axial thread, 
and the formation of the oblique branchlets of the terminal swelling of the latter. 
This influence may be inherent, arising naturally at a certain period of develop- 
ment in the spicule-building cells themselves, or it may be due to the resistance 
which the distal ray encounters at its tip whilst it is being pushed outward 
(downward) in consequence of the continued longitudinal growth of the proximal 
ray. The latter alternative seems a priori the more probable, but I am rather 
inclined to favour the former since young anchoring spicules, the distal ends 
of which do not protrude over the surface and have not yet reached the deep-sea 
deposit (ooze) into which they are afterwards driven, already possess a distal 
anchor-tyle. 

The terminal thickening of the axial thread with its branchlets in the 
anchor-tyle is in many respects similar to certain structures found in the cladomes 


1 PF. E. Schulze. Rept. Voy. Challenger, 1887, 21, pl. 16, figs. 11, 13 H. fibulatus; Hexactinelliden des 
Indischen Oceanes. II. Abh. Akad. Berlin, 1895, 1896, taf. 1, fig.6 H.robustus; Ergeb. Deutsch. tiefsee- 
exped., 1904, 4, taf. 1, figs. 4, 6 H. tenuis. 

2 F. EB. Schulze. Ergeb. Deutsch. tiefsee-exped., 1904, 4, p. 6. 


26 HOLASCUS EDWARDSII. 


of the anatriaenes of Thenea valdiviae ' and other tetraxonid sponges. In these 
the branchlets, however, appear to be rudiments of primary axial threads and 
morphologically equivalent to the axial threads of the rhabdome and the fully 
developed clades. Here in Holascus edwardsti they can only be considered as 
(secondary) axial thread-branches equivalent to the axial thread-branches in 
the end-clades of dichotriaenes. 

The large choanosomal pentactines (Plate 18, fig. 22a; Plate 20, figs. 1, 2) 
have straight or slightly curved conic rays, which are 75-145 » thick at the 
base. The lateral (paratangential) rays are long and form the edges of a low 
quadrangular pyramid, from the apex of which the short apical (distal) ray 
arises. The lateral rays, which extend longitudinally, are 13-19 » long, the lat- 
eral rays, which extend transversely, 7-11 mm. long. The apical ray has a 
length of about 1.5mm. The terminal parts of the rays bear scattered, small, 
broad, and blunt spines. The other parts of the rays are smooth. 

In the distal part of the lateral rays of these pentactines the axial thread is 
thickened at frequent intervals. These thickenings are, on the whole, conic 
and consist of verticils of short, rod-like, axial thread-branches diverging only 
slightly from the axis of the ray, extending backward centripetally and a little 
outward. The slightly granular substance, of which these rods consist, is 
apparently the same as the substance composing the axial thread. Sometimes 
a small cap, with the convex side turned towards the distal end of the ray, is 
found within the conic rod-verticil, just below its apex. These axially situated 
caps consist of a substance with a refractive index very different from that of 
the substance of the axial thread and the silica-layers of the spicule, and are 
consequently, in spite of their small size, very conspicuous. They look as if 
they were portions of tissue rich in water, entrapped by the growing spicule 
(axial thread). The conic verticils of rods (axial thread-branches) and these 
caps indicate that the growth of the lateral rays of the pentactines is inter- 
mittent; the rod-verticils and caps marking the positions of the ray-tips at the 
times of suspension of longitudinal growth. Each node of the ray between two 
adjacent thickenings of the axial thread is doubtlessly produced by the unin- 
terrupted work of a spicule-builder or a set of spicule-builders. The secession 
of work by the cell or cells causes the interruption of growth. After a time 
the same spicule-builder or same set of spicule-builders or a fresh one or fresh 
set recommences or commences work, whereupon the growth again goes on. 

The comitals (Plate 18, figs. 15, 16, 22b, 23) which hold the large pentactines 


1R, v. Lendenfeld. Die Tetraxonia. Ergeb. Deutsch. tiefsee-exped., 1907, 11, p. 200 ff. 


HOLASCUS EDWARDSII. Dil 


together are slender-rayed hexactines. The most frequent forms are triactines 
with a central thickening. Usually the rays are either well-developed and 
very long, or reduced to mere knobs arising from the centre. Rays intermediate 
between these extremes (Plate 18, fig. 23) are rare. The rays have a maximum 
length of 7 mm., are very slender, only 6-14 uw thick, usually nearly cylindrical 
and terminally rounded, more rarely considerably attenuated towards the end. 
The central thickening, which is composed of the knob-like rudiments of the 
aborted rays, is 15-32 » in diameter. 

The small choanosomal hexactine megascleres have straight, conic, pointed 
rays, 0.17—1 mm. long and 12-18 u thick at the base. 

The hypodermal hexactines (Plate 18, figs. 19-21, 24-26) have a more or less 
curved proximal ray, usually 1.2-1.5 mm. long and 5-7 u thick at the base. 
The lateral rays are fairly straight, have the same basal thickness, and are 
usually 180-240 u long. The distal ray is 180-260 u long, straight, and 6-13 p 
thick at the base. It is more or less club-shaped, thickened above, and abruptly 
pointed. At the thickest point, which is usually about 50 » from the end, the 
distal ray measures 13-23 », on an average (of twelve measurements) 18 » in 
transverse diameter. The proportion of the basal to the maximum thickness 
is 1:1 to 1:3, usually about 1:2. The distal ray is covered with spines. These 
are small and scarce below but become larger and more numerous above, towards 
the distalend. The spines are broad, conic, and pointed, with a maximum length 
of 2.5 u and are directed obliquely upward, towards the end of the ray. On 
account of their relatively great breadth and their obliquity, they appear as 
nose-like protuberances of the ray. 

The hypogastral pentactines (Plate 18, figs. 17, 18) are similar to the hypo- 
dermal ones but their distal rays are distally much less thickened. The 
maximum thickness of their distal rays is only 7-20 u, on an average (of twelve 
measurements) 13 4. The proportion of the basal to the maximum thickness 
isos A toil: 2: 

The abundant oxyhexasters, the rare hemioxyhexasters, and the still rarer 
microoxyhexasters (Plate 19, figs. 1, 2) are obviously all different forms of the 
same kind of spicule. They measure 108-180 » in total diameter. A difference 
in the size of forms with simple and with branched rays could not be detected. 
The main-rays, which are, in the same spicule, equal, and enclose right angles 
with their neighbours, are 8-12 » long and 2-4 » thick. Each one bears from 
one to four end-rays. The number of end-rays on the six main-rays of the same 
spicule is usually unequal; but the difference is generally only one, main-ray 


28 HOLASCUS EDWARDSILI. 


with only one end-ray being usually associated with bifurcate, bifureate with 
trifureate, and trifurcate with quadrifurcate ones. In the simple rays, that is 
in those consisting of a main-ray and a single end-ray, the point of demarcation 
between main- and end-ray is clearly marked by a thickening of the distal end 
of the former (Plate 19, figs. 4,5). I consider this thickening a rudiment of the 
other, reduced, end-rays. The end-rays arise steeply from the main-ray, but 
immediately curve outward, and are, farther on, usually nearly straight. Occa- 
sionally the proximal part of the end-ray, beyond the basal curve; is irregularly 
bent. The end-rays are conic, gradually attenuated to a fine point, 57-83 u 
long and 1.6—2.8 y» thick at the base. The bases of the simple rays have the 
same thickness as the main-rays. All parts of the spicule are perfectly smooth 
(Plate 19, fig. 11). 

The graphiocomes (Plate 19, figs. 12, 13) have main-rays which enclose 
angles of 90° with their neighbours and are equal in the same spicule. The 
main-rays are 11-17 w long and 2.5-3.5 uw thick. The single end-ray brush 
measured was 15 u long. 

The ring-shaped sigms (Plate 19, figs. 14-21), which, as above stated, may 
be skeletal structures foreign to the sponge, are rods, 1-2 u, rarely 2.8 u, thick in 
the middle, attenuated at both ends to fine points, regularly and uniformly curved 
so as to form a whole low spiral turn or, more rarely, a part of such a spiral. 
Lying flat they usually appear as circular rings with an interruption at one point. 
The rings formed by them are 17-57 » in diameter. The ends are usually simple 
and sharp-pointed (Plate 19, fig. 14); rarely they bear on the concave side one 
or two small, cylindrical, terminally rounded spines (Plate 19, fig. 18). Near 
the middle of the rod a slight irregularity can usually be made out, but this does 
not appear to be a thickening which could with any probability be considered 
as the rudiment of another ray. 

Although the upper end is missing in all the specimens and it must therefore 
be left undecided whether they possessed terminal sieves or not, I think that the 
want of parietal apertures, the spiculation, and the other characters described 
above show clearly that they belong to the genus Holascus. From the nine 
hitherto described species of this genus they differ by possessing ring-shaped sigm 
microscleres. Since, however, these ring-sigms may not be homologous to the 
sigms of H. fibulatus, but foreign to the sponge, I shall not consider them in the 
following systematic discussion. 

Apart from this, Holascus edwardsw differs from five of the nine Holascus 


species by the absence of calicocomes. Of the remaining four, one, H. undulatus, 


HOLASCELLA TARAXACUM. 29 


is distinguished from it by the possession of discohexasters; another, H. stellatus, 
by the possession of oxyhexasters (hemioxyhexasters) with strongly curved rays; 
and a third, H. fibulatus, which also has sigm microscleres, by the absence of oxy- 
hexasters. The fourth, H. obesus, which appears to differ from H. edwardsii 
only by its thicker body-wall and by having hypodermal hexactines with some- 
what longer distal ray, seems to be more closely allied to it. But the material 
on which F, E. Schulze bases this species was very fragmentary and his descrip- 
tion of it is somewhat incomplete. Therefore quite apart from the absence of 
ring-sigms in H. obesus and their presence in H. edwardsiwi, I should hesitate 
pronouncing these sponges, found respectively off Enderbyland in the Antarctic 
and off Peru in the Pacific, as specifically identical. 


HOLASCELLA, gen. nov. 


Tubular Euplectellidae (Euplectellinae) with root-spicule bundles and 
(probably) without parietal apertures. The body-wall is supported by a net- 
work of stout hexactines, pentactines, or tetractines held together by slender 
comitals. To discohexasters or microdiscohexactines, other hexasters, micro- 
hexactine forms, and pentactine and tetractine derivates of these may be added. 
The hypodermals are hexactines with spiny distal ray. The root-spicules are 
long, smooth shafts (rhabds or the long radial rays of pentactine anchors, the 
distal ends of which have been lost) and monactines with oblique, backwardly 
directed spines and a distal tyle, from which arise similar spines, representing 
anchor-teeth. The morphological centre (axial cross) of these spicules is situ- 
ated in the terminal anchor-tyle. 

The collection contains two more or less complete specimens and four frag- 
ments, which belong to three species, all of which are new. 


Holascella taraxacum, sp. nov. 


Plate 21, figs. 1-13; Plate 22, figs. 141; Plate 23, figs. 1-3. 


One specimen, the upper end of which is missing, but which is otherwise 
fairly complete, and three fragments of this species were trawled in the Eastern 
Tropical Pacific at Station 4649, on 10 November, 1904; 5° 17’ S., 85° 19.5’ W.; 
depth 4086 m. (2235 f.); they grew on a bottom of fine, sticky, gray mud; the 
bottom-temperature was 35.4°. 

The specific name refers to the similarity of the abundant discohexasters 
to the seed-balls of Taraxacum. 


30 HOLASCELLA TARAXACUM. 


Shape and size. The specimen (Plate 21, fig. 8), which is fairly complete 
apart from the missing upper end, consists of a nearly straight tube, open at 
both extremities, from the lower, somewhat attenuated end of which arise three 
dense bundles of root-tuft spicules. The tube is about 120 mm. long and has a 
circumference of 70 mm. at the upper end and of 40 mm. at the lower. It is 
now, although rather rigid, considerably compressed and flattened. In the fresh 
state it probably had a circular transverse section. The wall of the tube, that 
is the body proper of the sponge, is, for the most part, 2.5-3.5 mm. thick, and 
perforated by numerous apertures. These apertures are more or less circular 
in outline, 0.3-1.5 mm. wide, and quite irregularly distributed. Besides these 
apertures radial canals of similar width, but covered on the outer side by rem- 
nants of tissue, are observed in the tube-wall. For this reason, on account of 
their quite irregular distribution, and because the open apertures are destitute 
of a special marginal membrane, and all the larger and most of the smaller ones 
are traversed by rays of choanosomal spicules, I do not think that they can be 
considered as true parietal apertures. I believe myself justified in assuming 
that the tube-wall is, in the living sponge, continuous and destitute of parietal 
apertures, and that the openings now observed in it are post mortem artifacts, 
produced by the shrinkage and partial maceration of the soft parts, and the 
loss of extensive tracts of the dermal membrane. 

The three root-spicule bundles are very dense, 80-120 mm. long, con- 
siderably and uniformly curved, and attenuated distally to quite fine points. 
Proximally they widen out paratangentially and they pass, by the divergence 
of the spicules composing them, gradually into the lower end of the tubular 
body. 

Of the three fragments, one is the lower end of a tube similar to the one 
described above. It is 45 mm. long, circular in transverse section, slightly 
attenuated below, and open at both ends. Above it has a diameter of 14, below 
of 12mm. From its lower end three root-spicule bundles arise. The other two 
fragments appear to be parts of tubular bodies. 

The colour of the body proper is, in spirit, dirty brown; the root-spicule 
bundles are colourless. 

Skeleton. The chief support of the body consists of longitudinal and 
transverse bars, which form a paratangentially extending net with rectangular 
meshes. This net is composed of the paratangential rays of large stout principal 
spicules, held together and in position by slender comitals. Most of the prin- 
cipal spicules are hexactines, a few pentactines and tetractines. Each node of 


HOLASCELLA TARAXACUM. 31 


the net is occupied by the centre of one of these spicules. The two rays of the 
large principal hexactines, which extend longitudinally, are considerably longer 
than the other four. The two rays extending transversely are intermediate in 
size. The two rays extending radially are the shortest, the proximal one, 
pointing towards the axis of the tube, being the shorter of the two. The para- 
tangential rays of most of the principal pentactines and tetractines are simi- 
larly differentiated. The single radial ray of the pentactines points outward. 
Most of the comitals are centrotyle rhabds, a few tri-, pent-, or hexactines. 

Besides these spicules, there have been found in the body of the sponge 
hexactines intermediate in size, very long and slender, longitudinally extend- 
ing rhabds, minute rhabds, micro-tetractines, -pentactines, and -hexactines, 
oxyhexasters, discohexasters, onychhexasters, (calicocomes), and the central 
parts (main-ray crosses) of graphiocomes. The oxyhexasters, onychhexasters, 
graphiocome-centres, and minute rhabds are rare. One or the other of these 
kinds of spicules may possibly be foreign to the sponge. The other spicule- 
forms mentioned are abundant and doubtlessly proper to the sponge. 

Hypodermal and hypogastral hexactines with two axes (four rays) extending 
paratangentially and one axis (two rays) extending radially (vertically to the 
surface) are found below the dermal and the gastral surfaces. The proximal 
ray of these spicules is elongated, the distal ray spined and more or less thick- 
ened. Hexactines of this kind with greatly, and with only slightly, thickened 
distal ray are indiscriminately mingled both in the outer dermal and the inner 
gastral face of the tube-wall. The hypodermal and the hypogastral hexactines 
are very similar. The only difference between them which I could detect is that 
in some of the hypodermals the distal ray attains a greater length than in any 
of the hypogastrals, and that in some of the hypogastrals the lateral rays attain 
a greater length than in any of the hypodermals. It also appears that the 
distal rays of the hypodermals of the lower part of the sponge are on the whole 
thicker than those of the upper part. 

The root-spicule bundles are composed of numerous large, smooth rhabds, 
broken off below, and a few spined monactine anchors. 

The rays of the large principal hexactines (Plate 22, figs. 5, 6, 9, 10, 36; 
Plate 23, fig. 1) are slightly and irregularly curved (Plate 22, fig. 7) or, more 
rarely, angularly bent (Plate 22, fig. 9), blunt, and usually conic. In very long 
rays (Plate 22, fig. 7) the thickest point is often some distance from the base, 
and such rays are somewhat spindle-shaped. Rarely one of the rays is abnor- 
mally reduced in length and terminally thickened (Plate 22, fig. 6), or divided 


32 HOLASCELLA TARAXACUM. 


at the end into two branches (Plate 22, fig. 8). The rays are 100-160 » thick 
at the base; the longitudinal ones are 6—22.5 long, the transverse ones 2-10, 
the distal one 1.5—2.5, and the proximal one about 1 mm. 

In the proximal part of large rays a homogeneous central part, about 40 u 
thick, and a conspicuously stratified superficial part can usually be distin- 
guished. In the axis of the distal part of such large rays structures are observed 
somewhat similar to those described above in the corresponding spicule-rays 
of Holascus edwards. The axial thread is quite thin in the proximal part of 
the ray; in the distal part it is considerably thickened, and interrupted by caps 
composed of a substance of different refractive index from the axial thread and 
the silica-layers surrounding it (Plate 23, fig. 1). These caps are usually 4-6 u 
broad and so situated that the convex side lies distally. These caps are irregu- 
larly distributed along the axis and are very numerous. Sometimes quite a 
number of them follow in close succession. From the margin of most of these 
caps a distinct limit between successive silica-layers arises. These limits extend 
proximally, are conic in shape, and pass uninterruptedly into the limits between 
the silica-layers forming the outer, clearly stratified zone of the proximal part 
of the ray. These limits represent former surfaces of the spicule, whilst the caps 
mark the positions of the tip of the ray at various times. There can be little 
doubt that here, as in Holascus edwardsi, the growth of these spicules is intermit- 
tent, interrupted by periods of rest. Every time the longitudinal growth of the 
rays recommences after such an interruption a cap is formed. 

It has been stated above, that in some of the large principal hexactines one 
of the rays is reduced in length and terminally thickened. In the centre of the 
terminal thickening of such shortened rays the central, unstratified zone of the 
spicule ends in the shape of a slender, pointed cone. The terminal thickening 
itself is formed exclusively by the clearly stratified superficial zone, each layer 
of which is here markedly thickened. 

The few large principal pentactines and tetractines (Plate 22, figs. 7, 8, 11) are 
similar to the principal hexactines described above. Most of them differ from 
the latter only by the absence of one (the pentactines) or both (the tetractines) 
the radial rays. In some of them also the difference of the longitudinally and 
transversely extending rays is less pronounced than in the principal hexactines. 

The axes of the intermediate hexactines are not differentiated and, although 
the rays are in the same spicule often more or less unequal, they are apparently 
equivalent. The rays are 140-300 » long, usually cylindrical, 7-12 » thick, and 
rounded and often thickened at the end. The tips of the rays are spiny. The 


other parts of the spicule are smooth. 


HOLASCELLA TARAXACUM. 33 


The comital rhabds (Plate 22, figs. 29-36, 38-41) are diactines with a dis- 
tinct thickening lying more or less centrally. They are 5-15 mm. long and the 
two developed rays are, at their proximal end, near the centre of the spicule, 11— 
45 » thick. They taper distally and measure, at their thinnest point, which is 
usually situated a short distance from the end, 6-20 » in transverse diameter. 
The end itself is usually thickened, more rarely conic and pointed. 

The two ends of the same spicule usually differ considerably from each other. 
The terminal thickening is oval or club-shaped and 20-47 u» in diameter (Plate 22, 
fig. 38-40). The ends of these spicules are slightly spiny, all the other parts 
smooth. 

The more or less centrally situated tyle consists of four rudimentary rays, 
the axial threads of which can always be distinguished as an axial cross within 
it. The degree of reduction of these four rays is subject to considerable varia- 
tion, and not infrequently the four rudimentary rays of the same spicule are 
reduced to a very different degree. A series of forms representing different 
degrees of ray-reduction is reproduced (Plate 22, figs. 29-35). 

The tri-, pent-, and hexactine comitals are rather rare. The triactine forms 
are similar to the diactines above described and differ from them only by being 
smaller and by one of their four reduced rays being much longer than the others. 
The rays of these spicules are 17-25 » thick and the longest is 1.5-2.6 mm. long. 
The pentactines and hexactines have rays 1—2.5 mm. long and 13-20 u thick. 

The long slender rhabds are centrotyle and similar to the diactine comitals 
above described, so that one might consider them as giant forms of these. They 
attain a length of 36 mm. and a thickness of 27 uv. The central tyle has a maxi- 
mum thickness of 444. Some of them havea very large terminal tyle, sometimes 
70 » in diameter, at one end. Rays thus terminally greatly thickened are cor- 
respondingly reduced in length. The axial cross, which lies in the central thick- 
ening, is in some of these spicules very irregular, the axial thread-rudiments 
composing it enclosing angles very different from 90° with the axis of the two 
developed rays. 

The rare minute rhabds, which may perhaps be comitals of the distal ray of 
the hypodermal hexactines, but which were never seen in situ in this position, 
are about 260 » long and 1.5 mm. thick. 

The proximal and lateral rays of the hypodermal and hypogastral hexactines 
(Plate 22, figs. 1-4, 12-17) are 5-114 thick at the base, cylindrical or only 
slightly attenuated towards the end, and abruptly pointed or blunt. The proxi- 
mal ray is 0.8-1.8 mm. long, the lateral rays are 0.2-1 mm. The distal ray is 
160-500 u long, at the base 5-18 y» thick, and thickened more or less above. At 


34 HOLASCELLA TARAXACUM. 


its thickest point, which lies only a very short distance below the end, the distal 
ray is 16-60 » thick. The proximal and the lateral rays are often curved; the 
distal ray is straight. The proximal and lateral rays are smooth apart from their 
ends, which are often slightly spined. The basal part of the distal ray is smooth, 
or only slightly spined; its thickened end is covered with spines, situated very 
obliquely and directed upwards toward the tip of the ray. These spines are 
quite numerous and close together, have a maximum length of 5 u, and are 
about 4 » thick. They appear as oval protuberances, the ends of which are 
drawn out to sharp and slender points. The tip of the ray is free from spines 
for a distance of about 10 yw. In the distal rays of medium thickness the 
tip appears as a broad cone, in the very thick ones as a broad round dome. 
The proximal part of the axial thread of the distal ray is quite thin, its distal 
part thickened, and about 1.5 # broad. 

I have observed a few spicules in the spicule-preparations which alsfs appear 
to be hypodermal or hypogastral hexactines, but which differ from the spicules 
above described by one, two, or even three of their lateral rays being thickened 
and spined like the distal ray. 

The smooth root-spicules are all broken off at the lower, distal end. The 
longest fragments measured were 150-160 mm. long. Proximally these spicules 
are gradually attenuated to a fine point. Their thickest portion is about 120 
mm. from the proximal end; here they are 100-340 yu thick. 

The spined, anchor-like root-spicules (Plate 22, figs. 26, 37; Plate 23, figs. 
2, 3) are remarkably scarce. All those seen were broken so that I cannot give 
their length. To all appearance they are much shorter than the smooth root- 
spicules. Near their distal end these anchor-spicules are 12-17 » thick. The 
end itself is thickened to a terminal tyle, 48-56 » broad, 54-70 » long, and in 
shape like a blunt, inverted cone with convex sides or a rotation-paraboloid. 
From the shaft of the spicule and from the margin of the upper, basal face of the 
terminal tyle arise conic, obliquely situated, backwardly directed spines 7-17 u 
long. The axial cross (morphological centre) of the spicule lies in the terminal 
tyle (Plate 23, figs. 2, 3). These spicules are not, like the similarly shaped 
anchors of the species of Holascus, diactines, but monactine tylostyles. 

Among the micro-oxyhexactines, -oxypentactines, and -oxytetractines (staur- 
actines) (Plate 22, figs. 20-25), the hexactine forms appear to be the most 
abundant. The rays of these spicules enclose angles of 90° with their neighbours 
and are equal in most of the hexactines and stauractines. In the pentactines 
and some of the hexactines (Plate 22, figs. 20, 21) a differentiation of the three 


HOLASCELLA TARAXACUM. 30 


axes is to be noted, two rays of such hexactines lying in one axis, and the ray of 
the pentactines which has no opposite being longer than the four rays lying in 
the two other axes. The rays are straight, conic, pointed or blunt, 120-180 u 
long and 3-8 u thick at the base. With the exception of the base and the extreme 
tip, which are smooth, the rays are covered with spines, 1-1.5 ulong. The distal 
spines are distinctly recurved (Plate 22, figs. 18, 19), the proximal ones arise 
nearly vertically. 

The rare oxyhexasters (Plate 21, figs. 1, 2, 9) are about 95 uw in diameter. 
Their equal and regularly arranged main-rays are straight, fairly smooth, 19 u 
long, 4 u thick at the base, and slightly attenuated towards the distal end. Each 
main-ray bears a terminal verticil of usually three end-rays, enclosing angles of 
about 45° with the continuation of the main-ray. The end-rays are perfectly 
straight, 37 » long, 2 wu thick at the base, conic, sharp-pointed, and covered with 
minute spines. 

The rare onychhexasters (Plate 22, figs. 27, 28) are 98-105 u in diameter and 
have a thickened centre, 4-54 in diameter. The main-rays are regularly 
arranged, in the same spicule fairly equal, straight, on the whole cylindrical, 
8-11» long and 1.5-2.3 » thick. They bear from one to four, usually three, 
end-rays, and sometimes also one or a few irregular knob-like protuberances 
on their sides. The end-rays are 30-50 » long and 0.6-1 u thick at the base. 
Distally they taper gradually to about 0.3 4. The end-rays arise nearly verti- 
cally from the main-ray and are curved in an S-shaped manner, their proximal 
part strongly concave towards the continuation of the main-ray, their distal 
part slightly in the opposite direction. This curvature is different in different 
end-rays and the degree of divergence of the chords of the end-rays from the 
continuation of the main-ray is variable. Each end-ray bears several terminal 
spines. These generally arise at nearly right angles, are curved, concave towards 
the centre of the spicule, slender, and 2-5 » long. In view of the shape of the 
end-rays these onychhexasters might also be termed calicocomes. 

Of graphiocomes only a few centres (main-ray crosses) have been observed. 
The main-rays are regularly arranged, equal, 11-13 » long and 2.5-4 u thick. 

The abundant discohexasters (Plate 21, figs.3-7, 10-13) are regularly spherical 
and measure 180-290 » in total diameter. Their main-rays are regularly ar- 
ranged, in the same spicule equal, perfectly smooth, about 14 uw long, 3.5-5 u 
thick in the middle, and thickened at both ends; proximally to the centre of the 
spicule, distally to a stout, lens-shaped, transverse disc from the margin and 
distal face of which the end-rays arise (Plate 21, fig. 10). The end-rays are 


36 HOLASCELLA TARAXACUM. 


so numerous that it is exceedingly difficult to count them. So far as I could 
make out 23-27 end-rays arise from the terminal disc of each main-ray. The 
end-rays arising from the central part of the distal face of the terminal main- 
ray discs are nearly straight throughout, and extend in a radius from the centre 
of the spicule. The end-rays become longer, more curved and concave toward 
the continuation of the main-ray axis the farther they are situated from the 
centre of the disc. 

This curvature is restricted to the basal part; the middle- and end-parts are 
always straight. This increase of length and curvature towards the margin 
of the dise is such that the tips of all the end-rays are nearly equidistant and lie 
in the surface of a regular sphere, and that the straight middle- and end-parts 
of all the end-rays lie in radii from the centre of the spicule. In consequence 
of this, and because the crowd of end-rays hides the main-rays, the whole spicule 
appears as a regularly spherical aster composed of numerous straight, concentric, 
and equidistant radial rays. The end-rays are 80-140 » long and 2.5-3.5 
thick at the base. Towards the middle of their length they are attenuated to 
1.5-2.5 »; farther on they again become thicker, and attain a transverse diameter 
of 3.2-5 » at their distal end. At the base and just below the tip the end-rays 
are quite smooth for a short distance. For the remaining greater part of their 
length they are covered with oblique, backwardly directed and backwardly 
curved, conic spines, 1-2.5 » long. From the end arises a terminal verticil of 
about fifteen recurved spines. The basal parts of these spines are joined to 
form a dise with strongly convex distal face, from the margin of which their ends 
protrude freely for a distance of 2-3 u. The terminal spine-verticils (end-dises) 
measure 7.5-12 wu in transverse diameter. 

The general structure and spiculation of the sponges above described clearly 
show that they are Euplectellidae, whilst the presence of root-spicule bundles 
assign them to the Euplectellinae. Since, however, the upper part is not present 
in any of the specimens, and the state of their preservation is insufficient to deter- 
mine whether the wall of their tubular body is perforated by parietal apertures 
or not, it is somewhat difficult to decide in which genus they should be placed. 
Whether the upper end of the tubular body was open or covered by a sieve-plate 
of course cannot be decided. About the parietal apertures, however, we may 
with some confidence say, for the reasons above given, that the holes now ob- 
served in the body-wall are post mortem artifacts produced by shrinkage and 
maceration and that the sponge possesses no parietal apertures in the fresh state. 

At present three genera, Euplectella, Holascus, and Malacosaccus are dis- 


HOLASCELLA ANCORATA. 37 


tinguished in the Euplectellinae. The certain presence of discohexasters and 
the probable absence of parietal apertures preclude the sponges described above 
being placed in Euplectella. From the known species of Malacosaccus, which 
are soft, flexible, and sac- and cup-shaped, they differ by being hard and brittle 
narrow tubes. From all the known species of Holascus, except Holascus undu- 
latus F. E. Schulze! and the species collected by the Challenger and mentioned 
by F. E. Schulze* as Holascus sp., they differ by possessing discohexasters. 
The spicules of H. undulatus described by F. E. Schulze (loc. cit., 1899, p. 17) as 
discohexasters differ, however, considerably from the true discohexasters found 
in the sponges described above and have by F. E. Schulze himself lately * been 
declared to be calicocomes, and not discohexasters, so that this species also does 
not appear to be allied to the sponges above described. Their only closer allies 
appear to be the species of Holascus referred to and the new Pacific species 
described as Holascella ancorata, and H. euonyz. 

As they differ from all the hitherto described and named species of Holascus 
by possessing discohexasters, hemidiscohexasters, or microdiscohexactines, and 
as the absence or presence of such spicules should be considered as a difference 
sufficient for generic distinction, I name the new genus Holascella, on account 
of its similarity to and historic derivation from Holascus. 

From Holascus sp. Schulze and the sponge here described as Holascella 
ancorata, Holascella taraxacum differs by being destitute of floricomes, and 
from the latter also and from the sponge here described as Holascella ewonyx by 
the absence of discohexactines and hemidiscohexasters with large anchor-like, 
terminal spine-verticils. From H. ancorata and H. euonyx it is also distin- 


guished by its principals being mostly hexactines. 


Holascella ancorata, sp. nov. 


Plate 23, figs. 4-25; Plate 24, figs. 1-9. 


One specimen of this species was trawled in the Eastern Tropical Pacific 
at Station 4649 on 10 November, 1904; 5° 17’ S., 85° 19.5’ W.; depth 4086 m. 
(2235 f.); it grew on a bottom of sticky, gray mud; the bottom-temperature was 
35.4°. 
It has discomicroscleres with long, strongly recurved terminal spines 
not joined at the base to a terminal tyle (‘‘disc’’). The end-rays (rays) of 
E. Schulze. Amerikanische Hexactinelliden, 1899, p. 15, taf. 3, figs. 1, 2. 


1F, 
° F. E. Schulze. Rept. Voy. Challenger, 1887, 21, pl. 15, figs. 14-23. 
5 F. E. Schulze. Hexactinellida. Ergeb. Deutsch. tiefsee-exped., 1904, 4, p- 130, 131, 


38 HOLASCELLA ANCORATA. 


these spicules are exquisitely anchor-shaped in consequence. To this the name 
refers. 

Shape and size. The single specimen (Plate 23, fig. 9) is a conic tube 40 
mm. long. It is circular in transverse section, broken off at both ends, at one 
end 11 mm. in diameter, at the other 7 mm. _ Its wall is continuous, not perfo- 
rated by parietal apertures, and about 2 mm. thick. To the narrower end a 
root-tuft appears to have been attached. 

The colour in spirit is dirty brown. 

The skeleton. The chief support of the tubular body is a paratangential 
network of principal spicules held together and in position by slender comitals. 
The principals have from three to five, rarely six rays. Two opposite rays 
extend more or less longitudinally. One or both of these longitudinal rays 
are longer than any of the others. All the rays of the triactines and tetractines 
and four rays of the pentactines and hexactines lie paratangentially; one ray of 
the pentactines and two rays of the hexactines extend radially. These radial 
rays are always shorter than the others. The comitals, which are attached to 
the rays of these principals, are diactines, triactines, and tetractines. Besides 
these spicules a few tetractine and a good many hexactine megascleres, with spined 
rays, much smaller than the principals of the supporting network, occur in the 
choanosome. Hypodermal and hypogastral hexactines, with the two (opposite) 
rays of one of the axes differentiated, occur below the dermal and the gastral 
surface. One of these differentiated rays is elongated, the other thickened and 
more or less spined. The axis of the two differentiated rays is situated radially ; 
the elongated ray points inwards, the thickened and spined ray outwards. A 
few spined anchoring spicules have been found in the narrower part of the tube. 
They are probably root-tuft spicules of the sponge. In addition to the spicules 
mentioned, rods and tetractines to hexactines with very short, stout rays, 
probably foreign to the sponge, have been observed in the spicule-preparations. 
Of microscleres spined microhexactines, floricomes, onycho- and discomicro- 
scleres, and a few main-ray crosses without end-rays have been observed. Among 
the onycho- and discomicroscleres microhexactines and hemihexasters are 
much more frequent than true hexasters. Some of the main-ray crosses observed 
are the central parts of the floricomes; others may be centres of graphiocomes. 
The discomicroscleres are very numerous and doubtlessly proper to the sponge. 
All the other microscleres are rather rare and one or the other of them may be 
foreign to the sponge. 

Among the large triactine to hexactine principal spicules (Plate 23, fig. 4; 


HOLASCELLA ANCORATA. 39 


Plate 24, figs. 3, 8) the triactines to pentactines are much more numerous than 
the hexactines. Many of these spicules are very irregular, the rays, also opposite 
ones, frequently differing very greatly in length, and the longer rays being invari- 
ably more or less curved. Most of the triactine principals consist of two oppo- 
site longer rays lying in the same axis longitudinally, and one lateral (transverse) 
shorter ray, more or less vertical to the rhabd formed by the other two. In 
some of the principal spicules the rays are not only unequal but seem also to be 
irregular in position, to enclose angles other than 90° with their neighbours. 
A closer inspection, however, shows that the axial threads of the basal parts of 
the rays of such spicules are also regularly disposed at right angles (Plate 24, 
fig. 8), their apparent irregularity of position being due merely to strong curva- 
tures near their basal part. The rays are smooth and blunt-pointed. The 
shorter ones are simply conic and gradually attenuated to the end; in the long- 
est ones the thickest point often lies a short distance from the base, so that these 
rays appear somewhat spindle-shaped. Such rays are at the thickest point about 
7% thicker than at the base. The principal spicules are 18-42 mm. long, their 
longitudinally extending rays measuring 10-21 mm. in length, their transverse 
paratangential rays 3-15 mm. The rays are 70-160 u thick at the base. The 
basal thickness of the rays is, on the whole, proportional to their length. 

The rays of these large principals are, like those of the principal spicules 
of Holascella taraxacum, composed of a nearly homogeneous axial and a very 
clearly stratified superficial zone. In the tetractine (Plate 24, fig. 8) the axial 
zone is 18 uw in diameter near the centre of the spicule, whilst the clearly strati- 
fied superficial zone has here a thickness of 56 u. The layers of the latter are 
very unequal in thickness; distally they terminate in cones, the apices of which 
lie in the axial thread. 

In some of these spicules distinct signs of their having been broken at some 
time during the period of growth are to be noticed. In the portion of a ray of a 
principal spicule (Plate 23, fig. 4) a fracture is visible, which shows that the 
tip of this spicule-ray was broken off at a point where it was about 25 u thick, 
and that the ray continued to grow, not only in thickness but also in length, after 
this breakage. It is clearly to be seen that a new axial thread, lying exactly 
in continuation of the old broken one, was formed after the fracture. This new 
axial thread is widened proximally to a cone, which encloses the tip of the old 
broken axial thread. The new axial thread is a regenerate, the existence of which 
shows that the elements attached to the tip of a growing spicule-ray are not the 
only ones that can build up an axial thread, 


40 HOLASCELLA ANCORATA. 


The smaller, spined hexactine and tetractine megascleres (Plate 24, figs. 1, 2) 
are 1-4 mm. in maximum diameter. Their rays are unequal, often curved, 
up to 1.7 mm. long, 12-17 u thick at the base, and rounded at the end or blunt- 
pointed. The bases and often also the tips of the rays are smooth, the other 
parts show sparse, broad, sharp-pointed spines. 

The comital spicules (Plate 24, fig. 9) are di- to tetractine. Their rays are 
straight or irregularly curved, gradually attenuated distally, and terminally 
rounded. The end-part is usually somewhat thickened and spined. The other 
parts of the spicule are smooth. The rays attain a very considerable length. 
Measurements of this dimension cannot, however, be given since all the long 
rays observed were broken off. The longest intact ones seen were 1.5 mm. long. 
The rays are 8-28 » thick at the base and attenuated distally to 5-8 yu. The 
spined end-part is 7-10 » thick. In the tetractine and triactine comitals two 
opposite longitudinal rays lie in a straight line and are longer than the transverse 
ones (one). In the triactine forms the centre is markedly thickened on the side 
opposite the single transverse ray (Plate 24, fig. 9). The diactine forms are cen- 
trotyle. The central tyle measures 14-36 » in diameter. The proportion of the 
basal thickness of the rays to the transverse diameter of the tyle is 1: 1.4 to 1: 3, 
usually about 1:1.6. The two rays of these spicules are usually unequal in 
length and sometimes one of them is reduced to a mere knob. Such excessive 
longitudinal reduction is always associated with a considerable thickening. 


' In an extreme form of this kind one ray was observed to be over 2 mm., the 


other only 44 uw, long. The central tyle measures 40 u in diameter; the long ray 
is 16 » thick and nearly cylindrical. The short ray is 33 » thick at the base and 
farther on it is 44 « thick. This knob-like rudimentary ray is covered with small 
spines down to within a short distance of its base. 

The proximal and lateral rays of the hypodermal and hypogastral hexactines 
(Plate 23, figs. 12, 13) are 5-9» thick at the base. They are cylindrical or 
slightly attenuated distally, and usually rounded at the end, rarely pointed. 
Their tips are generally spined, their other parts smooth. The proximal ray 
is 0.9-1.5 mm. long, the lateral rays 370-450 ». The distal ray is 220-450 u 
long, at the base as thick or somewhat thinner than the other rays, and distally 
thickened. At its thickest point, which lies near the distal end, it measures 
17-40 w in diameter. The proximal part and the extreme tip are smooth, the 
other parts of it more or less spined. The spines increase in size and number 


* distally. They arise very obliquely and point towards the tip of the ray. The 


hypodermals are similar to the hypogastrals. Hexactines with thick strongly 


HOLASCELLA ANCORATA. 4] 


spined, and with thin only slightly spined, distal rays occur among both. The 
distal rays of the hypodermals appear to attain a greater length than the distal 
rays of the hypogastrals, the former being usually over, the latter under, 400 u 
long. 

The few root-tuft anchors observed are monactines. Their axial cross lies 
in their terminal anchor-tyle. The shaft is covered with very irregularly dis- 
tributed, backwardly directed spines 17 u thick just above the terminal anchor- 
tyle. The terminal anchor-tyle is similar to that of Holascella taraxacum. It 
is, with the spines, 57-65 uw broad and 74-90 » long. Its spines, the anchor- 
teeth, are very irregular. 

The microoryhexactines (Plate 23, fig. 8) measure 112-195 » in total diame- 
ter. Their rays are regularly arranged, in the same spicule fairly equal, straight, 
conic, pointed, 55-105 » long and 3-5 u» thick at the base. Their length is not 
in proportion to their basal thickness, the shorter rays of smaller microoxyhex- 
actines being often thicker than the longer rays of larger ones. The rays are 
rather sparsely spined. The spines are sharp, not over 1 u long, and directed 
obliquely backwards. 

The onychomicroscleres (Plate 23, figs. 10b, 11, 14b, 15, 16) measure 65-90 u 
in total diameter, and have one to three end-rays. Many are microonychhex- 
asters with only one end-ray on all the main-rays. Others are hemionychhex- 
asters, with one end-ray on some, and two or, rarely, three end-rays on the other 
main-rays. <A few are true onychhexasters with two to three end-rays on each 
main-ray. The main-rays are regularly arranged and, in the same spicule, 
fairly equal. They are cylindrical, smooth, about 5 1 long and 1.5-2 u thick. 
The end-rays are straight or only slightly curved, 28-50 u long, conic, at the 
base about 1 » thick, and at the end 0.5-0.8 u. They bear exceedingly minute 
spines along their length, and at their end there are several, usually three or 
four, large, more or less vertical spines. These terminal spines are not over 
7 » long, very slender, and curved, either simply, concave to the centre of the 
spicule, or in an S-shaped manner. When two or three end-rays arise from a 
main-ray, they enclose angles of 30° to 40° with its continuation; when there is 
only one end-ray it lies in the continuation of the main-ray, and usually passes 
into it so gradually that main- and end-ray together appear as a simple, conic 
hexactine ray. Sometimes a slight irregular thickening or change of direction 
indicates the point where the main-ray passes into the end-ray. Such simple 
rays are 33-35 w long. 

The discomicroscleres (Plate 23, figs. 5-7, 10a, 14a, 17-25) measure 130-220 


42 HOLASCELLA ANCORATA. 


in total diameter. They generally have only one, sometimes two, very rarely 
three end-rays. Most of them are microdiscohexactines with one end-ray on 
each main-ray; some hemidiscohexactines with one end-ray on some main-rays 
and with two end-rays on others. <A few are true discohexasters with two end- 
rays on all or with two end-rays on some and three end-rays on the other main- 
rays. The main-rays are regularly arranged and, in the same spicule, fairly 
equal. They are smooth, about 5» long and 2.5-3.7 » thick. The end-rays are © 
straight or slightly irregularly curved, 50-110 u long, thinnest some distance 
below the distal extremity, and thickened at both ends. The proximal end is 
2-3 » thick, the thinnest point 0.7—1.5 uw, and the distal end 2.6-4 ». The end- 
rays bear very minute spines on their sides and a verticil of large, anchor-teeth 
like, strongly recurved spines at their end. These terminal spines are conic, 
8-10 uw long and 1.2-1.6 uw thick at the base. They are not joined at the base 
to a terminal tyle or disc, and together form an exquisite anchor, 9-12 » broad 
and about as high. When two or three end-rays arise from a main-ray, they are 
usually arranged somewhat irregularly and enclose angles of 20°-45° with the 
continuation of the main-ray. When, as is the rule, there is only a single end- 
ray, it lies in the continuation of the main-ray, and usually passes into it so 
gradually that main- and end-ray together appear as a simple hexactine ray. 
Such simple rays are 65-115 uw long. 

Axial threads are found only in the main-rays. They appear as thin, fairly 
straight rods, are about 5 » long, and terminate abruptly at the point where the 
main-ray divides into the two or three end-rays (Plate 23, fig. 7, right), or passes 
into the single end-ray (Plate 23, figs. 6, 7, left, upper and lower). The simple 
rays with only one end-ray consequently possess an axial thread only in their 
basal (main-ray) part. 

The few main-ray crosses observed, which may be centres of graphiocomes, 
consist of regularly arranged, equal, straight main-rays 10 » long and 3.5 u thick, 
from the ends of which large numbers of end-rays arise. 

The floricomes (Plate 24, figs. 4-7) measure 48-60 in total diameter. 
Their main-rays are regularly arranged, in the same spicule equal, cylindrical, 
straight, 6-7 » long, and about 1.5» thick. Each main-ray bears a verticil of 
about twelve end-rays. All the end-rays arise at exactly the same level, 1-1.5 u 
below the distal end of the main-ray, which protrudes for that distance in the 
shape of a rounded knob beyond the ring-shaped line of their insertion. The 
end-rays of the same verticil are exactly equal in size, shape, and position, rela- 
tive to the main-ray from which they arise. They are, measured along their 


HOLASCELLA ANCORATA. 43 - 


chord, 20-23 » long and strongly curved in an S-shaped manner. Their basal 
part is directed outwards and slightly backwards, their central part upwards 
and slightly outwards, and their distal part again outwards and slightly back- 
wards. They are exceedingly thin at the base, but thicken distally and attain, 
a short distance from the end, a maximum transverse diameter of about 1.3 yu. 
The end-rays are smooth on the inner side, that is the side turned towards the 
continuation of the main-ray. On the opposite, outer side their thicker distal 
part bears fairly large spines. 

As far as the fragmentary condition of the specimen allows one to judge, the 
only species more closely allied to it is the specimen referred to by F. E. Schulze! 
as Holascus sp. and those described in this paper as Holascella taraxacum and 
H. euonyx. It is very clearly distinguished from Holascus sp. Schulze and 
Holascella taraxacum by the terminal spines of its discomicroscleres. In the 
sponges described above these are long, slender, strongly recurved, and isolated 
quite down to the base. In Holascella taraxacum they are certainly, and, to judge 
by the figures, in Holascus sp. Schulze most probably, short, divergent, and 
basally joined to form terminal tyles (‘‘end-dises”’). From the former H. ancorata 
also differs by the principals, which are in the sponge above described chiefly 
tri- and tetractines, in H. taraxacum chiefly hexactines; by the discomicroscleres, 
which have few end-rays in the former and very numerous end-rays in the latter; 
and by the floricomes which are present in the former and appear to be absent 
in the latter. There can, therefore, be no doubt that H. ancorata is specifically 
distinct from H. taraxacum. Whether it is also distinct from Holascus sp. 
Schulze, of which no adequate description exists, is not so easy to say, the 
figures of this sponge given make it highly probable, however, that it belongs 
to a different species. 

It appears to be more closely related to these species than to the sponge 
here described as Holascella ewonyx. From this it differs by the superficial 
hexactines, the distal rays of which are much thicker and more club-shaped in 
H. ancorata than in H. euonyx; by the discohexactines and hemidiscohexasters, 
the rays (end-rays) of which are more spiny and bear much smaller terminal 
anchor-teeth in the former than in the latter; by the onychhexactines and hemi- 
onychhexasters, which have much shorter terminal spines in the former than in 
the latter, and by the presence of floricomes in the former and their absence in 
the latter. 


1F, HE, Schulze. Rept. Voy. Challenger, 1887, 21, p. 86, 87, pl. 15, figs. 14-23. 


44 HOLASCELLA EUONYX. 


Holascella euonyx, sp. nov. 


Plate 24, figs. 10-17; Plate 25, figs. 1-24. 


A fragment of this species was trawled nearly under the equator in the 
Eastern Pacific at Station 4742, on 15 February, 1905; in 0° 3.4’ N., 117° 15.8’ 
W.; depth 4243 m. (2320 f.); it grew on very light, fine, Globigerina ooze; the 
bottom-temperature was 34.3°. 

It is characterized by possessing hemionychhexasters and onychhexactines 
with very long terminal spines (end-claws). To this the name refers. 

Shape and size. The single fragment (Plate 25, fig. 17) is a very slightly 
cylindrically curved plate which may have formed part of a wide tube. It is 
51 mm. long, 15 mm. broad, and about 1.5 mm. thick. 

The colour in spirit is brown. 

The internal skeleton is composed of parallel bundles of spicule-rays, and of 
loose spicules. Near the surface special superficial (dermal, gastral) hexactines 
occur. The bundles are composed of stout principals, for the most part tetrac- 
tine, and slender comitals likewise chiefly tetractine. The loose parenchymal 
spicules consist of numerous large and a few small simple hexactines; a few hemi- 
onychhexasters; numerous onychhexactines; numerous small discohexasters 
with many end-rays; very few large hemidiscohexasters with few end-rays; 
and numerous large discohexactines. The special superficial hexactines have a 
differentiated distal ray. 

Besides these spicules numerous small hexactines with curved rays, a few 
pinules, and a good many large amphidises have been observed both in the sec- 
tions and the spicule-preparations. These spicules are in all probability foreign. 

The distal ray of the superficial (dermal, gastral) hexactines (Plate 25, figs. 
14, 15, 21-24) is fairly straight, 235-270 uw long and about 6-10 u thick at the 
base. Towards the distal end it is thickened more or less, the end itself being 
abruptly pointed. At its thickest point, which lies a short distance below the 
end, the distal ray measures 9-16 » in transverse diameter. The basal part of 
the ray is smooth, the distal part covered with stout, very oblique spines 1-2 u 
long. These spines are somewhat curved, concave to the axis of the ray, and 
point towards its distal end. These distal rays consequently somewhat resemble 
wheat-ears. The axial thread extends quite to the tip of the ray, its end is not 
covered with silica (Plate 25, figs. 22, 24). The proximal and the lateral rays 
are curved, cylindroconic or conic, at the base about as thick as the basal part 


of the distal ray, smooth in their proximal part, and covered with minute oblique 


HOLASCELLA EUONYX. 45 


spines, inclined towards the end, in their distal part. The lateral rays are 215— 
420 u long and often thickened at the end. The proximal ray attains a length 
of 400-530 ». The fragmentary state of the specimen renders it impossible to 
determine which of the superficial hexactines observed are dermal and which 
gastral. 

The tetractine principal spicules (Plate 25, fig. 16) have two long rays extend- 
ing longitudinally and two shorter transverse rays. The four rays do not lie 
in one plane. The rays are 80-140 » and more thick at the base. About their 
length I cannot be definite, since the larger spicules of this kind were invariably 
broken. The longest longitudinal ray-fragment observed was 19 mm. long. 

The tetractine comital spicules (Plate 25, fig. 18) are similar to the principal 
ones, but have rays usually only 9-17 wu thick. 

The large loose hexactines (Plate 25, figs. 19, 20) have straight or curved, 
equal or unequal rays, which arise from a distinct central thickening, 38-50 u 
in diameter. The rays are 0.3-1.7 mm. long, at the base 10-35 u thick, usually 
10-15 w, and smooth or, more frequently, covered with sparse fairly stout, low 
spines. 

The small hexactines measure 120-150 in diameter, and have straight, conic 
rays, 6-7 uw thick at the base, and densely covered with rather large spines. 

The onychhexactines and hemionychhexasters (Plate 24, figs. 13, 14; Plate 
25, figs. 1, 6-9, 13b) are both derivates of onychhexasters, and there is no differ- 
ence between them, except that in the former (Plate 25, figs. 7, 9) all the main- 
rays bear only one end-ray, while in the latter (Plate 25, fig. 8) one or two of the 
main-rays bear two end-rays. When, as is the rule, only one end-ray is present, 
this either extends exactly in the continuation of the main-ray (Plate 25, fig. 9), 
or there is a slight, abrupt curvature at the point where the main-ray passes into 
the single end-ray (the upper ray, Plate 25, figs. 7,8). In any case the main- 
and the single end-ray together form a ray, simple in outer appearance. That 
these apparently simple rays are in truth composed of a main-ray and a (single) 
end-ray is, however, clearly shown by the axial thread, which is only 7-8 u long, 
and present in the basal (main-ray) part of the ray only. These onychhexac- 
tines and hemionychhexasters measure 53-95 u» in total diameter. Their simple 
rays are 25-45 » long. The main-rays which bear two end-rays are, like the 
axial threads of the simple rays, 7-8 » long. The simple rays are 2-3 yu thick at 
the base and taper distally to 1-1.5 4. They are either smooth throughout, or 
slightly roughened by exceedingly minute spines in their basal and middle-parts. 
Each ray (end-ray) bears at its end a verticil of four or, more rarely, three large 


46 HOLASCELLA EUONYX. 


curved, conic spines, 7-15 » long. The basal part of these spines is directed 
outward, slightly upward, and usually encloses an angle of 105°-102° with the ray. 
Their ends are bent downwards, towards the centre of the spicule. These spines 
are regularly arranged and, when four in number, form a regular cross. 

The small discohexasters (Plate 24, figs. 10-12, 13b, 14b, 15-17; Plate 25, 
fig. 13a) measure 38-44 » in total diameter. They have a centrum 3.3-4 yu 
in diameter, from which six equal and regularly arranged main-rays arise. The 
main-rays are cylindrical, 6.5—9 » long, 1-1.4 » thick, and simply rounded off at 
the end. About 1 » below the end each main-ray bears a high frill, which appears 
as a round, subterminal, transverse disc 5-7 » in diameter. From the margin 
and the upper distal face of this dise very numerous diverging end-rays arise, 
which together form a short and broad bunch, at the distal end 19-25 u in diame- 
ter. The individual end-rays are, at the base, curved, concave to the continua- 
tion of the main-ray axis, and in their distal and middle-parts straight. They 
are 13 » long, throughout about 0.2 « thick, covered with exceedingly minute, 
recurved spines along their length, and crowned at the end with a verticil of 
similar but larger spines. These terminal spines together form a kind of end- 
dise, generally a little less than 1 » in transverse diameter. 

The large hemidiscohexasters and discohexactines are very similar and 
differ from each other only in that one of the main-rays bears two end-rays 
(Plate 25, figs. 2-5, 10, 11) in the former, whilst all six main-rays bear only 
one end-ray in the latter. The large discohexactines measure 173-232 u in 
total diameter, usually 194-215 u. Their six simple rays are fairly equal and 
regularly arranged, straight or slightly: and uniformly curved, and sometimes 
just perceptibly abruptly bent at the point where the short basal part, which is 
the main-ray, passes into the long distal part, which is the single end-ray. The 
short basal (main-ray) part of the ray contains an axial thread 6-7 u long; 
6-7 » is accordingly the length of the main-ray. The long distal (end-ray) 
part is destitute of an axial thread. The rays of the large discohexactines are 
95-110 » long and thickened at both ends. They measure at the base 4.5-6 u, 
at the thinnest point, which lies somewhere near the middle of their length, 
2.4—5 uw, and at the distal end 5-6.5 4 in transverse diameter. Along their 
length these rays are either quite smooth or bear a few minute, recurved spines. 
The end is crowned by a terminal verticil of usually five or six recurved spines, 
7-12 uw long, and 1.8-4 » thick at the base. These spines are conic, uniformly 
recurved and rather sharply pointed; together they form an exquisite anchor 
15-22 » broad and 10-16 yp high. 


CAULOPHACUS. 47 


The nearest ally to this sponge appears to be Holascella ancorata. From 
this it is distinguished by its superficial hexactines having more slender distal 
rays, by its discohexactines having smoother rays and larger terminal anchor- 
teeth, by the terminal spines of its onychhexactines and hemionychhexasters 
being much longer, and by possessing no floricomes. On account of its general 
similarity to Holascella ancorata I assign it to the genus Holascella. It must, 
however, be borne in mind that the fragmentary condition of the specimen 
precludes the possibility of saying with certainty whether it really belongs to 
this genus, for if the sponge of which it formed part should have been destitute 
of a root-tuft, which is quite possible, it would have to be placed in Corbitella or 
another genus of the Corbitellinae. In this respect it is noteworthy that its 
discohexactines are rather similar to the discohexactines of Corbitella (Eudictyon) 


elegans Marshall.! 


CAULOPHACIDAE F. E. Scuuuze. 


Wineglass- or mushroom-shaped Hexasterophora with a firm stalk; soli- 
tary or forming branched colonies. With dermal pinules and large hypodermal 
pentactines. 

The collection comprises thirty more or less complete specimens and eighty- 
three fragments of specimens of this family. The position of three of the latter 
is doubtful. The others belong to the three genera Caulophacus, Caulophacella, 


and Calycosilva; the last two of these are new. 


CAULOPHACUS F. E. Scuuuze. 


Mushroom-shaped Caulophacidae with hollow stalk, discohexasters, and 
microdiscohexactines. 

There are twenty-eight more or less complete specimens and forty-nine 
fragments and stalks of Caulophacus, all of which belong to the same species. 


1 W. Marshall. Untersuchungen iiber Hexactinelliden. Zeitschr. wiss. Zool. Suppl., 1875, 26, 
p. 211, 212, taf. 16, figs. 66 a-l. J. Tjima. Studies on the Hexactinellida. II. Journ. Coll. sci. 
Tokyo, 1902, 17, p. 11-16, pl. figs. 13-15. 


48 CAULOPHACUS SCHULZEI. 


Caulophacus schulzei WIson. 
Plate 7, figs. 20-31; Plate 8, figs. 1-29; Plate 9, figs. 1-33; Plate 10, figs. 1-29; Plate 11, figs. 1-17. 


Mem. M. C. Z., 1904, 30, p. 43; Plate 4, figs. 1, 3, 5-10; Plate 5, figs. 1-6, 8-10. 


All the specimens referred to this species were trawled at Station 4651 off 
northern Peru on 11 November, 1904; 5° 41.7’S. 82° 59.7’ W.; depth 4063 m. (2222 
f.); they grew on sticky, fine, gray sand; the bottom-temperature was 35.4°. 

Apart from peculiarities due to differences of age and preservation, all 
these sponges are fairly identical. The nearly complete specimens are mush- 
room-shaped, composed of a discoid body and a stalk attached to the lower 
face of the disc. The fragments appear to be parts of similar sponges. Six 
specimens have been selected for detailed study, and to these all the figures 
on the plates refer. These specimens are marked A-F. A, B, and C are small 
specimens with discs 27-31 mm. in diameter. D, E, and F are large specimens. 
D had a dise 60 mm. in diameter. E was probably still larger, but is too frag- 
mentary for exact measurement. F is a detached stalk which appears to have 
belonged to a specimen with a dise also about 60 mm. in diameter. 

Shape and size. In the smallest nearly complete specimen, the dise-shaped 
body is oval in outline, 19 mm. long, 16 mm. broad, and 2.5 mm. thick in the 
middle. Towards the margin it thins out. The central part of the upper, gas- 
tral face is flat, its marginal part slightly convex. The stalk is eccentric, oblique, 
2 mm thick close to its point of insertion to the sponge-body (disc), and atten- 
uated below. In seven of the nearly complete specimens the disc is fairly flat, 
circular to oval in outline, 24-85 mm. in maximum diameter, and 5-7 mm. thick 
in the middle. One of these small specimens is represented on Plate 9, fig. 30. 
In these specimens the central part of the upper, gastral face is flat, slightly 
concave or slightly convex, the marginal part usually distinctly convex. The 
proximal end of the stalk is 2-5 mm. thick. The eccentricity of its point of 
insertion varies considerably and is in one of the specimens so great that its 
distance from the farthest point of the margin is thrice that of its distance from 
the nearest. In one small specimen (Plate 9, fig. 29) the disc is a little over 
30 mm. in diameter, 7 mm. thick in the middle, and folded in above. The upper, 
gastral face is, apart from the remarkable infolding, nearly flat in the middle 
and strongly convex towards the margin. The lower, dermal face is convex in 
the middle and flat near the margin. The margin itself is very clearly defined 
and sharp (Plate 8, figs. 28b, 29b). The stalk is, close to its point of insertion, 
4.5 mm. thick; 8 mm. lower, where it is broken off, it is only 2.2 mm. thick. 


CAULOPHACUS SCHULZEI. 49 


The remaining nineteen specimens, one of which is represented on Plate 9, 
fig. 28, are larger. Their irregularly oval discs are 40-64 mm. long, 34-54 mm. 
broad, and 7-12 mm. thick in the middle. The more or less eccentric and 
oblique stalk is, near its point of insertion, 2.5-7.5 mm. thick and quite rapidly 
attenuated below. The disc is flat, slightly convex or concave. The greater 
part or the whole of the marginal portion of the upper face is convex, so that 
the margin appears slightly bent down. 

The stalk is not intact in any of the specimens, but there are among the 
fragments three rather long stalks with intact lower (distal) end. These are 
30-40 mm. long, curved, particularly near the base, and 2 mm. thick (at the 
lower end) to 3.3 mm. (at the upper end). One of these stalks (Plate 9, fig. 28) 
appears to have been torn off the larger specimen. In the photograph this 
stalk is artificially attached to it. 

The specimens examined by Wilson (loc. cit., p. 43, Plate 4, fig. 3) were 
similarly composed of a calyculate, flat, or somewhat convex disc-shaped body, 
22-50 mm. in diameter, and a stalk invariably broken. 

The colour of all the specimens in spirit is brownish gray. 

General structure. Remnants of a superficial membrane supported by the 
lateral pinule-rays can be made out both on the dermal and the gastral faces 
of the sponge. This membrane lies on both sides, 70-100 » above the level 
occupied by the lateral rays of the hypodermal and hypogastral pentactines. 
In the intervening space shreds of tissue are observed, indicating that in life 
this zone was occupied by a network of trabeculae. Below the level marked by 
the lateral pentactine rays subdermal and subgastral cavities occur, which lead 
into canals extending more or less transversely, often through the greater part 
of the thickness of the whole disc (Plate 8, figs. 28, 29; Plate 9, fig. 32). The 
entrances to these canals are clearly visible, both on the dermal and the gastral 
face of the disc-like body. Where the superficial membrane is still present, 
they are covered by it; where this membrane has been lost, as is the case on 
nearly the whole of the surface in most of the specimens, they are freely exposed. 
The apertures of the dermal face resemble in shape and arrangement those of 
the gastral face, but are on the whole somewhat larger. The largest are always 
formed on the central part of the disc. Towards the margin they become 
smaller. Their distance from each other is in proportion to their size; the 
marginal ones lie much closer together than the central ones. The largest cen- 
tral apertures are 0.8—4 mm. wide, their width being, on the whole, in proportion 


to the size of the specimen. Apertures over 3 mm. in diameter have been 


50 CAULOPHACUS SCHULZEI. 


observed only in specimens with discs more than 50 mm. long. Apart from this 
it is also to be noticed that the smaller these apertures are, the better the speci- 
men is preserved. Their great width in indifferently preserved specimens is 
probably due to extreme post mortem shrinkage of the soft parts. 

The canals into which these apertures lead are 0.2-1.5 mm. wide in the best 
preserved specimens (Plate 8, figs. 28, 29). In specimens not so well-preserved 
the largest attain, probably in consequence of excessive shrinkage of the soft 
parts, a width of 3 mm. (Plate 9, figs. 32, 33). 

The spaces between these canals are occupied by a dense, readily stained 
tissue in which are observed traces of oval cavities 120-140 uw long and 70-90 u 
broad, which may be remnants of the walls of the flagellate chambers. 

The stalk is hollow (Plate 9, figs. 27, 33a). I failed to find any open com- 
munication between the cavity of the stalk and the wide canals of the body 
proper. 

The stalk is supported by a tubular network (Plate 9, fig. 27; Plate 10, 
figs. 8, 13, 14) composed of many longitudinal and a few transverse rhabds and 
other megascleres, joined by apposed silica, which solders these spicules together 
where they come in contact, and which forms short rods connecting adjacent 
spicules. It is to be noted also that pinules are embodied in this network (Plate 
10, fig. 8a). The longitudinal rhabds, of which this skeleton-net is chiefly com- 
posed, are in the outer part of the tube situated longitudinally. Towards 
its inner surface their position becomes on the whole more oblique, and here 
transverse rhabds also occur. The (mostly longitudinal) beams of the network 
are usually 20-60, thick, their (mostly transverse) secondary connections 
usually 4-12 u. Above, where the stalk passes into the body of the sponge, the 
longitudinal rhabds of its skeleton become free. ; 

The megascleres of the body are chiefly pinules, hypodermal and hypo- 
gastral pentactines, hexactines, and rhabds. Besides these a few large, not 
hypodermal or hypogastral, pentactine hexactine-derivates have been observed. 
The hexactines and pentactine hexactine-derivates are scattered throughout 
the choanosome. Some of the rhabds are isolated, most of them form bundles, 
which traverse the interior obliquely and extend paratangentially some distance 
below the surface. Hypodermal and hypogastral pentactines, with paratan- 
gential lateral rays and an apical ray directed radially inward, are noticed under 
the dermal and gastral surface. The whole of the surface is occupied by 
pinules, the lateral rays of which extend paratangentially in the superficial 
membrane. The gastral pinules and the dermal pinules of the body and the 


CAULOPHACUS SCHULZEI. 51 


stalk are quite similar. Nearly all the pinules are regularly hexactine. There 
are numerous forms of microscleres. These can be classified in two groups not 
connected by transitions. The first group comprises hexasters, hemihexasters, 
and hexactines, the rays (end-rays) of which are, when young, smooth, and 
sharp-pointed, when adult covered with numerous large lateral spines and 
crowded with a verticil of terminal spines. The young forms of this group 
appear as oxy-, the adult forms as disco-hexasters, -hemihexasters and -hexac- 
tines. The second group comprises discohexasters with generally smooth 
main-rays, from the ends of which arise regular verticils or bunches of slender 
end-rays. The end-rays are densely covered with small lateral spines, and 
crowned with a verticil of terminal spines. The spicules of this group appear to 
replace, in this and other species of Caulophacus, the plumicomes of Sympagella 
and Calycosilva. For this reason and because they differ very considerably from 
the discohexasters of the other group of microscleres I think it better not to 
describe them as discohexasters, as previous authors have done, but to give them 
another name, discocomes. 

The discohexasters, etc., occupy the choanosome in dense masses. One 
of the rays of those situated in the walls of the large choanosomal canals is 
usually directed canalwards and protrudes into the canal-lumen. The walls 
of these canals therefore appear somewhat spiny and the spicules rendering them 
so might be considered, to a certain extent, as canalaria. 

The discocomes are met with chiefly in the subdermal and the subgastral 
region, and here occasionally form clusters in which large and small ones are 
irregularly intermingled. 

The rhabds of the stalk (Plate 10, figs. 11, 12) are 14-28 » thick near the end. 
The end itself is more or less thickened. This terminal thickening is greater 
in the stout, than in the slender rhabds. When great it gives to the rhabd- 
termini the appearance of oval tyles. The thickened end-part (tyle) measures 
18-38 u in transverse diameter, and is 4-12 » thicker than the adjacent parts of 
the spicule. This more or less thickened end-part is densely covered with small 
spines; the remainder of the spicule is smooth. The terminal region occupied 
by the spines is 44-60 u long. 

The rhabds of the body proper (Plate 10, figs. 1-7, 9, 10) are more or less, 
sometimes very considerably curved, slightly attenuated toward the rounded, 
usually somewhat anisoactine ends, centrotyle, and everywhere smooth, except 
at the ends. The end-parts are covered with small spines, and sometimes slightly 
thickened. These rhabds are 1.2-4.8 mm. long, measured along the chord 


a2 CAULOPHACUS SCHULZEI. 


connecting their ends, and 7-26 thick near the middle. The central tyle 
measures 11—32 u in transverse diameter and is 2—9 uw, on an average about 4.4 yu, 
thicker than the adjacent parts of the spicule. In the central tyle a transverse 
cross is observed, composed of four rudimentary axial threads, about 1 uw long. 
At the ends, these rhabds are 0-4 » thinner than near the centre. Their aniso- 
actinity is not great, the difference in the thickness of the two ends usually not 
exceeding 2-3 ». The terminal spiny regions are 20-45 » long. The spines in 
them stand close together, attain a length of about 1 yu, and arise vertically. 
They are either straight or slightly curved backwards, towards the middle of 
the rhabd, at the end. 

In comparing the measurements of the rhabds of the body of the small 
specimen (with a dise about 30 mm. in diameter) with those of the rhabds of 
the large specimen D (with a disc about 60 mm. in diameter), I found no per- 
ceptible difference in their length, but a well-pronounced difference in their 
thickness, the body-rhabds of the 30 mm.-specimen B being 10-21 y» thick and 
having central tyles 15-26 uw in diameter; those of the 60 mm.-specimen D being 
10-26 » thick and having central tyles 16-32 y in diameter. 

Wilson (loc. cit., p. 45) states that in the specimens examined by him the 
rhabds were 1-4 mm. long, usually 1.5-2.5 mm.; 8-12 u thick, exceptionally 
24 w; and “‘subterminally roughened with microtubercles.” To me the sub- 
terminal protuberances appear as sharp-pointed spines and I should not eall 
them ‘“‘microtubercles.” 

The hexactine megascleres of the choanosome (Plate 7, figs. 20-31) measure 
1.2-3.2 mm. in total diameter. The rays of the same hexactine are fairly equal 
in thickness but differ more or less, often very considerably, in length. In 
many hexactines the longest ray is two to three times as long as the shortest. 
The rays are 250 »-1.4 mm. long, conic, blunt, 25-74 » thick at the base, and 
7-18 » just below the end. They are more or less, often considerably, curved, 
rarely angularly bent (Plate 7, fig. 28). The long rays are invariably smooth 
and attenuated toward the end. The rays reduced in length are either conic, 
pointed, and spiny (Plate 7, fig. 21) or, more rarely, cylindrical, terminally 
thickened, and smooth (Plate 7, fig. 29). 

In the shortened conic and spined rays there is a correlation between the 
number and size of the spines on the one hand, and the degree of longitudinal 
reduction of the ray on the other, the development of the spines being in pro- 
portion to the degree of reduction. Here, as in the similar case of Calycosilva 


cantharellus, this correlation between spine-development and reduction in length 


CAULOPHACUS SCHULZEI. 53 


is probably due to the potential energy of the silicoblasts building the short rays 
being partly diverted from their normal use of forming long rays and converted 
into the work of producing spines. The longitudinal reduction of the rare, 
smooth, terminally thickened, shortened rays is obviously of a different nature, 
the potential energy of the silicoblasts being in this case diverted in another 
direction. The difference of these two kinds of reduction is probably attribut- 
able to a difference in the cause of the reduction. 

There is no perceptible difference in the dimensions of the hexactine choano- 
‘somal megascleres of the small (B, 30 mm.-disc) and large (D, 60 mm.-disc) 
specimen. 

Wilson (loc. cit., p. 44) found the hexactine rays 0.7-1.2 mm. long, and 
28-48 » thick at the base. He occasionally observed hexactines with spines 
on all rays, but does not mention the forms with spines on the reduced ray only. 
In his figure (loc. cit., Plate 5, fig. 10) all the hexactines are drawn with stout, 
straight, and equal rays. My photographs (Plate 7, figs. 20-31) show that 
in the material examined by me their appearance is different. Since, however, 
the figure (Plate 5, fig. 10) of Wilson is a general view of a section, I believe 
myself justified in assuming that this difference is not real but merely due to the 
hexactines in the figure cited having been drawn schematically. 

The rare pentactine hexactine derivates (Plate 8, figs. 23, 24) are, apart 
from the suppression of one of the rays, similar to the hexactines. Some of 
them bear spines on all the rays. These pentactines are 1.1-3.1 mm. in 
diameter. The longest of their usually unequal rays, which may be the un- 
paired apical one or another, is 0.8-1.6 mm. long, their shortest ray 0.4-1.4 mm. 
The rays are 30-55 » thick at the base. 

The hypodermal and hypogastral pentactines (Plate 8, figs. 1-7, 12-22, 25-27) 
are very similar. Their lateral rays are either all properly developed and 
fairly equal (Plate 8, figs. 19-21, 25-27), or one, two, or three of them are more 
or less reduced in length, shorter than the others (other), and also, if more than 
one, unequal in length among themselves (Plate 8, figs. 12-14, 18, 22). The 
properly developed lateral rays are straight or slightly curved, conic, and very 
blunt. Their proximal part is either smooth or it bears a larger or smaller num- 
ber of spines. Farther on, and up to a short distance from the end, they are 
nearly always smooth. The end itself is either also smooth or densely covered 
with small spines. The proximal spines extend, when present, from over a 
quarter to nearly a half of the length of the ray. They are low, broad, pointed, 
and conic. In regard to their number the lateral rays, even of the same spicule, 


54 CAULOPHACUS SCHULZEI. 


are very unequal (Plate 8, figs. 13-15). Sometimes there are a good many, 
sometimes but a few, occasionally only one, and not infrequently none at all. 
When the spines are numerous a spiral arrangement of them can occasionally 
be made out quite distinctly (Plate 8, figs. 13, 15). 

When the lateral rays are markedly reduced in length, their ends are usually 
thickened (Plate 8, figs. 12, 14, 18, 22). The terminal thickening is either spiny 
(Plate 8, fig. 14) or smooth (Plate 8, fig. 12). 

The lateral rays are 250 u-1.1 mm. long, and 25-65 u thick at the base. 
The properly developed long ones taper gradually to the rounded end which 
is 5-12 » thick. The ends of the longitudinally reduced and terminally thick- 
ened lateral rays measure 15-25 » in transverse diameter. In some specimens, 
as for instance in the small one with 30 mm.-disc, the lateral rays of the hypo- 
dermal pentactines are slightly shorter than those of the hypogastrals, those 
of the former sometimes measuring in this specimen 0.9 mm. in length, those of 
the latter 1 mm. In the other specimens, as for instance in the large one D 
with 60 mm.-dise, the lateral rays of the hypodermal pentactines are consider- 
ably longer than those of the hypogastrals, those of the former measuring in 
this specimen up to 1 mm., those of the latter only up to 670 u in length. 

The proximal ray is straight or slightly, often irregularly, curved, and tapers 
gradually to the blunt or rounded end. The basal part of the proximal ray is 
smooth for a short distance, then follows a region which usually bears broad 
and low, conic spines. The number of these spines is variable. Sometimes 
(Plate 8, figs. 7, 16, 17) there are a good many, sometimes only few (Plate 8, 
figs. 1, 5), and sometimes none at all (Plate 8, fig. 6). When these spines are 
numerous, the portion of the proximal ray bearing them is usually more or less 
thickened. The distal and the middle-part of the ray are generally smooth. 

The proximal ray is 600 u-1.1 mm. long, and 30-55 uw thick at the base. 
The maximum thickness of the spiny part is 1-4, rarely as much as 7 p greater 
than the thickness of the base of the ray. 

The difference in the length of the proximal ray of the hypodermal and 
hypogastral pentactines is similar to, but not so great as, the difference in the 
length of their lateral rays. In the small 30 mm.-dise specimen B the proximal 
ray of the hypodermals is not over 0.95 mm. long, that of the hypogastrals not 
over 1.1 mm. In the larger 60 mm.-dise specimen D the proximal ray of the 
hypodermals is not over 1.1 mm. long, that of the hypogastrals not over 0.96 mm. 

Also in the specimens examined by Wilson (loc. cit., p. 46) the hypodermal 
and the hypogastral pentactines were very similar, Wilson (loc. cit., p. 46, 47) 


CAULOPHACUS SCHULZEI. 55 


remarks that there is no trace of a (sixth) distal ray. In the pentactines of the 
specimens examined by me, such a trace occurs as a short continuation of the 
axial thread of the proximal ray beyond the centrum. The measurements 
given by Wilson (loc. cit., p. 47) are: — lateral rays 0.4-0.75 mm. by 36-48 y, 
proximal ray 0.78-1 mm. by 50-60 4. In his drawing (loc. cit., Plate 4, fig. 9) 
of a pentactine the spines are much smaller than in the pentactines examined by 
me with distinctly spined proximal ray (Plate 8, figs. 5, 7, 16, 17). 

The pinules (Plate 11, figs. 1-16, 17a) are nearly always regularly hexactine. 
Only exceptionally a pinule with a rudimentary proximal ray or some other 
abnormity is met with. Apart from certain differences in their dimensions, 
which will be dealt with below, the dermal pinules of the upper part of the stalk, 
the dermal pinules of the body, and the gastral pinules are identical. The 
lower parts of the stalks at my disposal are denuded of their pinules, so that I 
am unable to say what these may be like. Probably they are similar to those 
of the upper part of the stalk, but smaller. 

The distal pinule-ray is straight, 140-390 » long, and 8-23 » thick at the 
base. Above the ray-thickens, and it attains its maximum transverse diameter 
a little below the middle of its length, where it is usually a third to twice as thick 


as at the base. In four pinules measured, the thickness of the distal ray was :— 


at the base 14, at the thickest point 25 u 


a3 ce “ce 16 “ce ce a3 cc 28 u 
b) 

ce ce a3 18 ce ce ce a3 28 u 
) 

ce ims “eo 20 ce ce a3 (as 35 pw 
, 


Beyond the thickest place it is attenuated, at first slowly, then rapidly, to a 
rather sharp point. It consequently appears spindle-shaped. It is covered 
throughout with sharp-pointed, conic spines. The proximal spines are very 
small. Farther up they become larger and they increase in size to the middle 
of the ray, where they measure 18-22 » by 5-Su. From here onwards they 
again become smaller, but only very slightly, the uppermost spines still being 
quite large. The proximal spines arise vertically, those farther up obliquely, 
and the nearer we approach the middle of the ray the more inclined towards 
its tip do their basal parts become. The small proximal spines are straight, 
those farther up slightly curved towards the tip of the ray. The maximum thick- 
ness of the distal ray, together with its spines, is 25-70 u. 

The proximal ray is, when normally developed, straight, 70-145 u long, 
8-17 » thick at the base, and attenuated towards the blunt end, at first gradually, 


56 CAULOPHACUS SCHULZEI. ~- 


then abruptly. Its distal part bears numerous fairly large spines, its proximal 
part fewer and smaller ones. Sometimes this part of the ray is nearly smooth. 
Exceptionally the proximal ray is reduced or hypertrophied. When reduced 
it is 7-40 » long, more or less cylindrical, as thick throughout as the normal 
proximal ray at its base, and terminally rounded. A hypertrophic proximal 
ray observed (Plate 11, fig. 13) was 150 u long, considerably thickened in the 
middle, attenuated to a rather sharp point, and densely covered with large 
spines. It measured at the base 16 u and at its thickest point 25 uv in transverse 
diameter. Another still more hypertrophic one in all respects resembled the 
(opposite) distal ray. 

The lateral rays are similar to the proximal ray, but more frequently smooth 
in their basal part. They are 80-157 yu long, and 8-18 yu thick at the base. 

The lateral rays of the same spicule are usually fairly equal. But in one 
quite abnormal pinule which I found in the large specimen D they were very 
unequal. In this remarkable spicule two adjacent lateral rays were hyper- 
trophic, covered with long spines, and similar to the distal ray of an ordinary 
pinule, whilst the other two laterals were normal and the spinulation of the 
distal ray so much reduced that it resembled the (normal) proximal ray. 

I measured a good many pinules of four different specimens (B, C, D, and E). 
The results of these measurements are tabulated on p. 57. Specimen E, which 
was taken for detailed study because it appeared to be a part of a specimen 
larger than any of the nearly complete ones, was too fragmentary to allow of 
a distinction between its dermal and gastral faces. The dermal and gastral 
pinules of this specimen are therefore not distinguished in the table. 

From this table the following conclusion concerning the differences in the 
dimensions of the pinules can be drawn. There is, in specimens of similar 
dimensions (B and C), a not inconsiderable variation in the dimensions of the 
pinules, particularly the length of the distal ray. In the large specimen D all 
the rays of the body-pinules attain a greater thickness and the proximal and 
lateral rays also a greater length than the corresponding rays of the correspond- 
ing pinules (dermal and gastral) of the small specimens B and C. The rays 
of the dermal pinules are thicker at the base than the corresponding rays of 
the gastral pinules of the same specimen. This applies also to the maximum 
thickness of the distal ray with its spines in specimens C and D, but not in B. 
The distal rays of the gastral pinules attain a considerably greater length than 
the corresponding rays of the dermal pinules of the same specimen. The other 


rays are in some specimens longer in the dermal, in others longer in the gastral 


CAULOPHACUS SCHULZEI. 


PINULES. 


Distal apical ray 


Proximal apical 


57 


Lateral rays 


Specimen B 
(30 mm.-disc) 


Specimen C 
(30 mm.-disc) 


Specimen D 
(60 mm.-disc) 


dermal body 


gastral 


dermal body 


gastral 
| 
upper 
part 
of & 
stalk 


der- 
mal 


body 


gastral 


Specimen E (dise probably 
over 60 mm.); body 


ray 
z By | 2 FE 
¢ | 34 | 3 3 
coos Ne g |tensth| g | engin} § 
3 ES & 5 
= 4 5 “<j 
& s a B 
fay 215- 100- 90- 
limits p 340 10-19 | 25-40 129 | 10-12 149 | 10-14 
average of the ; : 
largest three u 289 16 37 112 12 128 13 
haat 240- 90- pieinie= 
limits 4 390 | 10-15 | 26-45 | 49 | 8-13] jos | 10-11 
average of the i ; 
largest three 337 13 38 103 10 120 11 
Aer il 
limits yy | 10-16 | 32-40 | 95 Ea ett [i 
228 
average of the i x 
largest three u 216 13 38 95 13 125 12 
Me: 280- 90- 
limits p 300 8-12 | 28-32 | 499 | 
average of the . 
largest three u 298 12 32 100 
S225 140— 70- 80- 
aa ZB0Ps ee al Pees | eos 120 
average of the ro ; Y 
largest three »| 727 12 45 97 110 
ab 210- 75- Bie 
limits » 319 | 11-21 | 30-68 124 10-17 170 9-15 
average of the : 
largest three u| 787 21 65 115 15 150 14 
a 215—- 80-4 2 100- f 
limits pz Ben | 18-19 | 87-87 || yas | 8-15 | ag, | 9715 
average of the 
largest three y 332 18 56 127 14 138 13 
aac 190— e 90- 90- 
limits 4 ape) (023°) 82-70 | jag | 8-17 | aay | 8-18 


538 CAULOPHACUS SCHULZEI. 


pinules. The dermal pinules of the upper part of the stalk are in all dimensions 
smaller than the dermal pinules of the body of the same specimen. This differ- 
ence is greatest in respect to the basal thickness of the distal ray. 

In the specimens examined by Wilson (loc. cit., p. 45) the proximal and lateral 
pinule-rays measure about 100 by 8-10 ». These rays, particularly the laterals, 
are, according to this, considerably smaller in Wilson’s specimens than in those 
examined by me. The distal pinule-ray is, according to Wilson (loc. cit., p. 45), 
covered with narrow scales not over 16-20 1 long. His measurements agree 
with mine, but it does not seem correct to call these structures scales. As my 
photographs (Plate 11, figs. 15, 16) show, they are ordinary conic spines with a 
fairly circular transverse section. Wilson (loc. cit., p. 46) gives sets of measure- 
ments of the distal pinule-rays of two specimens, one in which they are slender 
and one in which they are stout. The distal ray of the dermal pinules is (together 
with its spines) in the first 240-320 » by 36-40 u, in the second 210-240 » by 
44-56 uw; the distal ray of the gastral pinules in the first is 260-360 » by 32-36 un, 
in the second 280-320 u by 36-40 u. 

The oxyhexasters, hemioxyhexasters, and small oryhexactines, found in small 
numbers in several specimens, I at first took for skeletal elements sui generis. 
A careful search, however, revealed the presence of a few spicules connecting them 
with the discohexasters, hemidiscohexasters, and discohexactines, and the 
examination of these transitional forms made it clear that these oxyhexasters, 
etc., are young forms of the discohexasters, etc. 

The young oxyhexaster-like etc. of discohexasters ete. (Plate 9, figs. 14-16) 
measure 60-190 » in total diameter, and have six rays. These are 2-4 y thick 
at the base, conic, sharp-pointed, perfectly smooth, and either simple or provided 
with one or two, rarely three, branch-rays. The spicules of this kind with all 
six rays simple, which appear as small oxyhexactines, are very rare; in the 
majority one or more (Plate 9, figs. 14, 15) or, less frequently, all rays (Plate 9, 
fig. 16) bear branches. The simple rays are straight. Those bearing branches 
diverge a little above the branching point slightly in a direction opposite to 
that in which the branch lies, but are straight apart from this divergence. The 
branches arise at a distance of 12-20 u from the centrum of the spicule, steeply, 
sometimes nearly vertically, from the rays, but very soon curve sharply outward 
and then again become fairly straight, remaining so to the end. Like the main- 
rays themselves, these branches (branch-rays) are conic, sharp-pointed, and 
perfectly smooth. When a ray bears more branches than one, they usually 
arise at the same point and diverge in different directions. Exceptionally I 


CAULOPHACUS SCHULZEI. 59 


have seen two branches arising at different points and extending in nearly the 
same direction. 

Wilson (loc. cit.) does not mention such spicules as occurring in the specimens 
examined by him. 

In the rare transitional (adolescent) forms described above, connecting the 
oxyhexasters, etc., with the fully developed discohexasters, etc., the rays and 
branches are quite smooth along their length but crowned at the end by small 
verticils of recurved spines. By an increase in the thickness of all parts, by a 
growth of the terminal spines, and by the addition of lateral spines along the 
length of the rays and branches, these adolescent forms become adult discohex- 
asters, etc. 

The adult discohexasters, hemidiscohexasters, and discohexactines (Plate 8, 
figs. 10, 11; Plate 9, figs. 1-7, 9-13, 17-26; Plate 10, figs. 27a, 28a, 29a) have, 
including the branches, six to seventeen rays and measure 139-264 u in total 
diameter. In the large specimens D and E these spicules attain a larger size 
(diameter of largest 264 and 260 uv respectively) than in the smaller specimens B 
and C, where the largest measured were only 240 u in diameter. The basal 
thickness of the rays is 6-15 ». The total diameter, and to a certain extent also 
the basal thickness, of the rays are, as the subjoined table shows, in inverse 
proportion to the number of rays (branches). 


DISCOHEXASTERS, HEMIDISCOHEXASTERS, AND DISCOHEXACTINES:! 


Diameter of the spicules 
Number of rays Basal thickness 
and branches of the rays u 
limits average of the 
a largest three u 
6 170-264 254 7-15 
7-8 170-250 245 7-15 
9-12 140-230 238 7-15 
13-17 139-195 161 6-8 


In the large specimens D and E the discohexactines with six simple un- 
branched rays are the most frequent. In the small specimens B and C on the 
other hand the majority of these spicules are hemidiscohexasters and disco- 
hexasters with branches on one to all six rays. 


' This table is based on the measurements of the discohexasters, etc., of all the specimens examined. 


60 CAULOPHACUS SCHULZEI. 


Except in the vicinity of the branching points, the main- and branch-rays 
are fairly straight. All the rays, both main and branch, are conic and gradually 
attenuated to the end, which is 2-4 » thick. The simple stem-like basal part 
of the branch-bearing rays is smooth. Apart from this the rays and branches 
are entirely covered with stout, pointed, and strongly recurved spines 2-4 yu 
long. These spines are quite uniformly scattered along the length of the rays 
(branches) and congregated at their ends, where they form terminal verticils 
or bunches 7—-10.5 » in transverse diameter. Particularly when viewed with 
lower powers the terminal spine-verticils more or less resemble convex dises with 
deeply serrated margin. The lateral spines decrease in size toward the distal 
ends of the rays (branches). The most distally situated spines, which form the 
terminal verticil or bunch, are much larger than the adjacent lateral ones, about 
as large as the basal lateral ones. Exceptionally one single hypertrophic ter- 
minal hook-like spine replaces the verticil or bunch. 

The distance of the branching point of the rays from the centrum of the 
spicule, that is the length of the simple stem of the branch-bearing rays, is 15-22 u. 
These stems are very short accordingly, compared to the size of the whole spicule. 
Generally there is only one branch on a ray, but two or three are also frequently 
met with. More than three are rare. The largest number of branches on one 
ray observed was six. When there are more branch-rays than one, they arise 
either at the same or at different levels. When the number of branch-rays is 
great the latter is the rule. In most cases the main-ray is clearly distinguished 
from the branch-ray or branch-rays by its slighter divergence from the continua- 
tion of the axis of the stem, and by its greater length (Plate 9, fig. 21). Some- 
times, however, there is no such distinction, the distal part of the main-ray 
being as long and diverging as much as the branch, and the stem appearing to 
divide into equal branches (Plate 9, fig. 18). The angle between the distal 
part of the main-ray and the branches is variable, most frequently about 45°. 

Wilson (loc. cit., p. 48) states that in the specimens examined by him the 
rays of the discohexactines were 80-110 » long and 8 u thick at the base, their 
terminal spine-verticils or branches being 10-12 u in diameter and appearing 
as watch-glass shaped end-discs. To me these groups of spines, which are 
correctly represented in Wilson’s figures (loc. cit., Plate 5, figs. 4, 5, 9), do not 
appear as watch-glass shaped end-discs. 

The discocomes (Plate 10, figs. 15-26, 27b, 28b, 29b) normally consist of 
six main-rays joined at right angles, each of which bears a terminal verticil or 
bunch of end-rays. One discocome I saw had seven main-rays. The discocomes 


CAULOPHACUS SCHULZEI. 61 


measure 44-312 » in total diameter. The main-rays and end-ray verticils or 
bunches of the same spicule are equal. Exceptionally (Plate 10, fig. 17) one 
or two end-rays arise from a main-ray below the terminal verticil or bunch. 
In one discocome one of the main-rays bore a stout branch, which was crowned, 
like a main-ray, by a bunch of end-rays. In respect to these irregularities the 
rays of the same spicule are unequal. The main-rays are straight, 20-65 
long, cylindrical, and 1.5-7 » thick. At their distal end they are abruptly thick- 
ened to an inverted cone or convex disc, 7-16 » in diameter, from the distal 
face of which the end-rays arise. The main-rays are generally perfectly smooth, 
exceptionally they bear a few rather large spines. The axial thread of the 
main-ray ends abruptly in the terminal thickening and does not give off branches 
for the end-rays; the latter appear to be destitute of axial threads. The number 
of end-rays on each main-ray is from six to eighteen or more. When their num- 
ber is great, it is exceedingly difficult to count them. When few in number 
they form a verticil, when more numerous, a bunch or brush, in which they are 
fairly equidistant. The terminal verticils or bunches formed by the end-rays 
appear as inverted cones with apical angles of 25-100°. The individual end-rays 
are straight or curved in an S-shaped manner with outwardly directed distal end. 
Measured along their chord they are 18-103 » long. They are 2-3 u thick at 
the base and taper gradually to 1-1.5 » at the distal end. They are densely 
covered with lateral spines all along their length, and crowned by a verticil of 
terminal spines at the end (Plate 10, figs. 20, 21, 26). The largest spines are the 
terminal ones. The verticil formed by them somewhat resembles a convex 
end-dise with serrated margin and has in transverse diameter a maximum of 
4.5 u. The lateral spines usually decrease in size very considerably towards 
the proximal end of the end-ray, but in some of these spicules the proximal end- 
ray spines are quite large (Plate 10, figs. 15,16). All the spines arise obliquely, 
their basal parts being inclined towards the centre of the spicule; their ends are 
bent down in the same direction. They, therefore, appear strongly recurved 
(Plate 10, figs. 15, 16). All the spines on the end-rays of the large discocomes 
and the distal spines on the end-rays of all but the very smallest discocomes are 
clearly visible. The spines on the proximal parts of the end-rays of the smaller 
discocomes and all the spines of the smallest are, however, too minute to be 
clearly discernible as such; the presence of these spines is indicated only by 
the rough appearance of the end-rays. 

The individual discocomes differ very considerably in size. A cursory 


examination shows that the relative dimensions of the main- and end-rays, and 


62 CAULOPHACUS SCHULZEI. 


the number, position, arrangement, and shape of the latter are not the same 
in the large and small discocomes. To obtain an insight into the correlation of 
the various peculiarities of the discocomes of different size, I measured thirty- 
three of these spicules all from the same large specimen (fH). The smallest of 
which all the dimensions were taken was 70 u in diameter, the largest 312. 
Discocomes less than 70 » in diameter are rare, the smallest observed was 44 u, 
and these small ones are probably only young forms. As I was unable to take 
with sufficient exactitude all the measurements required of these small disco- 
comes I have not taken them into consideration in the correlations of the several 
characteristics. The difference of the diameters of the smallest (70 «) and the 
largest (312 ») completely measured discocome is 242 4. This 242 » represents 
the range of variation in size (diameter) of the thirty-three discocomes studied. 
The fourth part of it was taken, 242:4 = 60.5, and thus the variation-range 
itself divided into four equal parts, each extending over 60.5 u of diameter- 
variation. To the first of these four parts belong all the discocomes 70-130.5 u 
in diameter, to the second all 130.5-191 yu, to the third all 191—251.5 uw, and to 
the fourth all 251.5-312 ». The discocomes belonging to the same quarter of 
the diameter-variation range were considered as forming a group and their meas- 
urements combined. The subjoined table (p. 63), gives the measurements of 
the four groups of differently sized discocomes. 

The table indicates that the small discocomes (of group I) are more numer- 
ous than the larger, and that among the latter those of group III (191—251.5 u 
in diameter) are scarcer than those of groups IJ and IV. It further shows that 
the relative length of the main-rays is in inverse proportion and the relative 
length of the end-rays is in true proportion (total diameter) of the spicule, that 
is, the larger the discocome the relatively longer the main-rays and the relatively 
shorter the end-rays. 

The number of end-rays on each main-ray and the degree of their divergence 
(the width of the apical angle of the bunch or verticil formed by them) are in 
inverse proportion to the size of the spicule; largest in the smallest (group 1) 
and smallest in the largest (group IV). Besides these differences of the relative 
dimensions of the parts of larger and smaller discocomes, also differences in 
the shape and arrangement of the end-rays are to be noticed. In the small 
discocomes (Plate 10, figs. 17, 18, 24, 25) the end-rays are more or less curved 
in an S-shaped manner, in the large discocomes (Plate 10, figs. 19-21) they are 
straight. In the small discocomes, where they are more numerous, the end-rays 
form brush-like bunches, whilst in the large disecocomes, where they are fewer 


in number, they are arranged in a simple verticil. The terminal thickening of 


ee eS eee 


CAULOPHACUS SCHULZEI. 


63 


DISCOCOMES. 
Dimensional groups I II Lisi IV 
(diameter) (70-131.5) (131.5-191) (191-251.5) (251.5-312) 
Number of discocomes of i 3 P 
each group measured 5 7 
limits p 70-130 136-186 200-250 270-312 
Diameter 
average u 97.1 162.3 225 .4 296.5 
limits » 20-35 30-50 45-65 44-65 
Tength of average u 20.1 40 54.4 54.9 
main-rays 
average per- 
cent of total 27.9 24.6 24.1 18.4 
diameter 
num- a £ 9-18 6-11 
ber on limits and more and more 8 6-9 
each 
main- aver- 
an — about 16 8.5 8 8 
limit 
oa ‘ 18-35 25-48 55-60 70-103 
End-rays - —— 
length aver- 20 58.3 93 
age u st 41.2 ; 8 
aver- 
age 
per- 
cent of PPY A 25.4 25.9 31.6 
total 
‘diam- 
eter 
Apical 
angle of limits 40-100 28-60 30-35 25-35 
terminal = 
bunch or 
verticil of average 65 38 33 29 
end-ray 


the main-rays, from which the bunches or verticils of end-rays arise, is very 
different in discocomes of different size (Plate 10, figs. 17-25); long and conical 
in the large ones (Plate 10, figs. 19-21), and short and more disc-shaped in the 
small ones (Plate 10, figs. 22-25). 

In consequence of all these differences the large discocomes differ from the 


small ones very considerably in appearance; they nevertheless represent a fairly 


continuous series of forms. 


Some of the small discocomes here considered, like those less than 70 u in 


64 CAULOPHACELLA TENUIS. 


diameter, may be young forms of the large ones. Most of them, however, can 
not be considered as such, since their end-ray bunches could not be converted 
into end-ray verticils like those of the large discocomes by means of the apposi- 
tion of silica-layers and since no silico-clastie process is known to occur in sponges, 
which would make possible a conversion (development) of the end-ray bunches 
of the small discocomes into the end-ray verticils of the large ones. 

Wilson (loc. cit., p. 48, 49) is inclined to consider the large and the small 
discocomes as distinct forms, although he has himself observed transitions 
between them. The discocomes observed by him had main-rays 16-50 u» long, 
and on each main-ray five to twenty or thirty end-rays 16-100 u long. 

Wilson (loc. cit., p. 43) examined fourteen specimens from Albatross Stations 
3382 and 3399. Both lie off Panama, 3382 6° 21’ N., 80° 41’ W., 3399 1° 
7’N., 81° 4’ W. The depth at these Stations, 3279 m. (1793 f.), 3182 m. (1740 f.), 
is considerably less than at Station 4651 (2222 f.) where my specimens were 
obtained. 

There can be no doubt that the specimens described above belong to 
Caulophacus schulzei Wilson. Their similarity among themselves, and to 
those examined by Wilson, is indeed remarkably great. This great similarity 
makes it probable, first, that this species is very constant in character, and, 
secondly, that the conditions of life are very similar at the three Stations 3382, 
3399, and 4651. 


CAULOPHACELLA, gen. nov. 


Caulophacidae with oxyhexasters, without any other kind of microsclere. 
The collection contains one fragmentary specimen of this genus, which 


belongs to a new species. 


Caulophacella tenuis, sp. nov. 


Plate 12, figs. 1-19. = 


One fragmentary specimen of this sponge was trawled in the Eastern 
Tropical Pacific, southwest of the Garrett Ridge, at Station 4732, on 21 Janu- 
ary, 1905; 16° 32.5’ S. 119° 59’ W.; depth 3679 m. (2012 f.); it grew on a bot- 
tom of Globigerina ooze; the bottom-temperature was 34.8°. 

The specimen is a thin lamella. To this the specific name refers. 

The only specimen in the collection is a fragment, measuring 15 by 8 mm., 
of a flat lamella, about 1 mm. thick. 

The colour in spirit is nearly dark brown. 


CAULOPHACELLA TENUIS. 65 


General structure of the skeleton. Both faces of the lamella are covered 
with pinules occupying the usual position. The pinules on one side are much 
larger than those on the other. The face covered with the larger pinules I 
consider the dermal, the opposite face the gastral. Pentactines, with para- 
tangentially extending lateral rays, and an apical ray directed radially inwards, 
occur under both surfaces. The pentactines underneath the face with the larger 
pinules are much larger than those underneath the opposite face. The former 
are considered as hypodermal, the latter as hypogastral. Numerous slender 
and some large rhabds, a few large hexactines, and dense masses of oxyhexasters 
and hemioxyhexasters occur in the interior (Plate 12, fig. 13). The oxyhexasters 
are much more numerous than the hemioxyhexasters. 

Small hexactines with rays strongly curved at the end; large sword-shaped 
hexactines with stout and spiny sword-handle ray; middle sized hexactines with 
cylindrical, terminally rounded, strongly curved rays; and a few other forms 
have also been observed in the spicule-preparations. I consider these spicules 
as foreign to the sponge. 

The rhabds are 3-17 mm. long, 10-34 yu thick, rarely 50 u, and quite sharply 
pointed. 

The rare large hexactines have straight, conic rays, 0.5-1 mm. long and 
20-45 » thick at the base. The rays are smooth for the greater part of their 
length, their tips only being covered with small tubercles. 

The hypodermal and hypogastral pentactines differ only in regard to their 
size. Their lateral rays are straight, conic, and rather sharply pointed. Those 
of the former are 500-1100 » long and 14-32 u thick at the base; the correspond- 
ing measurements of the latter are 110-330 » and 7-14 ux. 

The dermal and gastral pinules (Plate 12, figs. 1-8, 14, 15, 19) also differ only 
in size. In both the distal ray is straight, stout at the base, and only slightly 
thickened above. Sparse, small spines arise from its basal part. Towards 
the end the spines become more crowded and larger, the largest attaining a 
length of 7 u in the dermal pinules and a length of 5 u in the gastral. These 
spines are sharp-pointed, directed obliquely upward towards the tip of the ray, 
and also curved in this direction. Their basal part is inclined at an angle of 
about 60° to the ray; farther on they bend, usually somewhat abruptly, towards 
the ray; so that the angle between their end-part and the ray is 45° or less. 
Usually the spines of the same region are fairly uniform. Sometimes, however, 
adjacent spines differ considerably in position. Occasionally I have observed 
pinules in which the distal spines all tended to one side as if bent by a lateral 


66 CAULOPHACELLA TENUIS. 


current. As arule (Plate 12, figs. 1-4; 7, 8) their curvature is simple, the spines 
extending in planes which pass through the axis of the ray. In a few cases, how- 
ever, the spines (Plate 12, figs. 5, 6) are curved doubly, and spirally twisted round 
the ray. 

The lateral rays are conic, straight or slightly curved, and rather uniformly 
and densely covered with small spines. The proximal ray is rudimentary, very 
considerably shortened, cylindrical, terminally rounded, and also covered with 
small spines, some of which arise from its apex. The dimensions of the dermal 
and gastral pinules are tabulated below. 


PINULES. 
Dermal Gastral 
pinules pinules 
length py 270-373 115-180 
thickness at 13 & 
base yu is Sof 
Distal ray | 
maximum trans- | 
verse diameter has “aXe 
(with the spines) 14-22 8-15 
above p 
length p 5-16 5-10 
Proximal ray SS 
thickness w 6-13 5-7 
length pu 120-232 | 85-130 
Lateral rays | 
thickness at 9 
pase 5-1 5-6 


The oxyhexasters and hemioxyhexasters (Plate 12, figs. 9-13, 16-18) measure 
100-125 uw in total diameter, rarely 137 u. The main-rays are in the same spi- 
cule equal, and regularly arranged, each one enclosing right angles with its four 
neighbours. They are straight, cylindrical, 8-11 » long, and 2.7—5 u thick, rarely 
as much as6 4. Hach main-ray bears from one to three end-rays. The number 
of end-rays is by no means always the same on the six main-rays of the same 
spicule. Most frequently oxyhexasters are observed with three end-rays on 
some main-rays and two end-rays on the others, and with two or three end-rays 
on all the main-rays. More rarely one or two main-rays bear only one end-ray, 
which is either clearly distinguished as such or gradually passes into the main- 


ray. These spicules, which appear as hemioxyhexasters, are, apart from their 


CALYCOSILVA CANTHARELLUS. 67 


hemioxyhexastrose character, identical with the oxyhexasters in structure. 
The basal part of the end-rays is usually directed obliquely outward and encloses 
an angle of 40°-45° with the continuation of the main-ray. A short distance 
from their origin the end-rays are curved rather abruptly toward the continua- 
tion of the main-ray, whereupon they straighten out, their middle- and end- 
parts being straight, or only slightly curved. The end-rays are 42-56 u long, 
and 1.5-3 » thick at the base. They are conic and taper very uniformly to an 
extremely fine point. The main-rays are smooth, the end-rays covered with 
rather numerous slender, oblique, backwardly directed spines, which attain a 
length of 0.3-0.5 u. 

The dermal and the gastral pinules and the spiculation generally indicate 
that the thin lamellar fragment above described formed part of a caulophacid 
sponge. It differs, however, from all the known forms of the Caulophacidae 
which comprise Caulophacus F. E. Schulze, Sympagella O. Schmitt, Aulascus 
F. E. Schulze (identical, according to Ijima, with Sympagella), and Calycosilva 
Lendenfeld (comprising part of F. EK. Schulze’s Calycosoma). The absence of 
discohexasters, hemidiscohexasters, and discohexactines makes it impossible to 
place it in the genus Caulophacus, the absence of plumicomes excludes it from 
Sympagella, Aulascus, and Calycosilva. The new genus is named Caulophacella 
on account of its similarity to Caulophacus. 


CALYCOSILVA, gen. nov. 


Stalked, calyculate or mushroom-shaped Caulophacidae. The choanosomal 
megascleres are rhabds and hexactines. Hypodermal pentactines are always pres- 
ent. Hypogastral pentactines are present or absent. The surface is covered with 
hexactine pinules which are similar on the dermal and gastral side of the body. 
The.proximal ray of some of the pinules may be reduced. The microscleres are 
onychhexasters and plumicomes to which oxyhexasters and helonychhexasters 
may be added. Without discohexasters and discohexactine microscleres. 

The collection contains one complete specimen and thirty-one fragments 
referred to this genus, all of which belong to a new species. 


Calycosilva cantharellus, sp. nov. 


helix, var. nov. 


Plate 1, figs. 1-8, 20-24; Plate 2, figs. 3, 7-13, 15; Plate 3, figs. 1-5, 8-30; Plate 4, figs. 23, 24; Plate 5, 
figs. 1, 2, 4, 5, 7-9, 11-15, 18-20; Plate 6, figs. 5-21, 24-34; Plate 7, figs. 1-10, 12-14, 16, 17. 


68 CALYCOSILVA CANTHARELLUS. 


simplex, var. nov. 


Plate 1, figs. 9-19, 25-29; Plate 2, figs. 1, 2, 4-6,14, 16; Plate 3, figs. 6,7; Plate 4, figs. 21, 22; Plate 
5, figs. 3, 6, 10, 16, 17; Plate 6, figs. 1-4, 22, 23; Plate 7, figs. 11, 15, 18. 


megonychia, var. nov. 


Plate 4, figs. 1-20; Plate 5, fig. 21; Plate 7, fig. 19. 


All the specimens of this species were trawled at Station 4651 off northern 
Peru, on 11 November, 1904; 5°41.7’ S., 82°59.7’ W.; depth 4063 m. (2222 f.); 
they grew on sticky, fine, gray mud; the bottom-temperature was 35.4°. 

The complete specimen shows that the sponge is, in outer appearance, similar 
to the mushrooms of the genus Cantharellus, and to this the specific name refers. 
It possesses spirally twisted onychhexasters, which I name helonychhexasters. 
Such spicules have not been found in any of the other (more or less fragmentary) 
specimens. In some of the latter the average and the maximum size of the 
onychhexasters is considerably greater than in the others. On account of this 
and other differences between them I distinguish three varieties within this 
species :— var. helix, with helonychhexasters (the complete specimen); var. 
megonychia, without helonychhexasters, with larger onychhexasters (six frag- 
mentary specimens); and var. simplex, without helonychhexasters, with smaller 
onychhexasters (twenty-five more or less fragmentary specimens). ‘'Twenty- 
four of the specimens of var. simplex are identical and obviously parts of the- 
body proper of the sponge. These are designated C. c. var. simplex (A). One 
corresponds to the basal part and the stalk of the complete specimen. This is 
designated C. c. var. simplex (B). 

Shape and size. The complete specimen of C. c. var. helix (Plate 6, fig. 18) 
appears as a horizontally expanded plate, from near the centre of the lower side 
of which a slender stalk arises. The stalk is 52 mm. long, nearly circular in 
transverse section, and at the lower end, where it was attached to the sea-bottom, 
4mm. thick. It gradually thickens above and measures at its upper end, where 
it gradually passes into the body proper of the sponge, 7 mm. in transverse diame- 
ter. Its lower portion is markedly bent and has the appearance of having first 
grown somewhat obliquely and later vertically. The plate, which is to be con- 
sidered as the body proper of the sponge, is irregularly oval in outline and 
measures 68 by 92mm. _ Its central part, to which the stalk is attached, is 6 mm. 
thick. Towards the margin it thins out. The plate is somewhat bent in an 


undulating manner and at one place strongly curved inwards. In the figure 


CALYCOSILVA CANTHARELLUS. 69 


(Plate 6, fig. 18) this involuted portion of the body, which extends quite to the 
centre, lies in front. 

The lower side of the plate-like body is the dermal, the upper, the gastral. 
They are identical in structure and both formed by a transparent membrane 
destitute of larger apertures. The entrances to the large afferent and efferent 
choanosomal canals are seen through this membrane. In some places where 
the superficial membrane has been lost these canal-entrances are bare. 

The six specimens of C. c. var. megonychia are fragmentary plate-like parts 
of the body proper of the sponge. Parts of some of these attain a thickness of 
8 mm., and these thin out to a rather fine margin at one side. The largest of 
these fragments is 49 mm. long and 35 mm. broad. 

The twenty-four fragmentary specimens of C. c. var. simplex (A) are parts 
of plates with a maximum length and breadth of 50 mm., and are at their thickest 
point 4-6 mm. thick. One of these fragments formed a central part of a sponge; 
to this the upper part of a stalk is attached. The surface has the same character 
as in C. c. var. helix, the only difference being that much more of the superficial 
membrane has been lost and that some slender spicules protrude from it to dis- 
tances of 10 mm. or more. Iam inclined to consider these hair-like spicules as 
foreign. 

The single specimen of C. c. var. simplex (B) (Plate 5, fig. 10) has the shape 
of a pipe. It is traversed by the fragment of a large foreign spicule, probably 
a root-tuft spicule of a hyalonematid. This foreign spicule, which forms the 
base of attachment is — for a length of 39 mm. — coated by a thin layer of the 
sponge. Thus a cylinder 39 mm. long and 2-3 mm. thick, appearing as the stem 
of the pipe, is formed. This stem is to be considered as the stalk of the sponge. 
From one end of this stalk, which probably lay horizontally on the sea-bottom, 
a structure 9 mm. thick and 15 mm. long, resembling the bowl of the pipe, 
arises at an angle of about 106°. This part of the specimen is to be considered 
as the upper end of the stalk and part of the body proper of the sponge. 

Colour. All the specimens are grayish brown. C. c¢. var. helix has a more 
grayish colour, C.c. var. megonychia and simplex are more brownish. The speci- 
mens of C. c. var. megonychia are rather darker than the others. 

General structure. A fine superficial membrane uniformly covers the 
dermal surface of the stalk and the dermal and gastral surfaces of the body 
proper. This membrane is supported by the paratangential rays of the pinules 
and perforated by pores which lead into a superficial cavity, 60-90 u high (radial 


dimensions), and traversed by numerous fine trabeculae. This cavity is limited 


70 CALYCOSILVA CANTHARELLUS. 


distally by the superficial membrane containing the paratangential pinule-rays, 
proximally by another perforated membrane or, to speak more correctly, a net- 
work of paratangential trabeculae, containing the paratangential rays of the 
(hypodermal and hypogastral) pentactines. The subdermal (Plate 5, figs. 1, 4f) 
_ and subgastral (Plate 5, figs. 1, 4b) cavities extend below this membrane or 
network. These are identical in shape, 300-600 u high (radial dimensions), and 
traversed by radial columns connecting their roof with their floor. Each of these 
columns consists of a proximal ray of a (hypodermal or hypogastral) pentactine, 
enveloped in a mantle of soft tissue. In the formation of many of them also the 
distal end of a transverse choanosomal rhabd takes part. The columns are on 
an average 250 « apart, and usually 30-40 u thick. Numerous fine, thread-like 
trabeculae arise from the columns and join to form close reticulations which sur- 
round them like trellis-work. Above and below these reticulations are very 
extensive, and join to form continuous networks extending along the roof and 
floor of the cavity. In the middle they appear to be less extensive. In the sec- 
tions large empty spaces are observed between the trellis of trabeculae surround- 
ing the columns in this region. I think it quite likely that in life these cavities 
are also traversed by trabeculae, and am inclined to ascribe their emptiness in 
the sections (Plate 5, figs. 1, 4) to the trabeculae having here been torn and lost 
through shrinkage when the sponge was captured and preserved. 

The floor of the subdermal and subgastral cavities is traversed by bundles 
of rhabds (Plate 5, figs. 1, 4c, f) and perforated by numerous apertures. These 
are more or less circular, both on the dermal and the gastral side, and in the best 
preserved specimens (parts) are sometimes 1.5 mm. wide. In specimens (parts) 
not so well-preserved and more strongly shrunken some of them attain a diameter 
of 3 mm. (Plate 4, fig. 20). On the gastral side their distance from each other 
nearly equals their diameter, on the dermal side they are farther apart. The 
apertures on the lower, dermal side lead into the afferent, those on the upper, 
gastral side into the efferent canals. The afferent and efferent canals are, in 
well-preserved parts of the plate-like body proper of the sponge, 0.75-1.5 mm. 
wide, and extend in a direction more or less vertical to the surface (Plate 5, figs. 
1,4, 16). Their length is on the whole proportional to their width. The widest 
reach to within a short distance of the floor of the (subdermal or subgastral) 
cavities on the opposite side. The stalk is hollow, with an eccentric, not axial 
cavity, and walls, which in the middle of the stalk of the specimen of C. c. var. 
helix are 2.5 mm. thick on one side and 0.7 mm. on the other. Vertical, appar- 
ently efferent canals of considerable width (Plate 5, fig. 16) leading up to the 


CALYCOSILVA CANTHARELLUS. 71 


central part of the gastral face of the sponge are observed where the stalk is 
attached to the body proper. 

Some canals are traversed by thread-like or membraneous trabeculae, others 
appear to be destitute of such. It is difficult to say whether the latter are empty 
in the living sponge, or whether they have lost their trabeculae after capture. 
I think, however, that the latter assumption is more likely to be correct than the 
former. 

The trabeculae traversing the cavity of the stalk are distinctly membrane- 
ous, and stouter and more distant than the ones spread out in the canals of the 
body proper of the sponge. 

The flagellate chambers (Plate 2, fig. 7a) form a continuous layer interven- 
ing between the afferent and efferent canals. They are more or less oval, wide- 
mouthed sacs and measure 70-100 u in transverse diameter. Their length varies 
considerably, from 120 to 220 u. 

More or less spherical bodies 2—5 » in diameter are met in various parts of 
the sponge. These lie either singly or in groups, and stain strongly with aniline- 
blue and magenta. The largest of the groups formed by them attain a maxi- 
mum diameter of 36 », and are composed of forty or more such bodies. Some of 
them, particularly the larger single ones, are enclosed in spherical envelopes, 
about 9 uw in diameter, which are often very distinct and appear as cell-walls. 
The space between the highly stained body and the envelope is occupied by a 
colourless (unstained) and transparent substance. The highly stained body is 

not always stained uniformly throughout. One can often distinguish within it 
a not so strongly stained ground-substance, and a very strongly stained, irregu- 
larly branched, apparently chromidial mass. On a few of the envelopes enclos- 
ing these bodies was observed a circle, 2 1 in diameter; this appeared as the 
margin of a round aperture, perhaps covered by an operculum. In one of 
these the stained body did not lie altogether within the envelope but had partly 
emerged from it through this aperture and filled it up like a plug. 

The spicules taking part in the formation of the skeleton are: — large, stout- 
rayed hexactines; derivates of these hexactines with less than six rays, mostly 
diactines (in C. c. var. simplex only); ordinary rhabds; slender, rectangularly 
bent diactines (in C. c. var. helix only); large, slender-rayed triactines (in 
C.c. var. megonychia only); pentactines; hexactine pinules with a fully developed 
or a reduced proximal ray; a few microhexactines (in C. c. vars. simplex and helix 
only); aseries of forms of regular onychhexasters; a few irregular onychhexasters; 
onychhexaster-derivate oxyhexasters (in C.c. vars. helix and megonychia only) ; 


Te CALYCOSILVA CANTHARELLUS. 


helonychhexasters (in C. c. var. helix only); and plumicomes (exceedingly scarce 
in C. c. var. megonychia). 

In the body proper of the sponge all the spicules are isolated and free. 
In the stalk the ordinary choanosomal rhabds are joined to form a dictyonal net- 
work to which also a few hexactines may be attached. 

In C. c. var. simplex (B) the skeleton-net of the stalk (Plate 5, figs. 3b, 10) 
closely surrounds the hyalonematid root-tuft spicule (Plate 5, figs. 3, 10a) 
which forms the base of attachment. The thinner distal end of this envelope, 
which corresponds to the lower end of the stalk, consists of a network with 
beams 12-35 » thick, and irregularly triangular or polygonal meshes, on an 
average about 100 ~ wide. In this network main longitudinal and secondary 
transverse beams cannot be distinguished. Farther on, towards the upper end 
of the stalk, the network becomes more regular and more and more distinctly 
composed of longitudinal main beams (15-65 » thick, usually 20-45 ), joined 
by short, transverse connections to a ladder-like structure. In consequence 
of the main beams not being quite parallel, and the transverse beams very irregu- 
larly distributed, the meshes of this part of the network are very unequal in size, 
5-50 » and more broad, 30-200 1 and more long. However different their 
size may be, in shape and position these meshes are very much alike, always 
elongated, oval, or rectangular with strongly rounded corners, and arranged with 
their long axis extending longitudinally. In some parts of this network the 
beams are smooth, in others covered by small, low, sharp spines. At the upper 
end of the stalk the transverse connections become less numerous and the net- 
work dissolves itself into a sheaf of longitudinal rhabds. 

Ends of the rhabds taking part in the formation of the net in many places 
freely protrude from it. These free rhabd-termini, which are rather scarce 
below, but become quite frequent above, are blunt-pointed or rounded, and 
just below the end, for a distance of 50-70 u, densely covered with fairly large 
spines. In the blunt-pointed ones the end itself is free from spines. In the 
terminally rounded ones the spines cover the end also. The spined part below 
the end, particularly in the blunt-pointed forms, is considerably thickened, club- 
shaped, and measures 15-28 y» in transverse diameter. 

The skeleton-net in the stalk of C. c. var. helix (Plate 5, figs. 5, 7) is similar, 
but smooth and still more ladder-like. Its beams are 10-53 wu, usually 20-40 yu, 
the free ends of the rhabds taking part in its formation, 15-30 u thick. At the 
upper end of the stalk the transverse beams become scarcer and the character- 
istically tubular network dissolves itself into a hollow sheaf of isolated longi- 


CALYCOSILVA CANTHARELLUS. 73 


tudinal rhabds. On reaching the body proper of the sponge this hollow sheaf 
of rhabds opens out ina calyculate manner and divides into numerous rhabd- 
bundles (Plate 5, figs. le, 4e, 16), which extend in the floor of the subdermal 
cavities paratangentially and more or less radially towards the margin of the 
plate-like sponge-body. Occasionally anastomosing they here form a kind 
of loose paratangential network with radially elongated meshes. 

On the gastral side, in the floor of the subgastral cavity, a similar network 
of preponderantly radially extending rhabd-bundles (Plate 5, figs. le, 4c) is 
observed. 

Besides these paratangential rhabd-bundles in the floors of the subdermal 
and subgastral cavities numerous isolated rhabds and loose bundles of them, 
situated obliquely or transversely (Plate 5, figs. 1d, 4d), are found in the choano- 
some. The ends of many of the transverse rhabds adhere to proximal rays of 
hypodermal and hypogastral pentactines. In the centre of the sponge-plate, 
near its junction to the stalk, some oblique rhabds, similar to these but very 
much larger, have been observed (Plate 5, fig. 16). 

At the point of junction of the stalk to the body proper of the sponge some 
long and slender diactines with actines enclosing an angle of about 90° (ortho- 
monaenes) have been observed in C. c. var. helix. 

The hexactines lie scattered rather irregularly in the choanosome. The 
thickness of their rays and the size of their spines are subject to considerable 
variations. The shortest rayed and most strongly spined are found in the 
centre of the body at its junction with the stalk. Towards the margin of the 
sponge-plate the rays of the hexactines become more slender and less spiny. 

Tetractine and triactine hexactine-derivates have been found in small 
numbers, chiefly in C. c. var. megonychia. The diactine hexactine-derivates 
are not numerous, and have been observed only in C. c. var. simplex in the 
region of the junction of the stalk to the body proper of the sponge. 

The gastral and dermal surfaces of the body proper and the surface of the 
stalk are uniformly covered by a dense pinule-fur (Plate 2, figs. la, 8a, 13a; 
Plate 4, figs. 21-24; Plate 5, figs. la, g, 4a, g, lla, g, 16a, g). The two kinds of 
pinules, with long, well-developed, and pointed proximal ray, and with short, 
rudimentary, rounded proximal ray, which are not, or hardly at all, connected 
by intermediate forms, are quite indiscriminately scattered, and although the 
former are relatively more numerous on the body and the latter predominate on 
the stalk, both kinds appear everywhere to be intermingled. Apart from the 
dermal pinules of the body being on the whole slightly larger and having slightly 


74 CALYCOSILVA CANTHARELLUS. 


larger distal rays than the gastrals, there seems to be no difference between them 
(Plate 4, figs. 21-24; Plate 5, figs. 1,4). The pinules of the stalk are consider- 
ably smaller than those of the body proper. 

The crosses formed by the four lateral rays of the pinules lie paratangentially 
in the superficial membrane (Plate 2, figs. 8a, 13a). Their centres are about as 
far apart as their rays are long. In some places they are arranged regularly, 
two rays of any two adjacent ones lying parallel and close together (part of the 
lower half of Plate 2, fig. 13). In other places their arrangement is not so regular. 
The (smaller) pinules of the stalk are much closer together than the (larger) 
pinules of the body. 

The apical distal ray is much longer in the larger pinules of the body 
than in the smaller pinules of the stalk and, as stated above, on the whole in the 
dermal body-pinules slightly longer than in the gastrals. But also apart from 
this, the distal pinule-ray is very variable in length, and we find everywhere 
pinules with long and with short apical distal ray intermixed indiscriminately. 
This renders the fur formed by these pinule-rays very shaggy (Plate 4, figs. 
21-24). 

In the outermost region, which is occupied by the superficial cavities and, as 
above stated, is 60-90 « thick, no skeletal elements other than proximal pinule- 
rays are met with. 

A membrane or network extends parallel to the surface below this region 
and separates it from the subdermal and subgastral cavities, forming the roof 
of the latter. The centres and the paratangentially extending lateral rays of the 
(hypodermal and hypogastral) pentactines are situated in this membrane. 
The apical rays of these spicules are situated radially and directed inward. The 
crosses formed by the lateral rays of the pentactines are for the most part regu- 
larly arranged. The distances between the centres of adjacent pentactines are 
in the same region fairly equidistant and a little shorter than the length of their ~ 
lateral rays. Two lateral rays of adjacent pentactines are parallel and lie 
close together (Plate 2, fig. 13b). The hypodermal and hypogastral pentactines 
of the body are quite similar and nearly equal in size; the hypodermal pentac- 
tines of the stalk are considerably smaller. The body-pentactines are accordingly 
also farther apart than the stalk-pentactines. The distances between the 
centres of these spicules being shorter than the length of their lateral rays, the 
tips of the lateral rays of each pentactine extend beyond the centres of the four 
adjacent ones. This renders the quadratic reticulations formed by the lateral 


pentactine rays quite firm, In some places small (probably young) pentactines 


CALYCOSILVA CANTHARELLUS. 75 


have been observed. The lateral rays of these spicules extend paratangentially 
like those of the larger ones, but are, apart from this, more or less irregularly 
disposed and lie anyhow in the meshes of the quadratic network formed by the 
lateral rays of the large pentactines. 

In most of the pentactines the apical ray is well-developed, longer than the 
lateral rays; in some it is reduced and considerably shorter than the laterals. 
The pentactines with short apical ray appear to be scattered indiscriminately 
among the pentactines with long apical ray. 

Most of the apical (proximal) rays of the pentactines penetrate and extend 
beyond the paratangential membranes or networks forming the floors of the sub- 
dermal and subgastral cavities. The end-part of many transverse rhabds are 
parallel to and in close contact with proximal pentactine rays (Plate 2, fig. 12b). 

The microhexactines are very rare and have been found only in the regions 
of the subdermal and subgastral cavities. 

The regular onychhexasters are abundant in the choanosome and in the 
floors of the subdermal and subgastral cavities (Plate 2, fig. 3; Plate 5, fig. 1). 
Some also occur in the proximal parts of the columns and threads which traverse 
these cavities. They are not confined to the body proper of the sponge and also 
occur in the stalk. These onychhexasters form a series, one end of which is 
represented by onychhexasters with short and stout end-rays, the other by 
onychhexasters with long and slender end-rays. The former are found in the 
proximal parts of the subdermal and subgastral regions of C. c. vars. simplex 
and helix, but appear to be absent in C. c. var. megonychia. The latter are, 
in all varieties, plentiful in the interior. Intermediate forms are met with 
wherever onychhexasters occur. 

The oxyhexasters occur in small numbers in the choanosome of C. c. var. 
helix and somewhat more frequently in C. c. var. megonychia. 

The helonychhexasters, which occur only in C. c. var. helix, are met with 
in fairly large numbers in the floors of the subdermal and subgastral cavities 
and are also found in the proximal parts of the columns and threads traversing 
these cavities. These spicules are not uniformly distributed throughout. this 
region, but in some parts of it are much more numerous than in others. 

The plumicomes are confined to the columns and threads which traverse 
the subdermal and subgastral cavities and are more numerous in their distal 
than in their proximal parts. Their paratangential distribution is fairly uni- 
form. They are quite abundant in C. ¢. vars. simplex and helix, but very rare 


in C. c. var. megonychia. 


76 CALYCOSILVA CANTHARELLUS. 


The ordinary rhabds (Plate 1, figs. 1-4; Plate 2, figs. 1b, 12b; Plate 5, figs. 
1, 2, 4, 8, 9, 11-16) are more or less, sometimes very considerably curved, usually 
in a somewhat wavy manner. They attain a length of 2.2-9.1 mm. and a 
thickness of 5-80 4. The ordinary stout rhabds, which are found in small 
numbers in the region of the junction of the stalk to the body proper, are in 
C.c. var. helix 45-55 u thick, in C. c. var. simplex 55-80 u. The ordinary slender 
rhabds, which form the paratangential bundles in the floors of the subdermal 
and subgastral cavities and which traverse the choanosome obliquely and trans- 
versely in large numbers, are 2.2-6.2 mm. long and 5-23 yu thick near the middle. 
They are in C. c. vars. megonychia and simplex on the whole somewhat thicker 
than in C.c. var. helix. Forms intermediate between the stout rhabds mentioned 
above and these slender ones occur, but they are rare. The longest rhabd ob- 
served, which measured 9.1 mm. in length, belongs to these intermediate forms. 

In these rhabds a longitudinal main axial thread is observed, which termi- 
nates just below the two ends in the adult spicules, but opens out freely, with a 
funnel-shaped widening, in some at least of the young. Besides this there are 
two short rudimentary axial threads, forming a cross. The two rudimentary 
axial threads are usually 1.5-4 » long. Very distinct rounded protuberances 
arise over most of the slender rhabds (Plate 1, figs. 3, 4; Plate 5, fig. 9). These 
protuberances are generally very low, lower than broad, and in that case the 
spicule appears as a centrotyle. Exceptionally they attain a greater length, and 
in that case the spicule appears as a tri- to hexactine, with two long rays, and 
from one to four perfectly smooth, terminally rounded, cylindrical, rudimentary 
rays. The longest rudimentary ray of this kind observed measured 38 yw in 
length. In some of the slender rhabds the central tyle is so small as to be 
hardly or not at all discernible (Plate 5, fig. 8). Hardly or not at all centrotyle 
rhabds are much more frequent among the thicker than among the slender 
rhabds and most of the thickest are not centrotyle at all. Twenty slender rhabds 
of C. c. var. helix which I measured were 7—20 » thick in the middle, close to the 
central tyle, which measures 10-23 » in diameter. In these spicules the central 
tyle was 1-7 u thicker than the adjacent parts of the spicule. This difference is 
correlated to the thickness of the spicule only in so far as it is on the whole some- 
what smaller in the thicker than in the thinner rhabds. 

Most of the ordinary rhabds are more or less anisoactine amphistrongyles 
or very blunt amphioxes (Plate 5, figs. 2, 12, 13). Their ends are usually about 
a third to a half as thick as their central part. Sometimes a slight spindle-shaped 
thickening is observed just below the end. Occasionally (Plate 5, figs. 14, 15) 


CALYCOSILVA CANTHARELLUS. 77 


one end is considerably thickened to a more or less spherical tyle, 24-50 u in 
transverse diameter. Only a few rhabds are smooth throughout. In most a 
spined zone, 10—90 u in extent, is observed at, or just below, the ends. In the 
terminally thickened tyle-ends, this spined zone is short and situated terminally, 
the spines being sometimes restricted to a small patch on the apex of the terminal 
tyle. Also in the cylindrical strongyle rhabd-termini the spines often extend 
quite tothe end. In the tapering rhabd-termini, which are usually slightly thick- 
ened in a spindle-shaped manner just below the end, the extreme tip is usually 
quite smooth. In such rhabd-termini the smooth terminal zone is sometimes 
27 » long, the spined zone appearing as a belt below the end. The spines are 
conic, simple, 1.5—4.5 » long, and crowded quite closely in the spined zones. 

Abnormal rhabds are rare. In one there were two distinct centres, 5 u 
apart, each with a cross of rudimentary transverse axial threads and a tyle. 
In another, one end was abruptly bent. Several show short rudimentary branch- 
rays, each with an axial thread, at one end. 

Some rhabds are corroded and have partly lost one or more of the super- 
ficial silica-layers composing them. In one, which had lost a part of its outer- 
most layer, a perfectly regular spiral split, forming six close turns, traversed the 
part of its still remaining portion bordering on the line along which the rest had 
broken away. 

The rectangularly bent diactines (Plate 5, fig. 20) have been found only in 
C. c. var. helix, and here also they are very rare. The two actines are straight 
or slightly bent, perfectly smooth, 1.3-2.3 mm. and more long and 32-35 u 
thick at the base. The angle enclosed by them is 89-99°. 

The large slender-rayed triactines (Plate 5, fig. 21) have been found only in 
C. c. var. megonychia, and here also they are very rare. Their rays are smooth 
and at the base about 24 « thick. Two lie in a straight line, from which the third 
arises vertically. 

The hexactines (Plate 1, figs. 14-24; Plate 2, figs. 4, 6, 9, 11, 14-16) of 
the two varieties are similar in shape and size. They measure 0.9-3.4 mm. in 
total diameter. Their rays are 0.16—2.2 mm. long, straight or slightly curved, 
very rarely angularly bent, and, on the whole, conic. At their base the rays are 
18-67 » thick and, for a distance of 40-160 u, smooth. Farther on they are cov- 
ered with spines for a distance of 140-450 uw. In this spined region the rays are 
thicker than at their base, and attain a thickness of 22-75 uw. In the rays reduced 
in length the spiny region extends quite to the end. In the normal long rays a 
distal part of considerable length, which is either smooth throughout or provided 


78 CALYCOSILVA CANTHARELLUS. 


only with a few small spines close to the end, follows the spiny region. This 
distal part of the ray is conic and tapers gradually to a rounded end, 5-17 u 
thick. This has been observed only rarely in the hexactines of C. c. var. megony- 
chia. One of the rays is thickened at the end, the terminal tyle attaining a trans- 
verse diameter of 35 yu. 

In some hexactines the rays are nearly equal in length. In most an often 
very considerable difference in length of the individual rays is to be noticed. This 
irregularity is usually due to one ray (Plate 1, figs. 16, 17, 22) or two rays 
(Plate 1, figs. 14,15) being more or less reduced in length. In the slender-rayed 
hexactines, which are probably young forms, the rays thus shortened are similar 
to the long ones. In the stout-rayed hexactines, which are certainly full-grown 
forms, this difference in ray-length is associated with and obviously correlated 
to a difference in the arrangement and shape of the spines, which renders the 
appearance of the shortened rays often very different from that of the long ones. 

The spines of the spiny regions of the long, not reduced, hexactine rays 
(Plate 1, figs. 14-18; Plate 2, figs. 4, 6, 11, 16) are conic, not very sharp-pointed, 
and 5-35 uw long. They arise quite or nearly vertically and are not very close 
together, on an average about 504 apart. In some cases they seemed to be 
arranged spirally, but I could not verify this and was indeed unable to prove the 
existence of any kind of regularity in their arrangement. The spines of the short, 
reduced, hexactine rays (Plate 1, figs. 14,15, 16; Plate 2, figs. 2, 14). are much 
closer together, often in contact with each other at the base, and occasionally 
branched. The branched spines (Plate 2, figs. 2, 14) consist of cylindroconic 
stems, the ends of which are split up into from two to four stout, conic, obliquely 
diverging, secondary spines. These spines somewhat resemble the protruding 
rays of the sterrasters of the Geodidae. 

The silicoblasts building the rays of the hexactines possess, when they start 
work, a certain amount of potential energy, E. This is expended in building the 
ray and in forming the spines. The production of the former requires the work 
W,, the production of the spines the work W2. When their task is done the whole 
of E will have been converted into work, W, and this W will be equal to W; + Wo. 
Under normal conditions there is a certain proportion between W, and Ws. 
When, however, a spicule or some other obstacle prevents the silicoblasts from 
producing a ray of the normal size, less than the usual proportion of W is ex- 
pended on W, so that, W being = W,; + We, more remains for Wo. This leads 
to the hyperdevelopment of the spines actually observed on the shortened rays. 


The ray being much shorter and the spines more numerous and on the whole 


CALYCOSILVA CANTHARELLUS. 79 


larger, there is no room on the ray for the development of a spineless distal part, 
and there is not even on the whole ray space sufficient for the spines to be placed 
at so great a distance from each other as in the spined regions of the normally 
developed long ones. It seems very probable that this crowding may lead to a 
partial concrescence of two or more adjacent spines and thus to the formation 
of the apparently branched structures above referred to, which I am inclined to 
consider as more or less coalesced groups of as many spines as they bear terminal 
spinelets. 

Of hexactine-derivates with less than six rays pentactine, tetractine, and tri- 
actine forms have been observed in all varieties, diactine ones, however, only 
in C. c. var. simplex. Several pentactine to triactine forms have been observed, 
in C. c. var. megonychia. In the two other varieties they are exceedingly rare. 
Apart from the smaller number of their rays, they do not differ from the hexac- 
tines above described. The diactine forms are much more frequent than those 
in C. c. var. simplex. 

The diactine hexactine-derivates (Plate 1, figs. 25-29; Plate 2, fig. 5), which 
I have found only in C. c. var. simplex, appear as straight, or slightly curved, or 
angularly bent, blunt, usually isoactine amphioxes. They are 2.6-3.3 mm. 
long and 40-90 u thick in the middle, where a slight thickening is sometimes dis- 
cernible. Some taper from here uniformly towards both ends, in others each 
actine is thickened some distance from the centre. The transverse diameter 
of these thickened parts is in such spicules 10-15 uw greater than that of the centre. 
These hexactine-derivate amphioxes bear spines, the size, number, and arrange- 
ment of which are subject to considerable variation. A part of the spicule, situ- 
ated at or near the middle of its length, is always free from spines (Plate 1, figs. 
25-29). Farther on the two actines bear spines, which are either sparsely and 
irregularly scattered (Plate 1, figs. 25-27) or restricted to distinct belts, one on 
each actine, within which the spines stand rather close together (Plate 1, figs. 28, 
29; Plate 2, fig.5). In shape and size the spines of these amphioxes resemble the 
spines of the hexactines above described. <A few of the spines are branched 
(bifureate). 

The pentactines have very much the same shape and size in the three varie- 
ties, and there seems to be hardly any difference between the hypodermal and 
the hypogastral pentactines of the body. The pentactines of the stalk are 
smaller and have a relatively shorter apical (proximal) ray. 

The four lateral rays of the hypodermal (Plate 6, figs. 1-8) and hypogastral 
(Plate 1, figs. 5-13) pentactines of the body proper are 250-770 uw long, usually 


80 CALYCOSILVA CANTHARELLUS. 


300-700 yu, 16-47 » thick, usually 19-32 » at the base, and on the whole conic. 
They taper gradually to the rounded end, which is 1-11 u thick, usually 2-4 u. 
In two belt-like regions, one a short distance from the base and the other a short 
distance from the end, each lateral ray usually bears small, low spines, the spines 
of the proximal belt being larger and more numerous than those of the distal 
belt. The base, the middle, and the end of the lateral ray are usually smooth. 

The angles between the lateral rays are always nearly 90°. In this respect 
the crosses formed by them are regular. The length of the lateral rays of the 
same spicule is, however, by no means the same. In this respect the crosses are 
irregular. Among all the many pentactines I measured I found not one with 
equally long lateral rays. The difference in the length of the longest and short- 
est lateral ray of the same spicule amounts to 20-320 u. 

The apical (proximal) ray is similar to the lateral rays in shape, but very 
variable in length, 0.15-1.37 mm. long, and at its base usually somewhat thicker 
than the lateral rays. In most of the pentactines the proximal ray is well- 
developed and longer, in some reduced, as long as or shorter than the lateral 
rays. Some of these reduced proximal rays are truncate at the end as much as 
15 » thick. A correlation between this occasionally occurring reduction of the 
proximal ray and the development of the lateral rays does not seem to exist. 
The influences (obstacles) which prevent the silicoblasts building the former 
from properly executing their task of producing a proximal ray of normal length, 
do not appear to affect in any way those building the latter. 

A crowding of the spines is observed in the reduced apicals of the pentactines 
similar to that in the reduced hexactine rays, described above; it is not, however, 
somarked. The cause of this crowding is doubtless in both the same. 

The lateral rays of the hypodermal pentactines of the stalk (Plate 6, figs. 9-12, 
13a) are 230-520 » long and at the base 17-42 u thick, usually 18-32 ». They 
are conic, have blunt ends, and are either quite smooth or provided only with 
’ very small spines. The crosses formed by them are, like those of the pentac- 
tines of the body, regular in respect to the angles between the rays, which are 
always about 90°, but irregular in respect to their length, which always differs 
more or less. The difference between the length of the longest and shortest 
lateral ray of the same spicule is in these pentactines 10-80 ». The apical (proxi- 
mal) ray is similar to the laterals in shape and usually about as long or only a 
little longer. 

As mentioned above there are two kinds of pinules; pinules with properly 
developed proximal and apical rays, and pinules with such rays rudimentary and 
not at all, or but slightly, connected by intermediate forms. Both kinds occur 


CALYCOSILVA CANTHARELLUS. 81 


both on the body and on the stalk. The dermal and gastral pinules of the body 
are very similar, and both differ from the pinules of the stalk. The pinules with 
rudimentary proximal ray do not differ from those in which this ray is properly 
developed in other respects. I shall, therefore, describe the pinules in two 
groups: — the dermal and gastral body-pinules with long and short proximal 
ray, and the dermal stalk-pinules with long and short proximal ray. 

The four lateral rays of the (dermal and gastral) pinules of the body (Plate 2, 
fig. 18; Plate 4, figs. 21-24; Plate 6, figs. 14-17, 19-25; Plate 7, figs. 6-19) 
have in all three varieties the same shape and size. They are 50-144 u long, 
enclose right angles, and form crosses 120-280 u in diameter (Plate 2, fig. 18a; 
Plate 6, fig. 23; Plate 7, figs. 16-18). The lateral rays of the same pinule are not 
equally long, but their differences in length are usually not great, the longest 
lateral ray being only 2-20 y, rarely as much as 45 u, longer than the shortest. 
The lateral rays are straight, 4-10 » thick at the base, nearly always conic, and 
pointed at the end. Pinules with one or more lateral rays reduced in length and 
terminally rounded (Plate 7, fig. 8), or very thick at the base and abruptly attenu- 
ated to a thin conic end-part, are exceedingly rare. The lateral rays bear vertically 
arising spines, which are very small and close together near the end but more 
distant and larger (1.5-3 uw long) in the middle and proximal parts of the ray. 
These spines are remarkably slender, even the longest is not much over 1 yp 
thick at the base. 

The apical proximal ray is, when properly developed (Plate 6, figs. 19-22, 
25; Plate 7, figs. 6, 7, 9, 10, 19), similar to the lateral rays in shape, spinulation, 
and size. When reduced (Plate 6, fig. 24; Plate 7, figs. 12-15) it is as thick, 
but in C. c. vars. simplex and helix is only 5-10 yp, in C. c. var. megonychia 5-20 pu 
long, and terminally rounded. On such proximal rays the spines are generally 
as far apart as on the long ones, and not crowded. One or two spines often arise 
from the rounded end of the ray. 

The apical distal ray of the body-pinules is longest in C. c. var. helix, 
shorter in C. c. var. simplex, and still shorter in C. c. var. megonychia. It is in the 


dermal body-pinules of all varieties longer than in their gastral ones, being 


in the dermal body-pinules of C. c. var. helix 130-385 yu 
simplex 100-290 u 
megonychia 100-180 wu 
gastral “ OS ae wma eee NEL 120-270 pu 
are : i Siem, SSI pled 100-240 yu 
megonychia 100-195 u long. 


ifs “cc 


ee) 
bo 


CALYCOSILVA CANTHARELLUS. 


This ray in all varieties is at its base 5-13 » thick, usually a little thicker 
than the other rays. It thickens above and attains its maximum thickness about 
a quarter of its length from the centrum of the spicule. From its thickest point 
it tapers gradually towards the stout, blunt-pointed, distal end (Plate 6, figs. 14— 
17). It bears numerous spines. These have the ordinary conic shape and are 
not at all broadened and flattened like scales. The spines arising from the basal 
part of the ray are vertical, quite distant, short, and straight (Plate 6, figs. 21, 22, 
24; Plate 7, figs.6,8-10). Farther up they become more numerous, longer, and 
more inclined toward the ray, their ends pointing obliquely upward. This oblique 
direction is attained partly by the spines of this region arising obliquely, partly 
by their being more or less abruptly bent in their basal portion. About two 
thirds or three quarters of the way up the ray these spines attain their maximum 
size. They are in this region about 15 uw long, 1.5—2 u thick at the base, and arise 
at an angle of about 70° from the ray. They are bent abruptly upwards 1-2 u 
from their base, the axis (chord) of their conic, slightly and somewhat irregularly 
curved end-part enclosing an angle of about 23-30° with the axis of the ray. 
Towards the end of the ray the spines gradually become smaller, those arising 
nearest its freely protruding tip being only 5 u long, or still shorter. The distal 
pinule-ray, together with its spines, resembles the tail of a mammal or wheat-ear 
more than the cone of a fir-tree. Its maximum breadth is 15-32 u. In respect 
to this dimension there is no perceptible difference between the dermal and 
gastral body-pinules and the body-pinules of the three varieties. 

The (dermal) pinules of the stalk (Plate 6, figs. 26-384) have the same struc- 
ture as the body-pinules but differ from them in their dimensions and the preva- 
lence of forms with reduced proximal ray. Their lateral rays are only 54-100 u 
long and the crosses formed by them 115-196 u in diameter. Their proximal ray 
is, when properly developed, 50-90 » long, when reduced, 4-10 u. These rays 
are 3-7 u» thick at the base. The distal ray is 55-115 uw long, and 6-10 uw thick 
at the base. The maximum breadth of this ray, with its spines, is 13-30 up. 
On the whole these pinules decrease in size from the upper to the lower end of the 
stalk. 

I have above drawn attention to the fact that there are no, or hardly any, 
intermediate forms connecting the pinules with reduced proximal ray with those 
in which this ray is properly developed. In fact I have not observed a single 
body-pinule with a proximal ray 21-59» long, the nearest approach to an 
intermediate form being the pinule (Plate 7, fig. 8) in which the proximal ray is, 


although 60 » long, nearly cylindrical and terminally rounded. 


CALYCOSILVA CANTHARELLUS. 83 


This absence of intermediate forms, and the fact that the spines are no 
closer together on the reduced than on the long proximal rays, show that the 
reduction of the short ones cannot be due merely to obstacles which impeded 
their longitudinal growth. It is, therefore, probable that we have here to deal 
with two distinct kinds of pinules, one with long, and one with short proximal 
ray, even though the pinules with short proximals are locally aggregated only 
in so far as they are relatively much more numerous on the stalk than on the 
body. 

The scarce microhexactines (Plate 3, fig. 1), which have been found only in 
C. c. vars. simplex and helix, measure 16-19 » in total diameter, and consist of 
six equal, cylindrical, terminally rounded rays, (without centrum) 6-8 u long, 
and 3-8 uw thick, which enclose right angles. The rays bear numerous larger or 
smaller spines on their sides and on their ends. 

At first I took these spicules for central remnants of hexasters which had 
lost their end-rays, like those described by F. E. Schulze! and Ijima? in other 
Hexactinellida. But since I found no indication of these spicules having once 
possessed end-rays, I think this view hardly tenable. 

Of hexasters two main groups can be distinguished:— one represented by 
the regular onychhexasters, the onychhexaster-derivate oxyhexasters, their 
regular onychhexasters, and the helonychhexasters; the other by the plumi- 
comes. 

The regular onychhexasters (Plate 2, fig. 3a; Plate 3, figs. 21-30; Plate 4, 
figs. 1-19) form a series commencing with small ones with stout end-rays and 
recurved terminal spines, and ending with large ones with slender end-rays 
and terminal spines directed obliquely outward. In C.c¢. vars. helix and simplex 
the whole of this series of onychhexasters is met with; in C. c. var. megonychia 
I have observed the large forms with slender end-rays only. The onychhexasters 
of C. c. var. hex are 39-88 uw in total diameter, those of C. c. var. simplex 48- 
106 u, and those of C. c. var. megonychia 80-130 u. They consist of a centrum, 
5-6 » in diameter, from which arise the six concentric and equal main-rays, the 
axes of which enclose angles of 90°, with trumpet-shaped, proximal extensions. 
The main-rays are smooth, 2-4 uv thick, (without the centrum) 1.5-6 » long, and 
thickened in a trumpet-shaped manner and divided into from two to five end- 
rays at the distal end. The end-rays of the same spicule are fairly equal in shape 


1 F. #. Schulze. Amerikanische Hexactinelliden, 1899, p. 31, taf. 5, fig. 8. 
21. Ijima. Studies on the Hexactinellida. I. Journ. Coll. sci. Tokyo, 1901, 15, p. 198, 292, pl. 4, 
fig. 20. 


84 CALYCOSILVA CANTHARELLUS. 


and size; the number of them on each of the six main-rays is, however, by no 
means always the same. The end-rays are 1.5-2 » thick at the base, and arise 
steeply, sometimes at nearly right angles, from the main-rays. Farther on 
they curve inward, towards the continuation of the axis of the main-ray to which 
they belong. Distally this curvature rapidly decreases and the end-part is 
for a smaller or greater, usually a very considerable length, either quite straight 
or only slightly curved, or irregularly bent like an oak-branch and knotty in 
appearance. Onychhexasters with end-rays thus bent have been chiefly found 
in C.c. var. megonychia (Plate 4, figs. 2-4, 14,17). In all regular onychhexasters, 
whether large or small, the centrum, the main-rays, and the proximal parts of the 
end-rays are nearly identical in shape and have the dimensions given above; the 
ereat differences in these hexasters observed are entirely due to differences 
in the degree of longitudinal development of the distal straight end-parts of 
the end-rays. In the smallest onychhexasters observed (Plate 3, fig. 21) this 
distal straight part is quite insignificant and hardly distinguishable. The 
larger the onychhexaster is, the longer and the more conspicuous does this part 
of the end-ray become (Plate 3, figs. 22-27; Plate 4, figs. 2-7). The end-rays 
are cylindroconic, attenuated distally. This attenuation is slight and very 
much the same in all end-rays, however long they may be. The consequence 
of this is that the thickness of their distal ends is in inverse proportion to the 
length of the end-rays; greatest in the shortest, and smallest in the longest. 
In the small onychhexasters, 39-45 u in diameter, of C. c. var. helix, the end-rays 
are 15-18 » long and 1-1.8 » thick at the end; in the largest onychhexasters, 
80-88 . in diameter, of the same variety the end-rays are 34-41 » long and only 
0.8-1 uw thick at the end. In the larger onychhexasters of C.c. vars. simplex 
and megonychia the same inverse relation between the length and terminal thick- 
ness of the end-rays is observed. The angles between the chords of end-rays 
arising opposite each other from the same main-ray are correlated and in inverse 
proportion to the size of the spicule and the length of the end-rays. In the small 
onychhexasters, 39-45 » in diameter, of C. c. var. helix, these angles are 70°—90° ; 
in the large ones, 80-88 » in diameter, of the same variety 59°—-77°. 

The end-rays bear numerous small recurved spines along their length 
(Plate 3, fig. 28; Plate 4, figs. 9, 10, 16) and one to five large spines at the end. 
The former are largest and most conspicuous in the smallest onychhexasters 
(Plate 3, fig. 22); in the large onychhexasters they are smaller. Their size is, on 
the whole, in inverse proportion to the length of the end-rays and the size of 
the whole spicule. In the smallest onychhexasters the terminal spines are 2-3 yu 


CALYCOSILVA CANTHARELLUS. 85 


long and generally strongly recurved, so that these end-rays become anchor- 
like. With the increase in size of the onychhexaster (length of the end-rays) the 
terminal spines become longer. In the largest onychhexasters they are 2-8 u 
long. At the same time they change their shape and their position relative to 
the end-ray from which they arise, generally being the more directed outward 
the longer the end-ray is. In the medium-sized onychhexasters (Plate 3, figs. 
24, 25, 28-30) they are usually more or less vertical to the end-ray, their end 
being slightly bent inward (Plate 3, figs. 28, 30) or outward (Plate 3, fig. 29). 
In the large onychhexasters (Plate 3, figs. 26, 27; Plate 4, figs. 2-4, 13-19) they 
are generally directed obliquely outward. This clearly pronounced correlation 
between the length of the end-rays and the position of the terminal spines is very 
remarkable. 

The oxyhexasters (Plate 3, figs. 4, 5; Plate 4, fig. 1) are not numerous and 
have been found only in C. c. vars. helix and megonychia. They measure in the 
former 90-94 » in total diameter, in the latter 100-133 u. From a centrum 
5-7 uw in diameter arise four smooth main-rays, 2-6 » long, 2—2.5 » thick in the 
middle, and thickened at each end. The main-rays of the same spicule are 
equal and their axes enclose angles of 90°. Each main-ray bears two to four 
end-rays, 40-60 » long and 1.5-2 uw thick at the base. The end-rays arise steeply 
- from the main-rays. Their proximal end is curved inwards, towards the con- 
tinuation of the axis of the main-ray to which they belong. Their distal and 
middle-parts are nearly straight. The chords of opposite end-rays of the same 
main-ray enclose angles of about 70°. The end-rays bear along their length a 
few very small spines, are conic, and taper gradually to a fine point. 

This description shows that these oxyhexasters are very similar to the largest 
onychhexasters and distinguished from them only by the tips of their end-rays 
being destitute of terminal spines. In some hexasters (Plate 4, fig. 1), similar 
in every other respect to the oxyhexasters above described, a slight angular 
bend is to be noticed 4-8 uw below the tip in one or more of the end-rays. In 
others again (Plate 4, figs. 16-18) this angular bend is more pronounced, the bent 
end-part diverging strongly from the continuation of the middle-part of the 
end-ray. In others again only some of the end-rays are simply pointed, the 
others bearing terminal spines, similar to those of the large onychhexasters. 

From these observations I conclude that the oxyhexasters above described 
are to be considered as onychhexaster-derivates. I think their appropriate 
place is in a continuation of the onychhexaster-series beyond the end represented 
by the large ones with long end-rays and outward-directed terminal spines. 


86 CALYCOSILVA CANTHARELLUS. 


It seems very probable that they have been produced by a further development 
of the onychhexasters in the direction of small forms with recurved terminal 
spines, or large forms with upward directed terminal spines. I think that the 
forms described above, in which the end-rays appear to be angularly bent near 
the end, have been developed out of large onychhexasters by a reduction of the 
number of the terminal spines to one, and by a further increase of the angle 
at which this single remaining spine arises from the end-ray. The bent terminal 
part which appears as the distal end of the ray is, according to this, not a part 
of the end-ray at all, but a terminal spine. When, by a further development 
in this direction and a further increase of the angle between the terminal spine 
and the end-ray, this angle becomes 180°, an apparently true oxyhexaster is the 
result. 

That the oxyhexasters are to be considered as such ultra-end forms of the 
onychhexaster series is corroborated by the fact that they are larger than the 
largest regular onychhexasters found in the same variety. 

In the not spirally twisted irregular onychhexasters (Plate 3, figs. 2, 3, 6, 7), 
which are very rare, the end-rays only or both the end- and the main-rays may 
be irregular. The onychhexaster (Plate 3, figs. 6, 7) is an example of the former 
case. In this spicule, which was found in C. c. var. simplex, the main-rays are 
regularly disposed, equal, abnormally stout, 7 4 long, and 5.4 thick. Each 
main-ray bears only one or two somewhat irregularly curved end-rays, which 
are also abnormally stout, being 2-3 » thick at the base. The terminal spines 
are 3 » long and recurved. The whole spicule measures 74 » in maximum diame- 
ter. The onychhexaster (Plate 3, figs. 2, 3) is an example of the latter case. 
In this spicule, which was found in C. c. var. helix, two opposite main-rays, lying 
in a line, are considerably longer than the other four, and the end-rays are not, 
as is invariably the case in the regular onychhexasters, arranged in a verticillate 
manner at the end of each main-ray, but arise from them at various points. 
The main-rays are 4 » thick, the end-rays basally 2». The terminal spines are 
irregularly disposed, and 3-5 » long. The whole spicule is 89 u long and 64 u 
broad. I consider these rare, not spirally twisted, irregular spicules as mere 
pathological abnormities. 

The helonychhexasters are onychhexasters in which most end-rays or all of 
them are spirally twisted. To this spiral twisting the name I have given these 
spicules refers. The helonychhexasters are quite abundant in C. c. var. heliz, 
but absent in the other two varieties. 

The helonychhexasters of C. c. var. helix (Plate 2, fig. 3b; Plate 3, figs. 8-20) 


CALYCOSILVA CANTHARELLUS. 87 


have a centrum 4-6 » in diameter, from which six main-rays arise. These are 
very similar to the main-rays of the regular onychhexasters, enclose right angles 
with their neighbours, are smooth, 2-4 thick, and (without the centrum) 
2-5 » long. Forms with long and slender end-rays and outward directed termi- 
nal spines, forms with short end-rays and recurved terminal spines, and inter- 
mediate forms, corresponding to the different forms of the regular onychhexasters 
described above, are met with also among the helonychhexasters. 

The twisted end-rays of the same spicule are always curved in the same 
direction and describe evolvent (spiral) curves extending in planes parallel to 
each other and vertical to one of the three axes of the spicule. The two (oppo- 
site) main-rays of the spicule representing this axis, lie in the axis, the four others 
in a plane parallel to the spirals accordingly. Each main-ray bears from one to 
four end-rays. When only one end-ray is present the main-ray usually passes 
into it gradually. The end-rays 10-35 u long arising from the main-rays, which 
lie in the axis of the spiral, often do not participate in the general twisting and 
are usually either irregularly curved throughout, or curved only basally and 
nearly straight distally, like the end-rays of the regular onychhexasters. The 
end-rays arising from the four main-rays parallel to the plane of the spiral twist 
are generally all affected by the torsion. At the base, where they are most 
strongly curved, their radius of curvature is about 7 4. Farther on their curva- 
ture, being a spiral or evolvent one, decreases. Still farther, at a smaller or 
greater distance from the distal end, the curvature is usually reversed, the 
terminal part of the end-ray being fairly straight and arising radially or obliquely 
from the convoluted central mass of the spicule. Depending, as it does, on the 
variable position of the point of recurvature, the length of this end-part is very 
variable. 

The transverse diameters parallel to the plane of spiral twist, which pass 
through the centrum of the spicule, represent the breadth of the spicule, while 
the diameter along the axis of torsion can be considered as its length. Taking 
breadth and length in this sense, we find that the spicule is 33-58 uw long, whilst 
its central convoluted mass measures 15-22 u, and the whole spicule 16-67 u 
in breadth. Numerous small, recurved spines, uniformly scattered along the 
length of the ray, and two to five larger terminal spines 1.7—4 uw long originate 
from the end-rays arising from the main-rays lying in the torsion-axis and also 
from those of the others in which the straight end-part attains a greater length. 
Accordingly the spinulation of these end-rays is very similar to that of the end- 
rays of the regular onychhexasters, The spinulation of the end-rays spirally 


88 CALYCOSILVA CANTHARELLUS. 


twisted for a greater part of their length is much more irregular. Here the spines 
scattered along the length of the end-ray are not uniformly distributed and often 
restricted to its outer, convex side; they are also unequal in size, some of them 
attaining a very considerable length. Such end-rays usually have only one ter- 
minal spine, sometimes 6.5 1 in length, which is directed obliquely outward. 
The angle between this terminal spine and the adjoining part of the end-ray 
usually is rather obtuse and not infrequently becomes 180°. In this case the 
terminal spine appears as the tip of the end-ray, and the end-ray itself becomes 
simple, as in the oxyhexasters above described. 

Intermediate forms with somewhat curved but not properly spirally twisted 
end-rays, connecting the helonychhexasters with the regular onychhexasters, 
have occasionally been found, but they are exceedingly rare. 

Spicules twisted spirally like the helonychhexasters of C. c. var. helix have 
repeatedly been noticed in Hexactinellida. 

Oxyhexasters and oxyhexaster-derivates with a reduced number of spirally 
twisted rays have been found by F. E. Schulze in Holascus stellatus" Holascus 
ridleyi,? and Rhabdocalyptus mollis* and by Ijima in the last named species,* 
in Hyalascus giganteus* and in Staurocalyptus pleorhaphides.° 

_ Discohexasters with the verticils of end-rays twisted spirally round the 
continuations of the axis of the main-rays from which they arise, have been 
found by F. E. Schulze in Hertwigia falcifera,’ Rhabdopectella tintinnus,*® and 
Saccocalyx pedunculata °. 

Clavules with branch-rays twisted spirally round the shaft have been 
found by F. E. Schulze in Farrea convolvulus © and by Wilson in Farrea occa 
claviformis |. 

The spirally twisted oxyhexasters of Holascus stellatus, Holascus ridleyt, 
Rhabdocalyptus mollis, Hyalascus giganteus, and Staurocalyptus pleorhaphides 
are similar to ordinary, not twisted oxyhexasters occurring in the same sponge 
and more or less connected with them by intermediate forms. The same applies 


1 Ff. EB. Schulze. Rept. Voy. Challenger, 1887, 21, p. 86, pl. 14, figs. 10-12. 

2 F.H. Schulze. Loc. cit., p. 90, pl. 17, fig. 7. 

3 Ff. EH. Schulze. Loc. cit., p. 157, pl. 64, figs. 10, 11. 

47. Ijima. Studies on the Hexactinellida. IV. Journ. Coll.sci. Tokyo, 1904, 18, p. 266, pl. 20, fig. 9. 

5]. Ijima. Loc. cit., p. 106, pl. 8, fig. 16. 

87. Ijima. Loc. cit., p. 229, pl. 16, fig. 8. 

7 PF. EH. Schulze. Amerikanische Hexactinelliden, 1899, p. 23, taf. 3, fig. 8. 

8 F. E. Schulze. Rept. Voy. Challenger, 1887, 21, p. 108, pl. 12, fig. 8. 

°F, #E. Schulze. Hexactinelliden desjIndischen Oceanes. II. Abh. Akad. Berlin, 1895, 1896, p. 55, 
taf. 5, figs. 4, 9, 10. 

0 Ff, #. Schulze. Amerikanische Hexactinelliden, 1899, p. 72, taf. 16, figs. 1, 2. 

1 H. V. Wilson. Mem. M. C. Z., 1904, 30, p. 59, pl. 7, fig. 3. 


CALYCOSILVA CANTHARELLUS. 89 


to the clavules with twisted branch-rays of Farrea occa claviformis and the 
helonychhexasters above described. The discohexasters with spirally twisted 
end-ray verticils of Hertwigia falcifera, Rhabdopectella tintinnus, and Saccocalyx 
pedunculata and the clavules with similarly twisted branch-rays of Farrea con- 
volvulus on the other hand do not appear to be associated with regular, not 
twisted spicules of the same kind. 

In studying the question how these spirally twisted spicules have been 
produced I gained the impression that the parts of the living mass’ which built 
them must have changed their relative positions in a torsional manner during 
the growth of those rays or portions of rays which are spirally twisted in the 
full-grown spicule. In the case of the oxyhexasters, helonychhexasters, and 
clavules with spirally twisted branch-rays there is only one torsion-axis corre- 
sponding to one of the axes of the spicule, and in these the torsion seems to 
have affected the whole living mass uniformly. In the case of the discohexasters 
there are six torsion-axes of this kind, corresponding to the axes of the six main- 
rays, and six different torsional systems in the living mass. 

In speaking of the spirally twisted oxyhexasters of Rhabdocalyptus mollis 
which were found in some, but not in all specimens, Ijima ” says: ‘‘T am therefore 
disposed to consider them as of inconstant occurrence in the species. Possibly 
they are produced only under certain abnormal conditions.” Also in Calyco- 
silva cantharellus they have been found in one specimen only. Since, however, 
this was obtained together with the others destitute of these spicules in the 
same locality, at a considerable depth, where doubtless the environment was 
very monotonous, it is hardly to be supposed that the external influences acting 
on it could have been in any way different from the influences acting on the 
others. A spiral twisting of some of the spicules is, as the above statement 
shows, if not a frequent, still a widespread occurrence in hexactinellids. It 
seems therefore improbable that the spiral twist is produced through the influence 
of abnormal conditions, and to be considered as an abnormity. Neither can it 
be ascribed to obstacles preventing the (twisted) rays from growing in the 
usual direction, because, in the first place, there are no such obstacles, and 
because, in the second place, their presence could not affect, all the actually 
twisted rays of a spicule in the same way and induce them to curve round spirally 
in the same direction. 


1T use the expression “ living mass,” because I do not know whether these spicules are built by 
distinct cells, and if so, by how many, or by syncitia, and if so, how many nuclei or chromidia or other 
centres of vital action, these syncitia contain. 

27. Ijima. Studies on the Hexactinellida, IV. Journ. Coll. sci. Tokyo, 1904, 18, p. 266, 267. 


90 CALYCOSILVA CANTHARELLUS. 


In view of these circumstances I consider these spirally twisted skeletal 
elements as spicules sui generis, and the difference between them and the similar, 
not spirally twisted spicules, as similar in nature to the difference between the 
simply curved and spirally twisted horns of closely allied forms of Bovidae. 

The plumicomes (Plate 2, fig. 12c; Plate 7, figs. 1-5) are quite abundant in 
C. c. vars. simplex and helix, but exceedingly rare in C. c. var. megonychia. 
Those of C. c. var. helix are 47—55, those of C. c. var. simplex 50-69 » in diameter. 
Those of C. c. var. megonychia seem smaller than those of the two other varieties. 
Measurements I cannot give, because I saw only few and these were broken. 
Four equal main-rays, which enclose angles of 90° with their neighbours, arise 
from a slight central thickening about 2.5 » in diameter. These main-rays are 
straight, cylindrical, smooth, 9-12 » long, 0.9-1.6 » thick, and simply rounded 
at the end. Some distance below the end each main-ray is thickened to a spheri- 
cal or oval tyle, 2-8 win diameter. The distal part of the main-ray, lying beyond 
this tyle, is 2-4 u long. A considerable number, twenty or more, branch-rays 
arise from the tyle of each main-ray. Their points of origin are fairly equidistant, 
but irregularly scattered over the surface of the tyle. The end-rays are very 
thin and strongly curved in an S-shaped manner. They terminate with fine 
points. A few small spines are occasionally observed on the concave side of their 
distal part. The end-rays are equal and regularly arranged so as to diverge 
above in a plumose manner. 

I think there can be no doubt about the close relationship of the sponges 
above described. All the specimens were found at the same station; the frag- 
ments appear to be parts of sponges similar in shape to the complete specimen; 
no difference could be detected in their soft parts; and the shape and arrange- 
ment of most of their spicules are the same in all. Still there are differences in 
the spiculation of the thirty-two specimens, according to which they fall into 
three groups. The chief differences between these groups, which I describe as 
distinct varieties, are tabulated on p. 91. 

The nearest allies of the sponges described above as Calycosilva cantharellus 
are the species assigned by previous authors to the genera Sympagella, Calyco- 
soma, and Aulascus: — Sympagella nux O. Schmidt 1870 (F. E. Schulze 1887, 
1897, 1899, 1900; Topsent 1904); Aulascus johnstonc F. E. Schulze 1887 (F. E. 
Schulze 1897); Calycosoma validum F. E. Schulze 1899; Sympagella anomala 
I. Ijima 1903; and Calycosoma gracile F. E. Schulze 1903. All these, with the 
single exception of Aulascus johnstoni F. EK. Schulze differ from Calycosilva 


cantharellus by being destitute of hypogastral pentactines. Aulascus johnstoni 


CALYCOSILVA CANTHARELLUS. 


91 


C. c. var. C. c. var. C. c. var. 
helix simplex megonychia 

Rectangularly bent diactine 
megascleres present absent absent 
Large, slender-rayed triactines 
with two rays ina straight line b me 
and the third arising vertically | “ pBent Buseut present 
from this 
Amphiox, diactine hexactine- 
dorivates absent present absent 

domnial distal ray distal ray distal ray 
Body-pinules 120-270 uw long 100-240 uw long 100-180 » long 

gastral distal ray distal ray distal ray 

120-270 uw long 100-240 uw long 100-195 yw long 
erchh et 39-88 yu 48-106 pu 80-130 p 
SS aie in diameter in diameter in diameter 

Oxyhexasters present absent present 
Helonychhexasters present absent absent 


F. E. Schulze differs from it by its shape and by some of its spicules. In Aulascus 


johnstoni all the pinules have a properly developed proximal ray, and discohex- 
asters and discohexaster-derivate discohexactines occur. In Calycosilva can- 
tharellus many pinules have a reduced proximal ray, and discohexasters and 
discohexactines are absent. Also the plumicomes are somewhat different. 
Among the above mentioned related forms without pentactine hypogastralia, 
Calycosoma gracile F. E. Schulze, which is not very different in shape and has 
very similar onychhexasters and plumicomes, appears to be most closely allied 
to Calycosilva cantharellus. The differences between the latter and the most 
similar of the allied forms (Aulascus johnstoni and Calycosoma gracile), let alone 
the others, are so considerable as to necessitate the establishment of a new 
species for its reception. 

Whilst I experienced no difficulty in coming to this decision about the estab- 
lishment of a new species, I found it exceedingly difficult to decide whether this 
new species should be assigned to one of the three genera mentioned, and if so, 
to which one. Ijima! attaches little systematic importance to the presence 


or absence of hypogastral pentactines and accordingly proposes to unite the 


1T. Ijima. Studies on the Hexactinellida. III. Journ. Coll. sci. Tokyo, 1903, 18, p. 96. 


92 CAULOPHACID. 


species referred by F. E. Schulze to the two genera Sympagella, without, 
and Aulascus, with hypogastral pentactines in one genus, which should, since 
this has priority, be named Sympagella. According to the diagnosis of this 
genus given by Ijima the species belonging to it possess discohexasters. Since 
discohexasters are entirely absent in Calycosilva cantharellus, we cannot, if we 
accept Ijima’s classification place this sponge in this genus or in Aulascus, united 
with it by him. If we follow Ijima’s example of not considering the presence or 
absence of hypogastral pentactines of systematic importance sufficient for generic 
distinction, we must place the sponges above described in the same genus as Caly- 
cosoma gracile F. E. Schulze. According to Ijima! the Caulophacidae are distin- 
guished from the Rossellidae 7. a. by the former possessing and the latter being 
destitute of true pinules with a well-distinguished distal ray. If this be accepted 
the two species (validum and gracile) placed by F. E. Schulze in Calycosoma must 
be generically separated, because only one (C. validum) has no true pinules and 
can be retained in the Rossellidae, where F. E. Schulze * although doubtful about 
it himself, places Calycosoma; whilst the other (C. gracile) possesses pinules 
with well-distinguished distal ray and must be assigned to the Caulophacidae. 
The first described of these two species is the rossellid Calycosoma validum. 
This must therefore be considered as the type species of the genus and for this 
the generic name Calycosoma must be retained. The other species, Calycosoma 
gracile, with which the sponges described above might be generically united, has, 
according to this, to be excluded from Calycosoma, and a new generic name 
has to be found for it. 

Under these circumstances I establish a new genus for the sponges described 
above, in which also Calycosoma gracile F. EK. Schulze 1903 might be placed. 
The name Calycosilva denotes its origin from Calycosoma on the one hand, and 
on the other indicates that the sponges are covered by a forest of pinules with 
well-distinguished distal ray. 


DOUBTFUL CAULOPHACID. 
Plate 32, figs. 10-12. 


The collection contains three fragments of skeleton-nets collected with the 
tangles at Station 3689 (A. A. 134) on 28 October, 1899; 18° 06'8., 142° 24’ W.; 
depth 1476 m. (807 f.); they grew on a bottom of fine coral-sand and manganese 
nodules; the bottom-temperature was 37.6°. 


17, Ijima. Studies on the Hexactinellida. ILI. Journ. Coll. sci. Tokyo, 1903, 18, p. 79,80, 112, 114. 
2 F, H. Schulze. Hexactinellida. Ergeb. Deutsch. tiefsee-exped., 1904, 4, p. 174, 176, 


ROSSELLINAE. 93 


The largest fragment (Plate 32, fig. 10) is apparently part of a stalk. It is 
99 mm. long., 12 mm. thick at the base, and 17 mm. at the upper end. At the 
thinner, probably the lower, end it is solid for a distance of 18 mm.; farther on it 
is tubular. The tube thus formed widens above in a calyculate manner and has 
a wall about 3 mm. thick. The two other fragments which are 57 mm. and 49 
mm. long respectively are curved lamellae, also about 3 mm. thick. They 
apparently formed parts of lamellar, calyculate sponges. 

The skeleton-net (Plate 32, figs. 11, 12) consists of main-beams 100-300 yu 
thick, which extend obliquely longitudinally or, more rarely, transversely. These 
main-beams form more or less distinct bundles, within which they lie quite close 
together and connected by numerous short, somewhat thinner, transverse beams. 
The bundles are on an average about 0.6 mm. thick and form a network with 
elongated spindle-shaped meshes, usually 0.4—-0.6 mm. broad and 1-3 mm. long. 
The individual beams are either smooth or bear a few scattered, low, blunt 
spines. Here and there the spines are more crowded. 

In some respects these specimens resemble the skeleton-nets of the stalk 
and the lower parts of the body of caulophacid hexactinellids, and they may have 
formed parts of such. 


ROSSELLIDAE (F. E. Scuutzre) Ima. 


Hexasterophora with special diactine to hexactine dermal, and pentactine 
hypodermal spicules, which latter sometimes project a considerable distance 
beyond the surface, their lateral rays then forming a veil covering the sponge. 

The collection contains twenty-two more or less complete specimens and 
twelve fragments of this family. 

F. E. Schulze! distinguishes three subfamilies in this family, all of which 


are represented in the collection. 


Rossellinae F. E. Scnuze. 


Rossellidae without discoctasters and plumicomes. 
The collection contains twenty more or less complete specimens and twelve 
fragments of specimens belonging to this subfamily. All are referred to the 


new subspecies Bathydorus laevis spinosissimus. 


1 Ff. E. Schulze. Hexactinellida. Ergeb. Deutsch. tiefsee-exped., 1904, 4, p. 176. 


94 BATHYDORUS LAEVIS SPINOSISSIMUS. 


BATHYDORUS F. E. Scuuuze. 


Thin-walled, sac-shaped, calyculate or lamellar Rossellidae (Rossellinae) 
with oxyhexasters and sometimes also hemioxyhexasters but no other micro- 
scleres in the choanosome. With hypodermal pentactines. The dermal 
spicules are usually chiefly tetractines (stauractines), but forms with fewer (one 
to three) or more numerous (five or six) rays may also occur, the forms with 
fewer rays sometimes predominating. The gastral spicules are hexactines, the 
distal ray of which may be differentiated so as to render these spicules somewhat 
pinule-like. 


Bathydorus laevis F. E. Scuuuze. 


F. E. Scuuuze, Abh. Akad. Berlin, 1895, 1896, p. 57, taf. 6, figs. 1-10. F. E. Scuunzn, Sitzungsb. Akad. 
Berlin, 1897, p. 535. I. Isrma, Annot. zool. Jap., 1898, 2, p.47. F. E. Scuuxzs, Indian Triaxonia, 
1902, p. 78, pl. 14, figs. 1-10. H.V. Witson, Mem. M. C. Z., 1904, 30, p. 51, pl. 5, figs. 11-13; pl. 
Gy figs. lp2: 


Bathydorus laevis spinosissimus, subsp. nov. 


Plate 14, figs. 1-32; Plate 15, figs. 1-22; Plate 16, figs. 1-24. 


All the specimens of this subspecies were trawled off northern Peru, Station 
4651, on 11 November, 1904; 5° 41.7’ S., 82° 59.7’ W.; depth 4063 m. (2222 f.); 
they grew on sticky, fine, gray sand; the bottom-temperature was 35.4°. Three 
specimens distinguished as A, B, and C were examined in detail. 

These sponges are related to Bathydorus laevis F. E. Schulze (loc. cit., 1896, 
p. 57). Within this species Wilson (loc. cit., p. 51) has distinguished the sub- 
species spinosus, which differs from the typical B. laevis by its spicules, particu- 
larly its dermals, which are much more spiny. In the specimens here described 
the dermals are still more spiny, and the pentactines, which are smooth in B. 
laevis spinosus, are also usually covered with spines. The name of this new sub- 
species refers to this further development of the spinulation. 

Shape and size. The best preserved specimens, one of which C (Plate 14, 
fig. 13), show calyces with rather broad bottom and a thin undulating wall. 
The margin, which is much torn, appears to have been lobose in the living sponge. 
In the calyculate specimens the two halves of the calyx-wall are quite flattened 
and pressed against each other. In the fresh state these calyxes were, no doubt, 
open. The other, fragmentary specimens are lamellae, which appear to have 
formed part of calyxes similar to those described above. The walls of the 
calyculate specimens are mostly 1-2 mm. thick, and thin out towards the margin. 
The fragmentary lamellae are 1-2.5 mm. thick. The largest calyculate speci- 


BATHYDORUS LAEVIS SPINOSISSIMUS. 95 


men (C) is 839 mm. high and of varying breadth, 7 mm. below, 45 mm. above. 
This specimen has a slender protuberance 11 mm. long and 2.5 mm. thick, 
which arises from the outer (lower) convex side of the broad rounded bottom of 
the calyx. Another calyculate specimen is more slender, 28 mm. high, 8 mm. 
broad below increasing to 25 mm. above. The lamellar fragments measure 
25-56 mm. in maximum diameter. 

Pores, mostly 200-400 » in diameter, on both sides of the calyx-walls 
are observed. These are now open. In the living sponge they were probably 
covered by (dermal and gastral) sieves. From the inner and the outer surface 
large and small prostal spicules protrude. Most of these, particularly the larger 
ones, are very slanting and enclose small angles with the surface. Pores are 
observed also on the surface of the fragmentary lamellae, but these no doubt in 
consequence of post mortem shrinkage and maceration are much wider than in 
the better preserved calyculate specimens and have a maximum diameter of 
1.5mm. These fragmentary, lamellar specimens show but little of the protrud- 
ing prostal spicules. 

The colour in spirit is light dirty brown with a greenish tinge. 

General structure. The superficial pores above referred to lead into canals, 
in specimen A 300-400 » wide, which traverse nearly the entire thickness of the 
lamella in a somewhat oblique direction (Plate 14, figs. 14, 15). Indications of 
flagellate chambers can be made out in parts of the sections of this specimen. 
It seems that they are small, spherical or slightly oval, and 70-120 u in diameter. 

The skeleton of the interior consists chiefly of rhabds and oxyhexasters. 
The former are exceedingly variable in size and extend paratangentially and 
obliquely. The proximal parts of the prostals, which are imbedded in the 
choanosome, also take part in the formation of its skeleton. Beneath the dermal 
and the gastral membranes paratangentially situated rhabds form loose reticula- 
tions. Fairly numerous hypodermal pentactines with rather long lateral rays 
arranged in the usual manner are observed below the dermal membrane. Hypo- 
gastral pentactines appear to be absent. The dermal membrane is occupied 
by dense masses of spicules, the rays of which are on an average about twice as 
long as the distance between their centres. These spicules are mostly regular 
tetractine stauractines, but similar spicules with one or two shortened or entirely 
suppressed rays (irregular stauractines, triactines, and diactines) occur. Similar 
spicules with five or six rays (pentactines and hexactines) also occur in the dermal 
membrane. The gastral membrane is occupied by more slender-rayed pinule- 


like hexactines, generally with one more or less differentiated, outwardly directed 


96 BATHYDORUS LAEVIS SPINOSISSIMUS. 


ray. These gastral spicules do not lie quite so close together as the dermals. 
The prostals which protrude from both surfaces are large and small rhabds. 

Besides the spicules described above, which I have observed in situ in the 
sections, some other forms, which I am inclined to consider as proper spicules of 
the sponge, also occur in the spicule-preparations. These are: — hemioxy- 
hexasters; angularly bent diactine megascleres; hexactine megascleres with 
fairly equal rays; hexactine megascleres, with one ray much longer than the 
other four; and pentactine megascleres, with relatively short lateral rays. The 
hemioxyhexasters, which are similar to the oxyhexasters, doubtlessly form part 
of the skeleton of the interior. The angularly bent diactines, and the hexactines 
with rays fairly equally long, may also take part in the formation of the interior 
skeleton. According to Schulze! such hexactines occur in the choanosome of 
the type of Bathydorus laevis. About the hexactines with one long ray and the 
pentactines with long proximal ray I have my doubts. Wilson’ says that 
hexactines with one elongated ray, 10 mm. long, occur in Bathydorus laevis 
spinosus and that these spicules are here so situated that their elongated ray 
protrudes freely beyond the surface, prostal-fashion. The hexactines with one 
elongated ray observed by me were much smaller and made rather the impres- 
sion of being derivates of hypodermal pentactines, with a short apical distal 
ray. The pentactines with short lateral rays are probably also hypodermal. 

The rhabds (Plate 14, figs. 1-10) vary exceedingly in size, and a continuous 
series of intermediate forms connects the smallest with the largest. They are 
1-21 mm. long, and 5-105 y thick at the thickest point. The small rhabds are 
distinctly centrotyle (Plate 14, figs. 5, 6), many of the large ones without a 
central tyle. The four rudimentary rays which compose the tyle are often very 
clearly distinguished, particularly in the small rhabds. Not infrequently they 
are unequal in length, in which case the tyle formed by them appears eccentric 
(Plate 14, fig. 5). The tyle may measure 22 u more in transverse diameter than 
the adjacent parts of the spicule. This difference is not only relatively but also 
absolutely greater in the small and slender than in the large and stout rhabds. 
Differences of over 11 ,» in thickness of tyle and adjacent parts of the spicule 
were only observed in rhabds less than 20 y thick. 

The end-parts of the rhabds are conic (Plate 14, fig. 7), eylindroconic 
(Plate 14, figs. 7, 9), or cylindrical (Plate 14, figs. 1, 3, 10), and terminally 


17. B. Schulze. Hexactinelliden des Indischen Oceans, Il. Abh. Akad. Berlin, 1895, 1896, p. 58, 
taf. 6, fig. 2; Indian Triaxonia, 1902, p. 79, pl. 14, fig. 2. 
2H. V. Wilson. Mem. M. C. Z., 1904, 30, p. 52. 


BATHYDORUS LAEVIS SPINOSISSIMUS. 97 


rounded or, rarely, sharp-pointed (Plate 14, fig. 2), or first thickened and then 
attenuated to a blunt point (Plate 14, fig. 4). The ends of the normal rhabds, 
with rays not differing very much in length, are 3-45 yu thick, which is a sixth to 
three quarters, sometimes nearly quite as thick as their middle-part. The small 
rhabds are on the whole less attenuated towards their ends than the large ones. 

The two rays composing the rhabds usually differ more or less in respect to 
the shape and thickness of their ends, and also in respect to their length. One 
end is often much more blunt than the other, and the difference in the thickness 
of the two ends is sometimes so great that one end is more than twice as stout 
as the other. The difference of the two rays in length is usually inconsiderable; 
occasionally, however, one ray is reduced very considerably in length, and then 
this difference is great. In four rhabds of this kind one (the normal ray) meas- 
ured over 2 mm. long, the other (the reduced ray) only 100-290 yu. These 
greatly shortened rays are terminally thickened either gradually or abruptly, 
in which latter case their end appears as a terminal tyle, the transverse diameter 
of which may be nearly twice as great as that of the base. 

In some of the large rhabds, particularly the large prostals, one or more 
thickenings are observed some distance below the end (Plate 14, figs. 7-9). 
Occasionally such thickenings also occur near the centre of the spicule. 

The end-parts of all the small and most of the large rhabds for a distance of 
about 80-100 uw are covered with vertically arising spines 1-2 uw high (Plate 14, 
figs. 1-4, 8-10). Some of the largest rhabds appear to have smooth end-parts 
(Plate 14, fig. 7). Apart from their end-parts the rhabds are perfectly smooth. 
On the end-parts of some rhabds the spines are more numerous than on the end- 
parts of others. Also in this respect the two rays of the same rhabd often differ. 
The ends of the rays reduced in length are always densely spined. 

Two kinds of angularly bent diactines (Plate 16, fig. 19) can be distin- 
guished, one with an obtuse angle between the two rhabd-rays, the other with 
an angle of 90° or less. The former are similar to the rhabds described above, 
from which they differ by the angle between the rays being only about 
120° instead of 180°. I consider these diactines as derivates of the ordinary 
rhabds. In the latter the angle between the two rays is usually 75°-90°. The 
rays of these spicules are 0.3-1.5 mm. long, 7—20 » thick at the base, straight, and 
rather unequal in length. At the point of junction of the two rays the spicule is 
thickened to a conspicuous tyle. I have not observed any angularly bent diac- 
tines with angles of 90°-120° which might be considered as transitions between 
the two kinds of these spicules observed, and I am not sure whether the forms 


98 BATHYDORUS LAEVIS SPINOSISSIMUS. 


with angles of 90° or less are to be considered as rhabd-derivates like those with 
obtuse angles. 

In all these diactines the two rays are of equal thickness at the base. I 
found, however, also an angularly bent diactine with an angle of 73°, in which 
one ray, 460 uw long and 7 u thick at the base, was curved concave towards the 
other, the other being straight, 850 » long and 23 u» thick at the base. 

The pentactines and apparently pentactine-derivate hexactines. Among the 
pentactines two groups can be distinguished, one with relatively long, and the 
other with relatively short lateral rays. The hexactines appear to be derivates . 
of pentactines belonging to the first group. 

The pentactines with relatively long lateral rays (Plate 16, figs. 4-8, 16, 17, 
20-24). The proximal ray is 0.5-1.5 mm. long, usually straight, conic, and 20- 
38 » thick at the base, and gradually attenuated to the blunt end, which meas- 
ures 4-8 y» in transverse diameter (Plate 16, figs. 4-6, 8). Rarely the proximal 
ray is either curved, or nearly cylindrical, rounded, and slightly thickened at the 
end (Plate 16, fig. 7). The lateral rays are generally straight, conic, and blunt, 
those of the same spicule being usually not very different in length (Plate 16, 
fig. 4). Sometimes, however, one of the lateral rays is either slightly curved 
(Plate 16, fig. 16) or greatly reduced in length, cylindrical, and terminally rounded 
(Plate 16, fig. 17). The longest lateral ray of the pentactine is 270-750 u long, 
the shortest 60-700 u. The lateral rays are usually about 2 » thinner at the base 
than the proximal ray of the same spicule. Their ends are 2.5-15 » thick. The 
lateral rays enclose angles of 76°—97°, usually considerably less than 90°, with the 
proximal ray. 

In many of these pentactines all the rays are rather densely covered with 
spines throughout their whole length (Plate 16, figs. 15, 20-23). These spines 
are conic, sharp-pointed, about 1 « high and, on an average, 4 » apart. Towards 
the ends of the rays the spines usually become smaller and less numerous. The 
ends themselves, however, generally bear considerably larger spines, which either 
pass gradually into the smaller ones, or are separated from them by a distinct 
limit, situated a short distance from the end of the ray. In some pentactines 
the spiculation is not so great, portions of the rays appearing quite smooth. Ina 
few hardly any spines, or no spines at all, could be detected. 

When these spicules are slightly heated, the superficial silica-layers partly 
split off and it is then clearly to be seen (Plate 16, figs. 20, 21) that the limits 
between the outermost and the next silica-layers are perfectly smooth. From 
this it follows that the spines are not formed until after the spicule has attained 


BATHYDORUS LAEVIS SPINOSISSIMUS. 99 


its full size. The partly and wholly smooth pentactines, above referred to, 
should, I think, therefore be considered as not completely developed, adolescent 
spicules, in which the spines are not yet, or as yet only partly, formed. 

The rays of the rare apparently pentactine-derivative hexactines (Plate 16, 
fig. 3) are 12-25 » thick at, the base. One of them is elongated and 570 u-2 mm. 
long. This ray corresponds with and is similar to the proximal ray of the pentac- 
tines above described. The four rays vertical to this elongated ray are, in the 
same spicule, more or less unequal in length, the longest being 160-500 u long, 
the shortest 135-225 ». They correspond with and are similar to the lateral 
rays of the pentactines. The sixth ray, which lies in the continuation of the axis 
of the elongated one, is straight, conic, blunt, and 88-420 u long. 

The pentactines with relatively short lateral rays (Plate 16, figs. 1, 2) have an 
apical (probably proximal) ray 780 »—2.7 mm. long and 13-22 u thick at the base. 
This ray is generally more or less curved. It is nearly cylindrical in its proximal 
part and gradually attenuated to a blunt end. The lateral rays of the same 
spicule usually differ in length, the longest being 200-290 yu, the shortest 145— 
221 wlong. They are at the base about as thick as the proximal ray, cylindrical, 
and blunt. The rounded end is usually one to two thirds as thick as the base of 
the ray. The lateral rays enclose angles of considerably less than 90° with the 
apical (probably proximal) ray, and are usually curved, concave to the latter. 
The lateral rays of these pentactines exhibit the same spinulation as the pentac- 
tines with long lateral rays described above. The proximal ray is less spiny, 
sometimes apparently quite smooth. 

The rare regular hexactines with fairly equal rays measure 0.6-2 mm. in 
diameter and have mostly smooth, rather straight, cylindroconic, terminally 
rounded rays 0.35—1.1 mm. long and 15—40 u thick at the base. 

Besides these regular ones I have found a few wrregular hexactines, one of 
which is represented on Plate 16, fig. 18. This spicule has rays 250-830 u long. 

The dermal spicules are di- to hexactine, by far the greater number of them 
being tetractine (stauractine). Most of these stauractines are fairly regular, 
having four properly developed, straight rays differing only slightly in length 
and enclosing equal angles with their neighbours. Besides these a few staurac- 
tines occur in which either one, two, three, or all four rays are greatly reduced 
in length, or one or more rays are strongly bent, or the angles between the rays 
are unequal. 

The regular stauractines (Plate 14, fig. 11; Plate 15, figs. 1, 2, 19; Plate 16, 
figs. 138, 14) generally measure 80-215 » in diameter. In specimen A, I have 


100 BATHYDORUS LAEVIS SPINOSISSIMUS. 


found besides the ordinary ones also, however, a few 220-320 » in diameter. 
Their rays do not lie in one plane but form the edges of low obtuse pyramids 
with quadratic bases. In consequence of this and the fact that the rays are, 
in the same spicule, nearly equally long, the ray-length is a little more than half 
the diameter of the spicule. The basal thickness of the rays is in the regular 
stauractines 80-215 »; the diameter is 4.5-9, generally 5-7 ». The rays of the 
giant stauractines 220-320 » in diameter, above referred to, are 6-15 uw thick at 
the base. The rays are generally terminally rounded and either cylindrical, at 
the end as thick as at the base; or, more frequently, cylindroconic, at the end 
only one to two thirds as thick as at the base; very rarely the ends are pointed. 
In respect to the degree of attenuation towards the end the rays of the same 
spicule are often unequal. 

The whole of the spicule is densely and uniformly covered with sharp conic 
spines, its central part being quite as spiny as the distal parts of its rays. The 
proximal spines are nearly vertical, the distal ones directed more or less obliquely 
outward. Large and smaller spines are irregularly intermingled; the largest 
are sometimes 4 u long. 

Stauractines with one or more rays reduced in length (Plate 15, figs. 5, 9, 10, 
18, 21, 22) are quite frequently met with. Apart from the ray-reduction these 
spicules resemble the regular stauractines above described. When two of their 
rays are reduced, these reduced rays may be either adjacent (Plate 15, fig. 21) 
or opposite (Plate 15, fig. 5). A stauractine in which all the four rays are 
reduced is represented (Plate 15, figs. 9,10). This spicule is only 30 » in diame- 
ter, and has cylindrical, terminally rounded rays 8 u thick. 

Irregular stauractines with unequal interactine angles (Plate 16, fig. 12) or 
with curved rays (Plate 15, fig. 11) are met with much more rarely. Apart 
from the irregularities characteristic of them, they also resemble the regular 
stauractines above described. 

Among the dermal spicules with less than four rays, which are doubtlessly 
to be considered as stauractine-derivates with reduced ray-number, triactine and 
diactine forms occur. Most of the triactine stauractine-derivates (Plate 15, 
figs. 4, 6) are straight or curved rhabds, 83-125 u« long, from the central part of 
which arises a ray-rudiment 9-12 » long. Some of them, however, appear as 
more or less regular triactines with rays nearly equally long, enclosing fairly 
equal angles with their neighbours. The diactine stauractine-derivates are 
straight, or slightly curved, or strongly angularly bent. The latter resemble 
more or less widely open compasses. In regard to the thickness of their rays 


BATHYDORUS LAEVIS SPINOSISSIMUS. 10] 


and their spinulation the triactine and diactine stauractine-derivates resemble 
the regular stauractines above described. 

The dermal spicules with more than four rays, which I am inclined to con- 
sider as stauractine-derivates with increased ray-number, are pentactines and 
hexactines. The pentactine forms (Plate 15, fig. 20), which are met with rather 
frequently, have four fairly equal rays similar to those of the regular stauractines, 
and a fifth shorter ray vertical to the plane of the tips of the four others. The 
hexactine forms (Plate 15, fig. 3) are very rare. They appear either as fairly 
regular hexactines with nearly equal rays, enclosing angles of 90° with their 
neighbours; or they are irregular, having rays unequal in length and irregular 
in position. These spicules are 100-200 » in diameter. In regard to the thick- 
ness of their rays and their spinulation they resemble the regular stauractines 
above described. 

The more or less pinule-like gastral hexactines (Plate 14, fig. 12; Plate 15, 
figs. 7,8, 12-17; Plate 16, figs. 9-11) have five quite similar and one differentiated 
ray, which latter corresponds to the distal ray of true pinules. This differen- 
tiated (distal) ray is straight (Plate 15, figs. 12, 17; Plate 16, figs. 9, 10); or, 
much more frequently, curved (Plate 15, figs. 7, 8, 13-16; Plate 16, fig. 11), its 
curvature often being very considerable (Plate 15, figs. 8, 14, 16). It is at the 
base 2.5-6 » thick and, measured along its chord, 70-145 uw. It is attenuated 
uniformly towards the end, or cylindrical in its proximal and conic in its distal 
part, or even slightly thickened near the middle, and always terminates in a fine 
point. It bears spines along the whole of its length. The spines are small, 
rather scarce, and nearly vertical on its basal part. Farther on they become 
more numerous, larger, and inclined towards the end of the ray. They attain 
their maximum length of 3-8 » about half way up. Beyond this point the 
spines again become smaller, but retain their inclination towards the tip of the 
ray. The large spines are usually somewhat curved, concave towards the end 
of theray. At its thickest (most bushy) point the distal ray is, together with the 
spines, 6-15 » in transverse diameter. In some of the gastral hexactines of 
specimen A the distal ray is stouter and more bushy than in the gastral hexac- 
tines of specimen B, where its basal thickness does not exceed 4.5 yw, and its 
maximum transverse diameter, with the spines, 10 u. 

The four rays vertical to the differentiated one, which correspond to the 
four lateral rays of true pinules, are straight, usually rather abruptly pointed, 
43-94 » long, and 3-6 u thick at the base. They are covered with spines 1.5- 
2.5 w long, which either arise vertically, or are inclined towards the tip of the ray. 


102 BATHYDORUS LAEVIS SPINOSISSIMUS. 


These four otherwise quite similar rays sometimes differ considerably in regard 
to their spinulation. Thus the right lateral ray of the hexactine (Plate 15, 
fig. 7) bears more numerous, larger, and more inclined spines than the left one. 
The sixth ray, which lies in the continuation of the axis of the differentiated one 
and which corresponds with the proximal ray of the true hexactine pinule, is 
similar to the four (lateral) rays above described in size and spinulation, but is 
slightly, sometimes considerably, curved (Plate 15, fig. 8). Also these rays are 
on the whole stouter in the gastral hexactines of specimen A than in those of 
specimen B. 

The oxyhexasters and (rare) hemioxyhexasters (Plate 14, figs. 16-32) measure 
65-135 » in diameter. The main-rays are cylindrical, smooth, 4-12 » long, and 
2-4 » thick. They enclose angles of 90° with their neighbours. The main-rays 
of the same spicule are equal. From the distal end of each main-ray a verticil 
of from two to four end-rays, rarely only a single end-ray, arises. The main-rays 
are often unequal in respect to the number of end-rays which they bear. A 
single end-ray is found only on one or two of the main-rays of the spicule, the 
others bearing more than one. The spicules with a single end-ray on one or two 
of the main-rays, which must be designated as hemioxyhexasters, resemble the 
true oxyhexasters in every respect except in regard to the end-ray number. 
The end-rays arise very steeply from the main-rays but very soon curve outward, 
that is towards the continuation of the main-ray axis, and then straighten out, 
their distal and middle-parts being only slightly curved, or quite straight. The 
angle between the chord of the end-ray and the continuation of the main-ray 
axis is, on an average, about 45°. The end-rays are 30-60 u long and, at the 
base, 1.6-2.5 » thick, rarely as much as3 yu. They are conic and taper gradually 
to a very fine point. The end-rays are covered with rather sparse, backwardly 
directed, slender spines, which decrease in size from the base to the tip of the 
ray (Plate 14, figs. 24-82). The largest of these spines are 0.5-2 y long. 

The description given above shows that these sponges are most closely 
allied to Bathydorus spinosus F. E. Schulze! and Bathydorus laevis F. E. Schulze 
(Schulze and Tjima, loc. cit.) within which latter Wilson (Mem. M. C. Z., 1904, 
30, p. 51, pl. 5, figs. 11-18; pl. 6, figs. 1-2) has distinguished the subspecies B. 1. 
spinosus. According to F. E. Schulze (loc. cit., 1897, p. 535) B. laevis and B. 
spinosus are very similar and may be specifically identical. Judging from 


1 FPF. H. Schulze. Rept. Voy. Challenger, 1887, 21, p. 153, pl. 59, figs. 6-9. Sitzungsb. Akad. Berlin, 
1897, p. 534. J. Ijima. Annot. zool. Jap., 1898, 2, p. 46. EH. Topsent. Res. Voy. Belgica, 1901, 
p. 36, taf. 1, fig. 1. : 


LANUGONYCHIA FLABELLUM. 103 


E. Topsent’s description (loc. cit., 1901, p. 36) the B. spinosus examined by him. 
resembles B. laevis ¥. E. Schulze and also Wilson’s subspecies B. laevis spinosus. 
Of all the descriptions cited, Wilson’s of B. laevis spinosus (loc. cit., 1904, p. 51) 
agrees best with the sponges here under discussion. The latter differ, however, 
from that subspecies, and also from B, laevis and B. spinosus, by the pentactines 
being generally densely covered with small spines. For this reason, and because 
there are also other, minor differences, I establish a new systematic unit for 
them, which should, I think, be a subspecies of Bathydorus laevis, equivalent to 
Wilson’s B. laevis spinosus. 

However should future studies prove, as seems probable, that Bathydorus 
laevis and B. spinosus are identical, the latter having priority, the name Bathy- 
dorus spinosus spinosissimus would prevail. 

The specific name of Bathydorus laevis is variously given as laevis and levis. 


Lanuginellinae F. E. Scuuize. 


Rossellidae with plumicomes, but without discoctasters. 
The collection contains one specimen of this subfamily, a new species of the 


new genus Lanugonychia. 
LANUGONYCHIA, gen. nov. 


Rossellidae (Lanuginellinae) with onychhexasters, discohexasters, and plu- 
micomes. Without octasters. The superficial skeleton consists of hexactines 
in which all the six rays or only five, four, three, two or one are normally 
developed, the others being reduced to terminally rounded protuberances. The 
unreduced forms (true hexactines) preponderate in the gastral, the strongly 
reduced forms (hexactine-derivate diactines and monactines) are restricted to 


the dermal membrane. 


Lanugonychia flabellum, sp. nov. 


Plate 12, figs. 20-34; Plate 138, figs. 1-28. 


The unique specimen of this species was found northeast of Easter Island 
at Station 4695 on 23 December, 1904; 25° 22.4’ S., 107° 45’ W.; depth 3694 
m. (2020 f.); it grew on fine, light brown ooze. 

On account of its being fan-shaped I name it flabellum. 

Shape and size. The single specimen is somewhat fragmentary and macer- 
ated. It appears (Plate 13, fig. 8) as a flat, elongated, irregularly triangular 


104 LANUGONYCHIA FLABELLUM. 


lamella about 60 mm. long, 40 mm. broad, and 1 mm. thick, from the sharpest 
angle of which arises a uniformly curved stalk about 90 mm. long and 2-3 mm. 
thick. Whether the complete sponge, of which the specimen formed a part, 
was also fan-shaped, is hard to say. It may have been calyculate or even tubu- 
lar, but it certainly was thin-walled and stalked. 

The colour in spirit is rather dark reddish brown. 

General structure. 'The lamellar body is reticulate in structure (Plate 13, 
fig. 14), composed of a network of bands, mostly 0.2—0.5 mm. thick, which enclose 
round meshes, 1 mm. wide. These meshes are partly covered by remnants of 
superficial membranes. 

The skeleton of the stalk (Plate 13, fig. 7) consists chiefly of longitudinal 
beams 20-90 » thick (usually 40-80 y), about equally far apart, and joined at 
frequent intervals by short transverse bars. The latter are thickened, and 
trumpet-shaped at the base. The meshes of the whole ladder-like network 
formed by the beams and bars are rounded, usually oval, 35-210 » long and 25— 
90 » broad. Most of the longitudinal beams are rhabds; some appear to be 
elongated rays of pentactines and hexactines. 

The interior of the lamellar body is occupied by rhabds and great numbers 
of onychhexasters, and large and small regular discohexasters. Plumicomes 
and a few irregular discohexasters with primary and secondary end-rays have 
also been found in it. Besides these spicules several large amphiasters have been 
observed. These are, however, most likely foreign to the sponge. Very proba- 
bly small hexactines also occur in the choanosome. I am not, however, certain 
about these spicules; the ones observed may in truth have been gastral or dermal 
and brought down into the choanosome accidentally. Below the surface pentac- 
tines are met. The superficial (dermal and gastral) skeleton consists of hexac- 
tines and pentactine to monactine hexactine-derivates with only five to one 
properly developed and one to five reduced rays, which latter appear as short, 
terminally rounded protuberances of the centre of the spicule. The tetractine 
forms are stauractines; the diactine forms are mostly centrotyle amphioxes; a 
few of them appear compass-shaped. On one side of the lamella true hexactines, 
with all six rays fully developed, greatly predominate, spicules with only five or 
four fully developed rays (pentactines and stauractines) being rare, and spicules 
with only three or still fewer (triactines to monactines) absent altogether. On 
the other side of the lamella hexactine-derivates with fewer than six fully 
developed rays are more frequent than true hexactines and here also triactine to 
monactine forms with only from three to one fully developed rays are frequently 


LANUGONYCHIA FLABELLUM. 105 


met, the diactines being particularly abundant. Judging by analogy I should 
say that the surface, the skeleton of which consists chiefly of true hexactines, is 
gastral, the other dermal. 

The hexactine and pentactine forms are orientated in such manner that 
four of their rays extend paratangentially whilst one protrudes vertically out- 
ward. The stauractines, triactines, diactines, and monactines are usually 
extended wholly paratangentially. 

The rhabds are 4-20 mm. long and 5-140 uw thick near the middle. Those 
5-50 pu thick are usually 4-7 mm. long. The slender ones are always distinctly 
centrotyle, the tyle being 1-6 u» thicker than the adjacent parts of the spicule. 
In the stout rhabds the central tyle is only slightly developed, inconspicuous, 
and often altogether absent. The axial cross is equally developed in the stout 
non-centrotyle and the slender centrotyle rhabds. The smallest rhabds are 
nearly cylindrical and rounded at the ends. The rhabds 20-40 y thick in the 
middle taper gradually to 5-18 » towards the ends, which are usually unequally 
stout and simply rounded off. The large, stout rhabds generally have blunt, 
somewhat irregular, conic termini and are, just below the end, considerably 
thinner than the small slender rhabds. The measurements of five rhabds, 
tabulated below, indicate that these spicules are the more centrotyle and the 
more cylindrical the smaller they are, and vice versa. 


RHABDS. 
| 
Tyle Thickness 
Length difference be- 
mm. tweentransverse | of the spicule 
transverse diameter of tyle | close to the tyle, ahioueiend of the other 
diameter and thickness | near the middle fe end 
ofadjacent parts “ 
of the  spicule 
5 19 4 15 15 12 
5 23 3 20 11 5 
ove 56 3 53 12 8 
Gm | 53 1 52 18 14 
19 80 0 (no tyle) 80 5 4 


The ends of the rhabds are, for a short distance, covered with small spines. 
Apart from this these spicules are smooth. The spiculation of the end-parts is 
more conspicuous in the small than in the large rhabds. 


106 LANUGONYCHIA FLABELLUM. 


The (hypodermal and hypogastral) pentactines (Plate 13, figs. 10, 12, 13, 
16b) have an apical (proximal) ray 0.6—-1 mm. long, and lateral (paratangential) 
rays 400-800 u. The lateral rays of the same spicule are more or less unequal, 
the longest usually being 150-250 y» longer than the shortest. All the rays are 
straight, conic, blunt, and 20-40 yu thick at the base. The end-parts of the 
lateral rays bear quite numerous sharp-pointed spines. Proximally these spines 
become more blunt, lower, and less numerous, and they pass gradually into 
slight, hardly perceptible, flattened protuberances, finally disappearing alto- 
gether. The proximal parts of the lateral rays are smooth. 

Pentactines with very long apical rays (Plate 13, figs. 9, 16a) have also been 
observed. The apical (proximal) ray is in these spicules 3-9 mm. long. The 
lateral rays are usually broken; one intact one (Plate 13, fig. 9) was 1.85 mm. 
long and curved. These spicules may be foreign. Some of them are strongly 
corroded. 

A few large sword-like hexactines with the rays of one axis differently devel- 
oped from the rays of the other two axes have also been observed. The two rays 
in the differentiated axis represent the blade and the handle of the sword. The 
former is very long and broken off in the spicules observed. The latter is 165 » 
long and covered with spines. At the base it is 24-30 » thick and either cylindri- 
cal or terminally thickened, club-shaped. The other four rays, which represent 
the guard of the sword, appear to be long and equal among themselves. They 
were all broken off in the sword-like hexactine observed. These spicules seem 
to take part in the formation of the skeleton of the stalk; it is possible, however, 
that they are foreign. 

The small hexactines and hexactine-derivates (Plate 12, figs. 24-34; Plate 13, 
figs. 5c, 28) always have fairly straight rays, but are, apart from this, remarkably 
variable and irregular. In the first place the angles between adjacent rays are 
not, as is generally the case in hexactinellid spicules, invariably 90°. In a good 
many of the tetractine (stauractine) (Plate 12, fig. 33), the triactine, and particu- 
larly the diactine (Plate 12, fig. 26; Plate 13, fig. 5c) forms, other than right 
angles are enclosed by them. This angular irregularity is particularly pro- 
nounced in some diactines which appear as variously opened compasses (Plate 12, 
fig. 26; Plate 13, fig. 5c). In the second place one to five of the rays may be 
reduced to mere terminally rounded protuberances arising from the centre of 
the spicule. Finally the reduced rays and, to a certain extent, also the fully 
developed rays of the same spicules are frequently unequal among themselves. 
In spite of this variability there are, however, absolutely no transitions between 


the reduced and the properly developed rays. 


LANUGONYCHIA FLABELLUM. 107 


These hexactines and hexactine-derivates measure 134-318 w in total 
diameter. Their fully developed rays are 83-180 u» long and 5-14 u thick at the 
base. They are usually regularly conic and sharp-pointed, rarely cylindro- 
conic and somewhat blunt. The reduced rays are 6-25 uw long, 7-16 uw thick, 
cylindrical, and terminally rounded. The length and thickness of the properly 
developed rays is, as the subjoined table shows, in the monactine to pentactine 
forms in inverse proportion to their number. The hexactine forms apparently 
do not conform to this rule. Since, however, the state of preservation of the 
specimen renders it impossible to ascertain clearly whether the not numerous 
larger hexactines are choanosomal or superficial, it might be assumed that these 
large hexactines are choanosomal spicules and do not belong to the series repre- 
sented by the dermals and gastrals, to which that rule applies. The small 
hexactines conform to the rule, and some at least of these are certainly superficial. 


HEXACTINES AND PENTACTINE TO MONACTINE HEXACTINE-DERIVATES. 


Fully developed rays 


Length Basal thickness 
Number a = === = 7 == == 
limits average of the limits average of the 
Sl longest three mit thickest three 
6 83-140 132 5-10 9 
5 90-118 114 5-9 8 
4 95-125 120 6-9 8 
3 100-142 141 5-11 10 
2 105-160 152 6-11 10 
1 123-190 185 10-14 13 


Both the fully developed and the reduced rays are covered with spines. 
On the basal parts of the fully developed rays the spines are somewhat sparse 
and here they arise vertically. On their distal parts the spines are more numer- 
ous and here they point obliquely outward. The extreme tip of the ray is 
usually free from spines for a distance of 4 or 5 uw. The spines are conic, sharp- 
pointed, and 0.5-2 » high. Their size is in proportion to the thickness of the ray 
from which they arise, the stoutest rays bearing the largest spines. 

The cylindrical, terminally rounded, more or less knob-like, reduced rays 
are covered with similar spines, which are either similarly distributed as on the 
fully developed rays or more crowded. 


108 LANUGONYCHIA FLABELLUM. 


It has been stated above that some of the fully developed rays are more 
eylindroconie and less sharply pointed than the great majority of rays. Such 
blunt rays have only been observed in the hexactines and pentactines, and it is 
always the distal protruding ray of these spicules which exhibits this peculiarity. 
This differentiation is interesting, since it would, if further developed and associ- 
ated with an increase in the size of the spines, convert these superficial hexactines 
and pentactines into pinules. 

The onychhexasters (Plate 13, figs. 6b, 15b, 27) measure 86-135 y in total 
diameter. Their main-rays, which are regularly arranged and enclose angles 
of 90° with their neighbours, are 5-8 » long, thickened at both ends, and, in the 
middle, where thinnest, 2-3 « in transverse diameter. From the end of each 
main-ray several, most frequently four, branch-rays arise. These are con- 
siderably curved, convex to the centre of the spicule, at the base, but soon 
straighten out, often, however, exhibiting slight bends farther on. They are 
48-60 » long, 1.3-2 » thick at the base, and gradually attenuated to 0.3-0.6 u 
at the end. They bear along their length sparse, minute, backwardly directed 
spines, and on their ends two to four, most frequently three, slender terminal 
spines, 3-5 » long. These usually enclose angles of 90-120° with the end-ray, 
and are curved, concave towards the centre of the spicule, or nearly straight. 
They generally arise from the same point, quite terminally, and form a verticil. 
Sometimes, however, one is situated a little below the end of the end-ray. 

All the discohexasters (Plate 13, figs. 1-4, 5a, 6a, 15a, 17-26) have very 
much the same shape, but they differ quite considerably in regard to their size 
and the number of their end-rays. I measured 22 of them and found that 


QO was under’ 80 


2 were 81-100 
Ose 101-120 
3 en 121-140 
0 was 141-160 
2 were 161-180 
(he alld 181—200 
Slee 201-220 


0 was. over 221 
in total diameter. 
This gives the following frequency-curve (Fig. 3). 
From this remarkably regular double curve I conclude that two kinds of 
discohexasters are to be distinguished, a large kind over 150 » in diameter and a 


small kind under 150 uy. 


LANUGONYCHIA FLABELLUM. 109 


o>) 


! 

| 

| 

1 
SSeS oe 


Number of spicules observed. 
ie) 


Total B 
diameter. | 


(M4). 


Ot = 120. oee 
Se ees 
272A 


61 —180- 


Fig. 3.— Discohexasters. 


The large discohexasters measure 165-220 u in total diameter. Their main- 
rays, which are regularly arranged and enclose angles of 90° with their neigh- 
bours, are 8-10 » long and 4.5-7 u» thick. Each main-ray bears a terminal 
verticil of usually four end-rays, which arise steeply from the main-rays, but at 
once curve outwards, and are quite straight, apart from the short, curved, basal 
part. The basal curvature is such that the distal straight and middle-parts of 
all the end-rays become fairly concentric with the centre of the spicule, and also 
fairly equidistant; the whole discohexaster in consequence appearing as a quite 
regular rosette. The end-rays are 90-105 uw long and 3.5-6 » thick at the base. 
They are attenuated distally and are 1.5-3 uw thick at their thinnest point, a 
short distance below the end. From here they again thicken and measure, at 
the end itself, 3-5 » in transverse diameter. Below the thinnest point the end- 
rays bear minute backwardly directed spines. The spines are rather sparse at 


the base of the ray but become very numerous distally towards its thinnest point. 


110 LANUGONYCHIA FLABELLUM. 


The distal part of the end-rays, beyond the thinnest point, is smooth. At the 
end each end-ray bears a verticil of seven large anchor-teeth, like recurved spines 
with a maximum length of 11 ». The basal parts of these terminal spines 
coalesce to form a kind of convex terminal disc. The transverse diameter of 
these terminal spine-verticils is 12-16 ». The constancy of the number (seven) 
of these terminal spines seems very remarkable, since this number is apparently 
in no way connected either with the triaxon (hexactine) ground plan of all hexac- 
tinellid spicules, or the physical (crystallographic) properties of the silica of 
which they consist. 

The small discohexasters differ from the large ones described above only in 
regard to their size and the number of their end-rays. They measure 82-140 u 
in total diameter, and have main-rays 5-8 uw long and 2.7—5 y» thick. Each 
main-ray usually bears seven or eight end-rays 36-62 uw in length. These 
measure in thickness 1.5-3 w at the base, and 0.5-1.2 » at the thinnest point near 
the end, and 1-1.5 yu at the end itself. The terminal spine-verticils measure 6- 
11 yu in transverse diameter. 

The plumicomes (Plate 12, figs. 21-23) have a central thickening about 
3.5 « in diameter and regularly arranged main-rays, enclosing angles of 90° with 
their neighbours. The proximal part of the main-rays is cylindrical, and 1-1.5 » 
thick. Near their end they are thickened to an oval knob, 2-3 yu in transverse 
diameter, from which the end-rays arise. A terminal cylindrical rod, 0.8-1.4 u 
thick, 2-4 » long, and reunded at the end, arises from each knob. This rod, 
which lies in line with the proximal part of the main-ray, appears as its termina- 
tion. The total length of the main-rays (including the terminal rod) is 10-14 u. 
The end-rays, of which there may be about twenty on each main-ray, are curved. 
in an S-shaped manner, and are 30—40 uy long. 

The irregular discohexasters with primary and secondary end-rays (Plate 12, 
fig. 20) are very rare. I found only three. These spicules may be malformed 
discohexasters. Since, however, the three observed are very much alike and 
since no intermediate forms connect them with the other hexaster-forms, they 
may also be spicules sui generis. 

They measure 120-140 u» in total diameter. Their main-rays, which are 
regularly arranged and enclose angles of 90° with their neighbours, are 5-11 yu 
long and 3-7 w thick. Each main-ray bears two or three basally curved, but for 
the greater part of their length fairly straight, strongly spined, primary end-rays. 
These are 50-60 » long, 3-4 u thick at the base, and about 2 » at the end. The 
ends of many of them are divided into short and stout, irregularly bent, trans- 


LANUGONYCHIA FLABELLUM. 1 


verse branches. Slender secondary end-rays 8-17 » long arise from the sides 
and ends of the primary end-rays and their terminal branches. The basal parts 
of these are directed obliquely backwards towards the centre of the spicule, but 
they at once curve strongly outward, their distal and middle-parts being fairly 
straight and directed obliquely outwards. Each of these secondary end-rays 
bears a terminal verticil of relatively large, recurved spines, which appears as a 
terminal disc with strongly serrated margin. These terminal spine-verticils, 
which measure as much as 10 yw in transverse diameter, closely resemble the 
terminal spine-verticils of the discohexasters above described. In examining 
these remarkable spicules I gained the impression that their secondary end-rays, 
the basal parts of which are in exactly the same position relative to the primary 
end-rays as the spines, might be considered as hypertrophic spines. 

The amphiasters, which, as stated above, I believe to be foreign, have 
a shaft about 13 uw long and 1.2 uw thick, from each end of which arise three 
branch-rays, sometimes 23 » long. These branch-rays bear secondary branches 
at the end. 

The known species most closely allied to the sponge described above are 
Mellonympha velata (Wyv. Thoms.), Lanuginella pupa O. Schm., and certain 
rossellinas. It differs from all these by its spiculation to such an extent, how- 
ever, that a new species must be established for it. About this there can be no 
doubt. It is more difficult to decide in which genus this species should be placed. 
Is it to be assigned to one of the already established genera and if so to which 
one, or is a new genus to be established for it? 

In regard to its internal microscleres and to its large pentactines Lanugony- 
chia flabellum resembles most closely Mellonympha velata, the only species of 
Mellonympha. Since, however, its body is lamellar and thin, since its dermal 
spicules are reduced hexactines, mostly with only from one to four fully developed 
rays, since it is very doubtful whether the large pentactines observed in it pro- 
trude beyond the surface to form a veil, and since ordinary small, not protruding 
hypodermal pentactines certainly occur in it, I hardly think it advisable to place 
it in the same genus as this ovoid sponge with its large, freely protruding velar 
hypodermal pentactines and its pentactine dermals. 

Lanuginella pupa, the only species of Lanuginella, although also differing 
from Lanugonychia very considerably in shape, resembles it more closely in 
regard to its dermal and gastral spicules. It is, however, destitute of onych- 


hexasters, spicules which are very abundant in Lanugonychia flabellum. ITjima! 


17. Ijima. Studies on the Hexactinellida. IV. Journ. Coll. sci. Tokyo, 1904, 18, p. 12. 


112 STAUROCALYPTUS HAMATUS. 


has indeed observed small and delicate oxyhexaster-like spicules in rare instances 
in Lanuginella pupa. Since, however, he considers these spicules as young stages 
of the discohexasters, this observation does not invalidate the correctness of 
F. E. Schulze’s statement ' that the absence of onychhexasters (to which kind of 
spicules F. E. Schulze considers the onychhexasters to belong) is characteristic 
of Lanuginella. There being therefore no reason for altering this characteristic 
of Lanuginella I accept it and am consequently unable to place the sponge above 
described in Lanuginella. 

Since the otherwise similar species of Rossellinae differ from Lanugonychia 
flabellum by the absence of plumicomes, and since F. E. Schulze and I. Ijima 
consider the absence or presence of plumicomes in the Rossellidae as a difference 
sufficient for generic distinction, I do not think it advisable to place Lanugony- 
chia flabellum in any of the described genera. As it seems to be most closely 
allied to Lanuginella and as it differs from this genus chiefly in that it possesses 
onychhexasters, I propose Lanugonychia, the type and, at present, only species 
of which is the Lanugonychia flabellum. 


Acanthascinae F. E. Scuutze. 


Rossellidae with discoctasters. 
The collection contains one specimen of this subfamily, a new species of 


Staurocalyptus. 
STAUROCALYPTUS Iyma. 


Rossellidae (Acanthascinae) with oxyhexasters, small discohexasters, and 
discoctasters, and with hypodermal pentactines the lateral rays of which are des- 


titute of long curved spines. 


Staurocalyptus hamatus, sp. nov. 


Plate 16, figs. 25-43; Plate 17, figs. 1-25; Plate 18, figs. 1-14. 


One specimen of this species was trawled at Station 4642 on 7 November, 
1904; 1° 30.5’ S., 89° 35’ W.; depth 549 m. (300 f.); the bottom was composed 
of broken Globigerina and molluscan shells; the bottom-temperature was 
48.6°. It is characterised by the possession of numerous oxyhexactines and a 
few hemioxyhexasters with hook-like rays (end-rays). To this the name refers. 

Shape and size. The specimen has the shape of a shallow, inverted cup. 


1 F. E. Schulze. Revision des systemes der Asconematiden und Rosselliden. Sitzungsb. Akad. 
Berlin, 1897, p. 548. 


STAUROCALYPTUS HAMATUS. iis; 


Its lower, concave side fits the dorsal side of a crustacean, apparently a species 
of Dicranodromia, which firmly holds the sponge on its back by the dorsally 
directed, last pair of thoracic extremities. In its original position the sponge 
completely covered the Dicranodromia dorsally (Plate 18, fig. 14). Seen from 
above (Plate 18, fig. 5) or below (Plate 18, fig. 6) the sponge appears oval in 
outline, with a protuberance at one end. It is 35 mm. long and 28 mm. broad. 
The wall of the inverted cup, formed by it, is about 3 mm. thick. Scattered 
pores are observed both on the free upper convex side and the lower concave side 
which rested on the back of the Dicranodromia. Those of the upper side are 
mostly oval, with a maximum measurement of 1 mm. in length and 0.5 in breadth. 
Those of the lower side are relatively broader, more nearly circular, and reach 
1.5 mm. in diameter. Large prostal rhabds protrude both from the upper and 
the lower side. 

The colour in spirit is light brown. 

General structure. I found a few remnants of a dermal membrane both on 
the concave, lower, and the marginal part of the convex, upper side. Of a 
gastral membrane no trace could be detected. The remnants of the soft parts | 
in the interior indicate that the sponge has sac-shaped flagellate chambers, 80- 
100 uw long and 50-70 y broad. 

Skeleton. Spicule-bundles, 40-200 ,» thick, traverse the sponge. These 
bundles appear to be most numerous just below the lower, concave face of the 
sponge, where they extend chiefly paratangentially. They are composed of 
rhabds — of small rhabds only, or of a large rhabd accompanied and more or less 
enveloped by numerous, comital, small rhabds. Besides the rhabds forming 
the bundles, isolated rhabds also occur in large numbers. Oxyhexasters, hemi- 
oxyhexasters, and oxyhexactines with straight rays and end-rays, oxyhexactines 
with terminally curved, hook-like rays, and discoctasters of various size are very 
numerous. The last appear to be much more frequent in the interior than near 
the surface of the sponge. Small discohexasters, and hemioxyhexasters with 
rays, either all hook-like or partly hook-like and partly straight, are met with 
in smaller numbers. Hypodermal pentactines and a few triactine megascleres 
occur at, or just below, the surface. On those parts of the surface where rem- 
nants of the dermal membrane are left, spiny rhabds are observed. Most. of 
these are simple diactine rhabds. Some are centrotyle, and a few possess, 
besides the two properly developed rays, short rudiments of one or two further 
rays. These spicules and a few angular diactines and stauractines, similar in 


regard to size and spinulation, found in the spicule-preparations, I consider as 


114 STAUROCALYPTUS HAMATUS. 


the dermal spicules of the sponge. Spicules which might be considered as gas- 
trals were not observed. 

The choanosomal and prostal rhabds (Plate 16, figs. 25-38, 39a, b; Plate 18, 
fig. 13) are usually more or less curved, and exceedingly variable in size. They 
are 0.67-13 mm. long, and 5-175 yu» thick at the thickest point. The rhabds 
under 3 mm. in length are less than 50 u» thick, those 3-9 mm. in length are 40— 
100 » thick, those over 9 mm. in length, usually 100-160 ». Although there is, 
as this shows, on the whole, a certain correlation between thickness and length, 
the proportion between these two dimensions is nevertheless very far from being 
constant and varies between 50 to 1 and 122 to 1. The thickest point of the 
rhabd may be situated at or near the middle of its length (Plate 16, figs. 29, 39a), 
or it may be more (Plate 16, fig. 30) or less (Plate 16, fig. 34) approximated to 
one of the ends. A tyle is met with only exceptionally. It is, when present, in 
the small rhabds 4-6 u» more in transverse diameter than the adjacent parts of 
the spicule, and may be situated near the middle or nearer one end. Occasion- 
ally it lies quite terminally, in which case the spicule appears as a tylostyle. In 
the large rhabds the axial thread is usually somewhat thickened (Plate 16, 
fig. 36) at several points, but an axial cross can only rarely be made out. In the 
small rhabds an axial cross can generally be found. When a tyle is developed 
the axial cross generally lies in its centre. In the large rhabds the two rays taper 
towards the end and are usually abruptly and bluntly pointed (Plate 16, figs. 27, 
33, 35, 37), rarely rounded or sharp-pointed. In these spicules the ends are 
30-3 as thick as the thickest portion of the middle-part. In the small rhabds the 
ends are cylindroconic or quite cylindrical and terminally either abruptly and 
bluntly pointed, like the ends of the larger rhabds (Plate 16, fig. 26), or more 
rounded (Plate 16, figs. 25, 27). In these spicules the ends are from half as thick 
to quite as thick as, or even slightly thicker than, the thickest portion of the 
middle-part. In the rhabds in which the thickest part lies near one end, this end 
is conic and stout (Plate 16, fig. 33), the other being cylindrical and slender 
(Plate 16, fig. 31). 

The whole of the rhabd, with the exception of the two ends, is smooth. 
The ends are covered with broad, conic, vertically arising spines 0.5-1 y, rarely 
2 long. The terminal spiny region is 40-230 » long and passes, as the spines 
become scarcer and lower, gradually into the smooth middle-part of the spicule. 

In some of the rhabds an abrupt step-like attenuation occurs at a shorter 
or longer distance from one of the ends. Of other rhabd-irregularities noticed 
I mention slight transverse grooves which give to the contour an indented ap- 
pearance. As the figure (Plate 18, fig. 13) of such a spicule clearly shows, these 


STAUROCALYPTUS HAMATUS. 115 


indentures are not restricted to the outer surface but affect the whole of its 
superficial, clearly stratified part, down to the more homogeneous central part, 
the surface of which also shows the indentures. 

The hypodermal pentactines (Plate 18, figs. 8-10) have a straight or slightly 
curved proximal ray, which is 0.5-2.2 mm. long and 9-22 u» thick at the base. 
The lateral rays are vertical to the proximal ray and in the same spicule often 
unequal, the longest being 120-210 u, the shortest 80-170 » long. All these rays 
are blunt. The tips of the lateral rays are spiny. 

A triactine with one longer and two shorter rays, opposite in the same straight 
line (axis), which enclosed an angle of 70° with the axis of the long ray was 
observed in the spicule-preparations. The long ray of this spicule was 860 u 
long, the two short rays were 260 and 280 ». The distal parts of all the rays 
were spined. 

The dermal spicules (Plate 16, figs. 40-43) are usually simple, straight or 
slightly curved, diactine rhabds (Plate 16, figs. 42, 48), 335-470 uw long, and 7— 
13 » thick at the thickest point, which is usually situated near the middle. An 
axial cross can usually be discerned at or near the middle. The two rays are 
eylindroconic and terminally rounded. Their ends are usually a half to a third 
as thick as the thickest portion of the middle-part of the spicule. Sometimes, 
however, they are thinner than that, down to a quarter of the maximum thick- 
ness of the middle, or thicker, up to nine tenths of this, or even slightly more. 
The two ends of the same spicule are usually somewhat unequal, one being 1 u 
or so thicker than the other. The whole spicule is covered with conic, vertically 
arising spines, 0.5-2 » long. The spines are more numerous at the ends than in 
the middle. This difference in the degree of spinulation of the different parts is 
the more clearly pronounced the longer the spicule is. 

Besides these simple diactine dermal rhabds similar ones with a tyle, situated 
either more or less centrally or, rarely, terminally, are met with. The tyle may 
be a simple thickening, and concentric with the axis of the spicule, or it may be 
one sided (Plate 16, fig. 41), or composed of two protuberances (Plate 16, fig. 40). 
These protuberances, which are obviously ray-rudiments, are up to 10 u long and 
covered with spines like the other parts of the spicule. 

I found in the spicule-preparations a few tetractines (stauractines) and 
angularly bent diactines with rays similar in regard to their spinulation to those 
of the rhabds above described. The former have rather unequal rays 160-230 u 
long and 9-10 u thick at the base. One of the latter had rays 48 uw long, 8 
thick at the base, and 5 u» at the end. 

The oxyhexasters, hemioxyhexasters, and oxyhexactines with straight rays 


116 STAUROCALYPTUS HAMATUS. 


(Plate 16, fig. 39c; Plate 17, figs. 5-8, 9b, 10b) measure 96-165 y» in diameter 
and have from one to four end-rays. The forms with partly simple and partly 
bifurcated rays, that is the hemioxyhexasters with two end-rays on the branched 
main-rays, appear to be the most frequent. The true oxyhexasters usually 
have two or three, rarely three or four end-rays. The size of the spicule is, on 
the whole, in inverse proportion to the number of end-rays. The oxyhexactines 
and the hemioxyhexasters and oxyhexasters with two end-rays are 110-165 y» in 
diameter, the oxyhexasters with more than two end-rays on all or some of the 
main-rays 96-130 » in diameter. The main-rays (and simple end-rays) enclose 
angles of 90° with their neighbours. The simple rays are 54-84 y long, 3-4.5 
thick at the base, and conic. Their end is very slender and they terminate in an 
exceedingly fine point. The basal part of the ray is for a short distance smooth. 
Farther on it bears slender, straight, very oblique spines, which point backwards 
towards the centre of the spicule. The proximal spines are the largest and attain 
1 uinlength. Farther on they rapidly become smaller and on the distal part of 
the ray no spines at all can be detected. This decrease of the size of the spines 
towards the ray-end is either gradual throughout, or there is a step-like, abrupt 
decrease a short way up. The rays of these spicules, particularly those in which 
there is such an abrupt decrease of the size of the spines, resemble the threads of 
exploded enidoblasts of certain hydroids. I consider these simple rays as main- 
rays with a single end-ray; their proximal smooth part is their main-ray, their 
middle and distal spined part, their end-ray. The main-rays which bear end- 
rays are smooth and very short, only 4-8 u« long, and 3-5.5 » thick. The end- 
rays arise very steeply, often nearly vertically, from the main-rays and at once 
curve outwards, so that their nearly straight distal and middle-parts enclose 
angles of 30-35° with the continuation of the main-ray axis. Apart from their 
basal curvature these end-rays resemble in shape and spinulation the middle 
and distal spined part of the simple rays above described. The end-rays are 
spined quite down to the base, are 37-75 u long and 2.54 a thick at the base. 

Rarely hemioxyhexasters are met with some rays (end-rays) straight and 
others hook-like (Plate 17, fig. 4). These spicules appear as transitions between 
the straight-rayed spicules described above and the spicules with hook-like rays 
to be described below. The transitional hemioxyhexaster represented (Plate 17, 
fig. 4) measures 170 » in diameter, has two hook-like simple rays, two straight 
simple rays, and one main-ray with two straight end-rays. 

The oxyhexactines with hook-like rays (Plate 16, fig. 39d; Plate 17, figs. 1-3, 
10c) measure 140-227 » in diameter. The rays of the same spicule may be equal 


STAUROCALYPTUS HAMATUS. 7 


or unequal. The rays are, measured along the chord, 75-120 » long, and 2.5— 
8 » thick at the base. They are conic and gradually attenuated to a fine point. 
The proximal parts of the rays are straight and regularly arranged so as to enclose 
angles of 90° with their neighbours. Ata distance from the centre usually equal 
to from one half to three quarters of the length of the chord of the whole ray, 
the rays begin to curve either gradually or more often abruptly with a distinct 
angular bend. The distal part of the ray, beyond this point, is uniformly 
curved through an angle of at least 90°, usually more. Sometimes the curvature 
is so great that the end points directly backwards and the end-tangent becomes 
nearly parallel to the axis of the basal part of the ray (Plate 17, fig. 1). Excep- 
tionally the curved end-part forms nearly a whole turn (Plate 17, fig. 10c, the 
upper ray). In such eases it is clearly to be seen that the curvature is spiral, 
and it seems probable that it is of this nature also in those cases where the curved 
part of the ray is shorter, and the true nature of its curvature not so clearly 
discernible. 

Like the simple rays of the straight-rayed hemioxyhexasters and oxyhexac- 
tines described above, the rays of these spicules are smooth at the base, and 
farther on covered with slender, oblique, backwardly directed spines, which 
decrease in size distally, so that the end-part appears merely roughened or nearly 
smooth. 

Of hemioxyhexasters with hook-like rays I found only two or three. These 
had one bifureate and five simple rays. One of these spicules measured 210 u 
in diameter; its simple rays were 3 u thick at the base. 

The small discohexasters (Plate 17, fig. 10e; Plate 18, figs. 1-4, 7, 11b, 12b) 
measure 20-23 y in total diameter. The main-rays of the same spicule are equal 
and enclose angles of 90° with their neighbours. A central thickening, 3-4 yu in 
diameter, can clearly be made out. The main-rays are smooth, 3.5-4.5 « long, 
1.2-1.6 » thick in the middle, and thickened at both ends, proximally to the 
centrum, distally to the somewhat extended base, from which the end-rays arise. 
Each main-ray bears about 16 end-rays. The end-rays are curved, concave to 
the continuation of the main-ray axis, quite considerably at the base, but only 
very slightly, or not at all, towards the end. They are 7-8 u long, about 0.2 u 
thick at the base, and attenuated towards the end, which bears a thickening 
about 0.8 w in transverse diameter. This terminal thickening is certainly 
broader than high and convex on the outer side. However, in consequence of 
its small size more cannot be made out about its shape. This thickening may 
be, and, judging by analogy, probably is, a verticil of terminal, recurved spines. 


118 STAUROCALYPTUS HAMATUS. 


The discoctasters (Plate 16, fig. 39e; Plate 17, figs. 9d, 10d, 11, 12, 13d, 14- 
25) measure 58-320 » in diameter, usually 70-260 4. They consist of six short 
and stout main-rays, each of which bears several, in the regular forms, four 
end-rays. Hight groups of three of these (24) end-rays, belonging to three 
different main-rays, usually coalesce to as many single rays, which are divided 
distally into verticils of about six terminal branches. The main-rays in the 
same spicule are equal and their axes enclose angles of 90° with those of their 
neighbours. They are distally rounded, 6.5—9 » long and about as thick. The 
six main-rays together appear as a compact central body from which arise six 
dome-shaped protuberances, placed in the positions of the corners of an octa- 
hedron. Seen from above this structure appears, when standing upright (on a 
corner of the octahedron), as a cross with short stout arms (Plate 17, figs. 11, 19- 
23); when lying on one of the sides (of the octahedron) it is six-lobed in shape 
(Plate 17, figs. 16-18). The eight coalesced end-ray groups of three arise from 
the eight depressions between the dome-shaped tips of the main-rays, at points 
corresponding to the eight faces of the octahedron. These coalesced end-ray 
groups, which might be designated as pseudomain-rays, are 16-49 » long and 
3-10 » thick. They are on the whole, cylindrical, but usually somewhat irregu- 
lar, thickened here and there (Plate 17, figs. 14-16). The terminal branches 
of these pseudomain-rays, which may be designated as secondary end-rays, are 
slightly curved, convex to the continuation of the pseudomain-ray axis, and 
diverge from it at angles of 12-16°. They are 15-115 u long, 0.7—2 » thick at the 
base, and attenuated towards the end, where they measure 0.4—1.5 » in transverse 
diameter. They bear, along their length, very obliquely situated, backwardly 
directed spines, which are sometimes 1.5 » long and somewhat curved. Their 
end is crowned by a terminal verticil of similar but stouter and more divergent 
recurved spines, which together form a sort of terminal disc with serrated mar- 
gin, 1-2.5 uw in transverse diameter (Plate 17, fig. 24). 

The great differences in the size of the discoctasters is due chiefly to differ- 
ences in the length of the secondary end-rays, 15 » in the smallest, 115 » in the 
largest, and to a small extent also to differences in the length of the pseudomain- 
rays, 16 » in the smallest, 49 in the largest. The main-rays are in the largest 
discoctasters only 3 » longer than in the smallest. 

Not infrequently (Plate 17, figs. 13d, 14) a simple ray (end-ray), curved at 
the base and straight farther on, arises directly from the central mass composed 
of the main-rays, between the pseudomain-rays. These simple. main-rays are 
27-31 » long, and 1.5-2 » thick at the base. They are attenuated distally and 


FARREA OCCA SCUTELLA. 119 


provided with lateral spines and a terminal verticil (‘“‘dise’”’) of such, like the 
secondary end-rays. I consider these simple rays as ordinary end-rays which 
have not coalesced with others to form pseudomain-rays and which are not 
divided distally into branches (secondary end-rays). 

I am inclined to consider the specimen above described as the basal part of a 
higher, perhaps cup-shaped, sponge, the upper parts of which may have been 
either nipped off by the Dicranodromia, which used it as tent and shield, or torn 
off during capture. 

Since hexactine megascleres are absent and since the sponge possesses 
hypodermal pentactines, mostly diactine spiny dermals, oxyhexasters, hemioxy- 
hexasters, microoxyhexactines, small discohexasters, and discoctasters, I think 
there can be little doubt that it belongs to Staurocalyptus, although its gastral 
spicules are unknown. It differs from all the species of this genus hitherto 
described by the possession of oxyhexactines and hemioxyhexasters with hook- 
like rays. This and other minor differences necessitate the establishment of a 


new species for it. 
EURETIDAE Zire. 


Hexasterophora the body of which is calyculate or composed of ramified or 
anastomosing, thin-walled tubes. With a firm reticulate supporting skeleton- 
net. Among the free spicules are always uncinates and either scopules or 
clavules. With oxyhexasters or discohexasters or both. 

The collection contains nine more or less complete specimens and twenty 
fragments of this family. The generic position of two specimens and twelve 
fragments is doubtful. The others belong to the two genera Farrea and Eurete. 


FARREA BoweERrBANK. 


Kuretidae with clavules, without scopules. 

There are four more or less complete specimens which represent a new 
variety of Farrea occa Bowerbank. Hight fragments apparently belong to two 
distinct forms which, however, cannot be specifically determined. 


Farrea occa scutella, var. nov. 


Plate 25, figs. 25-29; Plate 26, figs. 1-21; Plate 27, figs. 1-17. 


The collection contains four more or less fragmentary specimens of this 
sponge, all trawled off the southern coast of western Panama at Station 4621 on 
21 October, 1914; 6° 36’ N., 81° 44’ W.; depth 1067 m. (581 f.); they grew on 
green mud and rock; the bottom-temperature was 40.5°. 


120 FARREA OCCA SCUTELLA. 


They resemble portions of wine-glasses with stems. To this the name of 
the new variety refers. 

Shape and size. From an extensive basal plate, which at one time was 
obviously attached to something hard on the sea-bottom, a short stem arises, 
which spreads out above to form a thin, curved, lamellar body (Plate 26, figs. 
16-21). One of the specimens has two basal plates and two stems (Plate 26, 
figs. 18, 19). This is probably the product of a concrescence of two specimens, 
originally distinct, which grew side by side. 

The basal plate measures 5-17 mm. in maximum transverse diameter, is 
1-2 mm. thick near the middle, and thins out towards the somewhat irregular 
lobose margin. The stem is 4-7 mm. broad and 2-3 mm. high. It consists of a 
vertical curved lamella, about 1 mm. thick, which appears as a portion of the 
wall of an upright cylindrical tube cut through longitudinally or obliquely. 
Above it is generally curved outward and abruptly extended into the lamella 
which forms the body proper of the sponge. This lamella is elegantly curved 
in a cylindroid or saddle-shaped manner and at the base, where it arises from the 
stem, is about 1 mm. thick. Towards the margin it gradually thins out. In all 
the specimens this lamella is more or less fragmentary. In the largest it is 19 
mm. long and 18 mm. broad, measured along the chord. 

The colour in spirit is ight brown. 

The skeleton consists of a network and loose hexactines, pentactines, 
uncinates, oxyhexasters, clavules with large teeth, and clavules with small 
teeth. 

The skeleton-net (Plate 25, figs. 25, 27-29; Plate 26, figs. 8-14, 16-21) 
pervades all parts of the sponge. On the lower side of the basal plate (Plate 26, 
figs. 10, 11) it is very dense and consists of smooth beams, 8-20 uw thick, which 
enclose round meshes 10-40 yu in diameter, so that this part of it appears as a 
perforated plate. On the upper side of the basal plate and in the stem (Plate 26, 
figs. 12, 13) it is composed of more or less spiny beams, 6-35 y» thick, which 
enclose irregular, square, or triangular meshes 30-180 » wide. In this region 
numerous small hexactines are attached to the beams of the network (Plate 25, 
figs. 25, 27-29; Plate 26, figs. 12, 18) with one thickened ray. These attached 
tree-like hexactines are 75-135 uw high. In some places other similar hexactines 
are soldered to these attached ones, whereby rudiments of a slender secondary 
network are here and there formed. In the proximal part of the lamellar body 
proper of the sponge the skeleton-net consists of an inner, regular layer with 
square, rectangular meshes (Plate 26, fig. 17), and an outer, irregular layer, with 


FARREA OCCA SCUTELLA. 121 


chiefly triangular meshes (Plate 26, fig. 16). The marginal and middle-parts of 
the skeleton-net of the body-lamella (Plate 26, figs. 8, 9, 14) consist of a single 
layer composed of longitudinal and transverse beams. The former are in some 
places curved, in others straight, and spread out towards the margin of the 
lamella in a fan-shaped manner. Here and there they divide into two equal 
branches, which, at first, diverge at an angle of about 30°, but very soon become 
parallel; thus the number of the longitudinal beams increases towards the margin 
of the body-lamella. The transverse beams are vertical to the longitudinal ones 
and accordingly also in some places curved, in others straight. All the beams 
of this network are quite smooth. The longitudinal ones are mostly 73-80 u 
thick, the transverse 75-90 yu. The meshes are mostly square and rectangular, 
more rarely quadratic, and exceptionally (where the longitudinal beams branch) 
triangular. The rectangular ones are 280-510 » long and 200-400 » broad. In 
some places this network is remarkably regular (Plate 26, fig. 8). From each 
node of this network two thorns, 32-45 » thick at the base, arise in opposite 
directions. Both are vertical to the surface in which the network extends. 
One is directed dermally, the other gastrally. These thorns are fairly straight, 
either conic or thickened near the end, and covered with protuberances. At the 
base these thorns are broad, rounded, and 6-8 » high; towards the end they be- 
come smaller and much more slender. 

Of the loose spicules the uncinates and clavules with short teeth are very 
rare and also the hexactines rather scarce. The other kinds of loose spicules, 
particularly the oxyhexasters, are abundant (Plate 26, fig. 8). The fragmentary 
condition of the specimens renders it difficult to ascertain the position of these 
spicules in the sponge. I can say, however, that there is no reason to assume 
that they are arranged otherwise than in the type of this species where their 
position has been described by Schulze.! 

The loose hexactines (Plate 25, fig. 26) are 110-190 u in total diameter, and 
have straight, conic, spined rays usually 3.5-4 » thick at the base. 

The pentactines (Plate 26, figs. 8a, 15; Plate 27, fig. 6a) have regularly 
arranged lateral rays, usually 180-255 uw long. The lateral rays of the same 
spicule are as a rule somewhat unequal. The difference in length between the 
longest and shortest is usually 15-30 ». Very rarely one lateral ray is greatly 
reduced in length, only 120 u long, and terminally thickened. When that is the 
case this difference is of course much greater. The lateral rays are straight or, 


more frequently, shghtly and uniformly curved, concave to the proximal ray. 


1F, EH. Schulze. Rept. Voy. Challenger, 1887, 21, p. 277 ff., pl. 71-73, 76, figs. 1-3. 


122 FARREA OCCA SCUTELLA: 


They are on the whole cylindroconic, about 9 » thick at the base, and attenuated 
distally to 4-6 u. The end is rounded off. Frequently a slight thickening is 
observed just before the end. The lateral rays are spiny. On the basal and 
middle-part of the rays the spines are 2-4 » high and arise vertically; on the end- 
part they are 1-1.5 » high and obliquely inclined towards the end of the ray. 
The spines of the lateral rays are larger in the dermal pentactines than in the 
gastral. In the former they are larger and much more numerous on the outer 
side of the rays than elsewhere, the inner side being often nearly destitute of spines. 
On the lateral rays of the gastral pentactines the concentration of spines on the 
outer side is not so pronounced. The axial thread traverses the lateral rays 
quite to their ends. The proximal ray is straight, 180-260 » long, and usually 
bears only small spines near the end. In most of the pentactines, particularly 
the dermal ones, a rudiment of the sixth distal ray is present. This is 14-17 » 
long, and as thick as the other rays. It bears a few large, upwardly directed 
spines. Sometimes only a single terminal spine is present. In this case the 
distal ray (together with the spine) appears a sharp-pointed, conic thorn. 

The uncinates are very rare and I cannot positively assert that those ob- 
served in the preparations really belong to the sponge. An intact one was 
straight, pointed at both ends, and measured 1.6 mm. long and 10 yu thick near 
the middle. Its spines were slender and 8 u long. 

The oxyhexasters (Plate 26, figs. 1-7, 8c; Plate 27, fig. 6c) are 105-140 yp in 
total diameter. Their main-rays enclose angles of 90° with each other and are, 
in the same spicule, usually equal; sometimes, however, considerable inequalities 
are observed in them, the proportion of the length of the shortest to that of the 
longest sometimes being 3:5. The main-rays are 22-37 y long, straight, cylin- 
droconic, 2.8-3.8 » thick at the base, and attenuated distally to 2-2.7 u. They 
are perfectly smooth and traversed by an axial thread, which terminates below 
the end and does not give off branches for the end-rays. Of end-rays there are 
one to four, usually two or three. The end-rays are slightly curved, concave to 
the continuation of the main-ray at the base, and farther on usually fairly straight, 
rarely considerably and irregularly curved. They are conic, uniformly attenu- 
ated to a fine point, 30-44 y» long, 1.3-2.2 » thick at the base, destitute of axial 
threads, and, like the main-rays, perfectly smooth. When only one end-ray is 
present, it extends in the continuation of the axis of the main-ray to which it 
belongs. When there are two they usually enclose an angle of about 60° and lie 
in or near a plane which passes through the main-ray from which they arise. 
The planes in which such end-rays extend are usually oblique to the two axial 


FARREA OCCA SCUTELLA. 123 


planes, passing through the axis to which these forks belong and either of the 
two other axes of the spicule. The end-ray forks of opposite main-rays do not 
lie in the same plane. As far as I could make out the planes of such forks are 
opposite, and usually symmetrical, in such manner that the angle enclosed by 
them with either of the two axial planes above mentioned are supplementary ; 
added together they give 180°. When there are three or four end-rays the most 
divergent usually enclose an angle of about 90°. 

The clavules with large teeth (Plate 27, figs. 1-5, 6b, 7-11, 13-17) are gener- 
ally 300-370 uw long; a few are shorter, down to 210 win length. They consist 
of a centrum, from the lower end of which there arises a shaft, and from the 
opposite, upper end of which arises a verticil of recurved teeth. The centrum isa 
short cylinder, 6.5-12.5 u, usually 9-12 y, in transverse diameter, which generally 
bears one or a few spines at its lower end. These spines are oblique, inclined 
towards the shaft, and 0.5-2.3 » long. Their size seems to be in inverse propor- 
tion to their number; the solitary ones are the largest. At the base, where it 
arises from the centrum, the shaft is 4-8 u thick; its basal part is conic; farther 
on it becomes nearly cylindrical; just before the end it is 2.5-4.5 » thick. The 
end is abruptly and bluntly pointed and frequently slightly thickened. The 
proximal and middle-parts of the shaft bear oblique spines, inclined towards 
its end. These spines are similar to those on the centrum, but smaller. The 
end-part bears stouter, vertical spines, 0.6-1.5 » long. The number of these 
spines is variable. Their size appears to be in inverse proportion to their num- 
ber. A smooth belt sometimes intervenes between the middle region with 
oblique, and the terminal region with vertical spines. There are usually nine, 
more rarely ten, recurved teeth which form the verticil at the upper, distal end 
of the centrum. They are fairly equal in the same spicule, and regularly ar- 
ranged, the angle between adjacent ones being the same. The verticils formed 
by these teeth measure 39-53 u» in transverse diameter. The individual teeth 
are conic, 5-7 u thick at the base, and uniformly attenuated towards the sharp- 
pointed end. They are uniformly curved, concave to the centrum, and their 
chords usually enclose angles of 55°-63° with the axis of the centrum and shaft. 
The teeth generally bear spines, sometimes 0.7 » long, some distance below their 
ends. These spines are confined to a median line following the outer, convex 
side of the teeth. Usually they form short saw-like rows on the upper margin. 
Sometimes they are very conspicuous (Plate 27, figs. 13, 14), sometimes so small 
as to be hardly visible (Plate 27, figs. 16, 17). The apex of the tooth-verticil is 
generally smooth and dome-like (Plate 27, figs. 1-5, 6a, 7, 8, 11, 13, 14, 16, 17). 


124 FARREA OCCA SCUTELLA. 


Sometimes a continuation of the shaft extends beyond it, forming an apical, 
distally rounded, smooth protuberance, 6-7 » long and 4.5-6 y thick (Plate 27, 
figs. 9, 10, 15). 

The rare clavules with short teeth (Plate 27, fig. 12) are, apart from their 
teeth, similar to but smaller than the large-toothed ones above described. Their 
teeth are very short, hardly at all recurved, and the verticils formed by them 
only 18 » in diameter. Whether these clavules are young forms of the large- 
toothed ones, or a distinct kind of spicule, I cannot say. 

Their spiculation assigns these sponges to Farrea. Their shape, however, 
does not accord with F. E. Schulze’s diagnosis! of the Euretidae to which Farrea 
belongs, for in this diagnosis it is stated that these sponges are tubular. E. 
Topsent ?, who has studied a sponge very similar to the one described above, says, 
concerning this part of Schulze’s diagnosis, “Il ne faut évidemment pas prendre 
ce caractére trop 4 la lettre” and places these sponges of his, in spite of their 
non-tubular shape, in Farrea. I also am disinclined to attach any great system- 
atic importance to that difference of shape and therefore also place the sponges 
above described in Farrea. 

Of all the known species Farrea occa Bowerbank is obviously most closely 
related to them. A great many specimens, by no means identical in structure 
and appearance, have been assigned by various authors to this species, and for 
some of them distinct varieties and subspecies have been established by Topsent 
and Wilson. Although it seems to me very doubtful whether all the sponges 
assigned to Farrea occa are really specifically identical and belong to this spe- 
cies, and although I think that the forms described as varieties and subspecies 
of it might very well be considered as distinct species, I provisionally accept 
this arrangement, because it would lead much too far to reinvestigate all these 
sponges, and if we accept this arrangement, we must assign to this species so 
wide a range of variation that the sponges described above find a place in it. 
Among the sponges described as Farrea occa, those for which Topsent * estab- 
lished the variety F’. 0. var. foliascens are obviously most closely allied to F. o. 
var. scutella. From these they differ by the abundance of clavules, the scarcity 
and size (or absence, vide supra) of the uncinates, and the larger dimensions of 
the superficial pentactines. Although these differences are not very great, 
they are, in my opinion, quite sufficient for varietal distinction particularly 

1 Ff. EB. Schulze. Wexactinellida. Ergeb. Deutsch. tiefsee-exped., 1904, 4, p. 177. 
2H. Topsent. Farrea occa (Bowerbank) var. foliascens n. var. Bull. Mus. océanogr. Monaco, 


1906, no. 83, p. 4. 
3H. Topsent. Loc. cit., 1906, p. 1. 


FARREA. 125 


when held together with the fact that the specimens of F. 0. foliascens were 
trawled in the tropical Atlantic, whilst the sponges described above come from 
the eastern Pacific. 

Farrea sp.? 


Plate 32, figs. 1-3. 


There are in the collection one large and three small fragments of skeleton- 
nets of this sponge, all trawled off the southern coast of western Panama, at 
Station 4631, 3 November, 1904; 6° 26’ N., 81° 49’ W.; depth 1415 m. (774 f.); 
they grew on green sand; the bottom-temperature was 38.0°. 

The large fragment (Plate 32, fig. 1) is 36 mm. long and appears as a part of 
the skeleton-net of a tube nearly circular in transverse section and about 10 mm. 
wide. Very short branch-tubes about 6 mm. wide arise from this tube, which 
can be considered as a main-tube. Attached to both sides of this skeleton-net 
are portions of network which form short tubular covered ways about 3 mm. 
high and broad. 

The skeleton-net (Plate 32, figs. 2, 3) of the main-tube and its branches 
forms a single layer and chiefly consists of smooth, longitudinal, and transverse 
beams, mostly 80-140 » thick. Here and there a short oblique beam of similar 
thickness is observed. The meshes are mostly square, rectangular, 350-600 yu 
long, and 180-240 » broad. A few are triangular. From each node of this net- 
work two thorns arise, one directed towards the inner gastral surface, the other 
towards the outer dermal surface. These thorns are conic, vertical to the sur- 
face, about 50 » thick at the base, and covered with very blunt spines. The 
gastral ones attain a considerable length. The skeleton-net composing the 
walls and roofs of the covered ways above mentioned is irregular and has 
mostly triangular meshes. 

A large number of hexactines 80-140 y» in diameter are attached, with one 
ray, to the beams of these networks. In places, other similar hexactines are 
soldered to these, forming here and there a fine net. 

The sponges to which these skeleton-nets belonged can be assigned with a 


considerable degree of certainty to Farrea. 


Farrea sp.? 


There are in the collection four slightly curved, small fragments, the largest 
19 mm. long, of simple skeleton-nets extending in two directions (one surface) 
only. These skeleton-nets were trawled in the southeastern Pacific, at Station 


126 EURETE ERECTUM. 


4685, on the 10 December, 1904. 21° 36.2’S., 94° 56’ W.; depth 4033 m. (2205 f.); 
they grew on dark brown clay; the bottom-temperature was 35.3°. 

These skeleton-nets are very regular and composed of smooth longitudinal 
and transverse beams, 40-60 » thick, which enclose square rectangular meshes 
about 750 uw long and 200-350 yu broad. 

The sponges to which these skeleton-nets belonged can be assigned with a 


considerable degree of certainty to Farrea. 


EURETE Semper. 


Euretidae composed of anastomosing tubes without central calyculate 
structure. With scopules, without clavules. 
The collection contains three specimens of this genus which belong to three 


species, one of which is new. 


Eurete erectum F. E. Scuuuzer. 


Plate 30, figs. 1-17; Plate 31, figs. 1-28. 


Eurete erectum ¥. KE. Scuuuzn, Amerikanische Hexactinelliden, 1899, p. 72, taf. 17, figs. 1-3. 

Eurete erectum subsp. tubuliferum H. V. Wruson, Mem. M. C. Z., 1904, 30, p. 63, pl. 7, figs. 9,12; pl. 8, figs. 
1-3, 6. 

Eurete erectum subsp. gracile H. V. Witson, Mem. M. C. Z., 1904, 30, p. 69, pl. 8, figs. 4, 5, 8, 9; pl. 
9, figs. 1, 3, 5. 


Two specimens of this species, a fairly complete larger and a fragmentary 
smaller one, were trawled off the southern coast of western Panama, at Station 
4622 on 21 October, 1904; 6° 31’ N., 81° 44’ W.; depth 1067 m. (581 f.); they 
grew on green sand and rock. 

Shape and size. The larger specimen (Plate 30, fig. 16) is a tube with quite 
regular circular transverse section. This tube is slightly spirally twisted, 67 mm. 
long, and throughout about 14 mm. in (outside) diameter. Its wall is 1-1.5 mm. 
thick and perforated by seven apertures. These are circular, arranged in a 
regular spiral, about 10 mm. wide, and surrounded by slightly protruding rims. 
The rims are in some places 5 mm. high and above strongly curved outward. 
They appear as rudiments of wide calyculate branches of the main-tube. The 
smaller specimen is a fragment of a similar but wider tube. It is 30 mm. long 
and the main-tube, of which it formed a part, must have been about 17 mm. in 
diameter. 

A thin, membranous aleyonarian colony, the outer surface of which extends 
in the level of the tips of the distal pinule-rays, covers large tracts of the outer 


dermal surface of the sponge. 


EURETE ERECTUM. 127 


The colour in spirit is light yellowish brown. When the tube-wall is ob- 
served by transmitted light, numerous small dark brown spots, about 1 mm. 
apart, make their appearance in it. These appear to be accumulations of deep- 
sea ooze in the bottoms of wide, vertical, sacular canals which lead from the 
outer surface into the deeper parts of the tube-wall. 

Canal-system. The flagellate chambers (Plate 30, figs. 7c, 10c, 17c) are 
spherical or short oval, and measure 60-80 u in diameter. 

Skeleton. A special dermal and a special gastral skeleton are developed 
besides the internal. The internal skeleton consists of a supporting network 
and loose spicules; the dermal and gastral skeletons are exclusively composed 
of loose spicules. 

The supporting skeleton-net (Plate 30, figs. 4-6, 10-12, 17; Plate 31, fig. 24) 
appears as a lamella corresponding in shape to the tube-wall, but thinner than 
this. It is composed of smooth beams, 30-105 yu thick. In its outer part 
(Plate 30, fig. 4) the meshes are irregular, mostly triangular, the larger ones 
generally a little under 200 » wide. Its inner part (Plate 30, figs. 6, 11) is more 
regular, composed chiefly of longitudinal and transverse beams enclosing square, 
rectangular meshes, mostly 370-400 uw long, and 170-400 » broad. Here and 
there small hexactines, 80-120 » in diameter, are attached vertically to the beams 
of the net by one of their rays. From both faces of the lamella formed by the 
skeleton-net large thorns protrude. These thorns arise from the superficial 
nodes of the net, point outwards, and are nearly vertical or, more rarely, oblique 
to the surface. They are straight or slightly curved, and quite regularly conic, 
pointed or, rarely, inflated at the end, and covered with broad and low, terminally 
rounded spines, which decrease in size distally. The thorns on the outer, dermal 
side (Plate 30, figs. 7e, 10e) are mostly 140-340 y» long, and 20-50 uw thick at the 
base. The thorns on the inner, gastral side (Plate 31, fig. 24g) are larger, 230- 
430 u long, usually 270-400 », and 35-60 wu thick at the base. 

The loose spicules of the choanosome are uncinates and discohexasters. The 
former are fairly abundant, the latter rather scarce. 

The dermal skeleton is composed of hexactine pinules and small scopules. 
The dermal pinules are very numerous and form a continuous layer on the outer 
surface. Their lateral rays (Plate 30, figs. 7a, 10a, 12a, 17a; Plate 31, fig. 22) 
extend paratangentially and together form a network, usually with more or less 
quadratic meshes (Plate 31, fig. 22). Their proximal and distal apical rays are 
situated radially (Plate 30, figs. 7d, 10d, 12d, 17d). Their centres are on an 
average 130 » apart. The dermal scopules are situated radially. Most of them 


128 EURETE ERECTUM. 


lie below the pinule-layer and their end-ray bunches do not, as a rule, protrude 
beyond the surface. They are not numerous. 

The gastral skeleton consists of hexactine pinules, regular and irregular, 
derivates of such with reduced distal apical (pimule) ray, and scopules. The 
pinules and pinule-derivates are very numerous and irregularly intermingled. 
They form, like the corresponding dermal spicules, a continuous superficial layer. 
Their lateral rays (Plate 30, figs. 12b, 15b, 17b; Plate 31, fig. 24b) extend para- 
tangentially, their apical proximal and distal rays (Plate 30, figs. 12h, 17h; 
Plate 31, fig. 24h) radially. The gastral scopules are situated radially. Most 
of them protrude a considerable distance beyond the zone of the lateral pinule- 
rays, and the end-ray bunches of many lie at a considerably higher level than the 
tips of the distal pinule-rays. The gastral scopules are much more numerous 
than the dermal. 

The dermal pinules (Plate 30, figs. 7a, d, 10a, d, 12a, d, 17a, d; Plate 31, 
figs. 2-5, 22) have a straight distal ray, 85-145 » long, usually 105-140 u, and 
at the base 8-18 » thick, usually 10-12 ». This ray is thickened above in a 
club-shaped manner and rounded distally. Its proximal part is smooth, its 
(thickened) middle- and end-parts covered with large spines. The maximal 
thickness of the distal ray (together with the spines) is 30-50 y, usually 40-48 u. 
The proximal spines are 5-8 » long, and nearly vertical to the ray, directed only 
slightly upwards. Distally the spines increase in size and become more and 
more inclined towards the tip of the ray; those arising from its summit are 
parallel to its axis. Half way up the spines attain the largest size. Here they 
are 8-13 »long. The proximal ray is usually straight. In its basal and middle- 
parts it is attenuated only slightly, at the end abruptly, towards the pointed end, 
like a Roman sword. It bears small spines near the end. The other parts of it 
are smooth. The proximal ray is 78-222 » long, usually 110-200 yu, and at the 
base 6-13.5 p» thick, usually 7-11 ». The lateral rays enclose angles of 90° with 
each other and are, in the same spicule, fairly equal. They are similar to the 
proximal ray in shape and spiculation, 108-152 long, usually 110-142 u, and 
at the base 6.5-15 » thick, usually 8-10 pu. 

The gastral pinules (Plate 30, figs. 1, 2, 9, 12h; Plate 31, fig. 24h) have a 
straight distal ray, 70-130 » long, and 11-17 u thick at the base. Its proximal 
part is smooth, its middle- and end-parts covered with short spines 10-17 u long. 
The number of these spines is variable and never great. Sometimes there are 
only a few. The spines point obliquely upward and are rather irregularly 
distributed. The fewer there are, the more marked does this irregularity of 


EURETE ERECTUM. 129 


their arrangement become. The proximal ray is straight, or slightly curved, 
and attenuated, proximally and medially very gradually, distally very abruptly 
towards the pointed end. It is 160-235, long, rarely as much as 290 yu, and 
8-13 » thick at the base. Its basal and middle-parts are smooth. Near the end 
it bears small spines. The lateral rays are in the same spicule usually fairly 
equal. They are straight or very slightly curved and generally not extended 
in a plane, but just perceptibly bent downward towards the proximal ray. The 
angles enclosed between their chords and the proximal ray are consequently 
somewhat smaller than 90°, those between them and the distal ray somewhat 
larger. Apart from this they are regularly arranged, their projections on a 
plane vertical to the axis of the apical rays enclosing angles of 90° with each other. 
The lateral rays are 187-240 uw long, 10-15 uw thick at the base, and slightly at- 
tenuated to the rounded end. Their middle- and end-parts bear small and 
pointed (Plate 30, figs. 1, 9) or large and blunt spines (Plate 30, fig. 2). The 
number of these spines is never great and on the whole in inverse proportion to 
their size. 

The gastral pinule-derwvates are connected with the gastral pinules above 
described by transitional forms, but these are remarkably rare. Most of them 
are fairly regular pentactines with an apical knob, the reduced distal ray; some 
are irregular. 

The regular pentactine-like gastral pinule-derivates (Plate 30, figs. 8, 13, 14). 
The proximal ray is usually straight, 250-320 » long, and 13-16 u thick at the 
base. In regard to shape and spinulation it resembles the proximal ray of the 
gastral pinules above described. The reduced distal ray is a rounded apical 
protuberance, usually 7-12 u high, 14-18 » broad, and beset with a few large 
spines. The lateral rays of the same spicule may be fairly equal or very unequal. 
In extreme cases the largest are 30% longer than the smallest. The lateral rays 
are slightly inclined toward the proximal ray and also a little curved in this 
direction (concave to the proximal ray); sometimes they are curved also in a 
transverse direction. The projections of their basal parts on a plane vertical to 
the axis of the proximal ray, however, always enclose angles of 90° with each 
other. The lateral rays are 200-328 » long, and 14-23 » thick at the base. 
Distally they taper gradually and they are, at the rounded end, 7-13 wu thick. 
They bear thick, usually quite blunt, vertically arising spines, 4-10 » long. In 
the middle-part of the ray these spines are large and sparsely scattered; towards 
the end they become smaller, particularly more slender, and more numerous, the 


end itself often being quite crowded with spines. I had the impression some- 


130 EURETE ERECTUM. 


times that the spines were arranged in elongate spiral rows; in other cases no such 
spiral arrangement could be made out. Often the spines are restricted to the 
distal and lateral sides of the rays; sometimes, however, they are also found on 
the proximal side. 

The irregular gastral pinule-derivates (Plate 30, fig. 3) are similar to the regu- 
lar pentactine-like ones and differ from them only in one or two of their lateral 
rays resembling the distal rays of pinules. 

The uncinates (Plate 31, figs. 13, 14) are slightly curved or nearly straight, 
pointed at both ends, 0.5-1.6 mm. long, and 4-9 » thick. Their spines are 7-274 
long, and 0.6-1 » thick at the base. They either diverge considerably (Plate 31, 
fig. 14) or are nearly parallel to the shaft (Plate 31, fig. 13). Their tips are 1.5— 
4 uw distant from the shaft. This elevation of their tips is by no means always in 
proportion to their length. 

The discohexasters (Plate 31, figs. 15, 18, 21) measure 50-70 u in total 
diameter. Their main-rays are regular, smooth, straight, 6-10 » long, and 1.6— 
3» thick. Hach main-ray bears from one to four end-rays. These are usually 
curved, concave to the continuation of the main-ray at the base, and nearly 
straight farther on. They are 18-26 uw long, 1.2-2 uw thick at the base, and 
attenuated distally to 0.8-1.5 uw. The end-rays bear along their length minute 
recurved spines, and at the end a terminal verticil of similar but larger spines, 
which together form a kind of terminal dise with deeply serrated margin 2.5-4 
in transverse diameter. 

It is possible that there are two kinds of discohexasters similar in size, but 
differing in respect to the end-rays, one with more slender and less spiny, the 
other with stouter and more spiny end-rays. Since, however, these asters are 
scarce I was unable to decide whether they all belong to the same series of forms, 
or whether two distinct varieties of them, as indicated above, should be distin- 
guished. 

The dermal scopules (Plate 31, figs. 16b, 17, 19) are 200-420 » long and 
consist of a centrum 4-10 » long and 5.5—-11.5 u broad, from which arises at one end 
(the inner) a simple shaft, and at the opposite (the outer) a bunch of end-rays. 
The centrum is not well-defined, often it passes quite gradually into the 
shaft. It and the proximal part of the shaft are densely covered with minute 
spines. The shaft is straight, cylindroconic, 170-330 u long, 3-6 « thick at the 
base, and pointed at the end. Sometimes, particularly in the dermal scopules 
with only two end-rays, this spinulation extends quite to the end of the shaft. 
Some of the dermal scopules have four end-rays, others only two, and a few have 
three. The dermal scopules with only two end-rays are fork-like. The end-rays 


EURETE ERECTUM. 1351 


are 20-76 » long and 1-3.5 uw thick at the base. They are usually attenuated 
towards the end, more rarely of uniform thickness throughout. The end itself 
is pointed, blunt, rounded or slightly thickened to a terminal “disc,” which, 
however, is always small, only rarely over 3 u in transverse diameter. The end- 
rays are usually curved in an S-shaped manner, rather strongly concave to the 
continuation of the axis of the shaft at the base, and very slightly, in the opposite 
direction, in their middle- and end-parts. These curvatures, particularly the 
basal, are subject to considerable variation. The breadth of the bunches formed 
by the end-rays is 11-25 ». The end-rays are uniformly covered by densely 
crowded minute spines. The terminal “‘disc”’ is, when present, composed of 
similar but slightly larger spines. 

The gastral scopules (Plate 30, fig. 151; Plate 31, figs. 1, 6-12, 16a, 20, 23, 241, 
25-28) are 0.6-1.18 mm. long, and consist of a centrum, from one (the inner) end 
of which arises a simple shaft, and from the opposite (outer) a bunch of end-rays. 

The centrum is sometimes (Plate 31, fig. 27) rather clearly defined, some- 
times it passes gradually into the shaft. It is 5-18 uw long, 6.5-17 » broad, and 
bears small backwardly directed spines, like those on the adjacent parts of the 
shaft and the end-rays. An axial cross, composed of six axial threads regularly 
arranged in the usual manner, can always be detected in the centrum. One of 
these axial threads is long and continued in the axial thread of the shaft. The 
one opposite this one is short, and terminates a considerable distance below the 
distal end of the centrum, without giving off branches for the end-rays. The 
other four axial threads are still shorter and equal among themselves. Some- 
times four very slight elevations arise from the sides of the centrum over them. 

The shaft is 0.52-1.05 mm. long, straight or slightly curved, and 3-11 yu 
thick at the base, where it arises from the centrum. In some gastral scopules 
it tapers toward the end, in its basal and middle-part, very gradually, in its distal 
part rapidly. In most, however, its middle-part is cylindrical or thickened 
and is 1-3 yu, sometimes 13.5 » thicker than the base in transverse diameter. 
_ The shaft terminates in a sharp point and is traversed throughout by an axial 
thread. At the base it is covered with a greater or smaller number of minute 
recurved spines, similar to those on the basal parts of the end-rays and on the 
centrum. Farther on it bears a few minute, isolated, vertical spines or is quite 
smooth. A little distance below the end larger vertical spines are observed. 

Of end-rays there are usually four; in some gastral scopules, however, three, 
five, or six have been observed. The end-rays are 75-133 uw long, and 2-8 u 
thick at the base. Generally the end-rays become thicker toward the distal end 
(Plate 31, fig. 1); sometimes they are of uniform thickness throughout (Plate 31, 


132 EURETE ERECTUM. 


figs. 10-12). Just below the distal end they measure 4-8 yu in transverse diameter. 
In these measurements the fact finds its expression that the basally thin end-rays 
are distally thickened, whilst the basally stout ones are of uniform thickness 
throughout. The end-rays are destitute of axial threads and usually rather 
densely covered with minute recurved spines, which increase in size from the 
base, where they are about 0.7 » long (Plate 31, fig. 27), to the end, where they are 
1.5-3 uw long (Plate 31, figs. 6-9, 26). The end of the end-ray is thickened to a 
tyle, 12-17 » in transverse diameter. This is particularly conspicuous in the 
end-rays which are thin at the base and thickened distally. The distal, apical 
face of the tyle is dome-shaped and usually quite smooth (Plate 31, figs. 6-9). 
Its sides are densely covered with spines, directed obliquely downwards. The 
spines nearest its apex are small, farther down they rapidly increase in size, and 
the lowest attain 2 1 or more in length. The spines of the tyle are, like those on 
the other parts of the end-ray, distinctly curved downwards. The end-rays are 
curved in an S-shaped manner, strongly, concave to the continuation of the axis 
of the shaft at the base, and slightly in the opposite direction in their distal 
and middle-parts. This second (outward) curvature is sometimes so light that 
the distal part of the end-ray appears straight. The degree of divergence of the 
-end-rays is variable. The bunch formed by them is 60-102 » broad. 

As examples the measurements of three gastral scopules of various dimen- 


sions are tabulated below. 


Total length Me 760 | 920 1180 
Breadth of the bunch of end-rays im 64 | 80 | 62 
length »| —s-642 | 789 1050 
Shaft in the middle bp S25 | 9 | 12 
thickness 
at the base mn 6.5 8 9 
length Be 13 18 | 10 
Centrum | 
thickness mn 12; 15 13 
length Me 105 113 120 
at the base m Bieta) | 5 5 
End-rays HW MOSSEESS | just below the 
2 : 4.5 8 5 
| terminal tyle Le 
transverse diameter of the 15 16 12 
terminal tyle nm 


EURETE ERECTUM. 133 


The statements given above show that the sponges here described are very 
similar to Hurele erectum F. E. Schulze.’ Wilson has established three subspecies 
of this species: —tubuliferum,? mucronatum,® and gracile.’ One of these, H. e. 
mucronatum, differs from the sponges above described, and also from Schulze’s 
type, and from the other two of Wilson’s subspecies, by possessing oxyhexasters 
instead of discohexasters. This difference is in my opinion of such systematic 
importance that I consider it distinct from the other sponges placed in Eurete 
erectum. 

After the exclusion of this subspecies, Schulze’s EHurete erectum, Wilson’s 
FE. e. tubuliferwm, Wilson’s FE. e. gracile, and the sponges described above, remain 
as forms of one species. A comparison of these shows, that, although similar 
in the main, they differ from each other:in several minor points. The tubular 
body of the sponge is in Schulze’s type dichotomously branched, in the three 
others simple. This tube is in Wilson’s FH. e. tubuliferum and in my specimens 
14-17 mm. wide, in Schulze’s type and in Wilson’s FE. e. gracile 8-12 mm. The 
distal rays of the dermal pinules are in Wilson’s LH. e. gracile 50 u thick, in Schulze’s 
type and in Wilson’s E. e. tubuliferum only 35-40 u. In the specimens examined 
by me, dermal pinules occur together with distal rays as stout as those of EH. e. 
gracile and as slender as those of the other two. In my specimens the lateral 
and proximal rays of the gastral pentactine-like pinule-derivates are considerably 
larger than the corresponding rays of the gastral pinules proper. In the other 
three no such difference occurs, their gastral pinules and pinule-derivates being 
about as large as the gastral pinules of my specimens. The greatest differences 
between these sponges are met with in their scopules. To facilitate a comparison 
between the scopules of these sponges, short descriptions of them are tabulated 
on p. 134. 

In respect to their other characters, particularly the shape and size of the 
uncinates and discohexasters, the four groups of forms appear to agree quite 
closely. Schulze’s type was collected at Albatross Station 2819, near the Gala- 
pagos Islands, depth 717 m.; Wilson’s HL. e. tubuliferum at the Albatross 
Stations 3358 and 3359, off the south coast of western Panama, depth 875 and 
1015 m.; Wilson’s H. e. gracile at Albatross Station 3380, Gulf of Panama, 
depth 1693 m.; and the specimens examined by me at Albatross Station 4622, 
off the south coast of western Panama, depth 1067 m. The differences between 

1 F. EH. Schulze. Amerikanische Hexactinelliden, 1899, p. 72, taf. 17, figs. 1-3. 
2 H. V. Wilson. Mem. M.C. Z., 1904, 30, p. 63, pl. 7, figs. 9, 12; pl. 8, figs. 1-3, 6. 


3H. V. Wilson. Loc. cit., p. 68, pl. 8, fig. 7. 
4H. V. Wilson. Loc. cit., p. 69, pl. 8, figs. 4, 5, 8, 9, pl. 9, figs. 1, 3, 5. 


134 


Dermal 
scopules 


Gastral 
scopules 


EURETE ERECTUM. 


SCOPULES OF THE DIFFERENT FORMS OF EURETE ERECTUM. 


A 
In Schulze’s type. 


Total length 200— 
600 u; 4-6 end-rays 
with pointed,  re- 
curved spines and 
terminal tyle with 
larger spines on lower 
side. 


Similar to the dermal 
but larger on the 
whole and with more 
divergent end-rays, 
these more frequently 
angularly bent. 


B 
In E. e. tubuliferum 
Wilson. 


Cc 
In E. e gracile 
Wilson. 


D 
In the specimens ex- 
amined by me. 


Two kinds. In one 
3-4 cylindrical end- 
rays, 40 by 2 yu, with 
minute sharp dentic- 
ulations and small 
smooth terminal tyle; 
centrum distinct; 
shaft 200-240 by 4 wu. 
In the other 4-10 
end-rays, 60-100 by 
2-3 4, with minute 
sharp denticulations 
and a terminal tyle 
5-8» in diameter, 
sometimes with re- 
curved spines; shaft 
a little longer than 
in the other form, 6 bu 
thick. 


Two kinds. In one 
4 end-rays, 50-70 by 
4-6», tapering dis- 
tally, with minute 
denticulations _ bas- 
ally, smooth distally, 
without tyle or a 
very small terminal 
tyle; shaft 300 by 
6-8 ». In the other 
4-6 cylindrical end- 
rays, 70-100 by 3-5 u, 
slightly roughened, 
with terminal tyle 
6-124 in diameter, 
and spines. Total 
length 600-700 yu. 


Total length  200- 
420. 2 or 4, rarely 
3 end-rays. 20-76 by 
1-3.5 w at the base, 
attenuated distally 
or cylindrical, the 
end pointed, rounded, 
or slightly thickened, 
densely covered with 
minute spines. Shaft 
3-6 uw thick. 


4-6 end-rays 70-80 pu 
long, either smooth, 
2 uw thick at base, and 
thickened to 4 » dis- 
tally, with terminal 
tyle 12 u in diameter 
with recurved spines 
on the lower side; or 
cylindrical, with mi- 
nute denticulations, 
with terminal tyle 
8m in diameter; or 
transitions between 
these; shaft 300 by 
5 wp. 


3-6 end-rays, 100— 
120 uw long, either cy- 
lindrical, 4-5 » thick, 
with terminal tyle, 
12 uw in diameter with 
recurved spines; or 
12,4 thick at base 
and tapering distally, 
without terminal tyle; 
or transitions be- 
tween these. Total 
length 0.6-1.5 mm.; 
shaft 8-16 » thick. 


Total length 0.6— 
1.184. 3-6, usually 
4 end-rays, 75-133 
by 2-8. at base, 
thickened distally or, 
rarely, cylindrical. 
Densely covered with 
minute recurved 
spines, with semi- 
spherical terminal 
tyle 12-17 yu in diam- 
eter, with large re- 
curved spines below. 
Shaft at base 4-11 » 
thick. 


the specimens examined by Schulze and Wilson and those described in this 
paper indicate that the former differ from the latter quite as much as the latter 


differ among themselves. 


This is particularly noticeable in that the former 


possess dermal scopules with only two end-rays, which are absent in the latter, 
and that the gastral pentactine-like pinule-derivatives of the former are much 


larger than the corresponding spinules of the latter, 


The general agreement of 


all these sponges, the localities from which they were obtained, and particularly 
the fact that the differences between them appear to be virtually confined to the 
superficial spicules, which are of course most liable to be influenced by the 
environment, make it very doubtful, however, whether they should be considered 


EURETE SPINOSUM. 135 


as distinct subspecies. To me it seems that a subdivision of the species into four 
local forms (A, B, C, and D) adapted to different surroundings, but congenitally 
hardly at all different, would more correctly express the relation between them. 


Their distinctive features are the following: — 


Eurete erectum A. (Murete erectum F. E. Scuuuze, 1899). 


Main-tube dichotomous. One kind of scopule with 4-6 end-rays with 
terminal tyle. Total length of scopules 400-600 x. 


Eurete erectum B. (Hurete erectum subsp. tubuliferum Wiison, 1904). 


Main-tube simple. Several kinds of scopules with 3-10 end-rays, all with 
terminal tyle. Total maximum length of scopules 400 ». Distal ray of dermal 


pinules under 40 u thick. 


Eurete erectum C. (Hurete erectum subsp. gracile WiLson, 1904). 


Main-tube simple. Several kinds of scopules with 3-6 end-rays. These 
in some with terminal tyle, in others distally attenuated and without tyle. 
Total length of longest gastral scopules 1.5 mm. Distal ray of dermal pinules 
50 va thick. 


Eurete erectum D. 


Main-tube simple. Several kinds of scopules. Some small dermal ones 
with only 2 end-rays without terminal tyle. The others with 3-6 end-rays. 
These either distally thickened and with terminal tyle or, more rarely, cylindrical 
or attenuated distally, without terminal tyle. Total length of largest gastral 
scopules 1.18 mm. 


Eurete spinosum, sp. nov. 


Plate 29, figs. 1-26. 


One fragmentary specimen of this species was trawled off northern Peru, 
west southwest of Aguja Point, at Station 4656 on 13 November, 1904; 6° 54.6’ 
S., 83° 34.3’ W.; depth 4062 m. (2222 f.); it grew on fine, green mud mixed with 
gray ooze; the bottom-temperature was 35.2°. 

The lateral rays of its superficial pentactines bear exceedingly large spines. 
To this the name refers. 

Shape and size. The single specimen is a lamellar fragment 25 mm. long, 
20 mm. broad, and 2 mm. thick. It is curved in one direction, the radius of 


136 EURETE SPINOSUM. 


curvature being about 20 mm., and may originally have formed part of a cylindri- 
cal tube about 40 mm. in diameter. 

The colour in spirit is dirty brown. 

The skeleton consists of a continuous net, which pervades the whole lamella, 
and of loose pentactines, hemioxyhexasters, and scopules. Long, slender 
rhabds have also been observed, but it is doubtful whether they belong to the 
sponge. The pentactines form a continuous layer on the intact parts of the 
surface. Their lateral rays extend paratangentially, their apical ray points 
inward. The hemioxyhexasters are exceedingly numerous and appear, so far 
as can be judged by the fragmentary specimen, to occur in dense masses in all 
parts of the choanosome. The large (perhaps foreign) rhabds lie more or less 
parallel to the surface. 

The skeleton-net (Plate 29, figs. 18, 19, 23-25) is by no means uniform in 
structure throughout the thickness of the lamella. In the dermal zone (Plate 29, 
figs. 18, 23) it is rather irregular, composed of beams 8-40 yu thick, usually 20-— 
35 y», and here its meshes are triangular or irregularly square, not rectangular, 
and 0.2-0.4 mm. wide. In the gastral zone (Plate 29, figs. 19, 25) on the other 
hand the network is very regular, composed of longitudinal and transverse 
beams. The former are 18-50 u thick, and on an average about 0.23 mm. apart; 
the latter are 8-86 » thick, and individually usually extend obliquely but col- 
lectively from zones which are 0.8—1 mm. apart, and extend transversely, vertical 
to the longitudinal beams, quite across the whole specimen. With the exception 
of a few, usually thin ones, which are quite smooth, the beams of the skeleton-net 
are covered with conic spines, 2.5—-8 u high, mostly 5-6 ». The spines of the thin 
and thick beams are nearly equal in height but differ, often very considerably, 
in breadth, those on the thicker beams being usually much stouter than those on 
the thinner beams. Freely terminating rays of the hexactines, by whose concres- 
cence the network seems chiefly to be formed, arise from the beams in many 
places. These spine-like protuberances are thinner than the beams of the net- 
work and are only 4 » thick. Here and there local thickenings are observed in 
the beams. Cylindroconic, terminally rounded spines attaining 25 u in length 
and 9 u» in thickness arise from these thickenings. These spines are parallel to 
the surface of the sponge and the thickenings from which they arise also chiefly 
extend in this direction. The thickenings with their spines have a cockscomb- 
like appearance (Plate 29, fig. 24). The comparison of a number of these struc- 
tures has convinced me that they are in truth hemioxyhexasters which have been 
soldered to the growing skeleton-net and the rays of which have been secondarily 


EURETE SPINOSUM. 137 


thickened by the apposition of silica-layer, together with the beams of the skele- 
ton-net which had, as it were, incorporated them. 

The rhabds, which may, as above mentioned, be foreign, are long, smooth 
centrotyles. They are about 15 yw thick near the centre. The tyle measures 
about 17 » in transverse diameter. 

The superficial pentactines (Plate 29, figs. 20-22) usually have fairly equal, 
straight, conic, terminally rounded lateral rays, which enclose angles of 90° with 
their neighbours (Plate 29, fig. 20). Rarely (Plate 29, fig. 21) the lateral rays 
are cylindroconic, curved, and irregularly arranged. The lateral rays are 150- 
270 uw long, 12-22 » thick at the base, and covered throughout with vertically 
arising spines. The spines on the proximal part of these rays are 8-12 y long; 
distally they become smaller. The apical (proximal) ray is smaller than the 
lateral rays and destitute of large spines. 

The hemioxyhexasters (Plate 29, figs. 9-17, 26b) measure 80-122 uy in total 
diameter, usually 90-110 u. Two of their rays, which extend in the same axis 
and lie opposite each other, are usually conic, short and simple, and only excep- 
tionally bear an end-ray. These two rays I designate the apical. The four 
other rays, which lie in a plane vertical to the axis of the other two, nearly always 
bear end-rays. These four rays I designate the lateral. The simple stems 
(main-rays) of these lateral rays always enclose angles of 90° with their neigh- 
bours and are, in the same spicule, usually fairly equal (Plate 29, fig. 10); only 
exceptionally they differ in length (Plate 29, fig. 12). In the ordinary regular 
hemioxyhexasters the lateral main-rays are 16-24 yu long; in the rare irregular 
forms the shortest is sometimes only 14 uw long, or still shorter. The lateral 
main-rays are cylindroconic, at the base 3.5-6.5 » thick, usually about 4 u, and 
uniformly attenuated towards the end, the transverse diameter of which is about 
three quarters of that of the base. The thickness of these main-rays is not in 
proportion to their length, the thickest not being longer, often indeed shorter 
than the thinner ones. The lateral main-rays bear minute spines which decrease 
in size proximally. In the thinner ones these spines can only be made out in the 
distal part, and also here only in the u. v. photographs (Plate 29, fig. 9). The 
thick ones are covered with clearly visible spines throughout (Plate 29, fig. 12). 

Each lateral main-ray bears three regularly disposed end-rays which lie in 
the plane of the four lateral main-rays. One of them extends in the same direc- 
tion as the main-ray to which it belongs, and appears as a continuation of the 
latter. The other two lie symmetrically on the two sides of this central one. 
These regularly disposed end-rays are, in the same spicule, usually equal (Plate 


138 EURETE SPINOSUM. 


29, fig. 10). In the few hemioxyhexasters, however, in which the main-rays are 
unequal, a corresponding irregularity is also observed in the end-rays (Plate 29, 
fig. 12). The regularly disposed end-rays are conic, sharp-pointed, and covered 
with minute, backwardly directed spines (Plate 29, fig. 14). In a few hemioxy- 
hexasters with exceptionally thick lateral main-rays the regularly disposed end- 
rays are reduced in length and terminally rounded. In the normal, regular 
hemioxyhexasters the end-rays are 25-44 » long, and 1.8-3.7 u thick at the base. 
In the irregular forms the shortest are sometimes only 13 » long. The central 
end-ray of each group of three is straight throughout; the two lateral ones are 
either also straight throughout (Plate 29, fig. 12) or, much more frequently, 
straight only in their middle- and end-parts, but curved at the base, concave to 
the central end-ray. The chords of the lateral end-rays enclose angles of 47—52° 
with the central end-ray. 

Besides these regularly disposed end-rays other end- or branch-rays some- 
times arise from the lateral main-rays. Occasionally one or two supernumerary 
end-rays are added to the regularly disposed three. These additional end-rays 
extend, like the latter, in the plane of the lateral main-rays. More frequently a 
branch-ray is seen arising some distance below the end of the lateral main-rays. 
These branch-rays extend more or less vertically to the plane of the lateral 
main-rays, and are parallel to the apical rays. In size and spinulation the 
supernumerary end--and branch-rays are similar to the regularly disposed end- 
rays; they are, however, more frequently irregularly curved. 

The axis of each lateral main-ray is occupied by an axial thread (Plate 29, 
figs. 14-17, 19). This terminates at the end of the main-ray and does not send 
branches into the end-rays. The latter are destitute of axial threads. 

The scopules (Plate 29, figs. 1-8, 26a) are 140-288 » long. They consist of a 
centrum, 3.8—7 » in diameter, usually 4—5 yu, from one side of which arises a shaft, 
and from the other arise four or, rarely, five or six end-rays. The shaft is conic, 
straight, or slightly curved, 115-261 y» long, and 1.9-2.4 » thick at the base. 
Near the distal end and often also near the base it bears minute spines. The end- 
rays diverge distally and together form a brush-like verticil 9-18 » broad at the 
end. The individual end-rays are very slightly curved, concave to the continua- 
tion of the shaft at the base, and nearly straight in their remaining part. They 
are 20-44 yu long, 0.9-1.5 u thick at the base, very slightly attenuated towards the 
end, and densely covered with minute, backwardly directed spines. At the end 
they bear a verticil of larger, recurved spines, which together form a kind of 


terminal dise with strongly serrated margin (Plate 29, figs. 7, 8). 


EURETID. 139 


Although the specimen at my disposal is but a small fragment there can be 
little doubt that it belongs to the group of sponges represented by Hurete bower- 
bankii F. E. Schulze and Hurete marshalli F. KE. Schulze'. Since, however, it 
differs from these species by its superficial pentactines, which are much more 
spiny than in either H. bowerbankw or E.. marshalli, and since its hemioxyhexasters 
have relatively longer end-rays than those of EH. bowerbankii® and relatively 
shorter end-rays than those of H. marshalli,*’ it cannot be assigned to either of 


them and must be considered as a new species. 


EURETID FROM STATION 4641. 


Plate 106, figs. 1-3. 


The supporting skeleton-nets of three euretids, one large fairly intact, and 
two small fragmentary ones, were trawled near Chatham Island, Galapagos, at 
Station 4641 on 7 November, 1904; 1° 34.4’ §., 89° 30.2’ W.; depth 115 m. 
(633 f.); they grew on a light gray Globigerina ooze; the bottom-temperature 
was 39.5°. 

The larger supporting skeleton-net (Plate 106, fig. 3) is 47 mm. long and 
consists of a tube, 7 mm. wide, with nearly circular transverse section, which 
rises vertically from the base of attachment. This tube is straight for the greater 
part of its length, but bent abruptly to one side a little below its free upper end. 
Kighteen tubular branches, with a maximum length of 7 mm., and about as wide 
as the main-tube, arise from this tube. These branch-tubes are arranged in a 
spiral line. Some of them are distinctly widened distally, funnel-shaped. The 
basal part of the main-tube, and the lowest branch-tubes have walls about 2 mm. 
thick. Distally the walls become thinner, the uppermost being about 1 mm. 
thick. In the smaller specimens the main-tube is shorter and a little wider. 

The beams composing these skeleton-nets are, in the middle-part of the 
length of the main-tube of the largest specimen, mostly 40-80 u thick. The 
meshes of the network are, in the inner, gastral parts of the tube-walls, 100-300 u 
wide and square with strongly rounded corners (Plate 106, fig. 1). In the outer, 
dermal parts of this portion of the skeleton-net the meshes are mostly 80-350 u 
wide and more frequently triangular with rounded corners (Plate 106, fig. 2). 
The axes of the rays of the spicules, through the concrescence of which these 


E. Schulze. Rept. Voy. Challenger, 1887, 21, p. 297. 


Es 
2 F. EH. Schulze. Loc. cit., pl. 79, fig. 13. 
3 F. EB. Schulze. Loc. cit., pl. 79, fig. 3. 


140 EURETID. 


skeleton-nets have been produced, are very distinct. In many places small 
hexactines, attached by the tip on one of their rays, arise vertically from the 
beams of the skeleton-net. 

I think there can be no doubt that these skeleton-nets belong to a euretid 
sponge, but since no loose spicules were found in them, I am unable to say to 
which genus they should be assigned. 


EURETID (?) FROM STATION 4651. 


Plate 32, figs. 4-6. 


There are in the collection a fairly complete skeleton-net and three lamellar 
fragments of this sponge, all trawled off the coast of northern Peru, at Station 
4651 on 11 November, 1904; 5° 41.7’S., 82° 59.7’ W.; depth 4064 m. (2222 f.); 
they grew on sticky, fine, gray sand; the bottom-temperature was 35.4°. 

The fairly complete skeleton-net (Plate 32, fig. 4) consists of a dense basal 
mass with digitate processes, some of which are 10 mm. long and 6 mm. thick, 
from which arises a broad and low calyculate, funnel-shaped lamella. The margi- 
nal parts of the funnel are, for the most part, broken off. What remains of it is 
65 mm. in maximum transverse diameter. Proximally, where it arises from the 
basal mass, the lamella forming the funnel is about 1.5 mm. thick. Towards 
the margin it thins out to 1 mm. 

The skeleton-net of the basal mass is very dense and irregular. Its beams 
are mostly 15-100 » thick, and its meshes 15-220 nw wide. The small meshes 
are round, the large ones triangular or irregularly square. The outer (dermal) 
zone of the skeleton-net of the funnel (Plate 32, fig. 6) is irregular, composed of 
beams 20-180 u thick, which enclose mostly triangular meshes up to 700 » wide. 
The inner, gastral zone (Plate 32, fig. 5) is more regular, but does not attain such 
a degree of regularity as is often observed in the corresponding zone of the skele- 
ton-nets of the Euretidae. It is chiefly composed of smooth longitudinal and 
transverse beams, but a fair number of usually spined, oblique beams also occur 
in it. The longitudinal beams are 50-100 u» thick, the transverse beams are 
sometimes 160 y thick. The oblique beams dre much thinner, usually only 
15-30 » thick. The meshes are square or, less frequently, triangular. The 
square ones are usually somewhat irregular, not rectangular, 600-900 u long, 
and 190-550 » broad. 

These skeleton-nets, which are similar to the ones from Station 4695, proba- 
bly belonged to a euretid., 


EURETID. 141 


EURETID (?) FROM STATION 4685. 


There are in the collection three small, flat, lamellar fragments about 1 mm. 
thick, the largest of which is 16 mm. long, trawled in the southeastern Pacific at 
Station 4685 on 10 December, 1904; 21° 36.2’ S., 94° 56’ W.; depth 4033 m. 
(2205 f.); they grew on dark brown clay; the bottom-temperature was 35.3°. 

These lamellae are skeleton-nets composed on one face of longitudinal and 
transverse beams, mostly 40-50 yu thick, which enclose square, rectangular 
meshes, generally 300-500 » long and 200-250 » broad; on the other face of 
considerably thinner beams, which enclose smaller, irregularly triangular meshes. 
The beams are mostly spined. The spinulation is more developed in the irregu- 
lar than in the regular part of the network. Numerous hexactines, 100-150 u 
or more in diameter, are attached by one ray to the beams of this network. 

These skeleton-nets probably belonged to a euretid. 


EURETID (?) FROM STATION 4695. 


There are in the collection four fragments of skeleton-nets of this sponge 
trawled northeast of Eastern Island, at Station 4695 on 23 December, 1904; 
25° 22.4’ S., 107° 45’ W.; depth 3694 m. (2020 f.); they grew on fine, light 
brown ooze. 

The largest and least incomplete is 32 mm. high, and appears as a tubular 
stalk, extending above to a thin-walled funnel 22 mm. in diameter. The stalk 
is about 10 mm. long, and in the middle, where it is somewhat attenuated, of 
oval, transverse section, 6.5 mm. broad and 4.5 mm. thick. 

The skeleton-net of the stalk is irregular, composed of longitudinal and oblique 
spined beams, the former about 90 » thick, the latter 15-50 ». In places the 
stout longitudinal beams of this part of the net bear numerous, vertically arising 
thorns, 6-10 » thick at the base, and of varying length. The meshes of this 
network are irregular, generally 50-200 » wide. The skeleton-net of the funnel 
is more regular, chiefly composed of longitudinal and transverse beams. Oblique 
beams, however, also occur in it, particularly in its outer zone. The beams of 
this network are smooth and 50-130 y» thick, the meshes in the inner zone 
square, rectangular, in the outer zone more frequently triangular. The rec- 
tangular meshes of the inner zone are mostly about 600 » long and 300-400 u 
broad. Verticil thorns, directed towards the funnel-cavity, arise from the nodes 
of the inner part of this network. 


142 CHONELASMA. 


These skeleton-nets may have belonged to a euretid sponge. They are 
similar to those described above from Station 4651. 


COSCINOPORIDAE ZitTre.. 


Lamellar, calyculate, or more complicated Hexasterophora consisting, if 
lamellar, of a simple plate; if calyculate or more complicated, of a rather thin 
wall enclosing a wide cavity. This plate or wall is traversed by straight, conical, 
blindly ending, sac-shaped afferent and efferent canals. With a firm supporting 
reticulate skeleton and uncinates and scopules. 

The collection contains one specimen of this family, which belongs to a 


species of Chonelasma. 
CHONELASMA F. E. Scuuuze. 


Funnel-shaped or lamellar Coscinoporidae. 


Chonelasma sp. 


Plate 32, figs. 7-9. 


There is in the collection a rather large skeleton-net of this sponge, collected 
in the Paumotu Islands at Station 3689 (A. A. 184) on 28 October, 1899; 18° 
06’ S., 142° 24’ W.; depth 1476 m. (807 f.); they grew on a bottom of fine 
coral-sand and manganese nodules; the bottom-temperature was 37.6°. 

This skeleton-net (Plate 32, fig. 7) is a curved plate, 92 mm. long, 51 mm. 
broad, and 9-11 mm. thick. The sponge to which it belonged may have been 
tubular or calyculate; probably it was of large size. The convex, probably 
outer (dermal) zone of the skeleton-net (Plate 32, fig. 8) is on the whole smooth. 
It is composed of skeleton-net lamellae vertical to the surface, extending in- 
discriminately in all directions and crossing each other irregularly. These 
lamellae form a network, the meshes of which are represented by short vertical 
canals round or polygonal in transverse section and’ 0.5-2 mm. wide. The 
concave, probably inner (gastral) zone of the skeleton-net (Plate 32, figs. 7, 9) 
has some outgrowths. Most of these are quite small. One is 8 mm. high. 
Apart from a curved, obliquely transverse band 3-5 mm. broad, where the net- 
work is so dense as to appear nearly solid to the naked eye, the zone of the 
skeleton-net bordering on this inner concave, probably gastral surface is com- 
posed of skeleton-net lamellae, vertical to the surface and extending longitudi- 


nally. These lamellae are about 0.7 mm. apart and connected by numerous 


HEXACTINELLA. 143 


transverse beams, which, to a certain extent, also form skeleton-net lamellae. 
These transverse lamellae are, however, not nearly so compact and so regularly 
arranged as the longitudinal ones. Together the longitudinal and the transverse 
skeleton-net lamellae form a network with meshes about 0.7 mm. broad and 
0.7-1.5 mm. long. 

The skeleton-net lamellae of the outer zone, that is the one bordering on the 
convex side (Plate 32, fig. 8), are composed of a network of beams mostly 450- 
650 » thick, which enclose roundish irregular meshes, usually 1.5-2.5 mm. wide. 
The beams of this network are covered with large, rounded protuberances. Its 
meshes are either quite empty or contain only slight traces of a fine secondary 
network, similar to that in the inner zone, described below. The skeleton-net 
lamellae of the inner zone, that is those bordering on the concave side (Plate 32, 
fig. 9), are composed of a primary network in the meshes of which a fine secondary 
network is spread out. The primary network consists of smooth, longitudinal, 
transverse, and oblique beams. The longitudinal beams are situated either 
singly or in bundles of two or three. Those of the same bundle are connected 
at frequent intervals by short transverse beams. Here and there they even 
coalesce to form irregular stems sometimes 350 uw thick. The individual longi- 
tudinal beams are usually about 130 » thick, the transverse and oblique 60-110 xu. 
The meshes are very irregular and are sometimes more than 1 mm. long. Thorns 
about 200 u long, 40 uw thick at the base, and provided with low, rounded protu- 
berances arise from some of the nodes of this network. The secondary network 
extends in the meshes of the primary and in the transverse band above referred 
to, and also occupies the interstices between the lamellae. It is composed of 
beams, 5-10 » thick, which enclose square, rectangular, or, more rarely, irregular 
meshes 50-130 » wide. 


TRETOCALYCIDAE F. EK. Scuuuze. 


Hexasterophora with ramified afferent and efferent canals. With a firm 
reticulate supporting skeleton and uncinates and generally also scopules. 
The collection contains one specimen and three fragments of this family, 


which belong to Hexactinella. 


HEXACTINELLA Carter. 


Tretocalycidae which are calyculate or composed of simple, ramified, or 


anastomosing tubes; with firm reticulate supporting skeleton, uncinates, scopules, 


144 HEXACTINELLA MONTICULARIS. 


and discohexasters or oxyhexasters or tylehexasters or two of these forms. With- 
out microonychhexactines and tylostyles with slender branch-rays, bearing end- 
discs, on the tyle. 

The collection contains one specimen and three fragments of this genus. 
The specimen is insufficiently preserved for specific distinction. The three 


fragments all belong to a new species. 


Hexactinella monticularis, sp. nov. 


Plate 28, figs. 1-28. 


Three fragments of the skeleton of this sponge were trawled south of Chat- 
ham Island, Galapagos, at Station 4642 on 7 November, 1904; 1° 30.5’ 8., 89° 
35’ W.; depth 549 m. (300 f.); they grew on broken Globigerina shells; the 
bottom-temperature was 48.6°. 

From the surface broad and truncate conic protuberances arise and to these 
the name refers. 

Shape and size. The three fragments measure 16, 17, and 20 mm. in maxi- 
mum diameter respectively. All appear to be parts of an irregular massive 
sponge with stout, truncate, conic protuberances. One of these protuberances, 
which is about 4 mm. high and 8 mm. broad at the base, is represented (Plate 
28, figs. 23, 28). 

The colour in spirit is brown. 

The skeleton consists of an internal and superficial network and loose hexac- 
tines, pentactines, uncinates, discohexasters, and scopules. 

The internal skeleton-net (Plate 28, figs. 23, 24, 26, 28) forms meandric 
lamellae, mostly nearly 0.5 mm. thick, which appear as the walls of tubes, with 
lumina more or less circular in transverse section and about 1 mm. wide. In the 
interior of the sponge these tubes are variously curved and irregular in their 
course. On approaching the surface they straighten out. On the whole they 
extend chiefly radially and longitudinally from the base to the upper and lateral 
parts of the surface, where they open out. The openings are fairly equidistant 
and uniformly distributed, as numerous on the summits and the sides of the 
monticular processes as on the other parts of the surface. Since most of the 
tubes reach the surface obliquely their superficial openings are more or less oval 
(Plate 28, figs. 23, 28). It is to be presumed that the tubes form two systems, 
one afferent, vestibular (‘‘Epirhysen”’); the other efferent, preoscular (‘‘ Apo- 


rhysen’’). 


~ 


HEXACTINELLA MONTICULARIS. 145 


The lamellae separating these tubes consist of a network of beams, mostly 
40-100 » thick, with meshes 100-200 » wide. Some parts of this network are 
quite irregular, others more regular, with more or less quadratic meshes. The 
beams generally bear small, broad, sharp-pointed, conic spines (Plate 28, fig. 22). 
Large, freely terminating, conic protuberances, which are hexactine rays and may 
be designated as thorns, arise from the beams in many places. In the inner part 
of the lamellae these thorns are not numerous; they are small, usually 90-200 u 
long (Plate 28, fig. 22). In their superficial part they are more numerous, more 
or less vertical to the surface of the lamella, and larger, 120-360 » long, and about 
60 u thick at the base. These superficial thorns are covered with spines similar 
to those on the beams, but on the whole larger and more densely crowded. 

The superficial skeleton-net (Plate 28, figs. 21, 27), remnants of which have 
been found in several places, extends paratangentially on the surface. It is 
rather loose and irregular, and consists of pentactines the lateral rays of which 
have been more or less soldered together. 

The loose hexactines (Plate 28, figs. 17, 18) found in the interior are probably 
destined to be soldered together to form the internal skeleton-net. The small, 
probably young forms have straight, or slightly curved, nearly smooth rays, 70— 
100 » long and 3 u thick at the base. In the larger, probably older ones (Plate 
28, figs. 17, 18) the rays are 100-260 » and more long, nearly cylindrical, and 
10-14 » thick. They are, in the same spicule, often unequal and always covered 
with spines. Most of these spines are small, whilst some, which lie irregularly 
scattered between the small ones, attain a very large size and measure 10-50 u 
in length. These large spines, of which each ray bears from five to ten or more, 
increase in size towards the distal end of the ray. The largest of them bear 
small secondary spines. Several, usually three, are situated terminally. These 
are always the largest. The large spines along the length of the rays arise nearly 
vertically, the terminal ones usually point obliquely outward. 

The pentactines (Plate 28, figs. 19, 21, 27) are situated superficially. Their 
lateral rays, which form the superficial net, are 120-200 » long, 4-10 » thick at the 
base, and slightly attenuated towards the end. They are covered throughout 
with vertically arising spines. Young, still free, superficial pentactines (Plate 28, 
fig. 19) have slender rays and very small spines. Older ones, already incor- 
porated in the superficial net (Plate 28, figs. 21, 27), have stouter rays and longer 
spines. 

Of wncinates two kinds, a smaller and a larger, can be distinguished. 

The smaller uncinates (Plate 28, fig. 10), which are very numerous and 


146 HEXACTINELLA MONTICULARIS. 


doubtlessly proper to the sponge, attain a length of 225-420 y». They are 
centrotyle and anisoactine, the tyle, which marks the morphological centre, 
being situated much nearer the end from which the spines diverge than the 
other. The proportion between the length of the two actines is 2:3 to 1:3. 
Close to the tyle these uncinates are usually 2-3 y» thick, the tyle itself being 
about 0.7 more in transverse diameter than the adjacent parts of the spicule. 
The spines are numerous, very oblique, and so thin that it is impossible to see 
them with ordinary light. The u. v. photographs, however, show them clearly 
enough (Plate 28, fig. 10). I should say that these spines are scarcely thicker 
than 0.1 p. 

The large uncinates are rare and may be foreign to the sponge. All those 
observed were broken. The largest fragments were 600-800 u long and about 5 u 
thick. Their spines are strongly inclined, nearly parallel to the shaft, and 
exceedingly thin. 

Two kinds of discohexasters, a larger and a smaller, can be distinguished. 
These are, it is true, connected by intermediate forms, but the latter are so rare 
that the distinction between them is quite clearly pronounced. 

The large discohexasters (Plate 28, figs. 12, 15, 16, 25) measure 52-62 wu in 
total diameter, usually about 60 », and have equal and regularly arranged, fairly 
smooth main-rays, 5-6 » long and about 1.8 » thick. Hach main-ray bears four 
rather strongly divergent end-rays. The end-rays are curved, concave to the 
continuation of the main-ray at the base, and straight or slightly curved in an 
irregular manner farther on. The end-rays are about 23 u long, 1.2-1.3 » thick 
at the base, and attenuated distally to 0.7-1 ». They bear along their whole 
length numerous minute, backwardly directed spines and at the end a verticil 
of larger, recurved spines, which together form a kind of convex terminal disc 
with strongly serrated margin, 1.5—2.2 » in transverse diameter (Plate 28, fig. 12). 

The small discohexasters (Plate 28, figs. 11, 20) measure 30-47 uw in total 
diameter, and have equal, regularly arranged, fairly smooth main-rays, 4.5-6.5 yu 
long and 1-1.6 wu thick. Each main-ray bears four, exceptionally five, end-rays. 
These are curved at the base, concave to the continuation of the main-ray, and 
nearly straight farther on. In these small discohexasters the basal curvature 
usually extends farther than in the large discohexasters. The end-rays are 
9-18 » long, 0.5-1 uw thick at the base, and attenuated distally to 0.4-0.7 u. 
They are covered along their whole length with numerous minute, backwardly 
directed spines, and usually bear at the end a verticil of four or more larger 


recurved spines, which, when seen in profile, together appear as a convex terminal 


HEXACTINELLA MONTICULARIS. 147 


disc, 1-2.5 » in transverse diameter (Plate 28, figs. 11, 20). Sometimes these 
spines are so small that the end-rays appear terminally rounded and destitute 
of terminal discs. 

The scopules (Plate 28, figs. 1-9, 13, 14) are 220-400 » long. They consist, 
of a stout centrum, from one side of which arises a simple shaft, and from the 
opposite a verticil of end-rays. Sometimes one or two end-rays are also attached 
to the sides of the centrum. 

The centrum is 6.2-9.6 » broad, 4-9 » long, and has four lateral protuber- 
ances arranged regularly crossways. When small these protuberances appear 
as slight rounded elevations (Plate 28, figs. 7-9), when large as short, cylindrical, 
terminally rounded ray-rudiments, equaling the shaft in thickness (Plate 28, 
figs. 5, 6). The centrum and its protuberances are uniformly and densely 
covered with minute spines. 

The shaft is 200-345 yw long, straight or, rarely, curved. It is nearly 
cylindrical for the greater part of its length, and rather abruptly attenuated to a 
sharp point. It is 3-4.5 » thick at the base, where it rises from the centrum; 
in the middle of its length it is slightly thinner, or, not so frequently, as thick or 
slightly thicker than basally. The middle-part of the shaft is nearly smooth. 
The proximal part, for a distance of about 30 » from the centrum, is, like the 
centrum, densely covered with minute spines. Ina belt which is 10-20 » broad 
and situated a short distance from the distal end, larger, particularly broader 
sparsely scattered spines occur. 

Of end-rays there are from five to nine, most frequently seven. As men- 
tioned above, these generally all rise from the apex of the centrum, that is the 
face opposite the shaft. These terminal end-rays are slightly curved, concave 
to the continuation of the axis of the shaft for a short distance, and, for the 
remainder of their length, straight or curved slightly in the opposite direction 
(outwards). They diverge above more or less and together form a stouter or 
more slender, brush-like or calyculate verticil, 9-22 » broad at the distal end. 
These end-rays are 11-65 » long, most frequently 11-30 ». Of 33 measured: — 


0 was under 10 wu long. 1 was 36-40 » long 
5 were 11-15 u a Om SS Ale 
9 “ 16-20 u nS 1 “ 46-50 4 “ 
CO 2S 2bin S Ones tol-a5) 7 
he 51 226-30) OM 856-60 Ge 
2 31-35 in e eer s61=65ij0 


0 was over 66 » long 


148 HEXACTINELLA MONTICULARIS. 


These end-rays are, at the base, 1-2 u thick, very rarely 2.6 u, and attenuated 
towards the distal end to 0.6-1 y, rarely 1.4 ». They are densely covered with 
minute, backwardly directed spines, and usually bear a terminal verticil of 
larger, recurved spines which together form a kind of convex terminal dise with 
deeply serrated margin, 1.2-2.5 » in transverse diameter. Sometimes the termi- 
nal spines are so small that no disc-shaped terminal thickening at all can be 
detected. 

The exceptionally occurring lateral end-rays are more divergent, more 
curved, and shorter than the terminal ones above described, which they resemble 
in all other respects. 

From a point in the middle of the centrum six axial threads extend in three 
straight lines vertical to each other. One of these is long and well-developed. 
This one is continued in the axis of the shaft, which can be traced quite to the 
end of the latter. The other five axial threads are short, rudimentary, and 
terminate within the centrum. The one in line with and opposite the axis of 
the shaft is directed towards the terminal end-ray verticil, and ends before 
reaching it without giving off branches. The end-rays are destitute of axial 
threads. The other four axial threads terminate in the four lateral protuber- 
ances of the centrum. 

The shape of the scopules and the arrangement of their axial threads indi- 
cate: — that the upper part of the centrum, from which the end-ray verticil 
arises, is, as far as it is traversed by the axial thread, an end-ray bearing main- 
ray; that the shaft is a well-developed, simple ray; that the four lateral pro- 
tuberances of the centrum are rudimentary simple rays, and that the end-rays 
are homologous to hexaster end-rays. Thus the whole scopule appears as a 
hemihexaster. Since its end-rays bear the terminal verticils of recurved spines 
characteristic of the discohexasters and hemidiscohexasters, these scopule- 
hemihexasters are discohemihexasters. 

In view of this I think it not unlikely that the seopules of the Hexactinellida 
generally are to be considered as apically highly differentiated hemihexasters, 
the scopules of the sponge here described being not quite so far advanced in this 
development and not so far removed from the ancestral form as the scopules 
destitute of lateral protuberances of the centrum of other hexactinellids. 

The comparability of the scopules with hexasters was first noticed by F. E. 
Schulze who says! concerning their end-rays, ‘I should be more inclined to 
compare them with the terminal rays of the rosettes.” But this author does not 


1 Ff. E. Schulze. Rept. Voy. Challenger, 1887, 21, p. 34. 


HEXACTINELLA. 149 


draw the same conclusion as I should concerning their origin from this com- 
parability and their general structure, and expresses ' his inclination to consider 
them ‘‘as diacts or monacts.” 

In spite of the fragmentary condition of the specimens they can, with a 
sufficient degree of certainty, be assigned to Hexactinella. Of all the known 
species only two, H. ventilabrum Carter and H. labyrinthica Wilson, have, like 
them, discohexastrose microscleres. From both of these species the sponge 
above described differs by the scopules, which have four end-rays in the former, 


and usually seven end-rays in the latter. 


Hexactinella sp. indet. 


Plate 32, figs. 13-15. 


A skeleton-net probably a species of Hexactinella was trawled off the south- 
ern coast of western Panama at Station 4631, on 3 November, 1904; 6° 26’ N.., 
81° 49’ W.; depth 1415 m. (774 f.); they grew on a bottom of green sand; the 
bottom-temperature was 38°. 

This skeleton-net (Plate 32, fig. 13) has the shape of a funnel 30 mm. high 
and 52 mm. in maximum breadth above. The funnel-wall is 4 mm. thick. 
Both the upper marginal part and the lower end, which latter may have been 
attached to a stalk, are broken off. The funnel-wall consists of skeleton-net 
lamellae extending radially and longitudinally from the base towards the margin. 
These lamellae are mostly a little over 1 mm. apart and joined to each other by 
groups of oblique beams, which, on the inner side of the funnel, form a honey- 
comb-like net (Plate 32, fig. 15) composed of lamellae vertical to the surface 
and enclosing short, likewise vertical canals, round or polygonal in transverse 
section, and mostly 1.5-2.5 mm. wide. 

The skeleton-net of these lamellae consists of smooth beams, on an average 
about 100 » thick, which in some places extend longitudinally and transversely 
with rather large square, rectangular meshes, but which are generally, particu- 
larly in the inner honeycomb zone, so variable in their direction, so crowded, 
and joined at so frequent intervals, that they form a quite irregular and very 
dense network. 

1 F. H. Schulze. Loc. cit., p. 35. 


150 HYALONEMA. 


Amphidiscophora F. E. Scuuuze. 


Hexactinellida the spicules of which are always isolated; with amphidises; 
without hexasters. 

Of the two families into which F. E. Schulze! divides this suborder, one, 
the Hyalonematidae, is represented in the collection. 


HYALONEMATIDAE (Gray) F. E. Scuuuze. 


Amphidiscophora in which the afferent apertures all lie in one area, the 
gastral face. 
The collection contains fifty-seven more or less complete specimens and six 


fragments of this family. All belong to the genus Hyalonema. 


HYALONEMA Gray. 


Hyalonematidae with gastral cone, without conuli-like protuberances on 
the dermal face; with one or, exceptionally, several stalks composed of long 
intertwined anchoring spicules; with acanthophores in the lower end-part of 
the body. 

Two specimens cannot be specifically determined. The other fifty-five, 
and the six fragments, belong to twenty-four species, twenty-two of which are 
new. 

Hitherto fifty well-defined species of Hyalonema have been described. To 
these twenty-two are added in this Report, so that there are now seventy-two 
valid species of Hyalonema. The number of species being so great I en- 
deavoured to arrange them in subgenera. In attempting to do this I first 
thought it might be possible to fall back on F. E. Schulze’s” original division of 
the genus into the subgenera Hyalonema (with a special gastral sieve-mem- 
brane) and Stylocalyx without such a structure. I found, however, as Schulze 
himself did on reconsideration,’ that this could hardly be done with advantage. 
Then I tried to attain my object with the help of the key given in Schulze’s 
Valdivia report,’ but this also helped me only to a small extent. I therefore 

1 F. EH. Schulze. Hexactinellida. Ergeb. Deutsch. tiefsee-exped., 1904, 4, p. 181. 

2 F.H. Schulze. Rept. Voy. Challenger, 1887, 21, p. 189. 

3 Ff. H. Schulze. Revision des systemes der Hyalonematiden. Sitzungsb. Akad. Berlin, 1893, no. 


30, p. 554. 
' FP. H. Schulze. Hexactinellida. Ergeb. Deutsch, tiefsee-exped., 1904, 4, p. 163. 


HYALONEMA. 151 


propose a new arrangement, based on the results of my examination of the 
twenty-four Pacific species. 

These results have led me to think that certain characters of the amphi- 
dises could be utilised for this purpose. It is true that the numerous very differ- 
ent forms of these spicules are to a great extent connected by transitions; there 
are, however, in spite of this, some amphidisc-forms not so connected. 

The anchor-teeth of the amphidiscs of most of the Pacific Hexactinellida 
have smooth margins. In five of them, however, there occurs a particular kind 
of amphidiscs with serrated anchor-teeth. For these I establish the subgenus 
Prionema. Of the fifty species previously known there are, I believe, only two, 
H. poculum ¥. BK. Schulze! and H. validum F. KE. Schulze,” in which amphidiscs 
with serrated teeth have been noticed and described. I think it highly probable, 
however, that such amphidises occur in others also, as for instance in H. lusita- 
nicum Bocage, and H. cupressiferum F. EK. Schulze, where they have not been 
mentioned either because they were overlooked — they are generally small and 
clearly visible only with high powers — or because the authors who studied these 
sponges did not consider them of importance. 

Most of the species of Hyalonema examined by me in which the anchor- 
teeth of all the amphidisc forms are smooth-margined, generally have hyper- 
bolic, semispherical, or bell-shaped anchors and measure from about a quarter 
to a third of the whole spicule in length. In some of them, however, the amphi- 
dise-anchors are of other relative dimensions and often also of another shape. 
In five of the Pacific species examined, one of which had been previously de- 
seribed, the anchors of a certain kind of amphidiscs are more or less semi- 
spherical and about half as long as the whole spicule, so that the two anchors 
of the same spicule nearly or quite meet in the middle. For these species I 
establish the subgenus Oonema. Of the species previously described there are, 
besides the one in the A. Agassiz Pacific collection above referred to, four (H. 
lenerum F. IX. Schulze, H. robustum F. E. Schulze, H. globiferum F. FE. Schulze, 
and H. pedunculatum Wilson) which can certainly, and one (H. ovuliferum 
F’. E. Schulze) which can perhaps, be assigned to this subgenus. 

In two of the Pacific species examined by me, one of which had been previ- 
ously described, the anchors of the largest amphidises are small and relatively 
very short and broad. For these species I establish the subgenus Phialonema. 


'F. EB. Schulze. Rept. Voy. Challenger, 1887, 21, p. 208. (This serration is not shown in the 
figure of a macramphidisce of this species. Loc. cit., plate 33, fig. 4). 
2 F. BE. Schulze. Hexactinellida. Ergeb. Deutsch. tiefsee-exped., 1904, 4, p. 82, taf. 34, fig. 8. 


152 HYALONEMA. 


Of the species hitherto described there is, besides the one reéxamined by 
me which is referred to above, one (H. pellucidum Ijima) at least, probably 
several, which can be referred to this subgenus. 

In two of the Pacific species examined one kind of amphidise has broad and 
rather low, umbrella-like amphidisc-anchors. For these I establish the sub- 
genus Skianema. 

In one of the Pacific species examined I found a peculiar kind of amphidise 
with from one to three branches on the convex side of some or most of its anchor- 
teeth, which give to the anchors the appearance of being doubled. For this 
species I establish the subgenus Thallonema. 

The remaining species of Hyalonema, in which none of the different kinds of 
peculiar amphidises referred to above occurs, can be divided, in accordance with 
the primary division used in F. E. Schulze’s key, into those in which the largest 
amphidises are stout and have a thick shaft; subgenus Hyalonema, and into 
those in which these amphidises are slender and have a thin shaft; subgenus 
Leptonema. 

Nine of the Pacific species examined by me, two of which were insufficient 
for exact description and for naming, and the great majority of the species of 
Hyalonema previously described, belong to the subgenus Hyalonema. 

One of the Pacific species examined by me, and at least five previously 
described species (H. poculum F. E. Schulze, H. solutum F. E. Schulze, H. 
urna F. E. Schulze, H. divergens F. E. Schulze, H. depressum F. EK. Schulze) 
belong to the subgenus Leptonema. 

Possibly H. lusitanicum Bocage and H. cupressiferum F. E. Schulze men- 
tioned above as probably belonging to the subgenus Prionema, and H. ovuliferum 
F. E. Schulze assigned to the subgenus Oonema may also belong to the subgenus 


Leptonema. 


HYALONEMA (Gray) LENDENFELD. 


Species, the amphidises of which have hyperbolical, semispherical, or bell- 
shaped terminal anchors from about one fourth to one third of the whole spicule 
in length; without amphidises of any other kind. The largest amphidises are 
stout and have a thick shaft. 

The collection contains twenty-three more or less complete specimens and 
three fragments of this subgenus. Two of the specimens, apparently represent- 
ing two distinct forms, could not be specifically determined; the twenty-one 
others and the three fragments belong to seven different species, all of which 


are new. 


HYALONEMA (HYALONEMA) OBTUSUM. 158 


Hyalonema (Hyalonema) obtusum, sp. nov. 


gracilis, var. nov. 


Plate 33, figs. 1-24; Plate 34, figs. 1-19; Plate 35, figs. 1-387; Plate 36, figs. 1-45; Plate 37, figs. 1-22; 
Plate 38, figs. 1-8; Plate 39, figs. 1-10. 


robusta, var. nov. 


Plate 39, figs. 11-41; Plate 40, figs. 1-22. 


Two specimens were trawled at two stations in the Tropical Pacific: — 
Hyalonema (H.) obtusum var. robusta at Station 3681 (A. A. 2) on 27 August, 1899; 
28° 23/ N., 126° 57’ W.; depth 4330 m. (2368 f.); it grew on light brown volcanic 
ooze; the bottom-temperature was 34.6°. H. (H.) o. var. gracilis at Station 3684 
(A. A. 17) on 10 September, 1899; 0.50’ N., 187° 54’ W.; depth 4504 m. (2463 f.); 
it grew on light yellow-gray Globigerina ooze. These sponges are distinguished 
from their nearest allies by the stout truncate or terminally rounded spines on 
their macramphidisc-shafts. To these the name refers. 

Although on the whole very similar in their spiculation, these two sponges 
differ in respect to their external appearance and certain characters of their 
skeletal element so that I consider them distinct varieties. The spicules of the 
specimen from Station 3681 (A. A. 2) are generally speaking stouter, those from 
Station 3684 more slender. I therefore name the former H. (#.) o. var. robusta, 
and the latter H. (H.) o. var. gracilis. 

Shape and size. The specimen of var. robusta is rather fragmentary, its super- 
ficial parts having to a great extent been lost. It consists (Plate 39, fig. 33) of a 
flattened body, 65 mm. long, 12 mm. thick, and 42 mm. broad above. Below 
it becomes narrower, and there protrudes from its rounded lower end a bundle 
of stalk-spicules. This bundle, where it arises from the sponge-body, is about 
2.6 mm. thick. The stalk-spicules forming it are broken off at a distance of 
35 mm. from the lower end of the sponge. 

The specimen of var. gracilis is well-preserved, but destitute of the stalk; the 
sponge-body having apparently been pulled off the stalk-spicules by the trawl. 
It has the shape of a short and broad spindle or top (Plate 33, fig. 15), is 47 mm. 
long (high), and has a maximum transverse diameter of 30 mm. The lower end, 
from which in life the large stalk-spicules arose, is now simply rounded off. 
The upper end consists of a gastral cone closely enveloped by the thin, frill-like 
margin of the wall surrounding the gastral cavity. The cone (Plate 33, fig. 16a) 
is 9 mm. high, nearly cylindrical, circular in transverse section, terminally 
rounded, 6 mm. thick at the base, and 4 mm. at the end. Its end is slightly 


154 HYALONEMA (HYALONEMA) OBTUSUM. 


bent to one side (Plate 34, fig. 3c). The frill surrounding it terminates with a 
fairly circular margin which lies in the level of the summit of the cone. The 
gastral cavity appears as a narrow fissure 5-12 mm. deep but only 0.4-1 mm. 
wide (Plate 33, fig. 16; Plate 34, fig. 3b) separating the gastral cone from the 
marginal part of the sponge-body. 

The surface of the cone, and the inner face of the upper tubular marginal 
part of the wall surrounding the gastral cavity are smooth and destitute of aper- 
tures of any kind, the efferent openings being restricted to the bottom of the 
fissure-like gastral cavity. The intact parts of the outer surface exhibit a fine 
reticulate structure with meshes about 0.7 mm. wide (Plate 33, fig. 15). 

The colour of the specimen of var. robusta in spirit is rather dark reddish 
brown, that of var. gracilis light greenish brown. 

Canal-system. The state of preservation of the specimen of var. robusta 
renders it impossible to say anything about the canal-system. In the specimen 
of var. gracilis subdermal cavities (Plate 34, figs. 1b, 3, 4, 19¢), mostly 0.3-0.7 
mm. high and 0.2-0.5 mm. broad, are spread out below the dermal membrane 
(the outer surface). These cavities are generally separated from each other by 
thin partitions. From most of them small afferent canals take their origin; 
some are directly continued in large afferent canal-stems, 0.3-0.7 mm. wide, 
which extend somewhat tortuously towards the interior, and ramify in the 
central part of the sponge. Occasionally junctions of two such afferent canal- 
stems have been observed. The choanosome, that is the region occupied by the 
flagellate chambers, does not extend, for the most part, beyond the level of the 
floors of the subdermal cavities. In a few places only broad, conical groups of 
flagellate chambers rise between adjacent subdermal cavities, up to a distance 
of only 0.1 mm. from the outer surface. 

The individual flagellate chambers appear to be broad oval or nearly 
spherical, and attain a maximum diameter of 60-100 yu (Plate 34, fig. 2). The 
efferent canals join to form canal-stems up to 1.2 mm. wide, which, as above 
mentioned, open out into the bottom of the narrow, fissure-like gastral cavity. 
The larger of these canals are considerably contracted at the mouth. 

The skeleton of var. gracilis. The outer surface is covered with dermal 
pinules, micramphidises, and small macramphidiscs. Most of the pinules are 
pentactine, some hexactine. Their paratangentially extending lateral rays lie 
in the dermal membrane; their radially extending and freely protruding distal 
rays form a fur about 150 » high (Plate 35, fig. 24). The micramphidiscs 


are, in some places at least, exceedingly numerous. They seem to be quite 


HYALONEMA (HYALONEMA) OBTUSUM. 155 


irregularly situated. The small macramphidiscs are also numerous and often 
arranged in groups (Plate 34, figs. 1, 19b; Plate 35, fig. 24b). Their shafts ex- 
tend radially or obliquely and their distal parts protrudefreely beyond the 
surface. 

The dermal membrane is supported by hypodermal pentactines very 
variable in size. In the upper parts of the sponge the large pentactines greatly 
predominate, at the base the small ones are more numerous. The centres of the 
large hypodermal pentactines are about 0.7 mm. apart. The apical rays of 
these spicules are directed radially inward (Plate 34, fig. 1c); their lateral rays, 
which are markedly inclined towards the apical ray, extend nearly paratangen- 
tially in the beams of the superficial network above referred to. Uncinate 
amphioxes, situated for the most part radially or obliquely, are met with in the 
subdermal region. The superficial part of the choanosome underlying the 
dermal surface is occupied, down to a depth of about 2.5 mm., by hexactine 
megascleres, rather regularly arranged in several paratangentially extending 
layers. These hexactines are situated so that two of their rays extend radially 
(Gnwards and outwards), two longitudinally (upwards and downwards), and two 
transversely (to the right and left). The distance between the centres of these 
spicules is less than the length of their rays, and the opposite rays of adjacent 
ones usually extend for some distance side by side and close together (Plate 34, 
fig. 19d). These hexactine megascleres, therefore, form a three-dimensional 
network with fairly regular, somewhat cubic meshes. These spicules vary 
greatly in size; the larger are situated proximally, the smaller distally. 

Numerous rhabd-megascleres and a few angularly bent diactines of similar 
dimensions occur in the choanosome. Most of the rhabds are blunt amphioxes 
or amphistrongyles, but styles and tylostyles also occur. Some of these rhabds 
are isolated; most of them, however, form loose strands. In the central (axial) 
part of the choanosome, the rhabds extend for the most part longitudinally; in 
the other parts of the choanosome they are mostly directed obliquely upwards 
and outwards, and generally lie in the walls of the canals. The styles and tylo- 
styles are situated so that their rounded (thickened) end points downward and 
inward, their pointed end upward and outward. The choanosome is rich in 
microscleres. Large numbers of micramphidises are imbedded in the canal-walls 
and throughout it are scattered some macramphidiscs, masses of microhexac- 
tines (Plate 34, fig. 2), and a few microhexactine-derivates, chiefly with only 
two opposite rays fully developed and the others more or less, sometimes entirely 


reduced. 


156 HYALONEMA (HYALONEMA) OBTUSUM. 


As above stated the sponge-body was in life obviously attached to a bundle 
of stalk-spicules, which have, however, been pulled out of it. Empty tubular 
spaces, sometimes 0.9 mm. wide (Plate 36, fig. 26a), the walls of which are 
formed by fine, highly stainable membranes, mark the places where the upper 
ends of the largest of these stalk-spicules were situated. These spaces lie in the 
axial part of the sponge-body. They are conical, attenuated above, and extend 
upwards to within a distance of 2 mm. from the summit of the gastral cone. 
In the lower part of the sponge-body these spaces are surrounded by a kind of 
cement, composed of dense masses of stout, one- to five-rayed, most frequently 
tetractine or diactine acanthophores (Plate 36, fig. 26). In this cement a 
few microhexactine-derivate pachymicrohexactines also occur. Quite at the 
bottom, a short distance below the dermal membrane, numerous slender-rayed 
spicules with long spines, which I consider as slender acanthophores, form a 
kind of felt. These spicules are mostly tetractines, but a good many triactines 
and a few diactines, pentactines, and hexactines also occur among them. Transi- 
tional forms, connecting these spicules on the one hand with the stout acantho- 
phores above referred to, and on the other with the dermal pinules, are also found 
in this part of the sponge. 

The thin marginal part of the circular wall which surrounds the gastral 
cavity, and forms the boundary between the dermal and the gastral parts of the 
surface, contains numerous, longitudinally situated, diactine pinules, the distal 
rays of which protrude freely beyond the surface. 

The gastral surface, that is the surface of the gastral cone, and the inner 
surface of the wall surrounding the fissure-like gastral cavity are covered with 
micramphidises and gastral pinules. The micramphidises are situated irregu- 
larly, and in some places are so numerous as to form dense masses. The gastral 
micramphidisc-layer does not terminate at the openings of the efferent canal- 
stems into the gastral cavity, but is continued in the walls of these canals and 
their branches quite down into the innermost parts of the choanosome. The 
gastral pinules are mostly pentactine, but hexactine forms also occur. Their 
centres are 30-100 » apart. Their lateral rays extend paratangentially in the 
gastral membrane; their distal apical rays arise vertically from the surface, and 
protrude freely beyond it, forming a dense fur about 125 » high (Plate 35, figs. 1, 
3,16). This pinule-fur is not, like the micramphidisc-layer, continued down the 
efferent canals, but terminates at their mouths. 

Small hypogastral pentactines, similar in position to the hypodermal pen- 


tactines above referred to, occur below the surface of the cone. 


HYALONEMA (HYALONEMA) OBTUSUM. 157 


Strands of longitudinal rhabds enter the wall of the gastral cavity and the 
gastral cone from below. The rhabds of the gastral wall for the most part 
follow the gastral membrane, and here form a dense and distinct subgastral 
layer. The rhabds of the cone lie partly superficially, partly axially. The 
superficial rhabds of the cone are more slender than the axial ones. The axial 
rhabds are congregated in strands which together form a loose column extending 
quite to the summit of the cone (Plate 34, fig. 3). A few hexactine megascleres 
apparently with long longitudinal and shorter transverse rays also take part in 
the formation of this column. The micramphidises not only form a dense layer 
on the outer surface of the gastral cone, but also extend for some distance into 
its interior. Farther down, at a level about 0.3 mm. below the surface, micro- 
hexactines and microhexactine-derivates, similar to those of the choanosome, 
make their appearance in the cone. These spicules extend down to a depth of 
about 0.8 mm., thus occupying a zone about 0.5 mm. thick. The microhexac- 
tines are very numerous in this zone, the microhexactine-derivates rare. The 
central part of the cone, in which the axial column of longitudinal rhabds ex- 
tends, is destitute of microscleres. 

The skeleton of var. robusta appears to be on the whole similar. The micro- 
hexactine-derivates are more various; the uncinates attain a larger size, and reach 
down to greater depths of the sponge. The upper ends of the large stalk-spicules 
are still present, and the felt formed by the slender acanthophores in the basal 
part of the sponge-body is denser and more extensive (Plate 39, figs. 22-24). 

The dermal pinules (Plate 35, figs. 23, 24a, 25, 29-37; Plate 40, figs. 4, 5) 
are mostly pentactine, but hexactine forms also occur, differing from the pentac- 
tine ones only by possessing a sixth, proximal, apical ray. The distal apical ray 
is generally straight, rarely angularly bent below the middle of its length (Plate 
35, fig. 25). In the dermal pinules of var. gracilis 137-165 yu, the ray is usually 
143-154 » long and 4-5 » thick at the base. Farther up it thickens and it gener- 
ally terminates with a stout, broad, and blunt cone 8-11 u thick. Rarely it is 
terminally rounded, dome-shaped, and has a maximum thickness of 12 uw (Plate 
35, fig. 31). The proximal part and the terminal cone (or dome) of the distal 
ray are smooth, its middle-part bears sharp, conic spines. The lowest of these 
spines are sparse, short, and strongly divergent. Farther up they become more 
numerous. ‘The size of the spines increases up to the middle of the length of the 
distal ray and then again decreases; the inclination of the spines towards the 
tip of the ray increases continuously quite to the end. The largest spines attain 
a length of 18-19 u, and are 2-4 uw thick at the base, usually about 3.5 uw. The 


158 HYALONEMA (HYALONEMA) OBTUSUM. 


maximum transverse diameter of the distal ray, together with the spines is 
18-32 yu. The distal ray of the dermal pinules of var. robusta is 140-172 yu 
long and 5-8 u thick at the base. The maximum transverse diameter of this ray, 
together with its spines, is 25-40 u. 

The proximal apical ray, of the hexactine forms of var. gracilis, (Plate 365, 
figs. 29, 30) is straight, 10-42 » long, and 3.7-4.5 yu thick at the base. It is 
cylindroconic, generally abruptly and sharply pointed, and covered with minute 
spines. 

The four lateral rays of the same spicule are usually fairly equal, the greatest 
difference of length observed not exceeding 4 yu. The lateral rays are straight; 
in the dermal spinules of var. gracilis they are 20-40 yu long, rarely up to 50 u, 
and 3-5 u thick at the base; in those of var. robusta they are sometimes (Plate 40, 
fig. 4) much shorter, 10-36 » long. They are cylindroconic, rounded or, more 
rarely, abruptly pointed, and covered with minute spines. 

The gastral pinules (Plate 35, figs. la, 2, 3a, 4-9, 16; Plate 40, fig. 3) are, like 
the dermal pinules, mostly pentactine; hexactine forms, however, also occur dif- 
fering from the pentactine only by possessing a sixth apical proximal ray. The 
distal ray is straight; in the gastral pinules of var. gracilis, it is 73-145 yu long, 
usually 77-135 y», and 4.5-5.5 u thick at the base, in the gastral pinules of var. 
robusta 94-140 » long and 5-7 u» thick at the base. It is thickened above, and 
attains its greatest thickness a little way beyond the middle of its length; then 
it again becomes thinner, and it ends in a usually sharp-pointed, rather slender, 
terminal cone, which does not exceed the proximal end of the ray in thickness. 
The proximal end-part and the distal cone of the ray are smooth; its middle-part 
bears spines. The spines on the proximal half of the distal ray are very sparse, 
point obliquely upward, and are strongly divergent, the angles enclosed between 
them and the ray being 40°-55°._ The spines on the distal half of the ray are 
smaller, more crowded, and less divergent, their size decreasing and their inclina- 
tion increasing towards the end of the ray. They attain a length of 15-25 yu 
and a basal thickness of 3-4.5 ». The maximum transverse diameter of the 
distal ray, together with the spines, is in both varieties 26—45 up. 

The proximal ray (of the hexactine forms) (Plate 35, fig. 4; Plate 40, fig. 3) 
is straight, 43-74 uv long, 4.5-5.5 uw thick at the base, conical, pointed, and spiny. 

The four lateral rays of the same spicule are fairly equal or rather unequal 
‘ in size; the maximum difference observed in their length was 15 ». The lateral 
rays are straight or, more rarely, slightly curved. Their length is subject to 


considerable variation. They are in the gastral pinules of var. gracilis 35-90 u 


HYALONEMA (HYALONEMA) OBTUSUM. 159 


long, usually 45-70 yu, at the base 4.5-5.5 w thick, rarely as much as 6 uy, conic, 
pointed or, more rarely, rounded at the end, and covered with spines, which are 
more conspicuous in the distal than in the proximal portion of the rays. In 
the gastral pinules of var. robusta the lateral rays are on an average somewhat 
longer, they measure here 47—75 wu in length. 

The marginal pinules (Plate 35, figs. 10-13, 26-28) have been found only in 
var. gracilis; in the specimen of var. robusta they appear to have been lost. In 
these pinules only the distal and proximal rays are properly developed, the lat- 
eral rays being altogether rudimentary, and together forming merely a tyle. 
These spicules consequently appear as centrotyle diactines. The outer, distal 
one of their two properly developed rays, which corresponds to the distal apical 
ray of the hexactine and pentactine pinules, is 304-860 u» long, rarely as much 
as 450 u, fairly straight, and 5-10 » thick at the base. Its proximal part, and its 
distal, conic, sharp-pointed end-part, are smooth. Its middle-part bears spines, 
which are rather strongly inclined towards the end of the ray, attain 6-10 wu in 
length, and are 1.5—2 » thick at the base. The maximum transverse diameter of 
this ray, together with the spines, is 17-20 u. 

The opposite, inner, proximal one of their two properly developed rays, which 
corresponds to the proximal apical ray of the hexactine pinules, is usually 490-— 
665 w long, fairly straight, at the base about as thick as the distal ray, and 
attenuated towards the end. Sometimes it is greatly reduced in length, only 50 u 
long, cylindrical, and thickened at the end to a terminal tyle 13 u in diameter. 

The central tyle, which is all there is left of the reduced lateral rays, is 3-7 
thicker than the adjacent parts of the spicules, and measures 8-15 u in transverse 
diameter. 

The hypodermal pentactines of the outer surface (Plate 33, figs. 5-14, 17, 24; 
Plate 34, fig. 1c; Plate 39, figs. 31, 32, 40, 41). The proximal apical ray is 
straight or, rarely, slightly curved, and usually properly developed, conic, and 
blunt-pointed, occasionally reduced, cylindrical, and terminally thickened 
(Plate 34, fig. 1c). Itisin the large hypodermal pentactines, which greatly pre- 
dominate in the upper parts of the specimen of var. gracilis, when properly de- 
veloped, 0.7—1.86 mm. long and, at the base, 30-75 yu thick, rarely 90 uv. When 
reduced it retains its thickness throughout, but is less than half as long. In the 
small hypodermal pentactines, which occur chiefly in the lower part of this 
sponge, the proximal ray measures 0.27—0.6 mm. by 10-23 yw. The lateral rays 
are inclined towards the proximal ray, and enclose with it angles of 73°—84°. 


The four lateral rays of the same spicule are usually very unequal in length; the 


160 HYALONEMA (HYALONEMA) OBTUSUM. 


longest is sometimes more than twice as long as the shortest. The greatest 
difference in length between the lateral rays of the same hypodermal pentactine 
observed was 310 ». The lateral rays are straight, conic, and blunt. They are, 
in the large hypodermal pentactines of var. gracilis, 240-730 u long and 32-60 u 
thick at the base. In the small ones they measure 135-440 u in length. The 
small hypodermal pentactines accordingly have, relative to the proximal ray, 
considerably longer lateral rays than the large ones. At the end the lateral rays 
are usually from one fifth to one third as thitk as at the base, and here measure 
5-22 w in transverse diameter. The hypodermal pentactines of var. robusta 
have a proximal ray 0.47-1.3 mm. long, and 40-80 y» thick at the base. The 
lateral rays are on the whole attenuated towards the distal end less than in the 
hypodermal pentactines of var. gracilis. They are, when not reduced, 250-750 
long and, at the base, about as thick as the proximal ray. 

The end-parts of the lateral rays of these spicules exhibit remarkable irregu- 
larities of external shape and internal structure. These irregularities are the 
more conspicuous the thicker (the more blunt) the rays. Such an irregular 
lateral ray-end of a hypodermal pentactine of var. gracilis is represented (Plate 
33, fig. 17). A rudiment of a branch-ray, arising a short distance from the tip 
of the main-ray, and a marked irregularity in the axial thread and the stratifi- 
cation of the siliceous body of the latter are noticeable in this spicule. I am 
inclined to ascribe these irregularities to the influence of the obstacles — other 
spicules — met by these rays during their longitudinal growth. The cells 
building the tips of these rays were forced to act in an abnormal manner; being 
prevented by other spicules from adding to the length of the axial thread and from 
depositing silica around it in a normal and regular manner, they produced the 
irregular structures observed. The obstacles (other spicules) which thus cause 
these irregularities are probably the stout proximal rays of adjacent hypodermal 
pentactines. 

The hypogastral pentactines of the gastral cone of var. gracilis have straight 
proximal apical rays, usually 240-400 » long, and about 12-20 yu thick at the 
base. The lateral rays are slightly inclined towards the proximal ray, straight, 
and generally 180-250 » long. In the specimen of var. robusta the parts contain- 
ing these spicules appear to have been lost. 

The hexactine megascleres of the distal part of the choanosome (Plate 34, 
figs. 5-18, 19d) are in both varieties very variable in size and have a maximum 
diameter of 350 »-2mm. The rays of the same spicule are often unequal. The 
greatest difference of length observed in them was 400 ». The rays are 130-950 


HYALONEMA (HYALONEMA) OBTUSUM. 161 


long, straight, conic, rather blunt-pointed, and 7-35 y» thick at the base. Their 
basal thickness is roughly speaking in proportion to their length. 

Very young stages of these hexactines appear as spheres, 20 » in diameter, 
perforated by six axial cylinder threads, 5 » thick, which are joined at right 
angles in the centre. Where these axial cylinder threads reach the surface of 
the sphere this is elevated in the shape of very thin-walled tubes rising about 
10 uw over the surface of the sphere (Plate 39, fig. 5). 

The hexactine megascleres of the loose axial spicular column, which were found 
only in var. gracilis, appear to be larger than the more superficially situated, but 
since I have not been able to find any intact ones, I can only say that their 
longitudinally extending rays appear to be much longer than their transverse 
rays, and that their rays are, at the base, about 40 u» thick. 

The stout acanthophores (Plate 36, figs. 1-25, 27-45; Plate 39, figs. 17-21, 
34-38) of the basal part of the sponge-body range from pentactine to monactine. 

The pentactines are rare. The few observed in var. gracilis were 225-530 u 
in diameter, and had rays, at the base, 12—29 uw thick. 

The tetractines (Plate 36, figs. 1-25, 27, 28; Plate 39, figs. 18-20) generally 
have more or less unequal rays. The inequality of the rays is often very con- 
siderable. The rays are exceedingly variable in size, curvature, shape, and 
spinulation, but constant and uniform in so far as their basal parts always form 
a fairly regular, rectangular cross, and as the rays themselves always appear to 
extend nearly in one plane. The tips of the rays are nearly always more or less 
spiny, only quite exceptionally (Plate 39, fig. 20) entirely smooth. In both 
varieties these spicules measure 180-840 » in total diameter. Among the irregu- 
lar ones all sizes between these limits are met. The regular ones never appear 
to exceed 500 u in diameter. The rays are generally wavy in outline, eylindro- 
conical or cylindrical, and distally thickened, or, more rarely, without a thick- 
ening at or near the end (Plate 36, fig. 1; Plate 39, fig. 20). The ray either 
terminates with the distal thickening and then appears simply rounded off at the 
end (Plate 36, figs. 22, 23,25; Plate 39, fig. 18), or it is continued beyond the distal 
thickening in the shape of a terminal cone (Plate 36, fig. 7). The rays of these 
spicules are in var. gracilis 35-380 » long and 12-85 » thick at the base; in var. 
robusta, where they are more irregular and stouter, 40-500 » long and, at the base, 
20-50 » thick. The distal thickening isin the tetractines of var. gracilis 10-40 u 
in diameter, in those of var. robusta 10-60 u. 

The thickness of the rays is not in proportion to their length, and varies in 
the rays of all lengths between similar limits. We consequently find among the 


162 HYALONEMA (HYALONEMA) OBTUSUM. 


short rays relatively much stouter ones than among the long rays. The rays 
most strongly reduced, that is those under 55 u in length, are by far the relatively 
stoutest. None of the rays as short as this was in gracilis under 25 p, several of 
them were here 35 yu thick. 

In both varieties the tips of the rays bear broad, conic, vertical spines with a 
maximum length of 4 » (Plate 36, figs. 27, 28). On the distal thickening these 
spines are usually densely crowded (Plate 36, figs. 6, 7, 9), more rarely sparsely 
scattered (Plate 36, fig. 4, fig. 18, the upper and lower ray, fig. 23, the upper and 
left ray). They are usually confined to the distal thickening, the proximal part 
of the ray and the conic tip (when present) protruding beyond it being quite 
smooth (Plate 36, figs. 1, 2, 4-25, 27, 28). Sometimes, however, the spines cover 
the whole ray (Plate 36, fig. 3) in greater or smaller numbers. 

It is to be noted that the axial thread is in many of these tetractines, particu- 
larly in the slender-rayed (perhaps young) ones, remarkably wide (Plate 36, 
fig. 27), sometimes as much as half as thick as the ray itself. 

The triactines (Plate 39, fig. 21) are obviously tetractine-derivates, in which 
one of the rays has quite disappeared. They are more frequent in var. robusta 
than in var. gracilis, measure in both 330-760 yu in total length, and have rays 
about 37-42 uw thick in the former, and about 20 » thick in the latter. 

The diactine and monactine rhabds are of two kinds: — shorter and stouter 
tetractine-derivates, and longer and more slender derivates of the ordinary 
rhabds of the choanosome. 

The tetractine-derivate rhabds of the cement-mantles (Plate 36, figs. 31, 
40-45; Plate 39, figs. 17, 34-388) are generally diactine and slightly and irregu- 
larly curved, rarely (Plate 39, fig. 17) strongly angularly bent. Such strongly 
bent, compass-like spicules have only been found in var. robusta. In var. 
gracilis some small spicules, also apparently belonging to this group, have been 
observed, in which the curvature is so great that one half of the spicule forms a 
complete circle (Plate 36, fig. 45). The tetractine-derivate rhabds in var. 
gracilis are 170-950 » long and 11-39 uw thick near the middle; in var. robusta 
450 »-1.42 mm. long and 6-50 u» thick near the middle. In the shorter spicules 
of this kind a central tyle is usually present, but the longer ones are often without 
it (Plate 39, figs. 34, 35, 37). When present the central tyle is, in var. gracilis, 
as much as 10 yn, and, in var. robusta, as much as 20 y, thicker than the adjacent 
parts of the spicule; in transverse diameter they measure in the former 13-39 u, 
and in the latter 25-70 ». It either passes gradually into the body of the spicule 
(Plate 36, figs. 40, 44; Plate 39, figs. 36, 38) or it is set off from it more or less 
distinctly (Plate 36, figs. 31, 41-43). Most of these spicules are fairly isoactine, 


HYALONEMA (HYALONEMA) OBTUSUM. 163 


some distinctly anisoactine (Plate 36, fig. 31; Plate 39, fig. 38). Their end-parts 
are thickened more or less to spherical tyles (Plate 36, figs. 31, the left one, 41, 
44: Plate 39, figs. 34, 35, 36, the right one, 37) or spindle-shaped tyles (Plate 36, 
figs. 40, 42, 43). These distal thickenings are in var. gracilis usually smaller, 
rarely (Plate 36, fig. 44, the right one) stouter, than the central tyle. In var. 
robusta they attain much larger dimensions and have a maximum diameter of 
90 u. The middle-part of the spicule is smooth. The two ends are generally 
covered with spines, for a shorter or longer distance (Plate 39, fig. 38, the left 
one); they are rarely smooth (Plate 36, fig. 41; Plate 39, fig. 37). 

Although doubtless derived from the tetractines (triactines) among which 
they occur, these rhabds are hardly at all connected with them by transitional 
forms, and therefore readily distinguishable from them. 

The acanthophore rhabds, which are to be considered as derivates of the 
ordinary rhabds of the choanosome, are in var. gracilis (Plate 36, figs. 29, 30, 32— 
39), where they appear to be more numerous than in the other variety, 0.6—-2 mm. 
long and 10-18 » thick in the middle. Most of them are rather uniformly curved 
throughout (Plate 36, figs. 29, 30, 32, 34-36), some are irregularly curved (Plate 
36, fig. 33), and a few strongly angularly bent near the middle (Plate 36, fig. 39). 
Some of them are fairly isoactine (Plate 36, figs. 30, 37-39), others distinctly 
anisoactine (Plate 36, figs. 29, 32-36). All these spicules are more or less thick- 
ened at both ends. In the isoactine forms both terminal thickenings are slight, 
spindle-shaped, and situated a short distance below the end (Plate 36, figs. 30, 
37, 38). In the anisoactine only one of the distal thickenings is of this nature, 
the other being stouter, 25-45 uw in diameter, spherical or oval, and situated 
terminally (Plate 36, figs. 29, 32-36). The spindle-shaped thickening usually 
passes gradually into the body of the spicule; sometimes it is distinctly set off 
from it (Plate 36, fig. 32). The shaft or body of the spicule is smooth. The ends 
are sometimes also smooth (Plate 36, fig. 33); usually, however, one (Plate 36, 
figs. 29, 36) or both (Plate 36, figs. 30, 32, 34, 35) of them bear spines. The axial 
thread is widened in the spindle-shaped distal thickenings (Plate 36, figs. 37, 38) 
and extends quite to theirend. In the ray-ends thickened to a stouter, spherical 
or oval terminal tyle, the axial thread does not extend quite to the end. The 
silica-layers of the isoactine forms therefore appear as tubes open at both ends, 
those of the anisoactine forms as tubes open at one end only. 

An abnormal stout acanthophore 220 » in diameter was found in var. gracilis. 
Its rays are straight, cylindrical, terminally rounded, and very unequal in length, 
but all about 10 u thick. 

The intermediate transitional acanthophores (Plate 39, figs. 1, 6, 11, 12) 


164 HYALONEMA (HYALONEMA) OBTUSUM. 


have rays which are in both varieties 4-6 » thick and covered with stout, blunt 
(Plate 39, fig. 1) or pointed (Plate 39, figs. 11, 12), usually curved, oblique spines 
2-4 y» long. 

The slender acanthophores (Plate 39, figs. 2-4, 13-16, 22-24) are mostly 
tetractine, triactine or diactine tetractine-derivates; a few hexactine and pentac- 
tine forms appear to be pinule-derivates. In both varieties the rays of these 
spicules are sometimes 200 » long and, at the base, in var. gracilis 1.3-1.5 p, in 
var. robusta 1.5-3.5 yw thick. They are usually curved more or less in an irregular 
manner and bear sparse, irregularly distributed spines. In both varieties these 
spines reach 6 » in length and are usually more or less curved. The spines 
arising from the end-parts of the rays are usually directed backwards and re- 
curved; the others are either also recurved, or vertical, or directed outwards. 
The basal parts of the rays appear always to retain their original, regular, relative 
position. In the tetractines these parts of the rays form regular rectangular 
crosses, in the triactines a T, and in the diactines usually a right angle. Whena 
ray entirely disappears, a large spine usually takes its place (Plate 39, fig. 16). 

The rhabds of the choanosome and gastral cone are for the most part blunt 
amphioxes or amphistrongyles, but a few styles and tylostyles are also found 
among them. 

The blunt amphioxes and amphistrongyles of the choanosome and cone (Plate 
33, figs. 1, 2, 18, 19, 21-23; Plate 39, fig. 39) are in both varieties nearly straight, 
slightly curved, or angularly bent, and usually provided with a more or less 
prominent central tyle. They are perfectly smooth. Their end-parts are 
generally somewhat wavy in outline. The amphioxes (amphistrongyles) of the 
upper part of the choanosome and the wall of the gastral cavity are 0.5-1.55 mm. 
long and 4-20 y» thick near the central tyle. The tyle is 2-8 uv thicker than the 
adjacent parts of the spicule, and measures 11-28 yu in transverse diameter. 
When there is an angular bend the apex of the angle invariably lies in the central 
tyle (Plate 33, fig. 2). In the basal and the axial parts of the sponge these 
amphioxes (amphistrongyles) attain a larger size. They are here 1-3.5 mm. and 
more long and 8-50 u thick. 

The styles and tylostyles of the choanosome and gastral cone (Plate 33, fig. 20) 
are in both varieties shorter than the isoactine rhabds above described, usually 
only 0.9-1.6 mm. long. The largest terminal tyles of the tylostyles observed 
were 30 wu in diameter. 

The uncinate amphioxes of the superficial parts of the sponge (Plate 33, figs. 3, 
4; Plate 39, figs. 25-30) are straight, or slightly curved, and sharp-pointed at 
both ends. They are in var. gracilis 580 uw long, and 4.5—9 u thick in the middle. 


HYALONEMA (HYALONEMA) OBTUSUM. 165 


In var. robusta they are larger, sometimes 1.1 mm. long and 20 » thick. A slight 
central thickening (tyle) with an axial cross in the interior can usually be made 
out, particularly in the smaller uncinates. This is generally about 0.5, rarely 
as much as | yu thicker than the adjacent parts of the spicule. The spicule is 
covered with slender spines, all strongly inclined in the same direction. Near 
the end from which these spines diverge, they are rather numerous, towards the 
other end they become very scarce. So far as I could make out these spines 
consist of a rather broad conic basal part and a fine, exceedingly slender, needle- 
like end-part. The basal conic part arises steeply from the shaft and bends 
round above, where it passes into the fine end-part, so that the latter comes to 
lie nearly parallel to the shaft. 

The large stalk-spicules (Plate 40, figs. 21, 22), in var. robusta 8 mm. below 
their upper ends, where they are all broken off, are 40-720 » thick. The empty 
spaces previously occupied by them in var. gracilis have a maximum width of 
900 u. The upper ends of these spicules of var. robusta are curved, the curvature 
increasing towards the (upper) end. The axial thread is for the most part 3-4 uv 
thick. It does not lie centrally, but describes a spiral line around the mathe- 
matical axis of the nearly cylindrical spicule. Itis by no means a simple cylindri- 
cal thread. Some parts of it (Plate 40, fig. 21) are uncinate-like, covered with 
strongly inclined spine-like processes directed upwards, others (Plate 40, fig. 22) 
are thickened, quite irregular, and attain 20 u in transverse diameter. 

In both varieties the regular microhexactines (Plate 35, figs. 14, 15, 17a, 18, 
19; Plate 40, figs. 6, 7, 20b) measure 42-80 » in diameter. The six rays of the 
same spicule are fairly equal, and regularly arranged. The chords of the rays 
are 20-43 long. The rays themselves are 1.5—2.2 » thick at the base, gradually 
and uniformly attenuated distally to a fine point, and covered with very minute, 
vertically arising spines. The basal parts of the rays are nearly straight, the 
distal parts strongly curved through an angle usually a little over 90°. The 
direction of curvature of the end-part of each individual ray is generally opposite 
to that of the end-part of the ray opposite it in the same axis. 

The microhexactine-derivates (Plate 35, figs. 20-22; Plate 40, figs. 8-15, 20c) 
represent two series of forms. One begins with microhexactines in which the 
two rays lying opposite in the same axis are longer than the other four, and ends 
with centrotyle diactines. The other begins with micropentactines with equal 
rays, and ends with style monactines. In var. robusta forms of both series are 
rather frequent; in var. gracilis hardly any but diactine forms, with the two fully 
developed rays opposite in the same axis, have been observed. 


First serves of microhexactine-derwates. One of the microhexactines, with 


166 HYALONEMA (HYALONEMA) OBTUSUM. 


two opposite longer, and four shorter rays, with which the first series commences, 
is represented in Plate 40, fig. 9. This spicule is 117 uw in length. Forms still 
farther removed from the regular microhexactine are produced by a further 
reduction of the four shorter rays of such a spicule. The reduction of the four 
shorter rays 1s either unequal or more or less equal. In the first case pentactines, 
tetractines, and triactines (Plate 40, fig. 11) with two opposite longer rays, and 
three, two or only one shorter, are produced; in the second case forms like those 
represented on Plate 35, figs. 20-22, and Plate 40, figs. 12, 13, and 20c. In the 
extreme forms of this series all that remains of the shorter rays is a slight tyle 
(Plate 35, fig. 22; Plate 40, fig. 12). It is to be noted that a distinct increase 
in size of the two opposite, developed rays is, in these spicules, associated with 
the reduction of the four other rays. Such diactine microhexactine-derivates 
are, particularly in var. gracilis, more numerous than any of the others. They 
are in both varieties 156-204 » long, but in var. robusta considerably stouter than 
in var. gracilis, the basal parts of their properly developed rays being in the former 
1.5-4 y, while in the latter only 1.5-2.5 » thick. The fully developed rays of 
these spicules are gradually attenuated to fine points, straight in their basal part 
and curved at the end. The reduced ones are straight throughout, cylindrical 
or cylindroconic, terminally rounded, and reach 6 y» in length. The terminal 
curvature of the fully developed rays is not so great as in the rays of the regular 
microhexactines, nor is its direction generally opposite. 

To the second series of microhexactine-derivates belong the spicules repre- 
sented on Plate 40, figs. 8, 10,14, and 15. The first (fig. 8) of these is a pentactine 
with equal rays, 100 » in diameter. The second (fig. 10) is a compass-shaped 
diactine. It consists of two fully developed rays, 47 » long, the basal parts of 
which enclose a right angle; and the insignificant rudiments of two other rays 
opposite to the two fully developed ones. The third and fourth (figs. 14, 15) 
are monactines. Such monactines are more frequent than the other forms of 
this series. They are 73-86 » long. Their single fully developed ray is 2.54 u 
thick at the base and tapers gradually to a fine point. It is straight in its basal 
part but strongly curved, through an angle of about 120°, in its distal part. 

These spicules are, like the regular microhexactines, covered with minute 
spines. In the larger ones the spines are more conspicuous than in the smaller 
ones, the size of the spines being, generally speaking, proportional to the thick- 
ness of the ray from which they arise. 

The pachymicrohexactines (Plate 39, figs. 7-10) are rather rare, and have 
only been found in the basal part of var. gracilis. I consider them as hypertrophic 


HYALONEMA (HYALONEMA) OBTUSUM. 167 


microhexactines. They consist of six fairly equal rays joined at right angles, 
and measure 52-80 u in total diameter. Their rays are cylindrical, of nearly 
uniform stoutness throughout, and rounded at the end. They are 26-42 u long, 
5-15 w thick, and generally quite smooth. Their basal part is straight, their 
end-part either straight (Plate 39, fig. 7) or more or less curved (Plate 39, figs. 
8-10). Axial threads, terminating however a considerable distance below their 
ends, can be easily made out in the rays of these spicules. 

Among the amphidiscs of var. gracilis two main groups can be distinguished 
morphologically : — large forms, the largest of which have broad and rather short 
terminal anchors and a stout, spiny shaft; and small forms the largest of which 
have long and very slender terminal anchors and a slender shaft with very small 
spines. In each of these main groups, which I name macramphidises and micr- 
amphidises respectively, two subgroups can be distinguished: —in the macram- 
phidises larger forms with relatively shorter, and smaller forms with relatively 
longer, terminal anchors; in the micramphidises larger forms with long and 
slender anchors, and smaller forms with shorter and broader anchors. 

The biological length frequeney-curve of these amphidises exhibits (Fig. 4) 
a gap between the lengths 54.76 » and 66.26 4. The amphidises, to which the 
part of the curve to the right of the gap pertains, are the amphidiscs referred to 
above as macramphidises; those to the left of the gap as micramphidises. Each 
of these two parts of the curve exhibits a conspicuous depression dividing it into 
two distinct elevations. These elevations correspond to the smaller and larger 
kinds of the macramphidises and the micramphidises, which are, as above stated, 
also distinguished from each other morphologically by the sHape of their terminal 
anchors. 

Thus both the morphological and the biometrical qualities of these amphi- 
dises show that four kinds of these spicules are to be distinguished in var. gracilis: 
— large macramphidises, small macramphidises, large micramphidises, and small 
micramphidiscs. 

The amphidises of var. robusta also fall into these four groups. 

The large macramphidiscs of var. gracilis (Plate 37, figs. 20-22) are some- 
what infrequent. They are 250-356 » long, most frequently about ' 264 yu, and 
have a straight shaft 8-14 » thick. This is thickened slightly and gradually 
to 14-22 » at the ends, and abruptly in its middle-part to a central tyle 15-18 u 
in diameter. The tyle never appears to lie quite in the middle; the difference 


‘This phrase ‘‘ most frequently about ” refers, throughout the descriptions, to the summit of that 
part of the length frequency-curve of the graph which pertains to the amphidises in question. 


168 HYALONEMA (HYALONEMA) OBTUSUM. 


Micramphidiscs Macramphidiscs 


Small Large Small Large 


me aie mle ee he a me em en ee ee ee en ee eo ee wee ces ayes = Pane 


ae ne ee ee ae ie on a ee en ele oe ee ee 


>= ----~~/----, -—"--\- ------~------- ~~ ~~ ~~ ~~ ef 


Number of Amphidiscs 


ee eee ee eee ee es 


! 
1 


pitti Fai paiinty 


88.20— 97.02 -+--}------- 


1, 


37.40— 41.14-44--1--1 


7 


207.97 — 228.76 
228.76 — 251.64 


19.19 |- crane 
251.64 — 276.81 


HONOMe cone intestate 
72.89 


156.25 — 171.87 4--t--r-----f--=----4--+- 
171.87 — 189.06 4---: 


41.14— 45.26 
80.18— 88.20-}-->> 

97.02 — 106.72 +--! 
106.72 — 117.39 + -- 
117.39 — 129.13 +-4--! 
129.13 — 142.04 +--+-------1---- 
142,04 — 156.25 =| --t--!-----t---- 


45.26— 49.78 
54.76— 60.24 


49.78 — 54.76 
60.24— 66.26 
66.26 — 
72.89— 80.18 
276.81 — 304.49 
304.49 — 334.93 
334.93 — 368.43 
368.43 — 405.27 


29.95— 28.10—--- 
28.10— 30.91 4.--|---> 
30.91— 34.00 

34.00— 37.40 
189.06 — 207. 


BAe 28 Oe cea ee 
23.23 — 25.55-|--------»-- obs 


V.42— 15.864----1- 42 
I586—= 7 45e 


10.83— 11.92 
(02 e1e | N 
To stee4p 2 eee 
17.45 — 


Length of Amphidiscs (,). 
Tig. 4.— Length frequency-curve. 


between its distances from the two ends is 7-37 yu, 3%-15% of the length of the 
whole spicule. In the shaft an axial thread is distinctly visible (Plate 37, fig. 21). 
This thread appears to be quite simple and it certainly does not give off branches 
in the central tyle. From the central tyle, and also from other parts of the shaft, 
spines arise. The spines of the central tyle are generally five to eight in number 
and arranged in a more or less regular verticil. They are conical, blunt-pointed, 
or truncate, 9-14 yu long, exceptionally 18 », and 5-7 u thick at the base; the 
truncate ones bear minute secondary spinelets on their ends. The other spines 
are irregularly scattered over the middle-part of the shaft. The thickened 
conical end-parts of the shaft are free from spines. These spines are not very 
numerous; often there are a good many more spines on one side of the central 
tyle than on the other. Most of these spines are vertical to the axis of the shaft; 
a few of them are, however, oblique, inclined toward the centre of the spicule. 
These scattered spines are similar in shape and about as stout, but, as a rule, 
are shorter than the spines of the central tyle. The spines are destitute of 
axial threads, 


HYALONEMA (HYALONEMA) OBTUSUM. 169 


The two anchors of the same spicule are equal or slightly unequal in size. 
The greatest differences between them in length and breadth observed were 12 
and 8 u» respectively. The anchors are 70-100 y, that is generally a little less 
than a third of the whole spicule in length, and 70-95 » broad. The proportion 
of length to breadth in these anchors is 100 to 60-108, on an average 100 : 93.2. 

Each anchor consists of eight recurved teeth. The teeth of the same anchor 
are fairly equal and regularly arranged. Their axes extend in planes passing 
through the axis of the shaft and enclosing angles of 45° with their neighbours. 
The individual teeth arise nearly vertically from the shaft, and then curve con- 
cave towards it. This curvature in the basal part of the tooth is for some 
distance fairly uniform, but it decreases distally. Towards its end the tooth is 
hardly at all concave to the shaft, or straight, or even slightly convex to the 
shaft. The whole curvature amounts to about 90°, the end-parts of the teeth 
being nearly parallel. Seen en face (from above) the individual teeth are elon- 
gate oval in appearance, 10-16 uw broad in the middle, and rounded or pointed at 
the end. Seen in profile they appear stoutest at the base and are at first gradu- 
ally, and near the end abruptly, attenuated to a sharp point. Each anchor- 
tooth somewhat resembles a T-iron. It consists of an outer band-shaped part, 
and an inner keel. The outer band-shaped part is broadest in the middle, at- 
tenuated towards both ends, and bent, concave to the shaft, both transversely 
and longitudinally. Its transverse convexity increases, and its longitudinal 
convexity decreases, towards the distal end. The inner keel is highest at the 
base of the tooth; towards its distal end it becomes lower, at first gradually, 
then more abruptly. 

The large macramphidises of var. robusta (Plate 40, figs. 1, 2, 19) are similar 
to those of var. gracilis, but larger and provided with somewhat thicker shafts 
and broader anchors. They are 235-335 » long, most frequently about 297 uy. 
The shaft is 10-17 » thick. Its central tyle measures 15-18 » in diameter. The 
anchors are 70-100 wu in length, that is about a third of the whole spicule, and 
90-110 » broad. The proportion of the length to the breadth of these anchors 
is 100 to 95-150, on an average 100 : 117.6. 

The small macramphidiscs of var. gracilis (Plate 34, fig. 19b; Plate 35, 
fig. 24b; Plate 37, figs. 12-19; Plate 38, figs. 4-8) are 86-212 u long, most fre- 
quently about 164 uw. The shaft is 2.5-9 uw thick, and thickened in or near the 
middle to a central tyle 4-12 « in diameter. The shaft bears spines similar to 
those on the shafts of the large macramphidises. These spines are 5-12 u long 
and 2-3.5 » thick. The terminal anchors are 32-72 u in length, usually a little 


170 HYALONEMA (HYALONEMA) OBTUSUM. 


more than a third of the whole spicule, and 16-69 » broad. The proportion of 
the length to the breadth of the anchors is 100 to 56-96, on an average 100 : 81.2. 
The individual anchor-teeth are strongly curved in their basal part. Distally 
their curvature decreases and their end-parts, a third to a half of their total 
length, are nearly straight and parallel. 

The small macramphidises of var. robusta are similar but stouter and pro- 
vided with broader terminal anchors. Their measurements are:— length, 146- 
205 wu, most frequently about 176 »; thickness of shaft 4-11 4; anchor-length 
45-80 u, usually a little over a third of the length of the whole spicule; proportion 
of anchor-length to anchor-breadth, 100 to 72-112, on an average 100 : 81.2. 

The large micramphidiscs of var. gracilis (Plate 37, figs. 6-11) are 28.5-68 pu 
long, most frequently about 32.4 ». The shaft is 0.8-1.5 uw thick. It always 
bears a few spines in or near the middle, and usually some also elsewhere. The 
central spines do not form verticils. The spines are 0.4-1 u long, about as thick, 
and usually cylindrical and terminally rounded, or truncate. 

The two anchors of the same spicule are very similar, the greatest difference 
observed in their lengths and breadths being 2 » and 1 yu respectively. The 
anchors are 11-24 yu in length, that is a little over a third of the whole spicule, 
and 6-10 u broad. The proportion of the length to the breadth of the anchors 
is LOO to 44-64, on an average 100 : 52.6. The individual anchor-teeth of the 
smaller forms of these spicules are strongly curved in their basal parts and fairly 
straight in their distal parts, their total curvature being such that their tips 
are nearly parallel (Plate 37, figs. 6, 7). In the larger forms the teeth are 
relatively longer, and the curvature of their basal part stronger, whilst their 
end-parts are slightly curved in the opposite direction, convex to the shaft. 
The tips of the teeth of these amphidises are parallel or convergent, and the 
anchors themselves at the end sometimes as much as 3 » narrower than in their 
broadest, more proximal part. This gives to these spicules quite a peculiar 
appearance (Plate 37, figs. 8-11). 

In var. robusta no amphidises have been observed similar to the larger forms 
of the large micramphidises with distally attenuated anchors; all the large 
micramphidises of var. robusta are similar in shape to the smaller forms of the 
large micramphidises of var. gracilis. The dimensions of the large micramphi- 
dises of var. robusta are:—length 27-64 yu, most frequently about 45.5 4; 
anchor-length 11-25 y», about two fifths of the length of the whole spicule; 
anchor-breadth 7-26 »; proportion of anchor-length to anchor-breadth 100 to 
64-104, on an average 100: 84. 


HYALONEMA (HYALONEMA) OBTUSUM. 171 


The small micramphidises of var. gracilis (Plate 35, fig. 17b; Plate 37, 
figs. 1-5; Plate 38, figs. 1-3) are 13-26 y» long, most frequently about 16.7 x. 
The shaft is straight and 0.5-1.2 » thick. It bears in its central part a few short 
and broad, terminally rounded protuberances. The terminal anchors are 5-9 yu 
in length, that is a third to two fifths of the whole spicule, and 4.2-8 u broad. 
The proportion of the length to the breadth of the anchors is 100 to 55-120, on 
an average 100: 90. 

The small micramphidises of var. robusta (Plate 40, figs. 16-18, 20a) are 
similar but somewhat smaller. Their measurements are: — length 12-23 u, 
most frequently about 16.2 u; anchor-length 3.8-7 u, that is about a third of the 
length of the whole spicule; anchor-breadth 4-5 u; proportion of anchor-length 
to anchor-breadth 100 to 72-125, on an average 100 : 90. 

A few young forms of micramphidises were observed in var. robusta. These 
spicules (Plate 40, fig. 18) have a centrotyle and spiny shaft thickened at both 
ends. Their anchors appear as terminal verticils of small vertically arising and 
slightly recurved teeth. 

The two specimens described are in respect to their spiculation similar 
enough to be considered the same species. Their skeletal elements, however, 
differ in detail, the spicules generally, and particularly both the stout and the 
slender tetractine and tetractine-derivate acanthophores, having much stouter 
rays. The uncinates are larger and the anchors of both kinds of macramphi- 
dises and of the large micramphidises are relatively considerably broader in 
the specimen from Station 3681 (A. A. 2) than in the specimen from Station 
3684 (A. A. 17). For this reason and because the two specimens differ con- 
siderably in outer appearance and come from localities a good distance (over 
3000 km.) apart, I think it advisable to consider them as two distinct varieties. 

The only species of Hyalonema which appears to be at all closely allied to 
these sponges is the one described in this report as Hyalonema (H.) agassizi.. From 
this they differ chiefly by their macramphidiscs and large micramphidises having 
more strongly curved and less divergent teeth, by their microhexactines being 
smaller and having more strongly curved rays, by the spicules of their acantho- 
phores being larger, and by the rays of the slender acanthophores having longer 
spines. 


172 HYALONEMA (HYALONEMA) AGASSIZI. 


Hyalonema (Hyalonema) agassizi, sp. nov. 


Plate 41, figs. 1-14; Plate 42, figs. 1-59; Plate 43, figs. 1-7; Plate 44, figs. 1-30; Plate 45, figs. 1-64; 
Plate 46, figs. 1-16; Plate 47, figs. 1-13. 


Eleven more or less complete specimens and three fragments of this species 
were trawled in the Tropical Pacific at five stations. One of these sponges is a 
very fine specimen, the best in the collection. It is therefore appropriate to 
name this new species after the leader of the several Albatross expeditions which 
brought home the material here reported on. 

Two of the five specimens from Station 4742 are cake-shaped, the three 
others more elongate, pear- or top-shaped. The general appearance and the 
spiculation of the fragments indicate that they are parts of similar pear- or top- 
shaped sponges. The two cake-shaped specimens from Station 4742 appear to 
be identical in structure among themselves, but to differ from all the rest. The 
same is to be said of the three pear- or top-shaped specimens and the fragments 
from the same station, and of the three specimens from Station 4740. The speci- 
mens from the three other stations all differ from each other and from the rest. I 
shall, for the reasons given below, describe these six different kinds as distinct 
“forms” :— 

A, the one taken at Station 4656 on 13 November, 1904; 6° 54.6’ S., 83° 34.3’ 
W.; depth 4063 m. (2222 f.); bottom composed of fine, green mud mixed 
with gray ooze; the bottom-temperature was 35.2°. 

B, the one taken at Station 4651 on 11 November, 1904; 5° 41.7’8., 82° 59.7’ W.; 
depth 4063 m. (2222 f.); bottom a sticky, fine gray sand; bottom-tempera- 
ture 35.4°. 

C, the three from Station 4740 taken on 11 February, 1905; 9° 2.1’ S., 123° 20.1’ 
W.; depth 4429 m. (2422 f.); bottom composed of dark gray Globigerina 
ooze; bottom-temperature 34.2°. 

D, the one taken at Station 3684 (A. A. 17) on 10 September, 1899; 0° 50’ N., 
137° 54’ W.; depth 4504 m. (2463 f.); bottom light yellow-gray Globi- 
gerina ooze. 

I, the two caked-shaped specimens, and 

I’, the three pear- or top-shaped specimens and the fragments, all from Station 
4742, on 15 February, 1905; 0° 3.4’ N., 117° 15.8’ W.; depth 4243 m. (2320 
f.); bottom composed of very light, fine Globigerina ooze; bottom- 
temperature 34.3°. 

Shape and size. The single specimen of form A (Plate 41, fig. 2) is well- 


HYALONEMA (HYALONEMA) AGASSIZI. 173 


preserved. Its body is broad top- or spindle-shaped, has at every level a nearly 
circular transverse section, and measures 66 mm. in length and 48 mm. in maxi- 
mum transverse diameter. At its apex the rounded summit of the nearly cylin- 
drical gastral cone is visible. The cone is surrounded by a cireular wall which 
terminates in a narrow frill, the margin of which appears as a circle 8 mm. in 
diameter. The circular wall is separated from the cone by a circular fissure 
about 1 mm. wide. This fissure is the gastral cavity. The outer surface of the 
sponge-body is quite smooth and continuous; apertures, visible to the naked eye, 
do not occur in it. From the lower, rounded end of the body the stalk arises. 
At its origin this is about 5 mm. thick, thickens slightly below, and measures a 
little over 40 em. in length. Thespicules composing it are all broken off at the 
lower end; in life the stalk was probably considerably longer. Its lower and 
central parts are quite straight. Its upper part is strongly and uniformly bent 
through an angle of about 60°. 

The single specimen of form B (Plate 41, fig. 1) is not so well-preserved. 
Of its dermal membrane only a few patches are left and the upper part is much 
torn. It is massive, pear- or club-shaped, 81 mm. long and 61 mm. broad. The 
stalk is straight, 7 mm. thick at the point of origin and broken off at a distance 
of 9 cm. from the sponge-body. Although, as above stated, the upper part of 
the sponge is much torn, one can make out in the middle of it a nearly cylindrical, 
terminally rounded gastral cone about 10 mm. thick, connected by four radial, 
vertical, membraneous plates joining it with the gastral wall. The surface 
appears very rough and uneven. This is doubtlessly due to the loss of the dermal 
membrane. 

The three specimens of form C are cake-shaped. Of their dermal mem- 
branes and the stalks only slight remnants remain. The best preserved one 
(Plate 41, figs. 13, 14) is a stout, marginally rounded disc, broad-oval, nearly 
circular in outline. It measures 66 mm. in length, 60 mm. in breadth, and 27 mm. 
in thickness (height). The lower face is nearly flat, the upper convex. The 
centre of the latter is occupied by a gastral depression 20 mm. in diameter, 
nearly circular in outline, and surrounded by a circular wall on the margin of 
which remnants of a thin frill can be made out. Where this frill is best preserved 
it appears to be turned outward. A low, dome-shaped, gastral cone about 6 mm. 
thick arises from the centre of the depression. This cone is connected with the 
gastral wall by four vertical, radial membraneous plates. The wide spaces 
between these radial plates appear as diverticular parts of the gastral cavity, 
which are continued down into the interior of the sponge. A few stalk-spicules, 


174 HYALONEMA (HYALONEMA) AGASSIZI. 


broken off 1-3 em. from the sponge, arise from the centre of the flat lower face. 
Many parts of the surface, particularly of the upper side, exhibit a reticulate 
appearance, caused by the presence of a superficial network with irregularly 
square meshes, the centres of which are about 1 mm. apart (Plate 41, fig. 14). 
The centre of each mesh is occupied by the circular entrance to an afferent 
canal. The other two specimens of this form are similar. One of them is about 
as long and broad as the one above described, but thicker (higher); the distance 
between the summit of its gastral cone and the slight protuberance on its lower 
face, from which the (absent) stalk arose, being 40 mm. The other is smaller, 
has no trace of a stalk, and measures 45 by 37 by 12 mm. 

The single specimen of form D is also indifferently preserved. A few small 
remnants of the dermal membrane and some stalk-spicules, broken off short, 
are, however, still present. This sponge (Plate 41, fig. 12) is also cake-shaped. 
It measures 51 mm. in length, 46 mm. in breadth, and 17 mm. in thickness 
(height). 

The larger and more complete of the two specimens of form E is cake- 
shaped, 36 mm. long, 28 mm. broad, and 25 mm. thick (high). In the middle of 
its flattened upper face there is a gastral depression, surrounded by a thin circu- 
lar wall with sharp margin. This margin is nearly circular and measures 13 mm. 
in diameter. In the centre of the depression a low gastral cone is situated, from 
which radiate several somewhat irregularly disposed vertical plates. Between 
these plates wide diverticula of the gastral cavity extend downwards to a dis- 
tance of about 14 mm. A protuberance 5 mm. high is observed in the middle 
of the lower, more convex face of the sponge. The holes in it indicate that, 
in life, the spicules forming the stalk arose from this protuberance. The other 
specimen of this form is very similar. It measures 34 by 28 by 21 mm. 

The most complete specimen of form F is laterally compressed and appears 
as an irregularly triangular plate about 5mm. thick. The plate is 30 mm. broad 
above and narrows below to 5mm. A bundle of stalk-spicules arises from the 
lower end. The other two specimens of this form are more fragmentary and 
consist only of the central and the attenuated basal part of the sponge-body, 
and the upper part of the stalk. One is (without the stalk) 37 mm. long, the 
other 35 mm. The largest of the fragments of this form is 28 mm. long. 

The colour of the specimen of form A in spirit is a rather rich coffee-brown, 
of form B a dirty light greenish gray, of form C a light reddish brown, of form 
D a light dirty brown, and forms E and F are whitish. 

Canal-system. The canal-system of form A (Plate 45, figs. 18, 23) seems to 


HYALONEMA (HYALONEMA) AGASSIZI. 175 


be similar to that of Hyalonema (Hyalonema) obtusum var. gracilis; the chief 
difference apparently being that the former is more dense and has narrower 
subdermal cavities and canals. The flagellate chambers are elongate and 50-80 u 
broad. In one of the specimens of form C the afferent canals are very clearly 
visible. ‘They here appear as tubes, about 0.5 mm. wide, which lie parallel side 
by side and extend vertically down into the interior of the choanosome. In 
this form, and in the forms B, D, and E, the gastral cavity is divided by radial 
vertical plates into diverticula. The plates are, in several of these specimens, 
four in number and regularly arranged in a cruciate manner. The diverticula 
extend downward, are tubular, very wide above, attenuated below, and nearly 
circular in transverse section. Their walls are perforated by numerous efferent 
apertures, many of which attain considerable dimensions. 

Skeleton. The whole of the outer surface of form A, and the (small) parts of 
it, in the other forms where the dermal membrane is still present, are covered 
by a dense pinule-fur (Plate 42, fig. 36; Plate 45, fig. 23a). Certainly in form A 
and probably also in the other forms, the pinules of all parts of the outer surface 
are similar, with the exception of the part close to the origin of the stalk. They 
are in all forms for the most part pentactines; a few, however, possess a more 
or less developed sixth, proximal ray, and appear as hexactines. Between the 
lateral rays of these dermal pinules a few micramphidises lie scattered on the 
outer surface. From the thin, upper, free margin of the wall surrounding the 
gastral cavity (fissure or depression) the distal rays of diactine pinules protrude. 
The gastral surface, that is the inner surface of the wall surrounding the gastral 
eavity, and the surface of the gastral cone are likewise covered by a pinule-fur. 
The pinules composing it are chiefly pentactines, more rarely hexactines, excep- 
tionally diactines. A few minute spiny pentactines have also been observed 
here. On these gastral surfaces also micramphidises occur. These spicules are 
here, however, much more abundant than on the outer surface, and in places 
form dense masses. Below, where the gastral cavity passes into the large effer- 
ent canal-stems, the pinule-fur ends; the coating of micramphidises, however, is 
continued along the walls of these canals quite down to the innermost parts of the 
choanosome. The micramphidises of the outer, dermal surface and of the 
surfaces bordering on the upper part of the gastral cavity and enclosing the inner, 
proximal parts of the efferent canals, are all or nearly all small ones. Those on 
the surfaces surrounding the lower proximal part of the gastral cavity and the 
mouths of the large efferent canals on the other hand are, certainly in form A, 


and probably also in the other forms, in great part large macramphidiscs. 


176 HYALONEMA (HYALONEMA) AGASSIZI. 


Just below the level in which the lateral rays of the dermal pinules of the 
outer surface extend, the paratangentially situated lateral rays of hypodermal 
pentactines are met (Plate 42, fig. 37a; Plate 45, fig. 23). In form C these 
lateral pentactine rays extend in the beams of the superficial network above 
described. The apical rays of the hypodermal pentactines extend radially in- 
ward. Inform A asuperficial zone about 0.6 mm. thick, underlying the dermal 
membrane, is occupied by dense masses of more or less radially arranged unci- 
nates and irregularly scattered microhexactines and microhexactine-derivates 
(Plate 45, fig. 23). This zone contains no spicules besides these and the proxi- 
mal rays of the hypodermal pentactines, which traverse it. Below this zone 
hexactine megascleres begin to make their appearance. Those lying nearest 
the surface are quite small, towards the interior they increase in size. Though 
often irregularly disposed in the sections, these spicules are, in the living sponge, 
in all probability regularly arranged in such a manner that two opposite rays 
extend longitudinally upward and downward, two radially outward and inward, 
and two paratangentially and laterally to the right and left. In most of the large 
and in a good many of the smaller hexactines the two opposite longitudinally 
extending rays are longer than the other four. Masses of large macramphidises 
are met with a little below the level where the hexactines begin to make their 
appearance. In some places these form but a thin layer, in others they extend 
a considerable distance, 2 mm. or more, into the interior of the choanosome. 

The inner parts of the sponge are occupied by the large hexactine mega- 
scleres referred to above, and also by rhabd-megascleres, uncinates, microhexac- 
tines, microhexactine-derivates, amphidises, and spheres. 

The large inner hexactines usually have two opposite, longitudinally extend- 
ing, greatly elongated rays and four shorter transverse rays. The rhabds of the 
axial part of the sponge are situated longitudinally and form a kind of axial 
column, which extends upwards to the summit of the gastral cone. Loose 
strands of rhabds diverge from this axial column and extend upwards and out- 
ward. Below, in the interior of the choanosome, these diverging rhabd-strands 
dissolve into scattered, obliquely situated, isolated rhabds; above they join to 
form distinct layers lying below the dermal and the gastral surfaces of the thin 
frill-like marginal part of the gastral wall. In the forms B, C, and D masses of 
longitudinal rhabds also occupy the vertical radial plates connecting the gastral 
cone with the gastral wall. Most of these rhabds are very blunt amphioxes or 
amphistrongyles; but sharp-pointed amphioxes, amphityles, styles, and tylo- 
styles also occur among them. In the axial column of form A both large and 


HYALONEMA (HYALONEMA) AGASSIZI. ey 


small rhabds are met. Outside the axial column, however, only the smaller 
ones have been observed. 

In the interior the uncinates are not very numerous and are irregularly 
scattered. Of amphidises both macramphidises and micramphidises occur in 
the interior. The former are very scarce, the latter, which appear chiefly to 
occupy the walls of the efferent canals, exceedingly numerous. The micro- 
hexactines and their derivates are, in the interior, rather frequent, but not nearly 
so abundant as in the superficial region. The spheres appear to be restricted 
to the axial column, where they occur singly or, more rarely, in clusters. They 
are rather numerous in form A and have also been found in form D. 

In the specimens of form A, B, and in two of the specimens of form F the 
stalk is more or less intact. It is in these forms composed of stouter and more 
slender rods, broken off at the lower, distal end. In the specimen of form A 
the stalk is over 40 em. long and now consists of twenty spicules; in life there 
may have been more. The spicules composing it are very distinctly spirally 
twisted, like the strands of a rope and also similarly entwined. The twist has 
the same direction in all. Progressing from the proximal to the distal end the 
spiral curvature is in the direction of the movement of the hands of a watch. 

The stalk-spicules extend for some distance upwards into the sponge-body, 
and they are, in the basal part of the latter, surrounded by masses of acantho- 
phores. These are stout-rayed, usually terminally spined tetractines (staurac- 
tines), derivates of these spicules, more or less spiny pentactines, modified 
pinules, and modified rhabds with spiny ends. In the basal part of some of the 
specimens spheres also occur. In the specimens of all the forms with the excep- 
tion of those of forms E and F, slender-rayed, long-spined spicules with four to 
six rays also occur just below the surface of that part of the body from which 
the stalk arises. Their absence in forms E and F is probably due to the frag- 
mentary nature of the specimens of these forms. 

The dermal pinules (Plate 42, figs. 20-23, 25-36, 37b, 42b) are nearly all 
pentactine; only a few are hexactine. Their distal ray, in form A (Plate 42, 
figs. 25-28, 35, 36), is straight, 93-110 » long, usually 94-107 uy, on an average 
100.4 4; and, at the base, 4.4~7 » thick, usually 4.5-6.7 ». Above it thickens, 
and it ends with a well-developed, smooth, terminal cone 6.5-11 » thick, usually 
8.5-9 u. The proximal, basal part of the ray and its terminal cone are free from 
spines; the rest of it, usually about 60% of its length, is covered with spines. 
The most proximal spines diverge strongly, and are often nearly vertical to the 
ray. Distally they become more inclined towards the tip, and the uppermost 


178 HYALONEMA (HYALONEMA) AGASSIZI. 


spines, which surround the terminal cone, are nearly parallel to the ray-axis. 
The lowest spines are straight and quite short. Distally they become slightly 
curved, concave towards the tip of the ray. Up to the middle of the length of 
the ray they increase in size; beyond they again become smaller. The largest 
spines on the middle-part of the ray are 10-20 » long and 2-4 u thick at the base. 
The maximum transverse diameter of the distal ray, together with its spines, is 
18-32 yw, usually 20-30 », on an average 23.6 ». The lateral rays of the same 
spicule are usually fairly equal (Plate 42, fig. 35), sometimes considerably unequal 
(Plate 42, fig. 36). They are 21-32 u» long, straight, nearly cylindrical in their 
basal part, attenuated toward the end in their distal part, and blunt-pointed or 
terminally rounded. The proximal parts of the lateral rays are usually rather 
smooth; their distal parts bear sparse small spines. <A sixth proximal ray is 
observed very rarely and, when present, is short and rudimentary. 

The dermal pinules of form B (Plate 42, fig. 29) are very similar but have 
a shorter and more bushy distal rays and longer lateral rays. The distal ray 
is 85-97 uw long, on an average 93 uw, and 3.5-6 » thick at the base. Its maximum 
transverse diameter, together with the spines, is 28-34 uw, on an average 29.2 uy. 
The lateral rays are 25-30 u long. 

The dermal pinules of form C (Plate 42, figs. 20-23) are even more similar 
to those of form A, but have a slightly more bushy distal ray and longer lateral 
rays. The distal ray is 95-114 uw long, on an average 104.9 u, and 4-6 uv thick 
at the base. Its maximum transverse diameter, together with the spines, is 
22-32 uw, on an average 27 wu. The lateral rays are 25-35 u long. 

The dermal pinules of form D (Plate 42, figs. 30-34, 42) differ from those of 
the other forms by the distal ray being not so long, having a shorter and stouter 
terminal cone, and being covered with more numerous and crowded spines. 
The distal rays of the dermal pinules of this form therefore appear, when com- 
pared with those of the other forms, more stunted, stout, and dense. The distal 
ray is 82-101 ,» long, usually 87-95 », on an average 89.1 uw, and at the base 
4.5-8 uw thick, usually 4.5-6 uw. Its maximum transverse diameter, together with 
the spines, is 23-32 yu, on an average 26.2 ». The terminal cone is 8-11 u thick. 
The lateral rays are 17-30 y long, exceptionally up to 88 pu. 

The dermal pinules of form E have a distal ray 70-94 u long, on an average 
86.7 w. Its maximum thickness, together with the spines, is 22-32 4. The 
lateral rays are usually 18-23 u long. 

The dermal pinules of form F have a distal ray 85-97 » long, on an average 
90 ». Its maximum thickness, together with the spines, is 23-25 uw. The lateral 


rays are usually 23-48 yu long. 


HYALONEMA (HYALONEMA) AGASSIZI. 179 


Peculiar, very variable, modified pinules (Plate 42, figs. 38-41, 48-45, 47, 
48) occur in the basal region, where the large stalk-spicules enter the sponge- 
body. These spicules appear to be dermal pinules changed in shape and in part 
pushed into the interior by the stresses arising in this region from the resistance 
of the embedded upper ends of the stalk-spicules to the weight of the sponge-body, 
and to such passive movements of it as may be caused by the impact of moving 
deep-sea animals. Transitional forms appear to connect these modified pinules 
with the slender-rayed, long-spined basal tetractines and other spicules described 
below. 

The modified basal pinules of form A (Plate 42, figs. 38-41) are pentactine 
or hexactine. The distal ray is straight, 78-120 » long, and 2.5-6 y» thick at the 
base. It bears, in its middle- and end-parts, sparse, strongly divergent spines, 
which are sometimes irregularly distributed, and are more numerous on one side 
than on the other (Plate 42, fig. 40). These spines are slender, conic, pointed, 
straight or slightly curved, simply or in an S-shaped manner; they are 15-29 u 
long and 1.3-3 » thick at the base. The maximum transverse diameter of the 
distal ray, together with the spines, is 18-42 u. The lateral rays of the same 
spicule are equal or unequal. They are straight, 30-57 » long, conic, usually 
pointed, and covered with spines directed obliquely outward. The largest 
of these spines are 1.5-2 4 long. The proximal ray (of the hexactine forms) 
is 42-55 » long; in shape and spinulation it resembles the lateral rays. 

The modified basal pinules of form B (Plate 42, figs. 47, 48) are similar but 
have shorter and stouter rays. The distal ray is 83-94 u long and 4-6 wu thick 
at the base. Its maximum diameter, together with the spines, is 28-35 un. 
The spines of the distal ray are 18-24 » long and 2.5-2.7 w thick at the base. 
The lateral rays are 25-32 u long. 

Some of the modified basal pinules of form C (Plate 42, figs. 43, 44) are 
considerably larger than those of the other forms. The distal ray is 101-135 u 
long and 4.5-5 yu thick at the base. Its maximum transverse diameter, together 
with the spines, is 13-33 ». Its spines are 14-15 » long and about 2.3 » thick 
at the base. The lateral rays are 20-80 yu long. 

In form D, E, and F, I found only few modified basal pinules (Plate 42, fig. 
45). One of form D which I measured had a distal ray 82 » in length and, 
together with the spines, 28 » in maximum thickness. Its largest spines meas- 
ured 18 by 2.5 u. 

The frill on the margin of the gastral wall, containing the diactine pinules, 
is preserved in a satisfactory manner only in the specimen of form A. The 
diactine marginal pinules of this form (Plate 44, figs. 1-5) have a total length 


180 HYALONEMA (HYALONEMA) AGASSIZI. 


of 350-640 u. The distal ray is 148-245 u long, fairly straight, 6-9 » thick at 
the base, and thickened above. It ends with a smooth, rather slender, sharp- 
pointed terminal cone. All parts of it, with the exception of its basal portion 
and its terminal cone, are covered with spines strongly inclined towards the tip. 
The largest spines are situated about a third of the length of the distal ray from 
the tip. From here they decrease in size both distally and proximally. The 
largest spines are 6-7 » long and 2-3 y thick at the base. The maximum trans- 
verse diameter of the distal ray, together with the spines, is 15-26 u. The lateral 
rays are generally reduced to mere rounded protuberances, only exceptionally as 
much as 9 » high (Plate 44, fig. 2, the left one). Together they form a central 
tyle 11-21 » in diameter. The proximal ray is straight or slightly curved, 
175-400 » long, and, at the base, as thick as the distal ray. It usually bears a 
few spines and a number of very low and broad rounded protuberances which 
render the appearance of its outline somewhat wavy. 

I have observed a few transitional forms which appear to connect these 
diactine pinules with ordinary, centrotyle, amphiox megascleres. The ray corre- 
sponding to the distal ray of the diactine pinules of one of these spicules, which 
I measured, was perfectly smooth, 680 » long, and 22 » thick at the base, and 
thickened above the middle of its length to 26 4. Its central tyle measured 
30 p» in transverse diameter. 

The gastral pinules (Plate 42, figs. 1-8, 10-19, 24). In form A, where 
the ‘gastral pinules both on the cone and on the inner face of the gastral wall 
could be conveniently measured, I found the distal rays of the former markedly 
longer than the distal rays of the latter, and also noticed that the distal rays of 
the pinules of the gastral wall decreased in length towards the upper, free margin. 

The gastral pinules of the cone of form A (Plate 42, figs. 1-8, 10-13) are for 
the most part pentactine; a few, however, are hexactine (Plate 42, figs. 1, 2) 
and one that I observed was diactine (Plate 42, fig. 13). The distal ray in these 
pinules, when normally developed, is 97-135 » long, usually 100-134 uw, on an 
average 118.2 yu, and 3.5-9.5 uw thick at the base. One (Plate 42, fig. 8) that 
had apparently been broken off during growth and then partly regenerated 
was only 65» long. The distal ray-ends with a smooth, blunt, terminal cone 
4.5-9 w thick. This and the basal part of the ray are destitute of spines. The 
remaining parts of it bear somewhat sparse spines. The proximal spines are 
strongly divergent, only slightly inclined, and curved towards the tip of the ray. 
Distally they become more inclined in this direction, but are, on the whole, much 
more divergent than those of the dermal pinules. The spines attain their great- 


HYALONEMA (HYALONEMA) AGASSIZI. 181 


est length near the middle of the ray and from here decrease in size both proxi- 
mally and distally. The largest spines are 10-21 » long and 2.5 uw thick at the 
base. The maximum transverse diameter of the distal ray, together with the 
spines, is 21-41 », usually 30-40 u, on an average 34.1 4. The lateral rays 
of the pentactine and hexactine gastral cone-pinules are, in the same spicule, 
fairly equal (Plate 42, figs. 1, 10, 11) or more or less unequal (Plate 42, figs. 3, 5, 
12), some of the lateral rays of the same spicule often being short, cylindrical, 
and terminally rounded, the others long, conic, and pointed. The individual 
lateral rays are 20-85 uv long, straight, cylindrical, and terminally rounded, or 
conic and pointed at the end. Their basal part is usually quite smooth, their 
distal part for two thirds or more of their length is covered with more or less 
conspicuous spines. The proximal ray in the hexactine forms is 17-76 u long, 
gradually attenuated towards the end, or abruptly pointed. It is smooth 
throughout, or covered with spines in its distal part. The proximal ray of the 
diactine cone-pinule (Plate 42, fig. 13) is 95 » long. 

The gastral pinules of the inner surface of the gastral wall of form A are 
similar to those of the cone, but have distal rays only 91-112 u long. 

The gastral cone-pinules of form B (Plate 42, figs. 14, 15) are pentactine or, 
more rarely, hexactine and similar to those of form A. They have, however, 
shorter distal rays with more divergent and longer spines. The distal ray is 
in these spicules 83-109 » long, on an average 98.2 y, and 5-7 uw thick at the base. 
Its maximum transverse diameter, together with the spines, is 27-45 », on an 
average 34.4 u. Its largest spines attain a length of 25 ». The lateral rays are 
30-48 y» long, the proximal ray (of the hexactine forms) is 12-27 u long. 

The gastral cone-pinules of form C (Plate 42, figs. 16, 17) have a longer 
distal ray than those of form B and resemble those of form A very closely. 
The distal ray in these spicules is 110-127 » long, on an average 118.5 u, and 
4.5-5.5 uw thick at the base. Its maximum transverse diameter, together with 
the spines, is 24-29 u. The lateral rays are 35-50 u long. 

The distal rays of the gastral pinules of the inner surface of the gastral wall 
of form C (Plate 42, figs. 18, 19) are similar in size but have more divergent 
spines and consequently, together with the spines, a greater maximum trans- 
verse diameter. ‘The divergence of the proximal spines from the tip of the ray 
is so great that some of them stand vertical, and some even point the opposite 
way. The distal ray is 103-126 u long, on an average 115 y, and 5-6 u thick at 
the base. Its maximum transverse diameter, together with the spines, is 28-35 u. 
The lateral rays are 36-50 u long. 


182 HYALONEMA (HYALONEMA) AGASSIZI. 


The gastral pinules of the cone of form D (Plate 42, fig. 24) resemble those 
of form A rather closely. They have a distal ray 98-113 » long, on an average 
106.7 uw, and 6.5-8.5 » thick at the base. Its maximum transverse diameter, 
together with the spines, is 25-38 ». The lateral rays are 26-64 y; the proximal 
ray (of the hexactine forms) is 38-50 u long. 

The gastral pinules of form E have a distal ray 69-103 » long, usually 83-— 
99 », on an average 90.5 uw, and 4.5—7 » thick at the base. Its maximum thickness, 
together with the spines, is 21-87 ». The lateral rays are 21-57 » long. In two 
hexactine gastral pinules of this form measured, the proximal ray was 42 and 44 y 
long respectively. 

The gastral pinules of form F have a distal ray 100-153 » long, on an average 
129 uw, and 5-6 » thick at the base. Its maximum thickness, together with the 
spines, is 25-40 ». The lateral rays are 50-62 yu long. 

Minute pentactines with spiny rays (Plate 42, figs. 9, 50) were found in small 
numbers in the spicule-preparation of the gastral cone of form A, and the basal 
part of forms A and B. These pentactines have straight, conic, blunt-pointed 
rays, smooth at the base, but covered with conspicuous spines in their distal part. 
Their apical ray in form A is 36-80 » long, in form B 43-65 yu, and is in both 
3-6 » thick at the base. The lateral rays of the same spicule are equal. In 
form A they are 40-50 u long, in form B 25-42 », and about as thick as the apical 
ray. 

The hypodermal pentactines of form A (Plate 41, figs. 3-11; Plate 45, fig. 23) 
have a fairly straight, conic, and blunt apical (proximal) ray, which measures 
0.3-1.5 mm. in length, and 18-90 u in thickness at the base. The lateral rays of 
the same spicule are fairly equal or more or less unequal. Among the small 
hypodermal pentactines forms with equal lateral rays predominate, but among 
the large ones forms with unequal lateral rays are the more numerous. The 
lateral rays are more or less oblique and enclose angles of 80°-88° with the apical 
(proximal) ray. They are usually somewhat curved, conic, and rounded at the 
end. The longest lateral ray is 0.25-1.3 mm. long. The ends of the lateral 
rays (Plate 41, fig. 9) are, as in Hyalonema obtusum, usually irregular, and proba- 
bly for the same reason (cf. p. 160). 

In the forms B, C, and D, in which the greater part of the dermal membrane 
is lost, only few hypodermal pentactines were found. All those observed in 
forms C and D were similar to those of form A. In form B spiny pentactines 
of similar dimensions were found, in addition to the ordinary smooth ones of the 
other forms. For the reasons given below (p. 183) I consider these spiny pentac- 


tines as foreign spicules. 


HYALONEMA (HYALONEMA) AGASSIZI. 183 


The hexactine megascleres of form A (Plate 45, figs. 6-13) measured were 
0.4—6 mm. in maximum diameter. The rays of the same spicule are in the smaller 
ones either equal or unequal, in the largest ones always unequal in length, two 
opposite ones being in these much longer than the other four. The four shorter 
rays are often also unequal among themselves. The rays arise from a central 
thickening 30-90 u in diameter, are smooth, conic, 10-58 uw thick at the base, 
and blunt or rounded at the end. They are in the small hexactines straight, 
in the large usually slightly curved. The longest ray is 220 »-3.2 mm. long. 

The hexactines of forms C and D are similar. In form B I found, besides 
hexactines similar to those of form A, one 11 mm. in maximum diameter with 
rays 70 » thick at the base, and only slightly attenuated to the rounded ends. 
In this form also spined hexactines, 2-5.5 mm. in diameter, occur. Although 
these are quite numerous and found in the depth of the choanosome, I do not 
believe that they really belong to the sponge. They are, like the large spined 
pentactines referred to above, identical with the spined hexactine and pentac- 
tine megascleres of Calycosilva cantharellus (Plate 1, figs. 5-24; Plate 6, figs. 1-12), 
a large number of specimens of which were trawled at the same station. Some 
of the spined hexactines and pentactines of these sponges may therefore have got 
accidentally into the sponge. 

In the basal part of the body, from which the stalk arises, slender acantho- 
phores, usually with four, more rarely with five or six rays (Plate 42, figs. 49, 51— 
59), are met in all the forms except E and F. Inform A these spicules (Plate 42, 
figs. 49, 51, 52) are 95-170, usually 110-135 yu in diameter, and generally consist 
of four rays lying in the same plane and enclosing angles of 90° with their neigh- 
bours. Sometimes a fifth ray, vertical to the other four, is present. The rays 
of these spicules are fairly straight, at the base 2.5—4 u thick, rarely 5 u, conic, and 
sharp-pointed. They bear numerous slender oblique spines inclined towards 
the tip of the ray. The largest spines are 4-12 u long. 

In form B these spicules (Plate 42, figs. 53, 54) are similar, measure 85-150 » 
in diameter, and have rays 2-4.5 thick at the base. Here only tetractines were 
observed. 

In form C these spicules (Plate 42, figs. 55, 56, 58) are larger, 120-210 yu in 
diameter, and have four or, more rarely, five fairly straight or considerably 
curved rays, 3.5-5 u thick at the base. 

In form D some of these spicules (Plate 42, figs. 46, 57, 59) attain a still 
larger size. They measure here 100-230 » in diameter and have usually five, 
more rarely four or six rays 2.8-6 « thick at the base. 

Transitional forms were found quite frequently in the basal part of the 


184 HYALONEMA (HYALONEMA) AGASSIZI. 


sponge-body, particularly in form C, apparently connecting these slender-rayed 
acanthophores with the modified basal pinules described above on the one hand, 
and the stout acanthophores described below, on the other hand. 

The stoul acanthophores surrounding the proximal end-parts of the large 
stalk-spicules (Plate 45, figs. 1-4, 14-17, 24, 25, 35-39) are mostly tetractines 
and diactine tetractine-derivates. However, similar pentactines, triactines, and, 
exceptionally, also monactines occur among them. Occasionally one meets 
with tetractines and pentactines of this kind with all the rays greatly reduced 
in length. These spicules appear as transitions, leading to the spheres described 
below. 

The rays of the same spicule are always more or less, and sometimes very 
unequal. They generally join at angles of about 90° or 180°, and are straight 
or curved, and cylindrical and terminally rounded, or conic and either blunt or 
pointed at the end. The diactine ones are either centrotyle or simply cylindrical 
in the centre, straight, slightly angularly bent in the middle, or, rarely, strongly 
curved. One 11 » thick, which I observed in form A, formed a complete ring 
65 » in diameter. Sometimes the rays bear rudiments of branch-rays. The 
basal parts of the rays are usually smooth or only sparsely spined; their end-parts 
bear numerous, rather large, generally nearly vertical spines, which stand close 
together. The smooth proximal part is usually a little longer than the spined 
distal part. 

In form A the larger, normal acanthophores are 200-690 » in maximum 
diameter and have rays 14-40 u thick at the base. The small ones transitional 
to the spheres (Plate 45, figs. 24, 25, 38) are 46-115 in diameter and have rays 
9-14 y» thick. 

In the other forms these spicules appear to be similar. Form D possesses 
mon- to pentactine spicules of this kind 195-550 » in maximum diameter with 
rays 15-35 » thick. The monactines are very rare. One that I measured was 
195 uw long, and at the rounded, somewhat thickened end, 12 yu in transverse 
diameter. 

In the preparations of one of the specimens of form F the stout acanthophores 
are particularly numerous. The triactine and tetractine forms here measure 
120-640 » in diameter, usually 420-590 », and have rays 20-40 » thick at the 
base. The diactine forms are usually fairly straight, rarely strongly angularly 
bent in the middle so that the two rays enclose an angle of 90° or less. The 
fairly straight diactines are 120-550 » long. Their rays have the same thickness 
as those of the triactines and tetractines. 


HYALONEMA (HYALONEMA) AGASSIZI. 185 


In the spicule-preparations of the basal part of this form numerous small, 
hollow, cross-like siliceous bodies were observed. The smallest of these are about 
20 uw in diameter, and consist of four somewhat conic rays, 10 uw long, about 16 » 
thick at the base, and hollowed out by cylindrical axial canals about 8 » wide. 
These smallest crosses are connected with the large normal stout-rayed tetractines 
above described by an uninterrupted series of spicules intermediate in size. 
The axial canals of these spicules are usually 5-9 » wide. The axes of the rays 
of the full-sized, stout-rayed basal spicules are occupied either by a fine axial 
thread, or a more or less widened axial canal. The broadest axial canals in these 
spicules were about 9 in diameter. In cylindrical, terminally rounded rays 
these axial canals are closed at the end; in conical and pointed rays they usually 
open out freely. 

The wide axial canals are regular or irregular. The regular ones are either 
cylindrical throughout or widened distally. Distal widenings occur both in the 
terminally open and in the terminally closed axial canals. The irregular ones 

.are of two kinds. In some the axial canals bear short, irregular, branch-like 
diverticula, which usually arise near the distal end, and are vertical or oblique, 
directed outward or, more rarely, inward. Others possess backwardly directed 
diverticula, which arise from their basal part and occupy interstices between 
adjacent silica-layers. 

It is obvious that the small forms of this series are to be considered either 
as the young of the full-sized ones, or as the last remnants of full-sized ones which 
have in great part been dissolved. The general appearance of the whole series 
seems to me to be in favour of the latter alternative. I accordingly assume that 
the stout acanthophores with wide axial canals are spicules in process of decay 
(solution), that this decay or solution is the further advanced the smaller the 
spicules are, and that the dissolving agency acts on the silica-layer both from 
the inner (the axial threads) and the outer side (the surface). No doubt the sea- 
water can and does dissolve the silica of the spicule in this way when the protect- 
ing organic or semiorganic sheath is lost, but it must not be overlooked that the 
living sponge-tissue of the sponge itself might possibly also attack and dissolve 
the silica in spicules which have become superfluous, and use the material thus 
obtained for building up other spicules. 

The spheres of form A (Plate 45, figs. 26-34) are irregularly nodular or 
spherical and measure 18-57 » in diameter. Most of them are smooth (Plate 45, 
figs. 26-29, 33, 34), some more or less spiny (Plate 45, figs. 30-32). They consist 
of concentric layers of silica. The centre around which these silica-layers are 


186 HYALONEMA (HYALONEMA) AGASSIZI. 


deposited may be a simple point, a short rod, or a cross. The spheres with a 
cross-shaped centre (Plate 45, fig. 29) lead to those short-rayed tetractines 
(Plate 45, figs. 24, 25) which have been referred to above as transitions between 
the normal long-rayed, stout, basal spicules and the spheres; I am inclined to 
consider the spheres as derivates of these spicules. 

I have not seen any spheres in the preparations of form B and C, but I 
found some, similar to those of form A, in form D. 

The microhexactines and their derivates form a series commencing with 
regular equal-rayed hexactines and ending with diactines and monactines. They 
fall into two groups:—1, regular and irregular microhexactines proper, and 
2, diactine and monactine microhexactine-derivates. 

The microhexactines proper (Plate 44, figs. 15, 16, 17b, 18-23, 25-30) have 
regularly disposed rays which enclose angles of 90° with their neighbours. The 
rays are conic and pointed. Their basal part is straight, their distal part nearly 
straight or curved more or less, sometimes considerably. In the forms E and F, 
where the microhexactines with the most strongly curved rays are found inter- 
mingled with the other, more straight-rayed forms, the degree of curvature 
appears to be in inverse proportion to the size of the spicule. The end-parts 
of opposite rays are usually curved in opposite directions. The rays of these 
spicules are beset with small backwardly directed spines. These are largest 
and most numerous on the middle-part of the ray; proximally they decrease 
in number, distally in size. It is also to be noted that these spines are on the 
whole much larger in the large (and straight-rayed) than in the small (and more 
curved-rayed) microhexactines. 

The microhexactines proper of form A (Plate 44, figs. 16, 17b, c, 18-20, 22, 
23, 30) are 50-144 uw in diameter and have rays 1.7—4 uv thick at the base. The 
irregular forms are larger (longer) and have thicker rays than the regular. The 
difference in the length of the rays of the irregular forms is sometimes very con- 
siderable, the length of the shortest ray being occasionally only a ninth of that of 
the longest. 

In the other forms the microhexactines proper are similar and also in these 
the irregular ones are larger than the regular. The maximum diameter of the 
microhexactines proper measured was in form B (Plate 44, figs. 21, 25, 27) 
66-145 yu, in form C (Plate 44, fig. 26) 44-130 u, in form D (Plate 44, figs. 28, 29) 
48-114 wu, in form E 53-157 yu, and in form F 52-160 u. 

The diactine and monactine microhexactine-derivates are by no means fre- 


quent. The diactine microhexactine-derivates of form A (Plate 44, fig. 24) are 


HYALONEMA (HYALONEMA) AGASSIZI. 187 


more or less centrotyle spiny rods, pointed at both ends. Their middle-part is 
straight, their end-parts are slightly curved. These spicules are 84—240 » long 
and 3.6—5 » thick near the centre. The central tyle measures 5.8-15 uw in trans- 
verse diameter and, when large, clearly shows that it is composed of four ray-rudi- 
ments. 

The monactine microhexactine-derivates are very rare. One of form A 
which I measured was 75 » long, and 3.5 » thick at the rounded end. 

Apart from the diactine pinules and the diactine and monactine derivates 
of the stout-rayed basal tetractines and the microhexactines above described, 
three kinds of rhabds can be distinguished : — ordinary rhabds of the choanosome 
and axial column, modified rhabds of the basal part of the sponge-body, and 
uncinates. 

The ordinary rhabds of the choanosome and axial column (Plate 45, figs. 19— 
22) are smooth, slightly curved or, rarely, angularly bent, 0.3-7 mm. and more 
long, as some long fragments observed indicate, and 7-50 u thick, rarely 95 yu. 
Most of them are blunt amphioxes or amphistrongyles, but amphityles, styles, 
and tylostyles also occur among them. The smaller amphioxes, amphistrongyles, 
and amphityles are generally distinctly centrotyle. Remarkably regular cylin- 
drical amphityles occur in the marginal part of the gastral wall of form A. These 
are mostly 0.7-1 mm. long and 26-30 thick; their spherical terminal tyles 
measure 40-50 » in diameter. A short somewhat spindle-shaped style 75 u 
thick at the rounded end and 95 uw at the stoutest point was observed in the axial 
column of this form. The axial canals (threads) of the small rhabds are usually 
quite fine, those of the large ones on the other hand generally wide, sometimes 
5 » or more in transverse diameter. 

The modified basal acanthophore rhabds (Plate 45, fig. 5) are centrotyle, usu- 
ally slightly curved, smooth in the middle, and strongly spined at the ends, which 
are generally somewhat thickened. The terminal thickenings are either spheri- 
cal or spindle-shaped, and in the same may be either similar or dissimilar, one 
end-thickening frequently being spherical, the other spindle-shaped. These 
spicules are 0.8-2.6 mm. long, and 7-22 » thick near the centre. The central 
tyle is 12.5-27 » in transverse diameter, the terminal thickenings 12-30 u. 
The spherical terminal thickenings are stouter than the spindle-shaped. The 
spiny end-parts are 80-260 » long. The axial canals (threads) of these spicules 
are often very wide. They are usually closed in the rounded ends and open in 
the spindle-shaped. 


The wncinates are mostly diactine, but monactines also occur. 


188 HYALONEMA (HYALONEMA) AGASSIZI. 


The diactine uncinates (Plate 44, figs. 6-14, 17a) are generally straight or 
slightly curved, simple amphioxes; considerably curved and centrotyle ones, 
however, also occur. The ordinary amphiox uncinates in form A are 330-800 u 
long, 5.5-12 » thick in the middle, and beset with spines. As far as I could make 
out these spines are 0.7-1.5 » long, and about 1 » thick at the base. Sometimes 
it appeared as if they were continued in a fine terminal filament which was, 
however, too thin to be distinctly projected even with the 280 » light. At one 
end of the spicule these spines are numerous, rather close together, and strongly 
inclined toward the opposite end. Toward the other end they become much 
scarcer and less inclined. Some of the spines nearest the latter end are vertical 
or even inclined in the opposite direction. In the centrotyle uncinates the cen- 
tral tyle is 15% to 45% thicker than the adjacent parts of the spicule. 

The monactine uncinates appear as tylostyles. In form A they are 260— 
293 » long and 9-12 » thick just below the rounded end. The rounded end itself 
is thickened to a more or less spherical tyle 14-16 y» in transverse diameter. 

The large stalk-spicules of form A (Plate 41, fig. 2; Plate 43, figs. 1-7) have 
a maximum length of 42 em. and all are broken off at the lower distal end. Where 
they arise from the sponge they are 0.05-0.95 mm. thick; 30 cm. lower, where 
most of them are stoutest, they are 0.5-1.3 mm. thick. 

One (Plate 43, fig. 1), which I studied in detail, is 160 » thick at the upper 
end, and rapidly increases in thickness to 730 » at 7 cm. from the end; it then 
gradually thickens down to 28 em., where it attains its maximum thickness 
of 1050 ». Farther on it again becomes thinner, and at the lower end, 42 em. 
from the tip, is 760 u thick. Its axial thread is for the most part thin. It is 
thickened, however, here and there in an irregular manner. The silica is very 
clearly stratified. The surface of the upper, proximal part of the spicule is quite 
smooth. Where the spicule attains its maximum thickness fine transverse lines 
(Plate 43, fig. 7) make their appearance on its surface, and 1 cm. above the distal 
end its surface, for a short distance, has quite a peculiar structure (Plate 43, 
fig. 4). Here a silica-layer is exposed which consists of lamellae overlapping 
like tyles, and composed of parallel rods about 10 » thick and lying close to- 
gether. These rods extend nearly but not quite paratangentially and longitudi- 
nally. They deviate slightly both radially and laterally from the direction of the 
axis of the spicule. The radial deviation is due to their forming the overlapping 
lamellae, and like the lamellae themselves they slightly diverge from the axis 
below. The lateral deviation is due to their lying somewhat obliquely in elon- 
gated spirals. 


HYALONEMA (HYALONEMA) AGASSIZI. 189 


Most of the other stalk-spicules exhibit, in their lower portion, the same 
transverse lines as the one described above, and in six of them the same spiral 
rods, combined to form tyle-like lamellae, are visible on portions of the surface 
near the end. 

The transverse lines may be considered as fissures in the superficial silica- 
layer. In the six spicules where it was observed, (and probably also in the 
others) the portions showing the superposed rows of spiral rods indicate that 
there are one or more silica-layers (composed of thin, spirally extending 
rods) quite different in structure from the rest. These layers are rendered 
visible where the disintegration (solution) of the spicule (which proceeds 
from the surface downwards) has just reached them; and their structure is 
probably brought out so clearly by the silica joining the rods having been partly 
dissolved. 

Being composed of layers differing in structure, one or more of which consist 
of superimposed rows of spirally arranged rods or threads, the stalk-spicules 
may, in respect to their internal structure, be compared to cables. 

No traces of backwardly directed spines or of terminal anchors could be 
found in any of the spicules. 

The amphidiscs (Plate 44, fig. 17d; Plate 45, figs. 40-64; Plate 46, figs. 1-16; 
Plate 47, figs. 1-13). The biological length frequency-curve of the amphidises 
of Hyalonema agassizi, form A, shows (Fig. 5), that, as regards the frequency of 
those of different length, these spicules fall, like those of Hyalonema obtusum, 
into four groups: — large macramphidises, small macramphidiscs, large micram- 
phidises, and small micramphidises. The second and third of these groups are, 
in respect to their length frequency, not as clearly distinguished from each other 
as from the first and fourth respectively. The parts of the curve pertaining to 
the large macramphidises and the small micramphidises each have two culmi- 
nations, a principal, and a secondary. The measurements and examination of 
the amphidiscs of various length of the three other forms show that these also 
fall into the four groups mentioned, and that, at least in two of them (B and (), 
the gap between the small macramphidises and large micramphidises is not so 
distinct as in the others. In the forms B and C these two kinds of amphidises, 
which can be readily distinguished by differences in their shape, slightly overlap 
in respect to their length. 

The large macramphidiscs of form A (Plate 46, figs. 2-5, 9, 12, 13; Plate 47, 
figs. 1, 2, 5, 6, 10) are 134-242 y» long, most frequently about 200 ». The shaft 
is straight, cylindrical, 7-13.5 » thick, and thickened abruptly at some point 


190 HYALONEMA (HYALONEMA) AGASSIZI. 


Micramphidiscs Macramphidiscs 
Niuber 0 ———————— 
Small , Large Small Large 
of es 
Spicules 
20 


15 


10 


Pale 


28.10— 30.91---- 
30.91— 34.00-4--- 


34.00 — 37.40 


> 


Length, (4). 
13.11— 14.42— 


14.42— 15.86 
17.45— 19,19-+--- -------------- 2202+ 2222 ene 


199s 21 Ss 
212323 a 


23:23 —) 25.5) 
45.26— 49.78-4------ 


41.14— 45.26—-- 
49.78 — 54.76 
80.18— 88.20 


88.20— 97.02 
97.02 — 106.72 


15.86— 17.45 
25.55— 28.1 
37.40— 41.14 
54.76— 60.24 
60.24— 66.26 
66.26— 72.89—-- 
72.89— 80.18 
106.72 — 117.39 


ia 
co t 
So 
on 
lo oan} 
man 
t © 
oS 
ma 
t™~ 0 
a x 


117.39 — 129.13- 
129.13 — 142.04 
142.04 — 156.25 


156.25 — 171.87 
276.81 — 304.49 
304.49 — 334.93 — 


| 
i<o) 
Se 
eo 
N 
N 
é 
ror) 
i 
i=) 
N 


228.76 — 251.64 
251.64 — 276.81 


Fig. 5— Form A. Amphidises. 


near its centre to 8-20, and gradually at both ends to 8-154. From the 
central thickening arises a regular, or irregular, verticil of conic truncate spines 
which is 2-8 » long, and 2-5 » thick at the base. The ends (terminal faces) of 
these spines bear clusters of small secondary spinelets. The other parts of the 
shaft usually bear a few, rarely a good many, very low protuberances covered 
with clusters of secondary spinelets. These protuberances are circular in outline 
and agree in breadth and secondary spinulation with the spines on the central 
thickening. The shaft is traversed by a fine axial thread which, where it passes 
through the central thickening, is slightly thickened to a small but well-defined 
point. Traces of branch-rays of the axial thread (an axial cross) could be 
detected neither here nor elsewhere. The terminal anchors are composed of 
eight to twelve recurved teeth. They are 40-80 u in length, that is about a third, 
generally a little less than a third, of the whole spicule, and 41-86 » broad. The 
proportion of the length to the breadth of the anchors is 100 to 91-120, on an 


HYALONEMA (HYALONEMA) AGASSIZI. 191 


average 100: 103. The anchor-teeth are T-shaped in transverse section. The 
upper part appears as a curved band, for the greater part of its length 8.7-11.5 u 
broad, and attenuated to a point or, more rarely, rounded off at the end. The 
teeth arise steeply and are uniformly curved, concave to the shaft. The curva- 
ture is not very great and never suffices to give the end-parts of the teeth a 
direction parallel to the shaft. The tangents on these end-parts enclose, in the 
adult large amphidises, angles of about 5° with the axis of the shaft. In young 
spicules of this kind (Plate 46, fig. 9) this angle is, of course, much greater. 

The large macramphidises of form B (Plate 46, fig. 15) are 126-310 u long, 
most frequently about 240 4. Their shafts are 8-14 y thick, and their anchors 
are 46-67 » long and 48-76 » broad. These spicules are longer and have smaller 
anchors than those of form A. 

The large macramphidises of form C (Plate 46, figs. 10, 11) are 110-290 u 
long, most frequently about 240 u. Their shafts are 6-10 » thick, and their 
anchors 40-63 » long and 35-75 u broad. They are very similar to those of 
form B, and are like them longer and provided with smaller anchors than those 
of form A. 

The large macramphidises of form D (Plate 46, figs. 6-8, 16) are mostly 
regular and similar to those of the other forms. They are 132-282 » long, most 
frequently either about 240 or 180 uw, with shafts 9.5-12 » thick, and with anchors 
52-73 w long and 48-66 u broad. In respect to their length the regular large 
macramphidises of form D are intermediate between forms B and C on the one 
hand and form A on the other. Their anchors are similar in size to those of 
forms B and C. In the specimen of form D I found an irregular large macram- 
phidise (Plate 46, fig. 7) 192 u long, with a shaft 4.4 » thick. The two anchors 
of this spicule are both about 26 « broad but very unequal in length, one being 
44 » long, the other considerably shorter. The shaft is beset with numerous 
large pointed spines, all strongly bent towards one end. These spines increase 
in size towards the end from which they diverge; the largest is 16 » long. 

The large macramphidises of form E are 150-280 » long, usually 170-256 yn, 
most frequently about 200 4. Their shaft is 6-12 » thick. Their anchors are 
51-67 uw long and 51-80 uw broad. 

The large macramphidises of form F are 112-260 u long, usually 150-232 y, 
most frequently about 200 u. Their anchors are 36-65 » long and 34-70 u 
broad. In a preparation of one of the specimens of this form I found an ab- 
normal large macramphidise, in which the central spine-verticil was replaced 


by an anchor similar to but slightly smaller than the terminal anchors. 


192 HYALONEMA (HYALONEMA) AGASSIZI. 


To attain a clearer insight into the range and character of the variation of 
the length of the large macramphidises in the four forms of this sponge I drew 
the following graph, in which the frequency of the large macramphidises of 
various lengths of all the four forms is represented. To make the curves in it 
commensurate I calculated the relation of the number of large macramphidises 
actually measured to 100, that is its percentage in each form, and multiplied all 
the numbers of amphidiscs belonging to the same category, in respect to length, 
by this number. These percentages are represented by the curves in Fig. 6. 


A 


Frequency 
(%) | 


Ts 


> 


=, 
| 


/ 
30% We 
Tar Cc 
/ 1 \\ if. 
ay) it 
25% 1 INGA 
20% ey 
tee 
15% : Ai 
ff Js ~ 
10% I pon 
Vane i eee 
rast ea : 
5% i : fae ; 
aa ee 
t 4 : 
; ' ' ' K 
0%: f Gees a, Form 
N [ep) (oe) =e tO tt i<o) ~~ ido} Be nl Dp ise) 39) 
~ BR ya Sy 5 Ge ca ees A 
= © M DD N ite) rt lop) i [o6) cml oo xs xt io 0) 
= 4B. SoS 2 -S. S&S. 8 SO Oe eee ee 
ef i ti) 1 0 
es © 82288 85 8 sg eB —-—- D 
28 § 5 8,8 8 & 2S 8g eee eee 
= col re a rt rH ton! N N N N ise) ise) ew 5 


Fig. 6.— Large macramphidises. 


The above curves, expressing the relative frequency of the large macramphi- 
dises of different lengths in the six forms, are based on 247 measurements. The 
curves pertaining to all the forms, except D, have one main elevation, the curve 
pertaining to form D has two. The second main elevation of this curve coin- 
cides with the main elevations of the curves of forms B and C, and with the 
considerable right secondary elevation of form E. All four lie at a point corre- 
sponding to amphidiscs about 240 » long. The main elevations of the curves 


of forms A, E, and F lie at points representing spicules about 200 » long. The 


HYALONEMA (HYALONEMA) AGASSIZI. 193 


first elevation of the curve of form D corresponds to still shorter amphidises, of 
about 180 » in length. The curves of forms A, D, and F have a small secondary 
elevation at about 290 wu. The curve of form B has a secondary elevation at 
about 164 »; the curve of form F has also an additional slight secondary eleva- 
tion at about 112 u. 

These curves indicate that A, E, and F have, on the whole, smaller large 
macramphidises than the other forms; that D possesses two nearly equally 
numerous varieties of these spicules, a larger and a smaller one; and that in C 
the small forms of the large macramphidises are much rarer than in the others. 
They further show that the large macramphidises of all the six different forms 
differ in respect to the character and range of the variation of their length. It is 
also to be noted that none of the curves are similar to a mathematical proba- 
bility curve; for these spicules do not, in respect to their length, vary uniformly 
round a mean. 

The small macramphidiscs of form A (Plate 46, fig. 1) are 62-115 u long, 
most frequently about 93 yu, and have a cylindrical centrotyle shaft 3-8 » thick. 
The central thickening bears a verticil of rather blunt spines 1.3-1.5 » long and 
about 0.5 » thick. Numerous similar spines are found on the other parts of the 
shaft. The anchors are 22-43 u long, that is about a third, generally a little 
more than a third, of the whole spicule, and are 16-42 » broad. The proportion 
of their length to their breadth, in the smaller forms under 80 y in length is, 100 to 
73-84, on an average 100 : 79; in the larger forms, over 80 » in length, it is 100 to 
76-105, on an average 100: 90. The shape of the individual anchor-teeth is, 
on the whole, similar to that of those of the large macramphidises; but it is to be 
noted that their curvature, in the smaller forms of these spicules, is considerably 
greater. 

In the specimen of this form (A) I found a remarkable hexactine spicule 
116 » in diameter, composed of four fully developed and two rudimentary rays. 
The four developed rays are cylindrical, 7.5 » thick, and bear at their ends verticils 
of large recurved teeth which together form somewhat irregular anchors 36 4 
long and about 64 » broad. One of the rudimentary rays is a short, terminally 
rounded cylinder; the other is bifurcate and slightly longer at the end. The 
whole spicule appears as 4 cross formed by two small macramphidises joined 
in the middle, from the centre of which two protuberances arise. 

Spicules of this kind have occasionally, but very rarely, been observed in 
other species of Hyalonema, as H. tenerum.! The only hyalonematid in which 


1 F. EH. Schulze. Rept. Voy. Challenger, 1887, 21, pl. 31, fig. 18. 


194 HYALONEMA (HYALONEMA) AGASSIZI. 


they are more abundant is Monorhaphis dives,‘ where they usually have six 
anchor-bearing rays. F. E. Schulze (loc. cit.) named these spicules hexadiscs. 
The spicule above described and others similar, like the one found in Hyalonema 
tenerum (loc. cit.), might, in an analogous manner, be called tetradiscs, or stauro- 
dises. 

In the other forms of Hyalonema agassizi only a few small macramphidises 
have been observed. Those seen were similar but smaller than those of form A. 
The small macramphidises of form B (Plate 45, fig. 53) are 53-101 » long. Their 
shafts are 2-4 » thick, and their anchors 18-27 » long and 18-33 » broad. Those 
of form C are 53-80 » long. Their shafts are 2—3.3 » thick, and their anchors 
20-24 » long and 16.5-20 » broad. In form D only a single small macramphi- 
dise was found. This was 84 » long. 

In form E the small macramphidises are 48-90 » long, most frequently about 
51 uw, and have anchors 10-33 » long and 10-25 » broad. In form F I found only 
two such spicules. These were 45 and 70 u long respectively. 

In form A the large micramphidiscs (Plate 45, figs. 46-49; Plate 47, figs. 11— 
13) are very numerous. They are here 42-60 » long, most frequently about 
52.3 uw. The shaft is 1.1-2 y» thick, cylindrical, or slightly and very gradually 
thickened, in a spindle-shaped manner, in or near the middle, but without a 
sharply defined central tyle. It is covered with numerous, slender, cylindrical, 
vertical or, more rarely, oblique spines, sometimes 2 «4 long. The anchors are 
relatively slender. They are 14.4—22 u long, that is a little more than a third 
of the whole spicule, and 8-14 » broad. The proportion of their length to their 
breadth is 100 : 53 (in one of the smallest), 100 :71 (in one of the largest), on 
an average 100:65. The individual anchor-teeth are about 1.5 « broad and 
strongly curved, so that their end-parts lie nearly parallel to the shaft or converge 
towards it. 

In form B, where they are rather scarce, the large micramphidises appear 
to be similar to those of form A, and measure 41-59 u in length, most frequently 
about 54.8 uw. 

In form C (Plate 45, figs. 59-61), where they are still more numerous than 
in form A, they measure 36-64 u in length, most frequently, as those of form A, 
about 52.3 » in length, and have spined shafts 1-1.7 « thick. Their anchors are 
17-23 » long and 10-13 « broad. One in which I was able to count the anchor- 
teeth had fourteen. The individual teeth in the larger forms are about 2.5 u 
broad. 


1 Ff. EB. Schulze. Hexactinellida. Ergeb. Deutsch. tiefsee-exped., 1904, 4, p. 124, taf. 43, figs. 1, 6, 7. 


HYALONEMA (HYALONEMA) AGASSIZI. 195 


In form D, where they are also rather frequent, the large micramphidiscs 
(Plate 45, figs. 63, 64) measure 35-55 u» in length, most frequently about 47.5 x. 
Their shafts are spiny and 1.5-1.7 u thick; their anchors are shorter than in the 
other forms, 15-17 » long, and 10-11 , broad. 

In the specimens of form E the large micramphidiscs are exceedingly abun- 
dant. They are here 40-69 u long, most frequently about 48 », and have anchors 
13-21 » long and 8-14 yu broad. 

In the specimens of form F the large micramphidiscs are not nearly so 
numerous. They are here 37-57 u long, most frequently about 52 y, and have 
anchors 14-20 » long and 9-14 u broad. 

According to the frequency of those of different length, three kinds of small 
micramphidiscs can be distinguished in form F, and two kinds in forms A, B, C, 
and E. The small micramphidises of form D are all of the same kind. The 
smaller (A, B, C, E) or smallest (F) kind is invariably the most abundant. The 
spicules belonging to the larger (A, B, C, E) or largest (F) kind have very slender 
anchors and appear as transitions between the (broad-anchored) small and the 
(slender-anchored) large micramphidises. Judged morphologically, by their 
shape alone, the larger (largest) kind of small micramphidises should, indeed, 
be considered as belonging to the large micramphidises. Since, however, in 
the smaller (A, B, C, E) or smallest and intermediate (F) kinds of small micram- 
phidises the relative breadth of the anchors decreases with the increase in 
the size (length) of the spicules, since in a few exceptional spicules of this kind 
the anchors are quite as slender as in the larger (largest) kind, and since they are, 
in the forms where they occur, separated biometrically much more clearly from 
the larger micramphidiscs than from the smaller kind of the small micramphi- 
dises, [ provisionally place them in the latter group. 

The small micramphidises of form A (Plate 44, fig. 17d; Plate 45, figs. 40—- 
45; Plate 47, figs. 3, 4, 7-9) are 15-36 » long, most frequently about 18.3 uy. 
The limit between the larger and the smaller kind lies at about 29 u. The shaft 
is straight or rarely bent, 0.6-1.4 « thick, cylindrical throughout, or slightly and 
gradually thickened in the middle. It is either quite smooth, or it bears near 
the centre an irregular cluster of a few spines, not over 0.5 u long, or it is covered 
with sparse, vertical, more rarely oblique, spines throughout. The anchors are 
4-13 » long, that is a quarter to a third of the whole spicule, and 4.7—9 » broad. 
They consist of fifteen or sixteen recurved teeth. In the larger kind of small 
micramphidises the proportion of the length to the breadth of the anchor is 
100 to 58-75, on an average 100: 64; in the smaller kind 100 to 75-135, on an 


196 HYALONEMA (HYALONEMA) AGASSIZI. 


average 100:93. It is to be noted that in the smaller small micramphidisces the 
relative breadth of the anchor is, on the whole, in inverse proportion to their size 
(length). The curvature of the individual teeth is such that the anchors appear 
rather broad above and that the end-parts of the teeth come to lie parallel or 
nearly parallel to the shaft. 

The small micramphidises of the other forms appear to be very similar to 
those of form A. Those of form B (Plate 45, figs. 50-52) are 13.5-31.5 u long, 
most frequently about 20.1 4. The limit between the larger and smaller kinds 
lies, as in form A, at about 29 uw. Those of form C (Plate 45, figs. 54-58) are 
14-30 » long, most frequently about 18.3 4. The limit between the larger and the 
smaller kind lies here at about 25.5 uw. Those of form D (Plate 45, fig. 62) are 
13-28 » long, most frequently about 20.1 1. The small micramphidises of form 
E are 15-34 u long, most frequently about 22.2 u. The limit between the larger 
and smaller kind lies at about 24.4 ». The small micramphidises of form F 
are 15-33 » long, most frequently about 18.3 ». The limits between the smallest, 
the intermediate, and the largest kind of small micramphidises of this form lie 
at about 20.2 » and 25.4 u. 

To obtain a clearer insight into the range and character of the variation 


of the length of the small micramphidises in the four forms of this sponge I 


Frequency 


ele 
Sor 


10% 


eek 


x 
> 


Caw 

0% Form 
8 4% 6% 425 8 BSasesea A 
SS Ga ies IS Fen SN ee TO eS Se SSS ee B 
a cael rc re tan! re N N N N ise) oD foe) i) C 
=A alee ie ie eee tee ms eee alae | lle | be eee 

F288 8 8 Ao. 8 ss 8 2 Soe 
aS Ss wl St 6 RS) ban Sareea = ia) coe eeu Se ID 

= a re = 4 4 I N N N N oD se) Se) SS ns HF 


Fig. 7.— Small micramphidisces. 


HYALONEMA (HYALONEMA) AGASSIZI. - 197 


drew (by the method already described) Figure 7, in which the relative 
frequency of the small micramphidises of various lengths of all the four forms is 
represented. 

The above curves, expressing the relative frequency of the small micramphi- 
dises of different lengths in the six forms, are based on 381 measurements. All 
have one main elevation; those of forms A, C, and E have one secondary eleva- 
tion, the curves of forms B and F have two. The main elevations of the forms 
A, C, and F correspond to amphidise-lengths of about 18.4 u, those of forms B 
‘and D to amphidise-lengths of about 20.1 u, those of form E to amphidisc- 
lengths of about 22.2 yu. 

The first and principal secondary elevation of form F, which is very con- 
siderable, coincides with the main elevation of form E at about 22.2 uw. The 
first secondary elevation of form B, which is quite insignificant, lies at about 
24.4 yu. The first secondary elevation of form E and the second secondary 
elevation of form F, which are both very well-pronounced, lie at about 26.8 x. 
The single secondary elevation of form C, which is inconsiderable, is situated 
at about 29.5 u. The second secondary elevation of form B and the single 
secondary elevation of form A both lie at about 32.5 ». The former of these is 
very well-pronounced, the latter insignificant. 

These curves clearly show that the small micramphidises of forms A, C, 
and F are on the whole relatively small, those of forms B and D intermediate, 
and those of form E relatively large, and further that all the six forms differ in 
respect to the range and character of the variation of the length of their small 
micramphidiscs. 

The description given above shows these sponges to be so similar that there 
can be no doubt about their belonging to one and the same species. They differ, 
however, more or less by their external shape, the structure of their gastral cavity, 
and the shape and size of their spicules. The variable spicule-characters which 
could be accurately ascertained in a sufficient number of spicules in all the forms 
are: — the length and maximum thickness (together with the spines) of the distal 
ray of the dermal pinules and gastral cone-pinules, the nature of the spinulation 
of the former, the diameter of the microhexactines, and the length of the large 
macramphidises and small micramphidises. In the following discussion I have 
considered only these spicule-dimensions, the shape of the sponge, and its gastral 
cavity. 

The specimens from Station 4651 and 4656 and some of the specimens from 


Station 4742 are massive, spindle-, pear-, top-, or club-shaped, the specimens from 


198 HYALONEMA (HYALONEMA) AGASSIZI. 


Station 3684 (A.A. 17) and Station 4740 and the other specimens from Station 
4742 are flattened, cake-shaped. In the specimen from Station 4656 the gastral 
cavity is a narrow fissure, uninterrupted by radial plates; in all the specimens 
from Stations 4651 and 4740, in the cake-shaped specimens from Station 4742, 
and probably also in the specimen from Station 3684 (A.A. 17), the gastral cavity 
is quite wide and divided into separate diverticula by radial plates. The dermal 
pinules of the specimens from Stations 4656 and 4740 have longer distal rays than 
the others. The dermal pinules of the specimen from Station 4656 and the pear- 
shaped specimens from Station 4742 have more slender distal rays (together with 
the spines) than the others. The spines of the distal rays of the dermal pinules 
of the specimen from Station 3684 (A.A. 17) are more crowded and form a more 
compact structure than those of the others. The distal rays of the gastral cone- 
pinules are of five sizes. Those of the cake-shaped specimens from Station 4742 
are on an average only 90.5 « long, those of the specimen from Station 4651 
98.2 u, those of the specimen from Station 3684 (A.A. 17) 106.7 wu, those of the 
specimens from Stations 4656 and 4740 128.2 w-128.5 u», and those of the pear- 
shaped specimens from Station 4742 129 w long. Those of the specimens from 
Station 4740 are (together with the spines) narrower than the others. The 
microhexactines are relatively large in the specimens from Stations 4651, 4656, 
and 4742, smaller in the specimens from Station 4740, and still smaller in the 
specimen from Station 3684 (A.A. 17). Inthe specimens from Stations 4651 and 
4740 the large macramphidises are of one kind and most frequently about 240 u 
long. In the specimens from Stations 4656 and 4742 these spicules may also 
be said to be of one kind, and they are here most frequently about 200 » long. 
In the specimen from Station 3684 (A.A. 17) a smaller kind, most frequently 
about 180 » long and a larger kind most frequently about 240 u« are nearly equally 
abundant. The small micramphidiscs in the specimens from Stations 4656 and 
4740 and the pear-shaped specimens from Station 4742 are most frequently about 
18.3 » long, those of the specimens from Stations 4651 and 3684 (A.A. 17) most 
frequently about 20.1 4, and those of the cake-shaped specimens from Station 
4742 most frequently about 22.2 u. 

This shows that the specimens of this species differ in respect to the follow- 
ing ten accurately determinable qualities: — a, the external shape, b, the nature 
of the gastral cavity, c, the length of the distal rays of the dermal pinules, d, the 
maximum thickness of the distal rays, together with the spines, of the dermal pin- 
ules, e, the density of the spinulation of the distal rays of the dermal pinules, f, 
the length of the distal rays of the gastral cone-pinules, g, the maximum thickness 


HYALONEMA (HYALONEMA) AGASSIZI. 199 


of the distal rays, together with the spines, of the gastral cone-pinules, h, the 
diameter of the microhexactines, 7, the length of the large macramphidises, and 
k, the length of the small micramphidises. The following table, arranged in 
pairs, shows which of these qualities the forms A to F have in common. 


4656 (A) and 4651 (B) 4 aegh 
i “4740 (C) 4 cefk 
g o “3684 (A.A. 17) (D) 1 g 
= : “4742 cake-sh. (E) g 4 eghi 
= se “* 4742 pear-sh. (F) = i abdeghk 
g 4651 (B) and 4740 (C) = 4 bdei 
£ i 3684 (A.A. 17) (D) 8 5 8 bedgk 
ee ie ake! “4742 cake-sh. (E) | @ 6 z= bedegh 
g | " “4742 pear-sh. (F) 2 5 = acegh 
ion|) 4740 (C) and 3684 (A.A. 17) (D) et 3 abd 
a a “4742 cake-sh. (E) a 4 abde 
& a “ 4742 pear-sh. (F) | 3 1 e 
HH 3684 (A.A. 17) (D) and 4742 cake-sh. (E) 5 abcdg 
“4742 pear-sh. (F) 4 egik 
4742 cake-sh. (EL) and 4742 pear-sh. (F) 4 cegh 


These affinities are shown in Figure 8. 

Of the five stations where these sponges were trawled, two, Stations 4651 
and 4656, lie near together off the Peruvian coast. The other three, Stations 
4740, 4742, and 3684 (A.A. 17), are a considerable distance apart in the central 
Pacific and are far from the two Peruvian stations. The degree of similarity 
of the specimens separated as the six kinds of Hyalonema agassizi stands in no 
relation to the distances of their localities from each other. Thus the cake- and 
the pear-shaped specimens from Station 4742 agree only in respect to four of the 
ten qualities, and the pair from Stations 4651 and 4656, which he very near 
each other, also agree only in respect to four qualities. The pairs which agree 
most are the pear-shaped specimens from Stations 4656 and 4742, which agree 
as to seven qualities, and the cake-shaped specimens from Stations 4651 and 
4742, which agree in respect to six. The units of the pairs of stations from which 
these come are very far apart. 

These and the other differences between the six kinds of Hyalonema agassizt 
are not systematically important individually; I believe, however, that several 
of them together demand recognition. Of the ten varying qualities here under 
discussion, nine are different only in two pairs from Stations 4656, 3684 (A.A. 17), 
and Stations 4740, 4742 pear-shaped. All the other pairs differ by from three 
to seven of these qualities. Since the units of the two mentioned strongly diver- 
gent pairs are connected in other ways, and since, as has been shown above, 
there appears to be no correlation between the degree of difference and the 
distance of the localities, I do not think that these differences warrant the 


200 HYALONEMA (HYALONEMA) AGASSIZI. 


Fig. 8. 


establishment of separate varieties. The distinction of different forms within 
the species, designated A, B, C, D, E, and F, is a sufficient division. 

The species composed of these six forms is most closely allied to the Hya- 
lonema (Hyalonema) obtusum and the Hyalonema (Hyalonema) polycaulum. 
The outer appearance of the variety gracilis of H. (H.) obtusum is indeed nearly 
the same as that of form A. These latter differ, however, from H. (H.) obtusum 
in the following respects:— the dermal pinules are considerably longer in both 
varieties of H. (H.) obtusum than in any of the forms described above; the 


HYALONEMA (HYALONEMA) POLYCAULUM. 201 


slender-rayed basal spicules are about twice as large, and the microhexactines 
are smaller, and composed of more strongly curved rays in the former than in 
the latter; the large macramphidises of H. (H.) obtusum reach 356 yu in length, 
have shafts bearing large spines along their whole length and possess anchors 
the end-parts of whose teeth are parallel to the shaft; the large amphidises of H. 
(H.) agassizi are not over 310 » long, have shafts destitute of large spines outside 
the centre, and possess anchors the end-parts of whose teeth diverge; the end- 
parts of the anchor-teeth of the large micramphidises are in the former far more 
curved than in the latter. 

Hyalonema (Hyalonema) polycaulum is in outer appearance, apart from its 
polycaule nature, similar to the forms described as C, D, and E. It differs from 
this species, however, by its large macramphidises, its pinules, and its mode of 
attachment to the sea-bottom. The large macramphidises are in the sponges 
described above considerably shorter, have relatively narrower anchors and 
anchor-teeth much more strongly curved in their distal part and less divergent, 
than in Hyalonema (Hyalonema) polycaulum. The distal rays of the pinules 
of the former are considerably thickened above the middle and have a stout 
terminal cone. In those of the latter such a thickening above the middle is 
either absent or very insignificant, and the terminal cone is much more slender. 
It is also to be noted that the distal rays of the pinules of the sponges described 
above bear more numerous spines than those of Hyalonema (Hyalonema) poly- 
caulum. The former is attached by a single stalk; the latter by several stalks. 


Hyalonema (Hyalonema) polycaulum, sp. nov. 


Plate 538, figs. 1-17; Plate 54, figs. 1-45. 


One specimen of this species was trawled in the eastern part of the Tropical 
Pacific at Station 4721 on 15 January, 1905; 8° 7.5’S., 104° 10.5’ W.; depth 
3811 m. (2084 f.); bottom composed of light brown Globigerina ooze. It appears 
to have possessed four distinct stalks. To this the specific name refers. 

Shape and size. The single, somewhat fragmentary specimen (Plate 53, 
fig. 4) is oval, 54 mm. long, 48 mm. broad, and somewhat flattened. Only slight 
remnants of the dermal membrane are left, the specimen appearing very porous 
in consequence. A group of large cavities, separated by thin plates, occupies 
one of the flat faces. A thickening at the joining line of these plates, which, 
however, does not project freely, is, as its internal structure shows, a gastral cone. 
The large cavities around it are parts (diverticula) of the gastral cavity. On the 


202 HYALONEMA (HYALONEMA) POLYCAULUM. 


opposite flat face of the sponge the superficial tissue is, in four places, consider- 
ably harder than elsewhere. These harder patches protrude more or less and 
appear as superficial knobs. They are distant from each other and rather uni- 
formly distributed over the face opposite the gastral. From two of these knobs 
a few broken stalk-spicules protrude. 

The colour in spirit is brown. 

Skeleton. Of the dermal pinule-fur only insignificant remnants are left; the 
gastral pinule-fur, however, is preserved in places. The dermal pinules have 
much shorter lateral rays than the gastral. Here and there, where the super- 
ficial parts of the sponge are still present, pentactine megascleres occur. The 
hard superficial knobs contain dense masses of tetractine (tetractine-derivate) 
stout, and diactine (diactine-derivate) more slender acanthophores. Here also 
slender-rayed, long-spined acanthophores are met. Large quantities of micro- 
hexactines, some microhexactine-derivates with fewer than six rays, and a good 
number of more or less pinule-like pentactines, which may be tubular pinules, 
and amphidisecs occur in the choanosome rhabd and hexactine megascleres. 
Certainly from two, probably from all the four hard superficial knobs bundles of 
rather large spicules, broken off at the surface of the sponge, extend towards the 
interior. One of these bundles leads up to the gastral cone above referred to. 
The spiculation of these knobs indicates that certainly from two and probably 
from all four there arise in life stalks composed of bundles of spicules. 

A good many anatriaenes with long and slender anchors, very large dicho- 
triaenes, and large spiny metasters, all foreign, and apparently belonging to some 
species of Thenea, are found in the sponge. <A few hexactinellid anchor- 
spicules, similar to those of the holascids, were observed in the hard superficial 
knobs. These spicules are 9-14 u thick, and have terminal tyles about 30 u» in 
diameter, beset with short anchor-teeth. I consider these spicules as foreign. 

The dermal pinules (Plate 54, figs. 35, 38-40) are generally pentactine, 
very rarely hexactine. The distal ray is 110-130 » long, and 4.5-9 yu thick at 
the base. It is straight, thickened above only very slightly or not at all, and 
ends with a slender and sharp-pointed terminal cone, only about 4 u thick at the 
base, that is at the point of insertion of the uppermost spines. The basal part 
and the terminal cone of the distal ray are smooth, its middle-part bears sparse 
spines. The lowest spines are short, arise steeply, and are usually slightly 
inclined towards the tip of the ray. Sometimes they are more strongly inclined 
in this direction, sometimes vertical, and sometimes even inclined towards the 


base. Distally the spines at first increase in size, and then again become smaller, 


° 


HYALONEMA (HYALONEMA) POLYCAULUM. 203 


Their inclination towards the tip generally increases uniformly towards the end 
of the ray. The individual spines are conic, pointed, and curved more or less, 
generally concave towards the tip (Plate 54, figs. 35, 40), sometimes in the 
opposite direction (Plate 54, fig. 38, the lowest) and occasionally in an S-shaped 
manner (Plate 54, fig. 39). The largest spines are 15-24 » long and 2.5-4 » 
thick at the base. The maximum thickness of the distal ray, together with the 
spines, is 24-40 u. The lateral rays are blunt-pointed or terminally rounded 
and 24-40 » long. They bear rather sparse, conspicuous spines. The proximal 
ray does not, when present, exceed the lateral rays in length. 

The gastral pinules (Plate 54, figs. 41-45) are also usually pentactine; hexac- 
tine forms are, however, not so rare among them as among the dermal pinules. 
The distal ray is 110-133 » long and 6-9» thick at the base. It is straight, 
simply conic throughout, or cylindrical basally and conic distally, or very slightly 
thickened below the middle of its length. It ends with a slender and very sharp- 
pointed terminal cone, 20-35 » long, and 3-5 uw thick at the base, that is at the 
point of insertion of the uppermost spine. Nearly the whole of the distal ray, 
with the exception of the terminal cone, is spined; a spineless basal region being 
absent altogether, or quite insignificant. The spines are sparse. The largest 
arise from the middle-part of the ray. From here they decrease in size both dis- 
tally and proximally. The basal spines are vertical or slightly inclined, either 
towards the tip or the base of the ray. Distally they become more and more 
inclined towards the tip of the ray. The individual spines are conic, sharp- 
pointed, straight or slightly curved, either uniformly concave towards the tip 
of the ray, or, more rarely, uniformly concave in the opposite direction, or in 
an S-shaped manner. The largest spines are 12-16 » long and 3-4 » thick at 
the base. The maximum thickness of the distal ray, together with the spines, 
is 25-40 ». The lateral rays are 40-60 u» long, usually conic, sharp-pointed, and 
in their distal two thirds or to a farther extent, often quite down to their base, 
they are covered with somewhat sparse, conspicuous spines. The proximal ray 
is, when present, similar to the lateral rays in shape and spinulation and has a 
maximum length of 50 u. 

The pinule-like pentactines, which may be canalaria (Plate 54, figs. 34, 37), 
have straight, conic, sharp-pointed rays, rather densely covered throughout 
with small spines. Their apical ray is 110-135 u» long, their lateral rays about 
65 uy. The rays are 5-6 u thick at the base. 

The (hypodermal and ? hypogastral) pentactine megascleres have fairly 


straight rays. The rays of the smaller forms are conic, very blunt-pointed, 


204 HYALONEMA (HYALONEMA) POLYCAULUM. 


smooth in their basal and spined in their distal part. Those of the large forms 
are often nearly cylindrical, rounded at the end, and entirely destitute of spines. 
In the smaller forms the apical (proximal) ray is usually about 300 » long, the 
longest lateral ray being 220-340 u. In the large forms the longest lateral ray 
attains a length of 650-1050 ». The basal thickness of the rays is 20-32 » in the 
former, and 40-80 u in the latter. 

The hexactine megascleres (Plate 53, fig. 8) have conic and blunt, usually 
fairly straight rays. In many, two opposite rays are longer than the other four. 
The intact hexactines observed were 0.6—-1.6 mm. in maximum diameter, and 
had rays 15-35 » thick at the base. Some fragmentary ones had rays as much 
as 40 uw thick. 

Among the stout-rayed tetractine and tetractine-derivate acanthophores (Plate 54, 
figs. 1-15), which form the principal part of the skeleton of the hard superficial 
knobs, forms occur with four, three, two, and one ray. Those with four rays, 
that is the tetractines (or stauractines), are the most frequent. The rays of 
these spicules are on the whole cylindrical or cylindroconic, and rounded or, 
more rarely, abruptly pointed at the end. They are straight or slightly curved, 
and generally somewhat irregular in outline. The end-part of the ray is always 
densely spined, the proximal part, usually one half to two thirds of it, is smooth. 
Sometimes the spines extend farther proximally, occasionally quite down to the 
centre of the spicule. The tetractines (stauractines) and triactines (tauactines) 
(Plate 54, figs. 1-10) are 150-650 uw in diameter, and have rays 10-37 u thick at 
the base. The diactines (Plate 54, figs. 11, 12) are usually straight (Plate 54, 
fig. 12) or more rarely abruptly rectangularly bent at the morphological centre 
(Plate 54, fig. 11). The morphological centre is always thickened to a central 
tyle, which is generally smooth, or more rarely spined. These spicules are 
usually 0.4-1 mm. long, and 20-25 » thick near the middle. The central tyle 
measures 30-50 » in diameter. The monactines (Plate 54, figs. 13-15) are usu- 
ally 250-450 » long, more or less cylindrical, 10-20 u thick, and closely resemble 
single rays of the other forms. The end corresponding to the morphological 
centre is thickened to a more or less spherical terminal tyle 18-40 u in diameter. 

The slender-rayed, long-spined acanthophores of the hard superficial knobs 
(Plate 54, figs. 30-33, 36) are usually hexactine, pentactine, or more rarely 
tetractine. The hexactines and pentactines form a series extending from regular 
hexactines (Plate 54, fig. 32) to pinule-like pentactines (Plates 54, fig. 35). 
The tetractines are to be considered as pentactine-derivates. These slender- 


rayed spicules measure 80-180 » in diameter. Their rays are straight, joined 


HYALONEMA (HYALONEMA) POLYCAULUM. 205 


at right angles, 3-8 » thick at the proximal end, conic, pointed, and covered with 
somewhat sparse spines quite or nearly down to the base. The largest spines 
are 5-15 » long and 2-3 uw thick at the base. The basal spines arise vertically; 
the distal ones are inclined towards the tip of the ray. 

The microhexactines (Plate 53, figs. 9-12, 14-16) measure 80-142 » in diam- 
eter, and have fairly equal, straight, or only very slightly curved, conic, and 
pointed rays, which are joined at right angles in the centre of the spicule. The 
rays are 2.5-4 » thick at the base and covered along their whole length with 
spines sometimes 0.4 » long. The basal spines are sparse and vertical, the distal 
more crowded and oblique, inclined backwards, towards the centre of the spicule. 

The rare microhexactine-derivates appear as spined amphioxes, from the 
centres of which arise terminally rounded rudiments of the four reduced rays. 
In respect to size and spinulation they agree with the largest regular micro- 
hexactines. 

The choanosomal rhabds are mostly centrotyle amphioxes, more rarely 
styles (tylostyles). They are mostly 1-2 mm. long and 10-20 4 thick. The 
central tyle is relatively much larger in the thin than in the stout amphioxes, and 
measures 15-35 » in transverse diameter. The proportion of the thickness of 
the parts of the spicule adjacent to the tyle and of the tyle itself is 100:110— 
100: 250. It is to be noted that the tyle, particularly in the slender rhabd, is 
often very eccentric, the four rays, the remnants of which it represents, being 
not all reduced to the same extent. 

The diactine (diactine-derivate) rhabd acanthophores of the hard superficial 
knobs (Plate 53, fig. 17; Plate 54, figs. 16-20) are simple or centrotyle cylindrical 
rods, often thickened, and usually densely spined, rarely smooth at the rounded 
or spindle-shaped ends. ‘They are straight or irregularly, sometimes (Plate 53, 
fig. 17) very strongly curved. These spicules are usually 0.6—-1.4 mm. long and 
4-20 » thick. The central tyle has a maximum in transverse diameter of 35 p. 
The smooth, strongly curved form (Plate 53, fig. 17) is only 5.5 u thick, and 
about 180 » long measured along the curve. 

The upper ends of the stalk-spicules found in the parts of the body underlying 
the hard superficial knobs attain 15 u» in length, and are 50-110 u» thick at the 
lower, broken ends and attenuated above. In places these rods are irregular and 
knotty. Their axial threads at these points exhibit remarkable irregularities, 
from which I inferred that the spicules had here been broken and then again 
joined by freshly apposed silica-layers. 


Of amphidiscs three kinds (which correspond to the large macramphidises 


206 HYALONEMA (HYALONEMA) POLYCAULUM. 


and the large and small micramphidises of Hyalonema (Hyalonema) obtusum) 
can be distinguished: — macramphidises, large micramphidises, and small 
micramphidiscs. 

The macramphidiscs (Plate 53, figs. 1-8, 13; Plate 54, figs. 28, 29) are 200- 
365 » long, most frequently about 293 4. The shaft is cylindrical, straight, 
6.5-12 » thick, and abruptly thickened in or near the middle to a central tyle 
12-18 » in diameter. The proportion of the thickness of the adjacent parts of 
the shaft to the thickness of the tyle is 100 » to 115-170. A verticil of truncate 
or blunt-pointed, often irregularly curved spines 3.5-7 » long and 2.54 yu 
thick arises from this tyle. Spines similar in shape but smaller (particularly 
shorter, only 1.5-8 » long and 2-3 » thick) are scattered in larger or smaller 
numbers over the other parts of the shaft. The tips of the spines are smooth 
or slightly roughened. The terminal anchors are 60-100 » long, usually consid- 
erably less than a quarter of the whole spicule, and 67-107 » broad. The pro- 
portion of their length to their breadth is 100 to 103.8-125.7, on an average 100: 
115.5. They consist of ten to twelve teeth. The individual teeth are curved 
in their (shorter) proximal part and generally nearly straight in their (longer) 
distal part. The latter usually diverges considerably and encloses an angle of 
about 20° with the shaft. The teeth are T-shaped in transverse section. Their 
upper part appears as a band about 10, broad and is abruptly attenuated 
to a point at the end. 

The large micramphidiscs (Plate 53, figs. 5, 6; Plate 54, figs. 26, 27) are 
30-56 » long. The shaft is straight, 1.2-1.7 » thick, and gradually thickened 
in a spindle-shaped manner in or near the middle. It bears a few small eylindri- 
cal spines. Some of these always arise from the central thickening. The 
anchors are usually 13.5-17 » long, generally considerably more than one third 
of the whole spicule, and 8-10 » broad. The distal parts of the individual teeth 
are fairly straight and generally nearly parallel to the shaft. 

The small micramphidiscs (Plate 58, fig. 7; Plate 54, figs. 21-25) are 13-27 u 
long, most frequently about 19.5 4. The shaft is straight, cylindrical, and 
0.7-1.5 » thick. Its central part usually bears a few spines. The anchors are 
4.5-7.5 uw long, usually a quarter to a third of the whole spicule, and 5-8 u broad. 
The individual anchor-teeth, of which there are about eighteen in one anchor, 
are more strongly curved some distance from the base than elsewhere. The 
end-part is nearly straight, and diverges very slightly or not at all from the shaft. 

The spiculation of the four hard superficial knobs indicates that the sponge 
above described had at least two, probably four, distinct and distant stalks, each 


composed of a separate bundle of spicules. 


HYALONEMA (HYALONEMA) PLACUNA. 207 


Authors attach considerable systematic importance to the structure of the 
organs of attachment in the hyalonematids, and have established genera (Phero- 
nema, Poliopogon) for sponges in which this attachment is effected by a broad 
spicule-brush or a number of separate spicule-bundles, and not, as in Lopho- 
physema, etc., and the species of the genus Hyalonema, by a simple slender stalk. 

Under these circumstances, and in view of the fact that the genus Hyalonema 
is characterized by the possession of a single slender stalk-spicule bundle, it at 
first sight seemed advisable to consider the sponge above described not as belong- 
ing to Hyalonema, and either to place it in one of the old polycaule genera 
(Pheronema or Poliopogon), or to establish a new genus for it. Since it has a 
rudiment at least of a gastral cone, which excludes it from Pheronema or 
Poliopogon; since it is very similar in habit and spiculation to the forms C, 
D, and E of Hyalonema (Hyalonema) agassizi; and since it seems to me very 
doubtful whether the difference between a monocaule and polycaule attachment 
is, by itself, sufficient for generic distinction, I place it in the subgenus Hyalo- 
nema. 

The nearest ally to it is H. (H.) agassizi. From this it differs by the large 
macramphidises, the pinules, and the mode of attachment. The large macram- 
phidises are considerably longer, their anchors relatively much broader, and the 
distal parts of their anchor-teeth more straight and divergent in the sponge above 
deseribed than in H. (H.) agassizi. The distal rays of the pinules of the former 
are more conic than those of the latter, and not distally thickened as in H. (H.) 
agassizi, the terminal cone consequently being much more slender than in H. 
(H.) agassizi. These pinule-rays differ also in respect to their spinulation, their 
spines being more numerous in H. (H.) agassizi than in H. (H.) polycaulum. H. 
(H.) agassizi has a single stalk, H. (H.) polycaulum has several. These, and other 


minor differences, render it advisable to separate these sponges specifically. 


Hyalonema (Hyalonema) placuna, sp. nov. 


Plate 63, figs. 29-51; Plate 64, figs. 1-19; Plate 65, figs. 1-23; Plate 66, figs. 1-5. 


Two specimens of this species were trawled in the Central Tropical Pacific 
at Station 3684 (A.A. 17) on 10 September, 1899; 0° 50’ N., 137° 54’ W.; depth 
4504 m. (2463 f.); they grew on a bottom of light yellow-gray Globigerina ooze. 

In their outer appearance they to a certain extent resemble Placuna shells 
and to this resemblance the name refers. 


Although similar and doubtlessly referable to the same species, the two 


208 HYALONEMA (HYALONEMA) PLACUNA. 


specimens differ in detail to such an extent that I have established two distinct 
forms, A and B. 

Shape and size. The specimen of form A is the better preserved. This 
sponge (Plate 64, fig. 11) appears as a thin, irregularly oval lamella with a slight 
marginal protuberance at one of the narrow ends. Part of its margin is torn 
off. The sponge is 65 mm. broad and, together with the protuberance, 80 mm. 
long. A number of transverse folds slightly protrude from its surface. These 
folds are strongly inclined towards what appears to be the upper end of the 
sponge, and are here more numerous and crowded than below. Their margins 
form more or less concentric curves, which are convex towards the upper end of 
the sponge and extend across the whole lamella. These folds, which are much 
more clearly marked on one face of the lamella than on the other, give to the 
sponge its Placuna-like appearance. 

The sponge is not, as at first sight appears, a simple plate, but is composed 
of two lamellae, 1.5-3 mm. thick, closely pressed together and joined along one 
side. In life it was probably a thin-walled sac, and I am inclined to ascribe its 
present lamellar shape to a compression and complete flattening after capture. 
The intact parts of the free margin of this sac bear a frill of freely projecting 
spicules. The protuberance (Plate 64, fig. 11) is part of this marginal frill. 
The outer surface appears rough and exhibits the folds mentioned above. Aper- 
tures (pores) were not found in it. The inner surface is smooth, and also bears 
a few strongly inclined projecting folds. 

The specimen of form B is similar (Plate 64, fig. 12), but more fragmentary. 
It appears as a lamella, about 3 mm. thick, with somewhat irregular outline, and 
is 65 mm. long and 42 mm. broad. 

The colour of both specimens in spirit is dirty white. 

Skeleton. The outer surface is covered with a dense fur of large dermal 
pinules (Plate 64, fig. 18a; Plate 65, figs. 22,23). Diactine pinules and centro- 
tyle amphioxes protrude from the sharp margin of the probably sac-shaped body. 
These pinules form the marginal frill referred to. The inner surface like the outer 
bears pinules. These gastral pinules are smaller, scarcer, and not nearly so 
densely crowded as the dermal. In form B two kinds of internal pinules can be 
distinguished, a larger with long lateral rays, and a smaller with apparently 
rudimentary lateral rays. The former are certainly gastral, the latter may be 
canaliculate. Megascleres are very abundant just below the surface and in 
the interior rhabds. Most of them are centrotyle amphioxes of moderate 


thickness; some are short spindle-shaped centrotyle amphioxes with remarkably 


HYALONEMA (HYALONEMA) PLACUNA. 209 


large tyle; a few are diactine centrotyle styles and tylostyles. Hypodermal and 
hypogastral pentactines occur below the outer and inner surface, and hexactine 
megascleres in the interior. Numerous microhexactines and a few diactine 
microhexactine-derivates are found in all parts of the sponge. Seven forms of 
amphidises can be distinguished: — 1, large macramphidises with apically broad 
anchors; 2, small macramphidises with apically narrow anchors; 3, large, 4, 
medium, and 5, small mesamphidises; 6, large micramphidises with narrow 
anchors; and 7, small micramphidises with broad anchors. In form B all the 
seven kinds of amphidises occur. In form A No. 1 (the large macramphidiscs) 
and No. 3 (the large mesamphidises) are very rare, and No. 5 (the small mesam- 
phidises) are apparently altogether absent. In form B I found a tetradisc. 

The dermal pinules (Plate 64, figs. 8-10, 13a, 14-19; Plate 65, figs. 22, 23) 
are nearly always pentactine, very rarely hexactine, and have a large, bushy 
distal ray and short lateral rays. Those observed of form A (Plate 64, figs. 8, 
14-16) were all pentactine. They have a straight distal ray, 414-475 u long, 
most frequently about 425-440 », and 7.5-10.5 » thick at the base. This ray 
ends with a stout terminal cone protruding about 20 » beyond the tips of the . 
uppermost spines. Apart from this terminal cone and the basal end-part, the 
whole of the distal ray is covered with spines. The lowest spines are strongly 
divergent and rather far apart. Distally the spines become more and more 
inclined towards the tip of the ray, and much more crowded. The uppermost 
spines are nearly parallel to the axis of the distal ray. The lowest spines are 
quite short. Distally they increase in dimension, and attain their maximum size 
at from two thirds to three quarters of the length of the distal ray from the 
centre of the spicule. Beyond this point they again become smaller. The 
largest spines are about 40 » long and 2-3 » thick at the base. It seems that 
the basal parts of these spines are somewhat flattened, their diameter in a direc- 
tion radial to the distal ray being smaller than their diameter in a direction verti- 
cal to this. These distal pinule-rays have the appearance of wheat-ears; this is 
due to a slight, just perceptible curvature of the spines towards the tip of the ray, 
to the increase in their size towards a point in the distal half of the ray, and to 
their density. The maximum thickness of the distal ray, together with the 
spines, is 32-50 », most frequently 38-47 ». This maximum thickness lies near 
the distal end of the ray. The proportion of the total length of the distal ray to 
the distance between the point of its maximum thickness, together with the 
spines, and the centre of the spicule (the base end of the distal ray) is 100 to 
65.1-83.3, most frequently 100 to 70-78, on an average 100 : 73.8. 


© 


210 HYALONEMA (HYALONEMA) PLACUNA. 


The lateral rays of the same spicule are usually all alike. They are 25-42 u 
long, attenuated distally, in their basal part very gradually, in their distal part 
abruptly, and pointed at the end. Sometimes one (Plate 64, fig. 8, to the left) 
or more (Plate 64, fig. 8, to the right) of them are reduced in length, only 20-24 u 
long, nearly cylindrical, and rounded at the end. The lateral rays are smooth, 
or provided with a few small spines. 

The dermal pinules of form B (Plate 64, figs. 9, 10, 17-19) differ from those 
of form A chiefly in the maximum thickness of their distal ray, together with the 
spines, which is situated farther up, nearer to the tip of the ray. These pinules 
are not, as those of form A appear to be, all pentactine, but some hexactines 
occur among them. The distal ray of these spicules is 385-458 » long, most 
frequently 399-445 », and 7-11 y thick at the base. The terminal cone is 
usually 18-27 » long. The maximum thickness of the distal ray, together with 
the spines, is 35-62 », most frequently 40-60 ». The proportion of the length of 
the distal ray to the distance between the point of maximum thickness (together 
with the spines) and the centre of the spicule (the base of the distal ray) is 100 to 
71-86, most frequently 100 to 76-84, on an average 100: 79.6. The lateral rays 
are 28-44 » long. The proximal ray of one of the hexactine forms is 34 » long. 

The ordinary gastral pinules of form A are nearly always pentactine, very 
rarely hexactine. In form B pentactine forms only were observed. The distal 
ray of the ordinary gastral pinules of form A (Plate 65, figs. 19-21) is straight 
or, rarely, angularly bent and 153-390 u» long, usually 200-360 ». It is somewhat 
spindle-shaped, thickest at a point about one third of its length from the base. 
At the base it measures 7-12 u, at the thickest point 10-16 u, in thickness, and it 
ends in a rather long and slender terminal cone. Its distal and its proximal end- 
parts are spineless. The remainder of it bears rather sparse and distant spines. 
The lower spines arise steeply or vertically from the ray and then curve upwards, 
often very markedly, towards its tip (Plate 65, fig. 21). The upper spines for their 
whole length are strongly inclined and slightly curved towards the tip of the ray. 
They decrease in size distally, the uppermost ones being very small. The maxi- 
mum thickness of the distal ray, together with the spines, is usually 30-38 u, 
rarely less, down to 22». The lateral rays are 37-85 u long, usually 40-70 un, 
conic, and pointed. They are in the distal half, or two thirds of their length, 
beset with somewhat sparse, conspicuous, vertical or outwardly directed spines. 
A good many of the pentactine forms of these spicules possess a large spine oppo- 
site the distal ray. This spine may be a rudiment of the proximal ray. In the 
rare cases where the sixth (proximal) ray is properly developed, it attains a length 
of 27-73 uy. 


HYALONEMA (HYALONEMA) PLACUNA. AV 


The ordinary gastral pinules of form B (Plate 65, figs. 16-18) are similar. 
All those observed were pentactine. Their distal ray is 164-286 » long, rarely 
330 uw, 8-11.5 uw thick at the base, and at the point of maximum thickness 11— 
17.5 » thick. Everywhere, except at the base and at the tip, it bears spines, 
which are larger (17-25 » long) and, particularly the upper, more divergent than 
inform A. In many of these spicules the lower spines are irregular and branched 
(Plate 65, fig. 17). The maximum thickness of the distal ray, together with the 
spines, is 28-52». The lateral rays are conic, pointed or blunt, 40-73 u long, 
and either quite smooth or provided with a few very minute spines. 

Besides the pinules described above, other much smaller pinules with appar- 
ently rudimentary lateral rays (Plate 65, figs. 9-12) have been found in the spicule- 
preparations of the interior of form B. As I have not seen them in situ in the 
sections, I cannot say with certainty whether they are gastral or canalar. The 
probability is that they are canalar. These pinules are pentactine. Their 
distal ray is straight and 172-200 u long, 7.5-9 u thick at the base. It is some- 
what spindle-shaped and measures in thickness 11—13 u» at the point of maximum 
thickness, which is about a third of the length of the distal ray distant from the 
base. The distal ray ends with a terminal cone. Everywhere, except at its 
base and at its tip, it bears large and sparse, more or less irregularly arranged 
spines. The lower spines arise steeply or vertically from the ray and are often 
branched; the upper are inclined towards the tip and simple; the latter decrease 
in size distally. The lateral rays appear as short stumps only 10-14 uw long. 
Sometimes it seemed to me that their shortness was due to their being broken; 
in other cases they appeared to be quite intact. Occasionally one or a few 
large and slender spines arise from the lower side of the laterals. Sometimes a 
large spine of this kind projects downward from the centre of the spicule (Plate 65, 
fig. 11). Such a spine appears as a rudiment of a sixth proximal ray. 

The diactine marginal pinules. In the somewhat fragmentary specimen 
of form B the margin is torn off and these spicules are missing. In form A they 
are abundant. In this form they are slightly curved or nearly straight, and 0.9— 
1.5 mm. long. The distal ray may be longer or shorter than the proximal. 
The former measures 520-700 in length, the latter 360-760 ». At their base 
both rays are 9-11 u thick. The centrum is thickened to a tyle 11-20 u in trans- 
verse diameter. The distal part of the distal ray bears spines strongly inclined 
towards the tip. This spiny part, which is usually 350-400 » long, has, together 
with the spines, a maximum diameter of 26-30 p. 

Of rhabds three kinds can be distinguished :— ordinary, isoactine, and centro- 


tyle amphioxes; anisoactine centrotyle rhabds with one longer and pointed and 


212 HYALONEMA (HYALONEMA) PLACUNA. 


one shorter and terminally rounded and usually thickened ray; and short and 
stout centrotyle amphioxes. 

The ordinary centrotyle amphiozes (Plate 63, fig. 46) are in both forms usu- 
ally 0.8-2 » long and 9-21 » thick near the centre. The central tyle is 14-22.5 u 
in diameter. The ends are blunt and usually irregular, with widened axial 
thread-ends. In these spicules the proportion of thickness (close to the tyle) 
to length is 1:50-72, on an average 1: 63.3. 

The anisoactine centrotyle rhabds appear as centrotyle tylostyles or, more 
rarely, styles. They are shorter than the isoactines, and 11—23 ,» thick near the 
terminal tyle (rounded end). The terminal tyle is often irregular, and measures 
in transverse diameter 13.5-37 u, sometimes 14 » more than the adjacent part of 
the spicule. 

The short and stout centrotyle amphioxes (Plate 63, fig. 47) are 0.6-1.6 mm. 
long, and 13-88 y» thick near the middle. The central tyle is 23-45 ,« in diameter. 
The proportion of the thickness (close to the tyle) to the length is 1: 37-52, on 
an average 1:44. 

The hypodermal pentactines (Plate 63, figs. 48-50) appear to be about the 
same in both forms. It is to be noted, however, that forms with lateral rays over 
480 » in length were found only in form A. The proximal ray is usually slightly 
curved, conic, blunt, 470-800 » long, and 9-55 uw thick at the base. The lateral 
rays may be fairly equal, or unequal in size. Sometimes their inequality is very 
great (Plate 63, fig. 48), the longest being nearly twice as long as the shortest. 
They are conic, very blunt, straight, or curved concave to the proximal ray, and 
usually also inclined in this direction. The longest lateral ray of the spicule is 
220 u-1.1 mm. long. 

Hypogastral pentactines were found only in the preparations of form B, and 
here also they are very scarce. Those observed had lateral rays 360-670 uw long 
and 18-35 » thick at the base. 

The hexactine megascleres are scarce, but have been found in both forms. 
In both they measure 0.8—1.2 mm. in diameter and have blunt conic rays 16-34 u 
thick at the base. 

The microhexactines and microhexactine-derivates form a series beginning 
with spicules composed of six fairly equal rays and ending with centrotyle diac- 
tines from the central tyle of which arise one to four ray-rudiments. The most 
frequent are the intermediate forms, representing the middle-part of this series, 
with two opposite rays longer than the other four. 

The regular microhexactines in both forms (Plate 64, figs. 4, 6, 7; Plate 65, 


HYALONEMA (HYALONEMA) PLACUNA. 213 


figs. 3-8) measure 60-140 » in diameter. Their rays are straight throughout or 
slightly bent in their middle-part, but never markedly curved in their end-part. 
They are 1.4-2.9 » thick at the base, conic, sharp-pointed, and covered with 
minute and slender, backwardly directed spines, only 0.3 » long. In the middle- 
part of the ray these spines are much more numerous than in the basal and end- 
parts. 

The irregular microhexactines have two opposite longer rays, and four 
shorter rays (Plate 64, figs. 2, 3, 5) vertical to the axis of the two longer. The 
two longer rays are usually fairly equal, the four shorter rays often very unequal. 
These spicules are in form A 120-195 uw long and 90-130 » broad; in form B 
110-170 uw long and 80-135 u broad. Their rays are similar to the rays of the 
regular microhexactines above described, and are 1.8-2.5 » thick at the base. 
Transitional forms connect these spicules on the one hand with the regular micro- 
hexactines and on the other with the diactine microhexactine-derivates. 

The diactine microhexactine-deriwates (Plate 64, fig. 1) are 220-330 u long. 
Their central tyle measures 4-5 » in diameter. Their two properly developed 
rays are similar to those of the microhexactines and are 2.5-3 uw thick at the 
base. The four other rays are reduced, often to quite insignificant protuberances 
of the central tyle. The degree of reduction of these four rays is, in the same 
spicule, usually different, some being generally 5-10 1 and more long, while 
others are represented only by slight protuberances of the central tyle. 

The regular microhexactines are 60-140 u long, the ordinary irregular micro- 
hexactines 110-195 » long, a transitional form with reduced rays 13-25 long is 
225 ulong, one 10-22 long is 270 u long, and one 2-5 long is 330 u long. 

A comparison of these dimensions shows that the total length of these 
spicules, that is to say the length of their two properly developed rays, is in 
proportion to the degree of reduction of their four other rays. 

This correlation is obviously comparable to that found by me! in the 
microscleres of the Tetraxonia, where the number of rays is usually in inverse 
proportion to their size. I am inclined to ascribe this in the case of Hyalonema 
(Hyalonema) placuna to the same cause as in the case of the tetractinellids. 
I believe that the cells or assemblages of cells building spicules like the asters of 
the tetractinellids and the microhexactines and microhexactine-derivates here 
under discussion contain a certain and definite amount of potential energy 
available for spicule-building and that this definite amount of energy is expended 
by the spicule-builders in H. (H.) placuna either in producing six smaller more or 


'R. v. Lendenfeld. Die Tetraxonia. Ergeb. Deutsch. tiefsee-exped., 1907, 11, p. 64. 


214 HYALONEMA (HYALONEMA) PLACUNA. 


less equal, or two larger and four more or less rudimentary rays. If this assump- 
tion is correct, and if the energy saved in the building of the smaller rays is 
utilised in increasing the size of the larger, the latter must be hypertrophic to 
a degree in proportion to the degree of reduction of the former as, in fact, 
they are. 

The amphidiscs. As these spicules are more numerous in form B than in 
form A, I shall commence the description of them with an examination of the 
amphidises of the former. 

The amphidises of form B are 18.5-367 » long. The frequency of those of 


different length is shown in Figure 9. 


Macramphidiscs 
eae 


Micramphidiscs Mesamphidiscs H ‘ 

ff Sern 7S peep 

A ' Small, with broad anchors —! ; : ' 
a ; ' H t ' 
File Large, with narrow anchors : 1 
A]: Small Medium Large Ais yi 

tre Yi alia ama ' Small} with! narrow anchors 
a pa 


Large, with broad anchors 


mo ne a ee ee ie ee 


Set A ee EO TEES pms, ee 


eee SS Sse Yah Se ee et ee 8s 


| | 
WO DMDAMNMOTAOOHODOAODDAOAADM HW rr C 
FH ANBARSFANRRRANHAASR RASA SSRESSRSH 
ZBHOBAAMNNDAOHHRHANDADSONSHNROGOKRDBAGSHDKROHOtHtOW 
SAANANAANANSHAHNTSTHTODSGRBSORBSOUNTOR OOK HOKSSDSS 
ms et et te st tt ON ON NT NN 09) 09) 0) 
ee Cee ee PEt clieii elie logh tte Tt | 
CUO MAMNNODHDOHTODOHORDONNAMHN KR OKROTHR 
Be NRA RN OR RSA SRR ERLES 
O~MDHAMNNASOHKRHAMOHAADONSCDAKONRSD On té ince) ee) 
BH ANNANDMOMNTT SD SORNDODSOUNT HER SSRHLKSSB 
Amt BM TTI NNNN MMO 


Fig. 9.— Form B. Amphidises. 


The figure shows that, apart from minor depressions of the frequency-curve, 
the amphidises can, biometrically (according to the frequency of those of different 
lengths), be divided into two main-groups, one comprising amphidises 18.5—48 yu 
long, the other amphidises 124-367 ». These groups dimensionally so very 
different are connected only by three of the 96 amphidiscs measured, which are 
55, 72, and 100 » long respectively. The part of the curve pertaining to the small 
amphidises exhibits three not very deep depressions, the part of it pertaining to 
the large amphidises one small and one considerable depression. The latter lies 
between amphidises 187 and 214 uv long. 


HYALONEMA (HYALONEMA) PLACUNA. 215 


All the amphidises under 30.5 » and the majority of those 30.542 » long 
have broad anchors (proportion of anchor-length to anchor-breadth 100 to 58— 
92). Some of the amphidiscs 30.5—-48 » long, and all 43-48 » long, have more 
slender anchors (proportion of anchor-length to anchor-breadth 100 to 50-56). 
The few dimensionally intermediate forms 55-100 » long, and the smaller of the 
forms belonging to the second main elevation of the curve (that is those 124— 
286 uw in length), have slender anchors (proportion of anchor-length to anchor- 
breadth 100 to 42-66). The largest measured amphidises, that is those 287— 
367 » long, have broad anchors (proportion of anchor-length to anchor-breadth 
100 to 72-107). Among the latter two kinds can be distinguished according to 
the shape of the anchors. In some of the smaller ones the anchors are narrow 
at the apex and composed of teeth terminally diverging from, parallel to, or 
only slightly converging to the shaft. In the smaller and all the larger ones, that 
is those 328 » and more long, the anchors have a broad apex and are composed 
of distally converging teeth. 

Taking into consideration both their length frequencies and the differences 
in the shape of their anchors, we come to the conclusion that, as stated above, 
seven kinds of amphidises are to be distinguished in this sponge:— 1, large 
macramphidises with apically broad anchors; 2, small macramphidiscs with 
apically narrow anchors; 3, large, 4, medium, and 5, small mesamphidiscs; 6, 
large micramphidises with slender anchors; and 7, small micramphidises with 
broad anchors. 

The amphidises of form A are similar to those of form B but on the whole 
smaller and, as stated above, not so numerous. Groups | and 3 contained only 
one amphidise each and group 5 contained none. 

The large macramphidiscs with apically broad anchors of form B (Plate 66, 
figs. 3, 4) are 287-367 u, most frequently about 320 wlong. The shaft is straight, 
cylindrical, 8.5-11 » thick, and abruptly thickened in or near the middle to a 
central tyle 13-17 » in diameter. An irregular verticil of truncate, cylindrical, 
vertical or, more rarely, oblique spines 8-14 uw long and usually about 5 » thick 
arises from this tyle. The remaining parts of the shaft bear a smaller or a larger 
number of exceedingly low, broad protuberances. The two anchors of the same 
spicule are equal or unequal. Their inequality is sometimes considerable. 
The greatest dimensional difference of the two anchors of the same spicule 
observed was 14 u in the length and 13 4 in the breadth. The anchors are 
100-132 » long, usually about a third of the whole spicule. They attain their 
maximum breadth some distance above the end, and here measure 79-118 » in 


216 HYALONEMA (HYALONEMA) PLACUNA. 


transverse diameter. The end-breadth is 6-9 yu less than the maximum breadth. 
The proportion of the length to the maximum breadth of the anchors is 100 to 
72-107, on an average 100:87.6. There are usually about ten teeth in the 
anchor. The teeth arise nearly vertically from the-shaft and are’curved rather 
strongly in their proximal part; distally their curvature decreases. Altogether 
it is such that the ends of the teeth converge towards the shaft, with the axis of 
which they enclose angles of about 7°. The teeth are T-shaped in transverse 
section. The distal band-shaped part, which corresponds to the horizontal 
stroke of the T, is uniformly about 12 » broad for the greater part of its length, 
and very blunt-pointed or rounded at the end. 

The dimensions of the single spicule of this kind found in form A are:— 
length 315 4; thickness of shaft 74; anchor-length 90 4; maximum anchor- 
breadth 95 «4; proportion of anchor-length to maximum anchor-breadth 100 : 106. 

The small macramphidiscs with apically narrow anchors of form B (Plate 65, 
fig. 1) are 296-319 u, most frequently about 308 » long, have a shaft 6-8.5 » thick, 
and are abruptly thickened in or near the middle to a central tyle 12-15 » in 
diameter. Several short truncate cylindrical spines, as much as 9 uw long and 4» 
thick, arise from this tyle. Low and broad truncate protuberances also occur 
on other parts of the shaft. The terminal anchors are 113-140 u long, usually 
a little over a third of the whole spicule, and 97-102 » broad. The proportion 
of their length to their breadth is 100 to 73-87, on an average 100:77.3. The 
anchor-teeth are usually arranged in the ordinary, strictly verticillate manner, 
but occasionally an amphidisc of this kind is met in which one of the teeth arises 
at a much lower level than the rest (Plate 65, fig. 1). The anchor-teeth arise 
nearly vertically from the shaft. They are curved more strongly in their basal 
part and less strongly in their distal part than the anchor-teeth of the large 
macramphidises with apically broad anchors described above. Their total curva- 
ture is such that their ends usually diverge slightly from the shaft. Sometimes, 
however, their tips are parallel or even slightly convergent. The ends of the 
teeth are usually pointed. 

In form A these spicules (Plate 66, figs. 1, 2, 5) are similar, but on the whole 
smaller. They are here 245-330 » long; the shaft is 7-10 » thick, and the central 
tyle 13-16 ». Cylindrical truncate spines 4 » long and 3-4 w thick arise from 
the latter. The remainder of the shaft usually bears a good many low and broad 
protuberances. The anchors are 95-130 » long and 80-105 » broad. The 
proportion of their length to their breadth is 100 to 79-88, on an average 


100: 83.6. 


HYALONEMA (HYALONEMA) PLACUNA. 217 


The three kinds of mesamphidises (Plate 63, figs. 29-35; Plate 65, fig. 2) 
all have much the same shape. They are distinguished morphologically by the 
anchors of the larger being on the whole somewhat narrower than the anchors 
of the smaller, and biometrically by well-marked depressions in the length 
frequency-curve. The shaft is gradually thickened towards the ends and 
abruptly thickened in or near the middle to a central tyle. The latter bears a 
verticil of conspicuous spines which are cylindrical or cylindroconic, truncate, 
or rarely irregular; usually they are irregularly curved, some in one direction, 
others in others. These spines reach 5 u» in length and 2 » in thickness. In the 
large and medium mesamphidises the remainder of the shaft bears remarkably 
numerous similar spines; these are shorter and usually straight. The terminal 
anchors are narrow. ‘The teeth arise nearly vertically from the shaft, are curved 
very strongly in their basal part and much less strongly and quite uniformly in 
their distal and middle-part. Often they are abruptly bent down near the base. 
Another inconsiderable abrupt inward bend is frequently seen a short distance 
from the end. When such a bend is present the distal part of the tooth, lying 
beyond it, is generally straight or slightly curved in the opposite direction, convex 
to the shaft (Plate 63, figs. 29-32). Altogether the curvature of the teeth is such 
that their end-parts generally slightly converge towards the shaft. Sometimes, 
however, they are parallel to it, or even slightly divergent. 

The measurements of the three kinds of mesamphidises of the two forms 
are tabulated on p. 218. 

This table shows that the mesamphidises are in form B 55-286 u long, in 
form A 105-197 uw. In the single large spicule of this kind observed in form A 
the anchors are broader (proportion of anchor-length to anchor-breadth 100 :73) 
than in the others (proportion of anchor-length to anchor-breadth 100 to 42- 
66). On the whole, as stated above, the smaller these spicules the narrower 
the anchors; the average proportion of anchor-length to anchor-breadth being 


in form B: — 


in the large mesamphidiscs 100 : 58.9; 
in the medium = 100 : 54.7; 
and in the small a 100 :52.7. 


The large micramphidiscs with slender anchors are not numerous. Those of 
form B (Plate 63, fig. 36) are 30.5-48 » long, most frequently about 38. The 
shaft is usually a little under 1 » thick and slightly thickened at some place near 
the middle. It usually bears several minute low and broad spines in the middle- 
part. The terminal anchors are 14-20 u long, usually a third to two fifths of the 


218 HYALONEMA (HYALONEMA) PLACUNA. 


Mesamphidises large medium small 
In form Al B A B A? B3 
limits 4 197 214-286 105-186 124-187 55-100 
Total length most 
frequently 249 143 163 
about / 
Thickness of shaft » 5 4-7 2-4 2-4 1-2 
Diameter of central tyle 7 6-11 2.8-6.5 3.5-6 oe 
limits 73 71-130 38-72 40-82 17-42 
Length of terminal 
ee most 
as frequently 108 51 63 
about 
limits 54 47-85 19.5-52 23-52 10-24 
Maximum breadth 
of terminal anchors mie 
= : frequently 65 31 44 
about / 
Proportion of Pa 3 
. limits 73 55-66 43-66 43-66 42-59 
length to maximum 
breadth of terminal |— SS 
anchors 100 to average 58.9 57 54.7 52.7 


whole spicule, and 6-11 » broad. The proportion of their length to their breadth 
is 100 to 50-56, on an average 100 : 52.3. The individual teeth arise vertically 
from the shaft, and are strongly bent in their proximal, and fairly straight in their 
distal part. Their straight end-parts are usually parallel to the shaft. 

In form A these spicules (Plate 63, fig. 42) are similar in shape, but smaller 
and provided with somewhat narrower anchors. Their dimensions are here 
the following: — total length 28-38 4; length of terminal anchors 12-15 y; 
breadth of terminal anchors 6-6.5 4; proportion of anchor-length to anchor- 
breadth 100 to 43-50, on an average 100 : 47.5. 

The small micramphidiscs with broad anchors are abundant. Those of form B 
(Plate 63, figs. 837-41; Plate 65, fig. 13) are 18.542 u long, most frequently 
26-32 ». The shaft is straight, 0.6-1 » thick, and either simple and cylindrical 
throughout (Plate 65, fig. 13) or thickened somewhere near the middle to a 
central tyle 1-1.3 » in diameter. This tyle and the middle-part of the shaft 
usually bear some minute low and broad spines, either on all sides or on one side 
only. The anchors are 6-16 u long, a little less than a third to two fifths of 


1 Only cne observed. * Apparently absent. 3 Only three observed. 


HYALONEMA (HYALONEMA) PLACUNA. 219 


the whole spicule, and 5-11 4 broad. The proportion of their length to their 
breadth is 100 : 58-92, on an average 100 :73.8. The teeth arise nearly vertically 
from the shaft, and are strongly curved in their proximal part. Their distal 
part is straight, or only slightly curved, concave to the shaft. Their end-parts 
usually diverge slightly from the shaft, sometimes they are parallel to it. 

In form A these spicules (Plate 63, figs. 483-45; Plate 64, figs. 14, 15) are 
similar. Their dimensions are here: — total length 21-34.5 », most frequently 
25-33 »; anchor-length 7-12.5 1; anchor-breadth 5-9 u; proportion of anchor- 
length to anchor-breadth 100 to 56-100, on an average 100 : 71.7. 

Tetradisc. In form B I found a tetractine (stauractine) spicule (Plate 63, 
fig. 51) with irregular terminal anchors on three of the rays. The fourth ray is 
broken off. The four main-rays of this spicule are densely spined, and the 
straight ends of the anchor-teeth, particularly of the longest, also bear conspicu- 
ous spines on their inner side. This spicule has a total diameter of 87 u. The 
anchors are about 35 » long and 36 y» broad. 

The above description shows that these two sponges differ from each other 
in respect to the shape and size of several of their spicules, particularly their 
dermal and gastral pinules. These differences are quite constant and striking. 
I do not, however, consider these differences sufficient for specific or varietal dis- 
tinction. I therefore place the two sponges in the same species and distinguish 
for them, within this species, two forms. 

There can of course be no doubt about this species belonging to the Hexac- 
tinellida Amphidiscophora. It is more difficult to determine the genus, as 
the remarkable shape indicates a new generic character. Since, however, the 
specimens on which it is based are somewhat fragmentary, and since no trace of a 
stalk or other supporting apparatus is present, [ refrain from doing so and place 
it provisionally in the genus Hyalonema, subgenus Hyalonema, some of the known 
species of which are quite similar in respect to spiculation. 

These sponges are distinguished by their shape and the dimensions of their 
spicules to such an extent that they can not be assigned to any of the described 
species. Their nearest allies are Hyalonema (H.) tenuifusum and H. (H.) tylo- 
stylum. From these they differ by the presence of protruding ridges (folds) which 
are absent in the two last named species; also by the dermal pinules being 
smaller and having much shorter lateral rays than in H. (H.) tenuifusum (the 
dermal pinules are larger than those of H. (H.) tylostylum); by their gastral 
pinules having longer distal rays than in H. (H.) tenuifusum (the gastral pin- 
ules are larger than those of H. (H.) tylostylum); by the microhexactines being 


220 HYALONEMA (HYALONEMA) SP. 


covered with conspicuous recurved spines; by the micramphidise being longer 
and having much larger anchors than in H. (H.) tenuifusum, and being shorter 
and having relatively much broader anchors than in H. (H.) tylostylum, and by 
other characters. These facts together with the widely separated habitats (fully 


50 equatorial degrees) are sufficient for specific separation. 


Hyalonema (Hyalonema,) sp. from Station 4656. 


Plate 68, figs. 26-33; Plate 69, figs. 1-5. 


Part of a macerated specimen was trawled off northern Peru, Station 4656, 
on 13 November, 1904; 6° 54.6’ S., 83° 34.3’ W.; depth 4063 m. (2222 f.); 
the bottom was composed of fine, green mud mixed with gray ooze; the bot- 
tom-temperature was 35.2°. It is obviously the basal part of a Hyalonema but 
cannot be determined specifically. 

The specimen (Plate 68, fig. 26) is an elongate, irregularly oval lamella 
60 mm. long, 22 mm. broad, and 8 mm. thick. A stalk 5 mm. thick and broken 
off short arises from one of the two narrow ends. The colour is brown. 

Amphiox megascleres, basal acanthophores, stalk-spicules, and microhexac- 
tines, which doubtlessly belong to the sponge, are found in large numbers in the 
spicule-preparations. Only a few hexactine and pentactine megascleres, pinules, 
and amphidises were seen. Some of these are probably proper to the sponge, 
others foreign, and it is impossible in every case to determine with certainty. 

The pinules which seem to be proper to the sponge are of two kinds, larger 
and smaller. Both are pentactine. The larger have a bushy distal ray 460-540 u 
long and 8-10 » thick at the base. The distal ray, together with the spines, 
is 40-60 » in transverse diameter at the point of maximum thickness, which lies 
high up. The lateral rays are 50-73 uw long. The dimensions of the smaller 
pinules (Plate 69, figs. 1, 2) are:— distal ray, length 124-360 u, basal thickness 
7-12 uw, maximum thickness, together with the spines, 15-48 wu; lateral rays, 
length 27-50 uz. 

A pentactine observed has conical lateral rays 750 » long and 35 u thick 
at the base. 

The hexactines are 0.7-1.5 mm. in maximum diameter. The rays are 
16-28 uw thick at the base, and usually somewhat unequal in size in the same 
spicule. 

The amphiozes are 1.8-2 mm. long and 10-17 » thick near the centre. Most 
of them are distinctly centrotyle. The central tyle is generally about 5 » more 


in transverse diameter than the adjacent parts of the spicule. 


HYALONEMA (HYALONEMA) SP. 221 


The basal acanthophores (Plate 68, figs. 27, 28, 31-33) have from two to 
six rays, the tetractine (stauractine) forms greatly predominating. The tri- 
to hexactines are 230-820 uw long and have rays 11-33 u thick at the base. The 
diactines are 0.7-1.15 mm. long and 7-30» thick near the centre. Most of 
them, particularly the shorter ones, are distinctly centrotyle; their central tyle 
is 12-62 u, which is sometimes 40 » more than the adjacent parts of the spicule 
in transverse diameter. The ends of the rays are thickened and densely cov- 
ered with rather large spines. The remaining parts of the spicules are generally 
smooth. In some stout-rayed tetractines a few spines arise also from the basal 
parts of the rays (Plate 68, fig. 31), and some diactines have a very spiny central 
tyle (Plate 68, fig. 27). 

In the lower part of the body fragments of wncinate anchor-spicules have 
been observed. A spicule of this kind measured is 11 » thick just above the 
anchor. The anchor is 25 » long and 18 uw broad. The anchor-teeth are rather 
numerous, irregular, strongly recurved, and very blunt. 

The microhexactines (Plate 68, figs. 29, 30) are mostly rather regular and 
measure 85-150 » in diameter. In some, two opposite rays are longer than the 
other four. Such microhexactines are sometimes 200 » long and 120 uw broad. 
The rays are 1.5-2.5 » thick at the base, and usually slightly curved a little 
beyond the middle of their length. This curvature is often unequal in different 
rays of the same spicule. 

Occasionally monactine microhexactine-derivates have been observed. A 
spicule of this kind measured appears as a tylostyle 120 u in length and 1 u 
in thickness, with a terminal tyle 3.5 » in diameter. 

Those amphidiscs (Plate 69, figs. 3-5) which can, with some degree of 
probability, be assigned to the sponge, fall into five categories:— large and small 
macramphidises, large and small mesamphidises, and micramphidiscs. 

The dimensions of these five kinds of amphidises are tabulated below :— 


Length of Breadth of Thickness of | Diameter of 
Total length anchor anchor shaft central tyle 
m7 a BK “ KB 

Large macramphidises 280-316 76-120 90-104 9-12 13-18 
Small macramphidises 220-225 77-80 60-70 8 10 
Large mesamphidises 136-168 46-66 22-43 2-6 2-8 
Small mesamphidises 45-69 23 15-18 1.5-2 
Micramphidises 20-29 4-7 6-8 0.6-1 


° 


222 HYALONEMA (HYALONEMA) TENUIFUSUM. 


In respect to its large pinules this sponge somewhat resembles Hyalonema 
(Hyalonema) placuna, in respect to its large amphidises Hyalonema (Hyalonema) 
polycaulum. 

Hyalonema (Hyalonema) tenuifusum, sp. nov. 


Plate 67, figs. 1-26; Plate 68, figs. 1-25. 


A larger (a), and several fragments of another, smaller (6) specimen of this 
sponge were trawled off the coast of northern Peru at Station 4656 on 13 No- 
vember, 1904; 6° 54.6’ S., 83° 34.3’ W.; depth 4063 m. (2222 f.); it grew on a 
bottom of fine, green mud mixed with gray ooze; the bottom-temperature 
was 35.2°. The name refers to the minute, exceedingly slender, centrotyle 
amphioxes so abundant in these sponges. 

Shape and size. Specimen (a) (Plate 67, fig. 1) appears as a somewhat 
lacerated lamella, irregularly oval in outline, 84 mm. long, and 56 mm. broad. 
At one of its narrower ends a stalk, 3 mm. thick, arises from its margin. This 
stalk lies in the same plane as the lamellar body of the sponge. The latter 
is stoutest some 20 mm. above the point where the stalk arises from it, and is 
here 12 mm. thick. Upwards and sideways the lamella gradually thins out 
towards the margin. The fragments of specimen (b) are lacerated pieces of a 
lamella 1.5-3 mm. thick. The lamellar body is not simple and solid throughout, 
in either of the specimens, but is partly composed of two lamellae in contact 
with each other. The inner surfaces of these lamellae are obviously gastral 
surfaces and it is probable therefore that these sponges are in truth calyculate, 
and that their present shape is due merely to a collapse of the walls, caused by 
pressure exerted during or after capture. 

The colour in spirit is brown, rather dark in (a), pale in (0). 

The skeleton. Both the outer dermal and the inner gastral surfaces are 
covered by a dense pinule-fur. Smaller gastral pinules have been found in the 
walls of some of the canals. Below the dermal and gastral surfaces masses of 
paratangential rhabds form a kind of felt. These rhabds are mostly centro- 
tyle amphioxes, but derivates of these spicules, with one actine reduced in length 
and often thickened and terminally rounded, also occur among them. This 
spicule-felt is pierced by the proximal rays of hypodermal and hypogastral 
pentactines. Similar amphioxes and amphiox-derivates and occasionally hex- 
actine megascleres were observed in the interior. The microscleres are regu- 
lar microhexactines, irregular microhexactines with two opposite rays much 


longer than the others, minute centrotyle amphioxes, minute tylostyles, large 


HYALONEMA (HYALONEMA) TENUIFUSUM. 223 


macramphidises, small macramphidises, and micramphidises. The large macr- 
amphidises are rather rare, the minute tylostyles, which may be foreign, very 
searce. All the other kinds of microscleres are abundant. At the point of 
emergence of the stalk, numerous monactine to hexactine, stout acanthophores, 
occur at the base of specimen (a). The stalk itself consists of a dozen stout, 
and a number of more slender spicules twisted in the usual way. 

The dermal pinules (Plate 68, figs. 18-21, 24, 25) are nearly always pentac- 
tine, very rarely hexactine. The distal ray is straight, 336-550 u long, generally 
430-530 u, and, at the base, 8-11 u thick, rarely as much as 13 yu. Its proximal 
end is smooth; for the rest of its length it is covered with upwardly directed spines 
which are sparse, stout, short, straight, or only slightly curved, and strongly 
divergent below, and which increase in density and length, and decrease in 
divergence and thickness above, up to a point a short distance below the tip of 
the ray. From this point onward to the end of the ray the spines again become 
smaller, less divergent, and more and more curved, concave to the ray, the 
distal parts of the uppermost spines being nearly parallel or even convergent. 
The maximum thickness of the distal ray, together with the spines, is 37-65 wu. 
The point of maximum thickness lies high up. The proportion of the total length 
of the distal ray to the distance of the point of maximum thickness from the 
centre of the spicule (the proximal end of the distal ray) is, in the dermal pinules 
of specimen (a), 100 : 64 to 84, on an average 100 : 79, in the dermal pinules of 
(b) 100 : 67 to 84, on an average 100 : 75.2. When the point of maximum thick- 
ness is very high up, the distal ray, together with the spines, appears club-shaped. 

The lateral rays of the same spicule are usually fairly equal, straight, eylin- 
droconical in the basal and middle-parts, and abruptly pointed at the end. 
They are, in the dermal pinules of specimen (a) rather smooth, and 52-90 u 
long; in those of (b) spiny, and 40-75 » long. The rare hexactine dermal pinules 
are quite similar to the pentactine. Their proximal ray reaches 103 yu in length. 
In a good many pentactine pinules of specimen (b) a little cluster of spines, 
about 4 » long, arises from the centre of the proximal face of the cross formed by 
the lateral rays. This central spine-cluster may be a remnant of a reduced 
proximal ray. 

The gastral pinules (Plate 68, figs. 2, 3) are, like the dermal, usually pentac- 
tine, rarely hexactine. The distal ray is 101-228 » long, and 4-10 u thick at the 
base. It bears sparse spines directed obliquely outward and upward. The 
spines are usually only slightly curved, concave to the ray. Occasionally, 


however, the lowest spines exhibit a strong curvature in this direction. The 


224 HYALONEMA (HYALONEMA) TENUIFUSUM. 


largest spines are usually those arising some distance below the middle of the 
length of the ray. Proximally they become shorter but remain nearly as thick; 
distally they become both shorter and more slender. The spines on the distal 
part of the ray are usually very small, often quite rudimentary. At the point 
of maximum thickness, which is generally situated below the middle of its length, 
the distal ray is, together with the spines, 10-46 y in transverse diameter. The 
gastral pinules of specimen (a) appear to have on the whole more slender distal 
rays than those of (b). The lateral rays are straight, ecylindroconical, and 39— 
92 » long, most frequently 45-70 u. They are spiny. In the gastral pinules 
of specimen (a) their spines are usually quite numerous and small, in those of (b) 
often sparse and very large, 2-4 4 long. The proximal ray of the hexactine 
forms is similar to the laterals but shorter. 

The canalar pinules (Plate 68, fig. 4) are very variable in appearance and 
form a series one end of which is represented by pinules similar to the gastrals, 
the other by pentactines the apical ray of which is only slightly longer and 
bears only slightly larger spines than the laterals. The distal ray is 68-120 u 
long, and 3.5-7 » thick at the base. It bears a few obliquely ascending, nearly 
straight spines, which attain a considerable size in the larger pinules of this kind. 
At the point of maximum thickness, which usually lies at or below the middle of 
its length, the distal ray, together with the spines, is 8-28 u thick. 

The hypodermal and hypogastral pentactines have a straight proximal ray 
0.5-1 mm. long, and 10-60 » thick at the base. The lateral rays are straight, 
usually inclined more or less towards the proximal ray, and 0.2-1.1 mm. long. 
I have often noticed a great inequality in the length of the lateral rays. In some 
of these spicules the longest lateral is nearly twice as long as the shortest. 

The choanosomal hexactine megascleres are 0.5-1.5 mm. in total diameter, 
and have conical rays 9-27 » thick at the base. Besides the more or less intact 
hexactines from which these measurements were taken, fragments of such 
spicules were observed which indicate that hexactine megascleres also occur of 
dimensions considerably exceeding those given above. 

The centrotyle amphiox megascleres are more or less curved, 0.9-3.4 mm. 
long, usually 1-2.4 mm., and 7-13 u thick near the middle. The central tyle 
measures 16-26 » in diameter, and is 1.2—2.9 times as thick as the adjacent parts 
of the spicule. The thin amphioxes have a relatively larger central tyle than 
the stout ones. 

The style amphiox-derivates are as thick as the amphioxes, but shorter. 


In these spicules one of the two rays is properly developed, the other reduced 


HYALONEMA (HYALONEMA) TENUIFUSUM. 220 


in length, rounded at the end, and thickened so as often to attain a transverse 
diameter nearly equal to that of the ‘‘central”’ tyle, which in these spicules is of 
course very eccentric. 

The spicules forming the stalk are, at the point where they arise from the 
sponge-body, sometimes 0.5 mm. thick. Fragments of rhabds 20-40 yw thick 
* found in spicule-preparations of the interior are probably parts of young stalk- 
spicules. All the stalk-spicules observed were smooth. 

The stout acanthophores (Plate 67, figs. 6, 7) have from one to six, most 
frequently from two to four rays. The rays usually taper distally, more rarely 
they are cylindrical. The end-part is densely covered with spines, generally 
somewhat thickened, and terminally rounded, or more rarely, pointed. The 
diactine forms are centrotyle. The three- to six-rayed forms are 335-580 u 
in diameter, and have rays 10-20 » thick. In the three-rayed forms all the rays 
lie in the same plane; two generally in a straight line, and the third at right 
angles to these. In the four-rayed forms the rays also lie in one plane, and the 
adjacent ones enclose angles of 90°. These spicules therefore appear as crosses 
(stauractines). In the rare pentactine forms four rays extend in a plane, enclose 
angles of 90° with each other and appear as lateral rays, whilst the fifth is verti- 
cal to the plane of the four others and appears as an apical ray. The rare six- 
rayed forms are regular hexactines. 

In the diactine acanthophores the rays lie in a straight or slightly curved 
line. These spicules are 675 y—-1.1 mm. long and 10-12 » thick. Their central 
tyle is 17-30 » in transverse diameter. They are connected by transitional forms 
with the ordinary centrotyle amphiox megascleres. These transitional forms 
are about as thick as the true diactine acanthophores, but longer, reaching 2.6 
mm. in length, and have smaller central tyles. The monactine forms are tylo- 
styles 0.8-1 mm. long and 10-13 u thick. The terminal tyle is about 22 yu in 
diameter. 

The regular microhexactines (Plate 67, figs. 10, 11) have six regularly dis- 
tributed, conical and sharp-pointed, straight or slightly curved rays. The 
curvature is, when present, usually greater in the proximal than in the distal 
part of the ray. The rays are nearly smooth, or slightly roughened by the 
presence of exceedingly minute spines, which appear to be directed backwards 
towards the centre of the spicule. In specimen (a) the regular microhexactines 
are 110-155 » in total diameter, and have rays 1.5-2 » thick at the base. In 
specimen (6) these spicules are somewhat smaller, 80-105 » in diameter, and 
have rays 1-2 » thick at the base. 


226 HYALONEMA (HYALONEMA) TENUIFUSUM. 


In specimen (b) I found a microhexactine with a branch-ray on one of its 
rays. 

In the irregular microhexactines (Plate 67, fig. 8; Plate 68, figs. 7-9, 12-15) 
two opposite rays, lying in the same spicular axis, are long and well-developed, 
the other four variously reduced. The two long rays may be considered as 
apical, the other four as lateral rays. The two long apical rays are considerably 
longer than the rays of the regular microhexactines, so that the maximum diam- 
eter, that is the total length of these spicules, exceeds the diameter of the regular 
microhexactines. The apical rays are straight or only very slightly curved in 
their basal and_middle-part, conical, pointed, smooth, or slightly roughened by 
very minute spines, and are 1—2.2 » thick at the base. The degree of reduction 
of the four lateral rays is equal or unequal, and is generally very considerable. 
They may all be present and equally long, or one, two, or three of them may 
be shorter or altogether absent. When one or more of these rays have dis- 
appeared altogether, the remaining lateral rays are usually very short. Spic- 
ules in which three of the lateral rays have disappeared altogether whilst the 
fourth is only slightly reduced in length (Plate 68, fig. 13) are very rare. It is 
to be noted that the reduced lateral rays are not only shorter, but often also 
thinner than the apical, the difference in the basal thickness of the apicals and 
laterals often amounting to 0.5 pu. 

The irregular microhexactines in both specimens are 125-400 » long and 
8-112 u broad. There is a very clearly pronounced correlation between the 
length of the apical rays (the total length of the spicule) and the degree of 
reduction of the lateral rays (the total breadth of the spicule); the longer the 
apicals and the whole spicule, the shorter are the laterals and the narrower is the 
whole spicule. 

The irregular microhexactines 125-170 long are 72-112 broad. 

“ 190-220 “ “ 33-85 fa 
es a 280-400 ‘“ “ 8-14 ¢ 

Thus these irregular microhexactines form a series connecting the (shorter) 
regular microhexactines described above with the (longer) minute centrotyle 
amphioxes described below. 

The minute centrotyle amphioxes (Plate 67, fig. 12; Plate 68, figs. 16, 17) 
are more or less curved, the central part usually in one direction, the two end- 
parts in the opposite, so that these spicules generally look like bows. They are 
mostly 580-830 uw long, and 1.5-2 » thick near the middle. The central tyle is 


oval and measures 3-5 u in transverse diameter. The two rays are conical and 


HYALONEMA (HYALONEMA) TENUIFUSUM. 227 


sharp-pointed. The whole spicule is entirely smooth. The largest of these 
spicules are quite similar to, and only slightly shorter than, the smallest centro- 
tyle amphioxes above described as megascleres, and they might indeed be con- 
sidered as small forms of these spicules. There is, however, a very conspicuous 
gap which lies between 2 4 and 7 » in the biometrical frequency-curve of the 
thickness of all these spicules taken together. This gap makes the distinc- 
tion easy between those 2 » thick and thinner, above described as minute 
centrotyle amphioxes, and those 7 » thick and thicker, above described as cen- 
trotyle amphiox megascleres. 

The rare minute tylostyles, which are perhaps, foreign, are 140-200 u long. 
The tyle is not situated quite at the end, is oval in shape, 5 u in diameter, and 
roughened by minute spines. The ray is 2-3 u» thick at the base, smooth, coni- 
eal, pointed, and straight, or slightly curved. 

The amphidiscs measured are 20-340 « long. Their biological length 
frequency-curve is interrupted by a large gap between 34 and 77 u, and by minor 
gaps the most conspicuous of which lies in the curve of specimen (a) between 
160 and 230 u, and in the curve of (b) between 152 and 202 u. The amphidises 
20-34 » in length form, morphologically, a fairly homogeneous group; they are 
to be considered as micramphidises. The amphidises 77-340 u in length are 
morphologically not homogeneous, the small ones having slender and long 
anchors, particularly in specimen (6), whilst the anchors of the large ones are 
stout and short. Since, however, the broad and narrow anchored forms are 
morphologically, connected by very numerous transitional forms intermediate 
in size, I think it best to consider all the amphidiscs 77-340 » long as one group 
of macramphidises. The larger (on the whole broad anchored) and the smaller 
(on the whole narrow anchored) macramphidises are distinguished biometri- 
cally by the gap above referred to in their length frequency-curve (for specimen 
(a) between 160 and 230 y, and for specimen (b) between 152 and 202 »). In 
accordance with this gap I distinguish two kinds of macramphidises, small 
macramphidises (in specimen (a) 129-160 » long, in (6) 77-152 u) and large 
macramphidises (in specimen (a) 230-330 u long, in (b) 202-340 1). 

The large macramphidises (Plate 67, figs. 2-5, 15, 26; Plate 68, fig. 1) are 
230-330 » long in specimen (a). The shaft is straight and cylindrical, 5-11 
thick, apart from an abrupt thickening somewhere near the middle and a gradual 
thickening towards both ends. The central thickening (tyle) is 10-20, in 
diameter, usually about twice as much as the shaft. It bears a verticil of fairly 


straight, truncate, cylindroconical spines which are vertical to the shaft ‘or, 


228 HYALONEMA (HYALONEMA) TENUIFUSUM. 


more rarely, slightly inclined, and measure 5-12 » long and 2-4 » thick. From 
the other parts of the shaft arise a greater or smaller number of low truncate 
or terminally rounded protuberances 1—2 » long and 2-3 » thick. The terminal 
anchors are 66-110 », about a third of the whole spicule, and 61-97 » broad. 
The proportion of their length to their breadth is 100 : 84 to 102, on an average 
100 : 93.6. The anchors in the larger forms are relatively broader than in the 
smaller, the fraction ie being, roughly speaking, in proportion to the length 
of the amphidisc. The anchor-teeth arise vertically from the shaft, and are 
curved concave towards it. This curvature decreases distally, and is on the 
whole such that the ends of the teeth converge more or less. When this conver- 
gence is great the anchor may be, at its end, as much as 10 » narrower than in its 
broadest part. The individual teeth are 10-15 » broad, and abruptly and not 
sharply pointed (Plate 67, figs. 3, 4; Plate 68, fig. 1). 

In specimen (b) the large macramphidises are similar but have narrower 
anchors. Their dimensions in this specimen are: — length 202-340 »; thickness 
of shaft 5-13 4; diameter of central tyle 8-22 »; length of anchors 46-114 uy; 
breadth of anchors 43-98 »; proportion of anchor-length to -breadth 100 : 65 to 
98, on an average 100 : 80.8. 

The small macramphidiscs (Plate 67, figs. 13, 14, 22-25; Plate 68, figs. 22, 
23) are in specimen (a) 129-160 u long, in (b) shorter, only 77-152 u long. The 
shaft is straight or, rarely, curved and 2-3 » thiek. A cluster of irregularly dis- 
posed, more or less oblique, and often considerably curved, cylindrical, truncate 
spines with a maximum length of 3 u arises from a point in or near the middle 
of the shaft. At this point the shaft is usually, but by no means always, gradu- 
ally thickened to a tyle sometimes 6 » in diameter. The remaining parts of the 
shaft are quite densely covered with smaller spines, generally cylindroconical 
and truncate, which have a maximum length of 2.3 4 and are 1 » thick. The 
terminal anchors are somewhat different in the two specimens. In (a) they are 
36—54 uw long, over one quarter to over two fifths of the whole spicule, and 22-30 » 
broad, the proportion of their length to their breadth being 100 to 48-64, on an 
average 100 : 58.5; in (b) they are 34-63 » long and 18—48 u broad, the propor- 
tion of their length to their breadth being 100 to 46-75, on an average 100 : 54. 
Relative to the length of the whole spicule these anchors in specimen (a) are 
considerably shorter than in (b).. The proportion of the total length of the 
spicule to the anchor-length is in (a) 100 : 27 to 34, on an average 100 : 30.5; in - 
(b) 100 : 34 to 44, on an average 100 : 38.8. The individual anchor-teeth are 
strongly curved, concave to the shaft at the base, and only slightly and rather 


HYALONEMA (HYALONEMA) TYLOSTYLUM. 229 


uniformly curved in the same direction for the remainder of their length. The 
tips of the teeth are sometimes abruptly bent inward. Occasionally in their 
middle-part, particularly in the forms with curved shaft, the teeth are slightly 
curved outward. 

The micramphidises (Plate 67, figs. 16-21; Plate 68, figs. 5, 6) are in speci- 
men (a) 24-34 u long, in (b) 20-32 ». The shaft is straight, cylindrical, and 0.8— 
1» thick. It bears a small number of irregularly scattered spines in its usually 
gradually thickened central part. The terminal anchors are in specimen (qa) 
5-8 u long, a quarter to a third of the whole spicule, and 5-9 » broad; in (6) 
7-10 » long and 6.2-10 » broad. The proportion of anchor-length to anchor- 
breadth is 100 : 87 to 130, on an average 100 : 99.1. 

The nearest allies of these sponges are Hyalonema (Hyalonema) placuna and 
H. (H.) tylostylum. From H. (H.) placuna they differ: — by their external shape; 
by possessing abundant minute slender centrotyle amphioxes; by having dermal 
pinules with much longer lateral and somewhat longer distal rays; by the distal 
rays of their gastral pinules being shorter; by their amphidiscs having smaller 
anchors; by their microhexactines being much less spiny; and by other char- 
acters. From H. (H.) tylostylum they differ by the larger size of their pinules; 
by the possession of numerous minute, slender amphioxes and microhexactines 
with four reduced rays; by the absence of tylostyles; and by having consider- 


ably smaller macramphidiscs. 


Hyalonema (Hyalonema) tylostylum, sp. nov. 


Plate 69, figs. 6-25; Plate 70, figs. 1-10. 


I establish this species for two specimens trawled off northern Peru at 
Station 4656 on 13 November, 1904; 6° 54.6’ S., 83° 34.3’ W.; depth 4063 m. 
(2222 f.); the bottom consisted of fine, green mud mixed with gray ooze; the 
bottom-temperature was 35.2°. 

Shape and size. Both specimens are compressed, lamellar, and broader at 
one end than at the other. The narrower end is rounded, the broader irregular 
and lacerated. A stalk about 2 mm. thick and broken off short arises from the 
middle of the convexity of the narrower, rounded end. One of the specimens 
(Plate 70, fig. 6) is 50 mm. long, 33 mm. broad, and 7 mm. in maximum thick- 
ness; the other measures 75 by 50 by 10 mm. _ In both specimens the upper part 
consists of two lamellae pressed together and joined laterally and below. This 
structure and the spiculation of the inner and outer surfaces of the lamellae 


230 HYALONEMA (HYALONEMA) TYLOSTYLUM. 


indicate that these sponges were, in life, cup-shaped and that they have lost 
their upper marginal part and have been compressed to lamellar structures 
without open gastral cavities during or after capture. 

The colour in spirit is dull brown. 

The skeleton. The distal rays of the dermal pinules form a dense fur on the 
intact parts of the outer surface (Plate 70, figs. 3b, 8). Numerous amphidises, 
chiefly small macramphidises, occur in and just below the dermal membrane. 
The shafts of these spicules are situated radially. About one half of each of these 
amphidises with one anchor protrudes freely beyond the surface; the other 
half with the other anchor is imbedded in the sponge (Plate 70, fig. 3a). The 
lateral rays of hypodermal pentactines extend just below the layer occupied by 
the lateral rays of the pinules. Large macramphidises with the shaft parallel or 
oblique to the surface occur a little farther. Besides these and down the proxi- 
mal rays of the hypodermal pentactines, small hexactine megascleres also occur 
in this region. The skeleton of the inner gastral face of the lamellae (cup-wall) 
consists of gastral pinules and hypogastral pentactines. Tylostyles, hexactines, 
numerous microhexactines, a few micropentactines, and a good many amphi- 
dises, chiefly small macramphidises and micramphidiscs, are met with in the 
choanosome amphioxes. 

The dermal pinules (Plate 70, figs. 1, 2, 3b, 8) are pentactine and have a 
straight distal ray. One of the many observed was hexactine, and one other 
had an angularly bent distal ray. The distal ray is 340-379 » long, most fre- 
quently 342-368 y, on an average 355 yn, and, at the base, 8-11 » thick, generally 
about 9. Its basal end-part, for a distance of about 30 u, is smooth, thence 
onward the distal ray is spiny. The lowest spines are scarce, short, and very 
divergent. Distally, up to a point 100-120 » from the tip of the ray, the spines 
become more crowded, longer and more strongly inclined towards the ray. 
Farther on they again decrease in length and divergence, the uppermost being 
nearly parallel to the shaft. At the point of maximum thickness, which lies high 
up, the distal ray, together with the spines, is 31-47 » in transverse diameter. 
The lateral rays are cylindrical, usually rounded at the end, spined, and 27-42 u 
long, on an average 35 uw. The single proximal ray observed was about as long 
as the laterals. 

All the gastral pinules (Plate 70, figs. 9, 10) observed were pentactine. 
Their distal ray is straight, 120-245 » long, most frequently 150-190 uw, on an 
average 166 uw, and, at the base, 5-10 » thick, generally about 8 uw. It is sharp- 
pointed and markedly thickened some distance below the middle of its length. 


HYALONEMA (HYALONEMA) TYLOSTYLUM. 231 


It bears spines which are somewhat irregular, strongly divergent, often vertical 
below, and which increase in inclination towards the ray distally. The longest 
spines arise from the thickest part of the ray, a little below the middle of its 
length. The maximum thickness of the distal ray, together with the spines, 
is 23-33 u. The lateral rays are conical, pointed or somewhat blunt, very spiny, 
and 45-68 uw long. 

The (hypodermal and hypogastral) pentactines (Plate 69, fig. 7) have a 
conical blunt proximal ray 0.5-0.8 mm. long, and 15-40 » thick at the base. 
The lateral rays are straight, conical, blunt, usually 0.3-0.5 mm. long, rarely 
up to 1.4 mm.; in the same spicule they are often unequal, and vertical to the 
proximal ray or inclined towards it. The angle between proximals and laterals 
is 80-90°. 

The hexactine megascleres (Plate 69, fig. 6) are 0.4-1.3 mm. in diameter. 
Their rays are conical, straight, and frequently unequal. Occasionally one ray 
is reduced in length, cylindrical, and terminally rounded. The basal thickness 
of the rays is 13-37 uy. 

The amphioxes (Plate 69, figs. 11-13) are generally slightly and uniformly 
curved, 0.6-3.4 mm. long, and 10-30 » thick near the middle. A central tyle ean 
usually be made out, but it is quite insignificant, as it was not more than 3 u 
thicker than the adjacent parts of the spicule in any of the amphioxes measured. 

The tylostyles (Plate 69, figs. 8-10) are nearly straight, and 0.8-3.1 mm. 
long. The terminal tyle is 6-22 « thicker than the adjacent parts of the spicule, 
and measures 16-52 y in transverse diameter. It is usually spherical and quite 
smooth. Sometimes (Plate 69, fig. 10) a short oblique spine arises from it. 
The shaft ends in a blunt point. Close to the tyle it is 10-30 » thick. In the 
small (short) tylostyles it tapers gradually from the tyle to the opposite blunt- 
pointed end. In the medium tylostyles it is cylindrical, of nearly uniform thick- 
ness for the greater part of its length, and tapers towards the blunt-pointed end 
only in the ultimate third of its length. In the large tylostyles the shaft is 
spindle-shaped and sometimes 20 » thicker in its middle-portion than just below 
the terminal tyle. 

The fragments of stalk-spicules observed are smooth and, at the point where 
they emerge from the sponge-body, have a maximum thickness of 0.5 mm. 

The microhexactines (Plate 70, figs. 4, 5a, 7) and their rare pentactine-deri- 
vates (Plate 70, fig. 5b) are quite regular, the rays of the same spicule being 
fairly equal in size. The total diameter of these spicules is 75-170 u, generally 


104-140 ». In most of them all the six rays are nearly straight. In some, one 


232 HYALONEMA (HYALONEMA) TYLOSTYLUM. 


ray or, rarely, several rays are markedly curved. In such rays the curvature 
is not confined to the end-part. The rays are conical, fine-pointed, distinctly 
spiny, and at the base 1.5-2.7 » thick, usually about 2 4. The rare pentactine 
forms differ from the hexactine ones only by having five rays instead of six. 

The amphidiscs are 29-410 » long. Their length frequency-curve exhibits 
one great interruption between 49 and 116 4. The amphidises under 49 uw in 
length (that is those between 29 and 49) have relatively shorter and broader 
anchors, the amphidises over 116 u in length (that is those between 116 and 410) 
have relatively longer and narrower anchors. Thus both from a morphological 
and a biometrical point of view, two kinds of amphidise are to be distin- 
guished :— micramphidises 29-49 » long with broad anchors, and macramphi- 
dises 116-410 uw long with slender anchors. The length frequency-curve of the 
macramphidiscs is somewhat irregular, and exhibits a broad depression at about 
250 uw. In the amphidises under 250. in length the average proportion of 
anchor-length to anchor-breadth is 100 : 58.8, in those over 250 u in length this 
proportion is 100 : 73.7. The macramphidises can therefore be subdivided into 
two groups:— small macramphidises 116-250 long with relatively more 
slender anchors, and large macramphidises 250-410 » long with relatively 
broader anchors. The length frequency-curve of the micramphidises is quite 
regular and has only one very pronounced summit. These spicules form a 
single, homogeneous group. 

The large macramphidiscs (Plate 69, figs. 14, 19, 24, 25) are 260-410 yu, most 
frequently about 378 u long. The shaft is straight, for the greater part of its 
length cylindrical, and 6-12 u thick. It is slightly and gradually thickened 
towards its ends, and to a greater extent and much more abruptly thickened at 
or near the middle to a central tyle. The ends are 2-7 u» thicker than the cylin- 
drical part of the shaft. The central tyle is 13-28 u» in transverse diameter, that 
is, 6-18 » more than the adjacent parts of the shaft. It bears a verticil of spines 
which are cylindrical, or only very slightly distally attenuated, terminally simply 
rounded or more rarely truncate, and more or less, often very considerably, 
curved (Plate 69, figs. 14, 19, 24, 25). The curvature is generally simple and 
extends in a plane which passes through the axis of the shaft. Usually all the 
spines of the tyle are curved in the same direction (towards the same end of the 
spicule) (Plate 69, figs. 19, 24). Occasionally the majority of them are curved 
towards one end and a minority of one or two towards the opposite end (Plate 
69, figs. 14, 25). Generally the spines are simple, exceptionally bifurcate (Plate 
69, fig. 14, the left one). These spines are 7-17 » long and 3-6 4 thick. The 


HYALONEMA (HYALONEMA) TYLOSTYLUM. 233 


remaining parts of the shaft bear a larger or smaller number of similar but much 
shorter and nearly straight spines, which are 3-6 uv long, exceptionally 12 u, and 
3-5.5 w thick. 

The terminal anchors are 95-148 wu long, usually a little over a third of the 
whole spicule, and 60-114 4 broad. The proportion of their length to their 
breadth is 100 to 57-89, on an average 100 :73.7. Although both in the larger 
and the smaller of these spicules relatively broad and relatively slender anchors 
are met, yet the relative anchor-breadth is, on the whole, correlated to the 
length of the spicule, so that, roughly speaking, the smaller the amphidisc the 
more slender the anchors. In the largest large macramphidises, over 350 u 
in length, the proportion of anchor-length to anchor-breadth is 100 to 62-89, 
on an average 100:78; in the smaller large macramphidiscs, under 350 u in 
length, this proportion is 100 to 57-79, on an average 100 : 68.6. 

The anchor consists of eight teeth. The individual teeth arise vertically 
from the shaft, are considerably curved, concave to the shaft in their proximal 
part, and slightly and quite uniformly curved in the same direction in their 
distal and middle-parts. The curvature is such that the end-parts of the teeth 
are parallel or slightly convergent. In the latter case the end of the anchor is 
of course narrower than a portion of its middle-part. The anchor-breadth 
measurements given above are always the maximum breadths. The anchor- 
end breadth may be 14 u less than the maximum breadth. The teeth have the 
usual T-shaped transverse section. The upper and outer part, which corre- 
sponds to the upper stroke of the T, is a thin band of a fairly uniform breadth of 
13-18 », to within a short distance of the end. The end itself is abruptly and 
not sharply pointed. The lower and inner keel, which corresponds to the lower 
stroke of the T, is 13-16 u high near the base of the tooth and becomes gradually 
narrower towards the tip. 

The small macramphidiscs (Plate 69, figs. 20-23) are similar to the large 
ones, but have relatively narrower anchors, less distinct central tyles, and more 
spines on the shaft. These spicules are 116-240 » long, most frequently 130- 
220 4. The shaft is 2.264. thick. The central tyle is 4-14 » in transverse 
diameter, that is 1.8-9 » more than the adjacent parts of the shaft. It bears a 
verticil of nearly straight, or, more rarely, strongly curved spines, which are 
vertical or oblique to the axis of the shaft. These spines are generally eylindro- 
conical, blunt, and 3-5 » long. The remaining parts of the shaft are covered 
with much smaller spines. These are the more numerous and the more slender 
the smaller the spicule, 


234 HYALONEMA (HYALONEMA) TYLOSTYLUM. 


The terminal anchors are 34-85 y» long, from less than a third to more than 
two fifths of the whole spicule, and 19-53 4 bread. The proportion of their 
length to their breadth is 100 to 46-88, on an average 100 : 58.3. As in the 
large macramphidises, the relative breadth of the anchors is, roughly speaking, 
in proportion to the size of the spicule. In the smaller small macramphidises, 
under 170 4 in length, the proportion of anchor-length to anchor-breadth is 
100 to 46-62, on an average 100 :55.8; in the larger, over 170 » ‘in length, 
this proportion is 100 to 48-88, on an average 100 : 60.8. 

The individual teeth are curved strongly in their basal part. Distally the 
curvature decreases, and it is on the whole such that the end-parts of the teeth 
are usually slightly convergent. 

In one of the spicule-preparations I found an amphidise with a supernu- 
merary anchor-crowned ray arising from the central tyle. The main shaft is 
110 » long and 2 4 thick. The central tyle is 4 u in diameter. The main ter- 
minal anchors are 32 uw long and 31 uw broad. The supernumerary ray is 27 pu 
long. Its terminal anchor is 18 » long and 28 » broad. The ends of adjacent 
teeth of different anchors lie in a straight line. The main shaft and the super- 
numerary ray are densely spined throughout. This spicule might be termed a 
triadise. 

The micramphidiscs (Plate 69, figs. 15-18) are 29-49 » long, most fre- 
quently about 35 » long. The shaft is straight, 0.7-1.1 » thick, and either uni- 
form in thickness, cylindrical throughout, or slightly and gradually thickened at 
or near the middle to a central tyle which is sometimes 1.3 » in diameter. The 
shaft is either quite smooth or it bears a larger or smaller number of minute 
spines. The anchors are 5-11 » long, a quarter to a fifth of the whole spicule, 
and 5-9 uw broad. The proportion of their length to their breadth is 100 to 65— 
150, on an average 100 : 88.9. The anchors of the largest micramphidiscs, that is 
those over 40 uw in length, are, on the whole, more slender than those of the 
others. The proportion of anchor-length to anchor-breadth is in these large 
micramphidises 100 to 75-87, on an average 100 : 80.8. The individual anchor- 
teeth are curved so that their end-parts are either parallel or convergent. 

The nearest allies of the sponges above described are the species Hyalonema 
(Hyalonema) placuna and H. (H.) tenwfusum described in this Report. From 
these they differ by possessing tylostyle megascleres; by being destitute of 
microhexactines with two longer opposite (apical) and four more or less reduced 
(lateral) rays; by the smaller size of the distal rays of their dermal pinules, and 


by other characters. 


HYALONEMA (HYALONEMA) GRANDANCORA. 239 


Hyalonema (Hyalonema) grandancora, sp. nov. 


Plate 78, figs. 16-45; Plate 79, figs. 1-26. 


One specimen of this species was trawled in the Southeastern Tropical Pacific 
at Station 4701 on 26 December, 1904; 19° 11.5’8., 102° 24’ W.; depth 4142 m. 
(2265 f.); the bottom was composed of dark brown chocolate clay; the bot- 
tom-temperature was 35.3°. It possesses very large macramphidiscs with 
broad anchors, and to these the specific name refers. 

Shape and size (Plate 79, fig. 12). The body of the sponge is upright, 
slightly compressed laterally, somewhat plicated, and rounded below. It 
is 35 mm. high, 42 mm. broad, and 20 mm. thick. The upper part is much 
injured. In the fresh state its apical face was probably concave, with a broad 
gastral cone arising from its middle-part. Around the gastral cone, which is 
still present, wide canals, separated by radial lamellae, extend downwards into 
the interior. An eccentrically situated stalk, 1.4 mm. thick at its point of 
origin, arises from the lower rounded end of the body. This stalk is broken off 
below. The upper part, which is still present, is 160 mm. long, and slightly 
curved in an irregular manner. 

To the upper half of the stalk a colony of eleven polyps (Palythoa sp.) 
is attached. The polyps of this colony are strongly contracted and about 
2mm. high. They have an oval transverse section 4 mm. long and 3 broad, 
elongated in the direction of the stalk of the Hyalonema. Their stomatodeum 
is also oval in section and measures 1 by 1.5 mm. The individual polyps are 
8-15 mm. apart (measured from centre to centre) and distributed all round 
the stalk in an irregularly spiral manner. The coenenchym forms a thin bark 
on the stalk of the Hyalonema. From this the individual polyps arise. 

The colour of the sponge-body and of the crust of the Palythoa in spirit 
is brown. 

The skeleton. A pinule-fur covers the surface of the body of the sponge. 
Radial pentactines occupy the subdermal and subgastral layers. Hexactine 
megascleres are abundant in the interior. Rhabd megascleres and micro- 
hexactines occur in all parts of the body. In its lower part are met slender, 
entirely spined pinule-derivate, and mon- to pentactine, ordinary stout and 
slender acanthophores. The mon- to pentactines with proximally smooth rays 
are much more abundant than the entirely spined ones. The stalk consists 
at its origin of nine fairly stout spicules. Four kinds of amphidises, all with 
smooth teeth, can be distinguished: — large and small macramphidiscs, and 


236 HYALONEMA (HYALONEMA) GRANDANCORA. 


large and small micramphidiscs. The large macramphidiscs and the small 
micramphidises are abundant, the others rare. A few amphidises 170-230 yu 
long, with serrated teeth, have also been found in the spicule-preparations. 
Since, however, these spicules are very rare and were not observed in the 
sections, I take them to be foreign. 

All parts of the individual polyps and the bark-like coenenchym of the 
Palythoa are protected by an armour which extends, in the inner dermal layer 
of the stomatodeum of the polyps, far down into their gastral cavities. This 
armour consists entirely of siliceous spicules identical with, or at least very 
similar to, the acanthophores of the sponge. In the Palythoa armour the 
acanthophores with only terminally spined rays form a small minority, the 
majority being entirely spined (Plate 78, fig. 20). 

The dermal pinules (Plate 78, figs. 41, 44, 45; Plate 79, fig. 20) of the upper 
and middle-parts of the outer surface are pentactine. The distal ray is 240-293 u 
long, and 7-10 y» thick at the base. Its proximal and distal end-parts are smooth. 
The latter appears as a rather long and slender terminal cone. The remaining 
part of the ray bears spines of medium size which are generally slightly curved, 
and concave towards the shaft. The maximum thickness of the distal ray, 
together with the spines, is 17-26 ». The lateral rays are 25-45 wu long, conical, 
and less rapidly attenuated towards the end in their proximal than in their distal 
part. They are smooth in their proximal part; their distal and middle-parts 
bear sparse, low, and broad spines. 

The dermal pinules on the basal part of the sponge are similar but have 
distal rays only 190-260 u long. 

The pinules in the walls of the large efferent canals (Plate 78, figs. 32, 43), 
which may be considered as gastral or canalar, are nearly all pentactines, only 
very few are hexactines. The distal ray is 250-395 u long, and 4-8 u» thick at 
the base. Its basal part is smooth for a considerable length, and the ray-ends 
in a slender and sharp-pointed terminal cone. The spines on its middle-part are 
rather small; its maximum thickness, together with the spines, is 11-23 u. The 
lateral rays are conical, slightly spined, and 48-72 u long. One of the few 
hexactine pinules, which I measured, had a proximal ray 50 u long. 

The (hypodermal and hypogastral) pentactines have straight conical rays. 
The proximal ray is 0.4-0.7 mm. long and 22-70 uw thick at the base. The 
lateral rays are straight, 0.2-1.2 mm. long, and generally just perceptibly inclined 
towards the shaft, so that the inner contour of any two opposite rays lies in a 
straight line vertical to the axis of the shaft. 


HYALONEMA (HYALONEMA) GRANDANCORA. DV 


The hexactines (Plate 79, figs. 13-19) are 0.4-3 mm. in diameter, and have 
nearly equal or somewhat unequal, conical and pointed, straight or slightly 
curved rays 10-80 u thick at the base. ; 

The rhabds are centrotyle, generally more or less curved, 0.8-1.3 mm. long 
and 10-20 » thick. The central tyle is 1-3 » more in transverse diameter than 
the adjacent parts of the spicule. 

Among the acanthophores the diactines and tetractines are much more 
frequent than the others. In the entirely spined forms the rays are shorter and 
thicker than in the ones with rays spined only terminally. The dimensions of 


these spicules are the following: — 


| 5 | 
with 1 or 2 rays; more with 3 more or less equally | with 4 or 5 more or less 
or less rod-shaped developed rays equally developed rays 


Acanthophores | 


| thickness of | thickness of thickness of 
total length rays | total length rays total length rays 
Be Me 


Me Me Me M 


with rays spined only at 


154-1100 10-41 
the end 


285-385 18-28 120-350 9-26 


147 30 90-152 20-26 


| 
ee ee ee | 
entirely spined 85-290 28-58 | 


In the rod-shaped monactines and diactines which are only terminally spined 

an inverse proportion between length and thickness is clearly pronounced: — 
the spicules of this kind 154-400 4 long are 26-41, on an average 29.7 u thick 

S . et ae AO B50 a 1GS2G) a (22 one 

au - ah ea sok LOOM A a WO-B 86 ce LOL 

The entirely spined spicules of this kind exhibit a similar relation between 
length and thickness: — 

those 85-120 u long are 35-58, on an average 43.3 uv thick 
oe V2I=200e 28-30, 6 ced ow rot eae 

The long and slender diactines which are only terminally spined have a 
central tyle 2-8 « more in transverse diameter than the adjacent parts of the 
spicule. In some of the shorter and stouter ones the tyle is relatively larger. 
The spines are broad and conical. In the entirely spined forms they are usu- 
ally about 7 », very rarely as much as 10 », long and broad; in those with rays 
only terminally spined they are smaller. 

Besides these spicules a few pinule-like, entirely spined pentactine and 
hexactine acanthophores with one differentiated ray were found in the basal 


part of the sponge. The dimensions of these spicules, which I consider as pinule- 


238 HYALONEMA (HYALONEMA) GRANDANCORA. 


derivates, are: — differentiated (distal) ray, 40-75 » long, at the base 6.5-7.5 uw 
thick, and in the middle (together with the spines) 6-8 » thick; lateral rays, 
45-57 » long; proximal ray, when present, about 15 u long. 

The few spicules with only terminally spined rays found in the Palythoa 
armour appear to be quite identical with the corresponding spicules (acantho- 
phores) in the basal part of the sponge. The entirely spined spicules which form 
the bulk of the Palythoa armour (Plate 78, figs. 20-40) are mon- to tetractine. 
The triactine and tetractine entirely spined forms, which are not numerous, are 
85-164 » in maximum diameter and have rays 20-47 » thick. The much more 
numerous entirely spined monactines and diactines are 90-193 » long, on an 
average 126.7 uw, and 24-60 » thick, on an average 43.5 uw. A correlation (inverse 
proportion) between their length and their thickness is not indicated. These 
spicules usually appear as stout, terminally rounded rods. They often have 
one or two protuberances which are considered as ray-rudiments. The shortest 
spicules, relatively, of this kind, with rays longitudinally most strongly reduced, 
are oval (Plate 78, figs. 23-26). The spines are conical and usually about 10 uv 
long and broad. The average dimensions (length and thickness) of the monac- 
tine and diactine entirely spined acanthophores 

in the sponge are 122 and 38.6 u, 
in the Palythoa 126.7 and 43.5 u. 

Thus we see that, although there is no great difference between the two, 
these spicules are somewhat larger, particularly in thickness, in Palythoa than in 
the sponge. A greater difference is found in the average size of their spines, 
which is considerably greater in the spicules of the Palythoa armour, than in 
the corresponding spicules in the sponge. Finally it must not be forgotten that 
the percentage of entirely spined acanthophores is much greater in the Palythoa 
armour than in the sponge. All this shows that the Palythoa does not indis- 
criminately gather and embody the basal spicules shed by the sponge, on the stalk 
of which it grows, but selects and retains only the stoutest and most spiny ones 
as material for building its armour. 

In connection with this I should like to point out that, in the literature on 
the armoured zoanthid colonies living as space-symbionts on the stalks of 
Hyalonemae, their armour is described as consisting of sand-grains only,’ or 
partly of sand-grains and partly of sponge-spicules and other material,” or of 
sand-grains and various other material in their lower part, but chiefly of the 


1J.S. Bowerbank. On Hyalonema mirabile. Proc. Zool. soc. London, 1867, p. 21, 23. 
2 R. Hertwig. Report on the Actiniaria. Supplement. Rept. Voy. Challenger, 1888, 26, p. 39. 


HYALONEMA (HYALONEMA) GRANDANCORA. 239 


spicules of the sponges to which they are attached in their upper parts which lie 
close to the sponge-body.'! In the Palythoae investing the stalks of Hyalonema 
(Hyalonema) grandancora, on the other hand, the armour is composed entirely of 
spicules of the sponge on which they grow. In these cases therefore the sym- 
biosis appears to be considerably closer than in the Hyalonema symbiont zoan- 
thid above referred to, which were examined by Max Schultze, Bowerbank, 
and R. Hertwig. 

The stalk-spicules. The parts of the stalk-spicules present in the specimen 
appear as rhabds with various markings on the surface. Near the point where 
they arise from the sponge they are 280-400 u thick. 

The microhexactines (Plate 79, figs. 21-23) are 100-170 yu in diameter, and 
have straight, conical, sharp-pointed rays, 3.5—4 » thick at the base. The rays 
bear spines. These are sparse, large, and situated vertically on their basal part; 
distally they become inclined backwards, towards the centre of the spicule, 
where they are more numerous and smaller. The largest spines are 0.8-1 yu 
long and 0.5-0.7 wu thick. 

From a morphological point of view two kinds of amphidiscs can be dis- 
tinguished: — those with relatively broad and short anchors, and few or no 
spines outside the central tyle on the shaft; and those with more slender anchors 
and spiny shaft. The amphidises are 17-510 uw long. 

Apart from the few amphidiscs with serrated teeth referred to above, which 
are to all appearance foreign, no amphidises over 80 and under 250 u in length 
were found. Thus there is, as the adjoined graph, based on 168 measurements, 
shows, a great gap in their length frequency-curve between 80-250 yu. The 
amphidises over 250 u in length are those with the broad anchors and more 
smooth shaft; the amphidises under 80 u in length are those with the narrower 
anchors and spiny shaft. Thus the morphological distinction between these 
two kinds of amphidises coincides with the biometrical, and I accordingly divide 
the amphidises into two main groups: — macramphidises with broad anchors 
and more smooth shaft over 250 » in length, and micramphidises with narrower 
anchors and spiny shaft under 80 uw in length. 

Of the eighty-five macramphidiscs measured one was only 250 y in length, 
the other eighty-four were 318-510 uw. Iam not quite sure whether the single 
macramphidise only 250 » long is to be considered as a normal amphidise proper 
to the sponge. Assuming this to be so, two morphologically similar kinds of 
macramphidises may be distinguished, a larger and a smaller, separated biomet- 


' Max Schultze. Die Hyalonemen, 1860, p. 29. 


HYALONEMA (HYALONEMA) GRANDANCORA. 


240 


Micramphidiscs Macramphidiscs 
——" a> or ee 

Numbers Small Large Small Large 
measured > “~~ FF 

Stevan lies ae NN We Oe rc Sc ae ee es ee ee ee 

30 | 

25 ee 

20 rt 


15 


10 


ee PENS SSS SES GS SOS SOON OS SS SES OS SO SS ESE SO SIO OS aa aoa 


Length, (y). 


14.42— 15.86 
15.86 — 17.45 


NAS OR 


19.19— 21.11 


21.11— 23.23 


23:23 — 20:09 


Ui —= 74 SKY 


2810 — 30:01 = 


30.91— 34.00 


34.00— 37.40-}~ 


41.14— 45.26-4-:- 


49.78 


Sf Wa tt i peat ee eee gate ge ee Hee af aa 

| | | 
WtOMRMOOCANNOMYPTMNOeOeOtTTDOOOh 
PANDANSCHNMAONDOMANOOTALTN 
HOWONOCMOHROrAANOARDKeAMAOtTTA' 
MWOORDADRHRDOHATHTORDAONMOCOMWLS 
Aneta AR DNANNAN MO OO SS 

! | 

a SIP tae sh) 
DOHORDRWDONNAMHMOPOROTTA|OMDM 
SBEANANDANSERASCNDNOARNROONA~ 
SBtSOensonarernanet ar anortte 
+ MOOR DDHDHOHANHHORWDONWMOEOSMO 
ere ta ECNEGNTIGNIE GNI GC 


37.40— 41.14 


45.26 — 


445.80 — 490.38 


490.38 — 539.41 


539.4 1——998.30 


Tig. 10.— Amphidiscs. 


HYALONEMA (HYALONEMA) GRANDANCORA. 241 


rically by a distinct gap in the length frequency-curve. The large macramphi- 
dises form, as the graph shows, a biometrically perfectly homogeneous group. 

Also among the micramphidiscs two morphologically and biometrically 
distinct kinds can be distinguished: — a larger kind, over 37 y» in length, with 
longer anchors and stout central tyle; and a smaller kind, under 31 , in length, 
with shorter anchors and a relatively much smaller central tyle, or no central 
tyle at all. The part of the length frequency-curve pertaining to the first, 
larger kind of micramphidises shows several ups and downs, so that this group 
cannot be considered biometrically homogeneous. However, in view of the 
morphological similarity of these larger micramphidises of various size, I do not 
think the depressions in this part of the curve (none of which extends down to 
the base (0) line) sufficient for a division of them into secondary groups. The 
second, smaller kind of micramphidises forms a biometrically homogeneous 
group. 

I distinguish accordingly four kinds of amphidises in this sponge: — large 
macramphidises, small macramphidises, large micramphidises, and small mier- 
amphidises. 

The large macramphidiscs (Plate 78, figs. 16-19; Plate 79, figs. 1, 2, 26) 
are 318-510 uw long, most frequently about 415 u. The shaft is generally straight, 
very rarely bent, cylindrical, 20-26 » thick, and thickened gradually towards 
the ends, and abruptly in or near the middle to a central tyle 24-30 u» in trans- 
verse diameter, that is 3-7 » more than the adjacent parts of the shaft. The 
central tyle bears a verticil of truncate conical spines. These spines are usually 
fairly equal, 10-20 u long and 10-12 u thick at the base. Sometimes one or two 
are large and the others more or less rudimentary. The remaining parts of the 
shaft are either quite smooth (Plate 79, fig. 2), or they bear only one or very 
few protuberances, about as broad as the spines of the central tyle, but 
generally much shorter. 

The terminal anchors are 83-125 » long, a quarter to a sixth of the whole 
spicule, and 135-200 u broad. The proportion of anchor-length to anchor- 
breadth is 100 to 142-190, on an average 100 : 165.4. The anchor consists of 
eight teeth. The individual teeth arise vertically from the end of the shaft, 
and are curved more strongly in their proximal than in their distal half. The 
extreme tips of the teeth are sometimes slightly and abruptly bent inwards. 
The curvature of the teeth is, on the whole, such that their end-parts generally 
diverge slightly from the axis of the shaft. 


The dimensions of the single small macramphidisc observed are: — length 


242 HYALONEMA (HYALONEMA) GRANDANCORA. 


250 w; thickness of shaft 13 1; diameter of central tyle 15 1; spines of central 
tyle 7 » long and 6 uw thick; anchors 74 » long and 110 » broad. 

The large micramphidiscs (Plate 79, figs. 24, 25) are 37-80 » long, most 
frequently about 43, 55, and 70 yw.’ The shaft is straight, 2-3.5 » thick, and 
somewhat gradually thickened in or near the middle to a stout, often rather 
irregular, and not very clearly defined central tyle, 3-6 » in transverse diameter, 
that is 1.5-3.5 » more than the adjacent parts of the shaft. The tyle and the 
remaining parts of the shaft are quite densely covered with small, slender spines. 
The spines on the tyle are scattered, not arranged in a verticil. 

The terminal anchors are 12-29 uw long, usually a little more than a third of 
the whole spicule, and 10.5-26 » broad. The proportion of anchor-length to 
anchor-breadth is 100 to 75-100, on an average 100 : 86.3. The individual 
anchor-teeth are strongly curved in their proximal parts and only slightly curved 
or nearly straight in their distal and middle-parts. Their ends generally diverge 
rather considerably from the axis of the shaft. 

The small micramphidiscs (Plate 79, figs. 3-11) are 17-31 » long, most 
frequently about 23.3 ». The shaft is generally straight, rarely bent in the 
middle, is 1.3-1.6 » thick, and in the larger forms often slightly and gradually 
thickened in or near the middle, in the smaller generally of uniform thickness 
throughout. The shaft is quite densely covered with small slender spines. 

The terminal anchors are 4-13 » long, a quarter to a third of the whole 
spicule, and 6-14 » broad. The proportion of anchor-length to anchor-breadth 
is 100 to 85-140, on an average 100 : 123. The anchor-teeth are curved more 
strongly in their basal than in their distal part. Their ends are parallel or 
nearly so. 

The species is very well characterized by the large size and the great relative 
breadth of the anchors of its macramphidisecs. The only species which has 
similar macramphidises and pinules is Hyalonema (Prionema) agujanum described 
in this Report. From this it is distinguished by the large and slender amphi- 
dises with serrated teeth which are exceedingly abundant in H. (P.) agujanum 


and absent in H. (H.) grandancora. 


1 Their length frequency-curve has three distinct elevations corresponding to these sizes. 


HYALONEMA (HYALONEMA) SP. 243 


Hyalonema (Hyalonema) sp. from Station 3684 (A. A. 17). 


Plate 80, figs. 1-16. 


A small fragment about 10 mm. long with several stalk-spicules was col- 
lected in the Central Pacific, Station 3684 (A.A. 17) on 10 September, 1899; 0° 50’ 
N., 137° 54’ W.; depth 4504 m. (2463 f.); it grew on light yellow-gray Globigerina 
ooze. This fragment appears to have formed part of a species of Hyalonema 

_not sufficiently well-preserved for specific determination. 

The spicules of this fragment are pentactine pinules with long distal ray, 
pentactine pinules with short distal ray, diactine pinules; hexactine, pentactine, 
and diactine megascleres; acanthophores; stalk-spicules; microhexactines; 
macramphidises; and micramphidiscs. 

The pentactine pinules with long distal ray (Plate 80, fig. 16). The distal 
ray in these spicules is 375-670 » long, and 5-8 u» thick at the base. It tapers 
gradually towards the fine-pointed end, and bears very small and rather sparse 
strongly inclined spines. These decrease in size distally. The lateral rays are 
spiny and 60-80 u long. 

The pentactine pinules with short distal ray (Plate 80, fig. 14). In these 
spicules the distal ray is 170-260 u long, and 4-8 u thick at the base. It bears 
rather strongly inclined spines, which are larger than in the pentactine pinules 
with long distal ray. The maximum thickness of the distal ray, together with 
the spines, is usually 11-16 u. The lateral rays are spiny and 60-70 u long. 

The diactine pinules (Plate 80, fig. 15). The total length of these spicules 
is usually 0.7-0.8 mm. The distal ray is 390-480 u» long, 5-8 uw thick at the base, 
and covered with small, strongly inclined spines. The lateral rays are reduced 
to smooth, cylindrical, terminally rounded protuberances, (measured from the 
axis of the spicule) 6-17 » long. The proximal ray is 305-330 u long. 

The pentactine megascleres have a proximal ray 450-600 uw long, and 10-35 u 
thick at the base. The lateral rays of the same spicule are more or less unequal. 
The length of the smallest is not infrequently only two thirds of that of the long- 
est, sometimes even less. The lateral rays are straight, conical, blunt, and 170— 
560 » long. 

The hexactine megascleres are 0.7—-1.8 mm. in diameter, and have rays 20-— 
40 uw thick at the base. 

The diactine megascleres are centrotyle. The diameter of the central tyle 
is sometimes as much as twice as great as the thickness of the adjacent parts of 
the spicule. 


244 HYALONEMA (HYALONEMA) SP. 


The acanthophores (Plate 80, fig. 13) have one to four more or less fully 
developed rays. The tri- and tetractine forms are 170-370 » in maximum 
diameter, and have rays 138-22 uw thick at the base. The diactine forms are 400- 
900 » long, and 7-10 u thick near the centre. Most of them are centrotyle. 
The central tyle is not infrequently more than three times as stout as the adjacent 
parts of the spicule. The single monactine form observed is 260 u long and 15 u 
thick. 

The stalk-spicules (Plate 80, figs. 11, 12) bear spiral rows of proximally 
directed spines on parts of their surface and terminate in anchors. The shaft 
of the stalk-spicule represented (Plate 80, figs. 11, 12) is 39 » thick just above the 
anchor, which is 145 » long and broad. 

The microhexactines (Plate 80, fig. 4) are 150-170 » in diameter, and have 
equal rays 3.5—4 » thick at the base. The rays are conical, fine-pointed, spined, 
and nearly straight in their proximal part, but rather strongly curved towards 
their ends. 

Of amphidiscs two kinds can be distinguished: — macramphidises and 
micramphidises. 

The macramphidiscs (Plate 80, figs. 1, 2, 5-10) are 380-570 uw long, most 
frequently about 470 and 530 yu. The shaft is straight, 20-25 » thick, and 
thickened in or near the middle, only very slightly, or not at all, to a tyle, which 
however is not clearly defined. This tyle may, when present, bear one or a few 
blunt insignificant spines. The rest of the shaft is generally quite smooth. 
The anchors are 120-228 u long, less than a third to nearly half of the whole 
spicule, and 215-263 » broad. The proportion of their length to their breadth 
is 100 to 115-191, on an average 100 : 147.8. The curvature of the anchor-teeth 
decreases distally, and their end-parts generally diverge. The extreme tip of the 
teeth, in the long anchors, is sometimes (Plate 80, fig. 2) bent inwards. The 
teeth have smooth lateral margins, and are pointed at the end (Plate 80, fig. 10). 

The micramphidiscs (Plate 80, fig. 3) are 26-28 u» long, and have terminal 
anchors 9-10 » long, about a third of the whole spicule, and 8.5-11 yw broad. 
The proportion of anchor-length to anchor-breadth is 100 to 85-115, on an 
average -100 : 102.5. 

Among the species of Amphidiscophora hitherto described, Hyalonema 
martabanense F. EK. Schulze! appears to be the one most closely allied to the 
fragment described above. This fragment differs from H. martabanense by 


1 Ff, BE. Schulze. Uexactinelliden des Indischen Oceanes. III. Abh. Akad. Berlin, 1900, p. 12, t. 2. 
Indian Triaxonia, 1902, p. 21, pl. 18. 


HYALONEMA (LEPTONEMA) CAMPANULA. 245 


having no smaller kind of macramphidises, no mesamphidiscs, and no spheres, 
and by the distal ray of its pinules being more slender, and its microhexactines 
much larger. Although these differences are very conspicuous and quite suffi- 
cient for specific distinction, there is a considerable degree of similarity between 
the two. 


LEPTONEMA, subgen. nov. 


Species of Hyalonema the amphidises of which have hyperbolic, hemispheri- 
eal, or bell-shaped terminal anchors about one fourth to one third of the whole 
spicule in length. Without amphidises of any other kind. The largest amphidises 
are slender and have a thin shaft. 


The collection contains one specimen of this subgenus. 


Hyalonema (Leptonema) campanula, sp. nov. 


Plate 81, figs. 1-26. 


A single specimen of this species was trawled in the Southern Tropical Pacific 
at Station 4721 on 15 January, 1905; 8° 7.5’ S.; 104° 10.5’ W.; depth 3811 m. 
(2084 f.); it grew on light brown Globigerina ooze. 

The terminal anchors of the macramphidises are slender and similar to the 
flowers of certain species of Campanula. To this the name refers. 

Shape and size. The specimen (Plate 81, fig. 15) is somewhat fragmentary. 
What there is of the body is an irregular mass, 18 mm. in diameter. It is drawn 
out to a conical protuberance in one place, and from this arises a curved stalk 
70 mm. long and about 1 mm. thick. 

The colour of the body in spirit is brown. 

The skeleton consists of pentactine and diactine pinules, pentactine, hex- 
actine, and diactine megascleres, modified basal spicules, stalk-spicules, microhex- 
actines, and amphidises. The diactine pinules are associated with ordinary 
diactine megascleres. Protruding freely they probably formed together with 
these spicules a fringe at the boundary between the dermal and gastral parts of 
the surface. Some of the pentactine pinules have a very long distal ray; in 
others, which appear to be confined to the basal part of the sponge, the distal 
ray is of ordinary length. The acanthophores are for the most part diactine and 
pentactine. The amphidises are of three kinds, macramphidises, mesamphidisces, 
and micramphidises. The macramphidiscs are very abundant, the other two 
rather rare. 


246 HYALONEMA (LEPTONEMA) CAMPANULA. 


The pentactine pinules with long distal ray (Plate 81, figs. 12, 13, 16-18). 
In these spicules the distal ray is 230-810 » long, most frequently about 600 yn, 
5-8 u thick at the base, and fairly straight or more or less, sometimes very con- 
siderably, curved. It is conical and it ends in an exceedingly fine, thread-like, 
spineless terminal cone. The spines of the distal ray are small, rather sparse, 
and strongly inclined towards the tip of the ray. They attain their largest size 
at a distance of a fifth to a quarter of the length of the whole ray from the centre 
of the spicule, and here the distal ray, together with the spines, attains its maxi- 
mum thickness of 9-18 ». The lateral rays are cylindroconical, abruptly pointed 
or blunt, and spiny in their distal part. Their length is, roughly speaking, in 
proportion to the length of the distal ray. In the pinules with a distal ray under 
400 » in length, the lateral rays are 43-52 » long; in those with a distal ray over 
400 » in length, 50-80 u long. 

The basal dermal pentactine pinules with shorter distal ray (Plate 81, figs. 
25, 26). In these spicules the distal ray is straight, conical, 100-165 » long, and 
5-6 » thick at the base. It bears rather sparse spines and ends in a sharp- 
pointed and rather slender terminal cone. Its maximum thickness, together with 
the spines, of 12-23 u is usually situated a little above the middle of its length. 
The lateral rays are cylindroconical, abruptly pointed or rounded at the end, 
distally spined, and 37-58 u long. 

The diactine pinules (Plate 81, figs. 1, 2, 14). In these pinules the distal 
ray is straight or curved, 0.73-1.2 mm. long, and 6-9 u thick at the base. It 
bears rather sparse strongly inclined spines. The largest are 10-16 » long, and 
arise about a third of the length of the distal ray from the centrum of the spicule. 
Here the distal ray, together with the spines, attains its maximal thickness 
of 12-18 u. Distally and proximally the spines decrease in size. The slender 
thread-like extreme tip and the basal part of the distal ray are free from spines. 
The proximal ray is usually fairly straight and 450-750 u long. The lateral 
rays are reduced to cylindrical, terminally rounded protuberances only 5-14 pu 
long (measured from the axis of the spicule). 

The pentactine megascleres (Plate 81, figs. 19, 20) have a straight proximal 
ray sometimes 1 mm. and more long, and 7-45 u» thick at the base. The lateral 
rays of the same spicule often differ very considerably in size. They are 230 u 
to 1 mm. long, straight, or somewhat curved, and slightly inclined towards the 
proximal ray; the angle between them and the proximal ray is usually about 85°. 
The lateral rays are generally conical and terminally rounded, rarely thickened 
at the end (Plate 81, fig. 19). 


HYALONEMA (LEPTONEMA) CAMPANULA. 247 


The hexactine megascleres are 550 »-1.8 mm. in diameter. Their rays are 
7-22 u thick at the base, usually more or less curved, and only slightly attenuated 
toward the rounded end. The end-parts of the rays, particularly of the smaller 
hexactines, bear minute spines. 

The diactine megascleres are centrotyle amphioxes. They are usually 
1-1.5 mm. long and 9-18 » thick near the centre. The central tyle is 12-22 y 
in transverse diameter, that is 2-4 « more than the adjacent parts of the spicule. 

The basal pentactine and diactine acanthophores are similar to the ordinary 
pentactines and diactines of the body, above described, but have rays reduced 
in length and somewhat thickened and spined at the end. 

The stalk-spicules (Plate 81, fig. 11) have a maximum thickness of 110 u 
and all are broken off at the lower, distal end. Their proximal, upper parts are 
smooth. Farther down minute, strongly inclined, upwardly directed spines 
begin to make their appearance. Distally these spines become larger and appar- 
ently also less numerous. The spines are partly scattered, partly arranged in 
oblique (spiral) transverse rows. 

The microhexactines (Plate 81, figs. 3-6) are 50-100 » in diameter. The 
rays are 1-1.5 » thick at the base, straight in their proximal, but curved in their 
distal part. This curvature is either fairly uniform or considerably greater just 
beyond the point where it begins than in the end-part, and on the whole such 
that the tips of adjacent rays come to be parallel or convergent. 

Morphologically two kinds of amphidiscs can be distinguished: — those 
with relatively thin shaft and slender, somewhat bell-flower shaped anchors; 
and those with relatively stout shaft and broader, oval anchors. The former 
are 150 » or more long, whilst the largest of the latter is only 118 w long. As the 
adjoined graph shows, a rather conspicuous depression in their length frequency- 
curve divides the large and slender-anchored amphidises biometrically into a 
larger and a smaller kind. In view of the morphological identity of the larger 
and smaller, I think that all these slender-anchored amphidises can be considered 
as amphidises of the same kind, and I shall describe them as macramphidiscs. 

The broad-anchored amphidises, 118 » or less in length, are divided bio- 
metrically by a very wide gap in the length frequency-curve, situated between 
26 and 77 yu, into a larger and a smaller kind. The larger of these amphidiscs 
I shall describe as mesamphidises, the smaller as micramphidises. Since the 
length frequency-curve in both exhibits several depressions, neither of them 
can be said to form a biometrically homogeneous group. Since, however, 


those depressions are not very great and since these amphidises are so rare that 


248 


HYALONEMA (LEPTONEMA) CAMPANULA. 


Length, (2). 


15.86 — 
17.45 — 
19.19 — 
21.11 — 


251.64 — 276.81 
276.81 — 304.49 
304.49 — 334.93 
334.93 — 368.43 


Fig. 11.— Amphidises. 


Taquiny 


SOSIpPIydweIdy 


SosIpryduesayyy 


sosiprydwiesseyy 


HYALONEMA (LEPTONEMA) CAMPANULA. 249 


I was unable to measure a number large enough to make the curves perfectly 
reliable, I shall not divide them into subgroups. 

The macramphidiscs (Plate 81, figs. 7-10) are 150-290 » long, most. fre- 
quently about 2504. The shaft is straight or more or less, sometimes very 
considerably, curved, and 1.5-5 uw thick. It is thickened gradually towards the 
ends and more abruptly at or near the centre to a tyle 2.8-7 » in transverse 
diameter, that is 1-3 » more than the adjacent parts of the shaft. A few spines, 
1-3 uw long and 1-2 u thick, forming a verticil arise from the central tyle. The 
remaining parts of the shaft are quite smooth or bear only one or a few small 
spines. 

The terminal anchors are 48-84 uw long, about two sevenths of the whole 
spicule, and 25-53 » broad. The proportion of their length to their breadth is 
100 to 46-69, on an average 100 : 57.8. The anchors are composed of eight teeth. 
The individual teeth are 9-12 » broad, hardly at all attenuated distally, and 
simply rounded at the end. They arise vertically from the shaft and are, at a 
distance of about one eighth of their length from the point of origin, abruptly 
and very strongly bent toward the shaft. The part beyond this bend, that 
is the distal seven eighths, is either quite straight or somewhat bent outward; 
rarely the end is slightly bent inwards. These long distal parts of the teeth are 
divergent and enclose angles of 9° or 10° with the axis of the shaft. 

The mesamphidiscs (Plate 81, figs. 23, 24) are 77-118 » long, most frequently 
about 84. The shaft is straight and 4-7.5y thick. It thickens gradually 
towards the ends, which are usually 3-4.5 » thicker than the middle-part. There 
is either no central thickening at all, or it is quite insignificant, not exceeding 
the adjacent parts of the shaft by more than 1 y» in thickness. The shaft bears 
a few terminally rounded spines 3-8 » long and 2-5 uw thick, which do not form 
a central verticil, but are scattered irregularly over its middle-part. Sometimes 
only a single large spine arises from the shaft. 

The terminal anchors are 30-43 y long, about a third of the whole spicule, 
and 40-47 » broad. The proportion of their length to their breadth is 100 to 
100-133, on an average 100:109. The anchor-teeth are in the medium-sized 
mesamphidiscs about 9 » broad. They are attenuated distally, terminally 
rounded, and curved toward the shaft throughout their length. This curvature 
is much greater in their proximal than in their distal portion, and on the whole 
such that their end-parts diverge. 

The micramphidiscs (Plate 81, figs. 21, 22) are 18-26 » long, most frequently 
about 24.5 ». The shaft is straight and 0.9-1.4 » thick. A slight, not well- 


250 PRIONEMA. 


defined central thickening can usually be made out. This is 1.2-1.9 » in trans- 
verse diameter, that is 0.2-0.5 » more than the adjacent parts of the shaft. 

The anchors are 5-11 » long, one third to two fifths of the whole spicule, and 
5.5-10 » broad. The proportion of their length to their breadth is 100 to 77-129, 
on an average 100: 107. The curvature of the anchor-teeth decreases distally, 
and their end-parts are usually fairly straight. The total curvature is such that 
the end-parts of the teeth are either parallel or slightly divergent. 

Besides the amphidises above described, I found an abnormal amphidisc 
with very unequal terminal anchors. This spicule is 42 » long and has a shaft 
2 u thick. One of its anchors measures 18 y» in length and 13 u in breadth, the 
other is 8 » long and broad. One half of this spicule appears as a mesamphidisce, 
the other half as a micramphidise. 

Of the species of Hyalonema hitherto described H. divergens F. E. Schulze ' 
appears to be the one most closely allied to the sponge above described. From 
this it differs, however, to a considerable extent by the shape and dimensions of 
the spicules. The large macramphidises 500 » long with ovoid anchors, which 
are present in H. divergens, are absent in H. (H.) campanula. The macramphi- 
dises with campanulate anchors are small and have a strongly spined shaft and 
pointed anchor-teeth in H. divergens, and are twice as large and have, apart 
from the centrum, a nearly smooth shaft and terminally rounded anchor-teeth 
in H. (H.) campanula. These and the other less conspicuous differences are, 


of course, quite sufficient for specific distinction. 


PRIONEMA, subgen. nov. 


Species of Hyalonema of which the amphidiscs of one kind have anchor-teeth 
with serrated margin. 
The collection contains twenty-one more or less complete specimens and one 


fragment of this subgenus. They belong to six species, all of which are new. 


1F. EB. Schulze. Rept. Voy. Challenger, 1887, 21, p. 199, pl. 28, figs. 1-11. 


HYALONEMA (PRIONEMA) AGUJANUM. 251 


Hyalonema (Prionema) agujanum, sp. nov. 
tenuis, var. nov. Form A. 


Plate 72, figs. 17-21, 23-25, 27; Plate 73, figs. 1-6; Plate 74, figs. 1-5, 8; Plate 75, figs. 1-13, 15, 17, 


25 
19-27, 29-37; Plate 76, figs. 1-7, 11, 12, 15-36. 


tenuis, var.novy. Form B. 


Plate 72, figs. 16, 22, 26; Plate 73, fig. 7; Plate 74, figs. 6, 7,9; Plate 75, figs. 14, 16, 18, 28; Plate 76, 
figs. 8-10, 13, 14. 


lata, var. nov. 


Plate 77, figs. 1-10; Plate 78, figs. 1-15. 


I establish this species for five specimens collected off northern Peru, near 
Aguja Point, at Station 4656 on 13 November, 1904; 6° 54.6’ S., 83° 34.3’ W.; 
depth 4063 m. (2222 f.); they grew on fine, green mud mixed with gray ooze; 
the bottom-temperature was 35.2°. The specific name refers to the locality. I 
distinguish two varieties in this species, one comprising four specimens, with 
narrow, one comprising one specimen with broader serrated amphidisc-anchors. 
In view of the difference in the anchor-breadth of these amphidises, I name the 
former tenuis, the latter lata. One of the four specimens of var. tenuis differs 
somewhat from the other three; I therefore distinguish two forms, A and B, in 
this variety. Form A comprises three specimens, form B one. 

Shape and size. All the specimens (Plate 75, figs. 28-30; Plate 78, fig. 4) 
are inverted, conical, and more or less flattened laterally. The better preserved 
ones have a broad and shallow depression on their upper face and a stalk which 
arises from the lower narrow end. I consider the apical depression a gastral 
cavity. In one specimen the remnant of a gastral cone is visible in its centre. 
The specimens are 19-29 mm. long, 23-30 mm. broad, and 8-16 mm. thick. 
The stalks present are broken off quite short. The longest is 24 mm. long. A 
few Palythoa polyps are attached to the proximal part of the stalk just below 
the point where it arises from the body (Plate 75, figs. 29, 30; Plate 76, fig. 7). 

The colour of all the specimens in spirit is brown. 

The skeleton. The dermal and gastral surfaces are entirely covered with a 
dense fur composed of the distal rays of pentactine pinules. In the spicule- 
preparations a good many diactine pinules were found. These in all probability 
occupy the margin of the apical (gastral) cavity. In the subdermal and sub- 
gastral zones radial pentactines and paratangential rhabds are met. Similar 


rhabds, hexactine megascleres, and microhexactines occupy the interior. Here 


252 HYALONEMA (PRIONEMA) AGUJANUM. 


also occur slender-rayed pentactine and hexactine pinules, and spicules transi- 
tional between these pinules and the microhexactines. These slender-rayed 
pinules, and more or less pinule-like transitions to microhexactines, probably 
occupy the canal-walls, and may be considered as canalar pinules. - Acantho- 
phores are met with in the basal part of the sponge. These vary greatly in 
thickness. Most of them are tetractine or diactine. Rhabds transitional 
between the more slender diactine basal acanthophores and the ordinary rhabds 
of the upper parts of the body are also abundant here. An exceedingly small 
minority of the short and stout acanthophores in the basal part of the sponge- 
body are spined not only at the ends of the rays, but entirely. The skeleton of 
the stalk is continued quite through the body up to the gastral cone (Plate 76, 
fig. 7). Where it arises from the lower end of the sponge-body, the stalk consists 
of about a dozen stout and a number of slender rhabds. Of amphidises four 
kinds can be distinguished: — macramphidises, serrated amphidises, large micr- 
amphidises, and small micramphidises. The large micramphidises are rare, 
the others abundant. The skeleton of the Palythoa (Plate 76, figs. 4-6, 34) 
consists entirely of acanthophores of the sponge. A large majority of these 
spicules are very short and stout, and entirely spined. These sponge-spicules 
form an armour of the whole polyp-colony. They occupy in large masses the 
lateral walls, the oral face, and the stomatodeum of the individual polyps and 
the superficial part of the coenenchym. 

The dermal and gastral pinules (Plate 72, figs. 20-25; Plate 78, figs. 9-11) 
do not appear to differ from each other appreciably. It is, however, to be noted 
that the dermal pinules of the basal part of the sponge have, at least in var. 
tenuis, form A, on the whole shorter distal rays than the other dermal and the 
gastral pinules. All the gastral and dermal pinules are pentactine. The distal 
rays are straight and end with a blunt or pointed terminal cone. This cone and 
the proximal end-part of the distal ray are free from spines. For the greater 
part of its length the distal ray is covered with nearly straight, mostly rather 
strongly inclined spines. Generally the spines are simple. Occasionally some of 
them bear secondary spinelets. The middle-part of the distal ray, together with 
the spines, is usually nearly cylindrical. The lateral rays are attenuated to- 
ward the abruptly pointed or blunt end. Distally for one half or two thirds of 
their length they bear rather large, stout spines. The dermal and gastral pinules 
of var. tenwis, form B, have more slender distal rays than those of var. tenuis, 
form A, and var. lata. Apart from this the dermal and gastral pinules of the 


three groups are very similar. Their dimensions are the following: — 


HYALONEMA (PRIONEMA) AGUJANUM. 253 


GASTRAL AND DERMAL PINULES OF HYALONEMA (PRIONEMA) AGUJANUM. 


Distal ray Lateral rays 
maximum 
thickness, to- 
; basal gether with 
length thickness the spines length 
Me Me Mh Me 
from the 
dermal | basal part of 123-258 8-12 28-35 42-52 
the sponge 
from the 
middle and 
form pinules | upper part 200-311 8-10 30-37 36-48 
ue A of the 
tenuis eee 
gastral pinules 251-300 9-11 30-39 40-52 
dermal and! gastral —'l\ 423-800 8-12 28-39 36-52 
pinules 
form Be ee 225-311 7-10 18-30 37-45 
pinules 
dermal pinules 218-302 7-11 22-36 32-57 
ee tite gastral pinules 215-300 7-13 | 25-38 30-50 
ee a 
esate enh ease 215-302 7-13 22-38 30-57 
pinules 


Besides the dermal and the gastral pinules described above, a considerable 
number of other pinules were found adhering to the surface or embedded in the 
superficial parts of the sponge. Some of these have long and bushy distal, and 
very short lateral rays. In others the distal rays are quite short and very 
slender and the laterals long. The former, which are quite frequent, resemble 
the pinules of Hyalonema tenuifusum and probably belong to that sponge, which 
was trawled at the same station; I accordingly consider them as foreign. The 
latter are rare. They may be proper to the sponge and would, in that case, 
have to be considered as transitions between the dermal pinules and the micro- 
hexactines. Dermal transitional pinules, if such, have been found in both forms 
of var. tenuis and in var. lata. The dimensions of the few observed are :— 


1 The single specimen of var. tenuis form B is not sufficiently well-preserved for a reliable distinction 
between dermal and gastral pinules; hence special measurements are not given. 


HYALONEMA (PRIONEMA) AGUJANUM. 


Distal ray Lateral rays 
maximum thick- 
ness, together 
length basal thickness with the. spines length 
be be Me 0 
form A 120-160 3-6 4-10 70-98 
var. lenuis 
form B 225-280 6-7 18-20 60-80 
var. lata 176-280 5-8 12-18 54-85 


Diactine, probably marginal pinules (Plate 78, fig. 3) have been observed 
Their distal ray 
is usually pointed, exceptionally reduced in length, and rounded and thickened 
at the end (Plate 78, fig. 3). 
directed, generally nearly straight spines. 


only in the preparations of var. tenuis, form A, and var. lata. 


It is covered with rather strongly inclined, distally 
The proximal ray is usually more or 
less spiny, and pointed or rounded at the end. A central tyle, the remnant of 
the (reduced) lateral rays, is always present. It is irregularly spherical or com- 
posed of four distinct lobes (ray-rudiments). Generally it bears several large 
spines which point obliquely upward and outward. 


The dimensions of the diactine pinules are:— 


Distal ray 
total length maximum 
we thickness, to- length of transverse 
basal gether with proximal diameter of 
length thickness the spines ray central tyle 
Me Ke be a Bb 
var. 
tenuis 400-610 200-290 5-10 17-20 190-320 16-21 
form A 
var. lata 410-490 167-260 6-9 26-33 160-260 12-23 


Pentactine and hexactine spicules with very slender rays have often been 
observed in the interior of var. lata. I consider these spicules, which are con- 
nected with the microhexactines by numerous transitional forms, as canalar 
pinules. In these spicules one ray is different from, usually longer, rarely shorter, 
than, the others. This differentiated ray, which is to be considered as the distal, 
bears oblique, distally directed spines. The other rays are also spiny, but their 
spines are much smaller and generally situated vertically. The ray to be con- 


sidered as the distal is 100-170 » long, 3.5-7 » thick at the base, and in its 


HYALONEMA (PRIONEMA) AGUJANUM. 255 


middle-part, together with the spines, usually about 6 » thick. The rays to be 
considered as the laterals are 60-120 » long. The proximal ray of the hexactine 
forms is 70-115 » long. The hexactine and the pentactine forms appear to be 
fairly equally abundant. 

The (hypodermal and hypogastral) pentactines (Plate 72, fig. 19) have 
smooth, conical, and straight, terminally rounded rays. The proximal ray is 
460-900 uw long and 17-34 u thick at the base. The lateral rays are 220-500 u 
long. In the same spicule they are usually very unequal in size, the largest 
being sometimes as much as twice as long as the smallest. 

The hexactine megascleres (Plate 72, figs. 26, 27) are regular or, more rarely, 
two opposite rays are longer than the other four. They measure 0.6-1.4 mm. 
in maximum diameter (length), and their straight, conical, blunt rays are 14— 
33 u thick at the base. 

Most of the rhabds of the body are centrotyle amphioxes, but tylostyles 
have also occasionally been observed. The centrotyle amphioxes are 0.8-3.3 
mm. long and 8-19» thick near the centre. The central tyle is 11-23 u in 
transverse diameter, that is 1.5-12 » more than the adjacent parts of the spicule. 
These spicules attain a larger size in var. lata than in var. tenuis. 

Among the basal acanthophores two kinds can be distinguished: — forms 
with long and slender rays, and forms with short and stout rays. The spicules 
of the first kind are all diactine, those of the second kind mon- to pentactine. 

The long and slender diactine acanthophores are connected by numerous 
transitional forms with the ordinary rhabds of the upper parts of the body. 
They are 0.6—1.6 mm. long, usually 6-9 » thick near the middle, and generally 
curved or, more rarely, angularly bent. The two rays of the angular forms 
are usually fairly straight. The curvature or angular bend of these spicules 
is sometimes very considerable, the latter occasionally such that the angle en- 
closed by the two rays is nearly a right one. The spined end-parts of the rays 
are often more or less thickened and often unequal. The following dimensions 
of a spicule of var. lata may serve as an example of this kind of spicule unequally 
thickened at the two ends: 
of one end 12, of the other 19 u. 


The stout and short mon- to pentacltine acanthophores can again be divided 


length 1.4 mm., thickness in middle 9 y, thickness 


into two groups of forms only slightly connected by transitions: — those with 
rays smooth in their basal part, spined only at the end, and longitudinally less 
reduced (found chiefly in the sponge); and forms with rays spined throughout 
their length and longitudinally more reduced (found chiefly in the Palythoa). 


256 HYALONEMA (PRIONEMA) AGUJANUM. 


The stout- and short-rayed proximally smooth mon- to pentactine acanthophores 
(Plate 76, figs. 8-16, 31, 32). The pentactine forms (Plate 76, fig. 32) are rare 
and have been found only in var. tenuis, form A. They are very much smaller 
than the others and may perhaps be spicules of another kind. The tetractine 
forms (Plate 76, figs. 8, 10-13) with four fairly equally developed rays are 
frequent in all the specimens. Their rays extend in the same plane and enclose 
angles of 90°. They are usually straight and attenuated towards the end. 
The triactine forms are not nearly so frequent. They are evidently tetractine- 
derivates and differ from the true tetractines only by one ray being much reduced 
or suppressed altogether. Transitions between the tetractines and triactines 
(Plate 76, fig. 10) are by no means rare. The diactine forms (Plate 76, figs. 14— 
16) are frequent. They sometimes possess, besides the two properly developed 
rays, a rudiment of a third ray (Plate 76, fig. 15). Those without such a rudiment 
are either centrotyle and spindle-shaped (Plate 72, fig. 14), or simply cylindrical 
and rather thicker at the ends than in the middle (Plate 76, fig. 16). The mon- 
actines (Plate 76, fig. 31) are rare. They appear as tylostyles. The dimensions 


of these spicules are the following :— 


Only terminally spined, basal spicules with 
5 | 4 | 3 2 1 
Hyalonema —— —___ —— _ —— — 
(Prionema) more or less fully developed rays 
agujanum 
a| % a| 4 al 4 =) [S ss a| % 
B. eee 2 Brel smh 2 Be alee 
Boe | a |Hee la" Bee e | esse 1a oe ee 
wae) ge /GE2| Se | gaP) de | BEB] Be | BEB) Be 
ag2| 32 |8s8| 82 | 888| S32 | 8S3| S2 | asé| Ss 
| 
167- a 230— i 117 
form A| 45 6 240 14-17 205 17-18 390 11-21 194 21 
var. tenwis ———- —_- — > 
140- 275- 570- 
2 5-2 
form B 440 11-28 340 15-20 1400 10-20 190 17 
0Q- = 
var. lata =e 12-14 870 12 
all forms and 140- 230- = 117- 190- 
me LF) —21 
varieties ue G 530 0 tE28 | gro 2? 7°. anne oe aoe 


As the entirely spined short-rayed basal acanthophores are sufficiently 


abundant for proper study and measurements only in the Palythoa, and as only 


HYALONEMA (PRIONEMA) AGUJANUM. 257 


two specimens of var. tenuis, form A, bear Palythoa on their stalk, I shall only 
describe these spicules of this form. 

The entirely spined short-rayed acanthophores (Plate 76, figs. 4-6, 17-30, 34) 
of var. tenwis, form A, are mon- to tetractine. The rays of the tri- and tetrac- 
tines always lie in the same plane. The rays are cylindrical and rounded, 
sometimes also thickened at the end. The whole spicule is quite uniformly and 
densely covered with spines, which arise vertically or more rarely obliquely 
from its surface. The oblique spines, which invariably point outwards, are 
confined to the ends of the rays. The spines are straight, conical, 4-6 » long, 
and 5-7 uw broad at the base. The entirely spined basal spicules measure 58- 
210 » in maximum diameter (length), and their rays are 14-45 » thick. It is to 
be noted that this thickness is by no means always in proportion to the length of 
the spicule. In the smaller forms, under 85 u in length, the rays are 15-22 » 
thick; in the intermediate, 85-100 uw in length, they are 14-45 uw thick, and in 
the larger, over 100 » in length, they are 15-34 wy thick. 

In view of the fact that the Palythoa doubtlessly derives the whole of the 
material wherewith it builds its skeleton from the basal part of the sponge to the 
stalk of which it is attached, it appears very remarkable that the basally smooth 
spicules, so frequent in the lower part of the sponge, are relatively so rare in the 
Palythoa; and that, vice versa, the entirely spined spicules, forming the bulk of 
the skeleton of the Palythoa, are so rare in the lower part of the sponge. In 
Hyalonema (Hyalonema) grandancora, where the relation between the skeleton 
of the lower part of the sponge-body and the skeleton of the Palythoa is the same, 
this difference appears to be due to the Palythoa selecting the stoutest and most 
spiny acanthophores of the sponge as material for building its skeleton. 

The stalk-spicules (Plate 75, figs. 29, 30; Plate 78, figs. 1, 2), at the point 
where they arise from the body, are in var. tenuis 180-600 u thick, in var. lata 
60-300 ». All those of var. tenuis appear to be smooth. Only some of those of 
var. lata are smooth, the others (Plate 78, figs. 1, 2) being provided with annular 
constrictions, usually much deeper on one side than on the other. These con- 
strictions have a maximum depth of 12 y, and follow each other at fairly equal 
intervals of about 110 ». They render the outline of the parts of the spicules, 
where they occur, wavy in appearance. In these regions the axial thread ex- 
hibits a more or less clearly pronounced thickening at or near the centre of many 
of the bulging parts lying between successive constrictions (Plate 78, figs. 1, 2). 
Some of the stalk-spicules of this variety are irregularly rounded at the proximal 


end. In one of them the rounded proximal end is 220 y thick. 


258 HYALONEMA (PRIONEMA) AGUJANUM. 


Among the microhexactines two kinds can be distinguished :— regular forms 
with equal rays, and irregular forms with one ray or two opposite rays longer 
than or otherwise different from the others. 

The regular microhexactines (Plate 72, figs. 16-18; Plate 76, figs. 1-3; Plate 
78, figs. 5-7) usually have perfectly straight rays. Very rarely one or the other 
of the rays is somewhat curved. The rays are conical and sharp-pointed. They 
bear conical, sharp-pointed spines (Plate 76, fig. 1). The spines on the proximal 
part of the rays are sparse, vertical, and about 0.6 w long. Distally the spines 
become more numerous, inclined backwards toward the centre of the spicule, 
and smaller; those a short distance below the end are 0.3 » long. The regular 
microhexactines of the two forms of var. tenuis are 100-180 u in diameter, of var. 
lata 110-240 ». The basal thickness of the rays is in the former 3-5 yu, in the 
latter 3-7 ». The centre, particularly of the larger microhexactines of var. 
lata, is often distinctly thickened. 

The irregular microhexactines are to be considered as forms transitional 
between the canalar pinules and the regular microhexactines, and in respect to 
shape and size intermediate between these. 

The amphidiscs were examined biometrically in the usual manner. I 
measured 238 of var. tenuis, form A; 66 of var. tenuis, form 6; and 142 of var. 
lata. To make these three sets of measurements directly comparable I multi- 
plied the numbers of amphidises of the same length-category of var. tenuis, 
form B, with 238:66 = 3.606, and of var. lata with 238: 142 = 1.677. The 
numbers thus obtained are the ones used in constructing Figure 12. 

Morphologically two main groups of amphidises are to be distinguished : — 
amphidiscs with serrated anchor-teeth, more slender shafts, and narrow anchors; 
and amphidises with smooth anchor-teeth, stouter shaft, and broader anchors. 
The amphidises of the first group, which I designate serrated amphidiscs, vary 
very considerably in size, their length ranging from 90 to 415 uw. The curves 
representing the frequency of the serrated amphidises of different lengths show 
numerous ups and downs, thus indicating that the serrated amphidises of differ- 
ent size differ in frequency. The irregularities of these curves are, however, 
hardly of a kind to allow of a distinction of different kinds of serrated amphidises 
according to their size. This is particularly noticeable in the curve of var. 
tenuis, form A. And as this curve is the most reliable one, on account of its 
being based on a much larger number of individual measurements than the curves 
of var. tenuis, form B, and var. lata, I refrain from subdividing the serrated 


amphidises into subgroups. 


Length, (1). 
15.86 — 17.45 


17.45 — 19.19 
19,19 — 21.11 
21.11 — 23.23 
23,23 — 29.55 
25.55 — 28.10 
28.10 — 30.91 
30.91 — 34.00 
34.00 — 37.40 
37.40 -— 41.14 
41.14— 45.26 
45.26— 49.78 
49.78 — 54.76 
54.76 — 60.24 
60.24 —- 66.26 
66.26— 72.89 
72.89— 80.18 
80.18 — 88.20 
88.20-—— 97.02 
97.02 — 106.72 
106.72 — 117.39 
M739 — 12913 
129.13 — 142.04 
142.04 — 156.25 
156.25 — 171.87 
171.87 — 189.06 
189.06 — 207.97 
207.97 — 228.76 
228.76 — 251.64 
251.64 — 276.81 
276.81 — 304.49 
304.49 — 334.93 
334.93 — 368.43 
368.43 -— 405.27 
405.27 — 445.80 
445.80 — 490.38 


Number of Amphidiscs 


~ to 


— bo 
o 1) oO on oO ao 


Fig. 12.— Amphidises. 


0€ 
S 


— 


eee me ee 


t---—~--—-- 


ee ee 


jo sosiprydureioey\[—-- -- — 


jo sosiprydwe pajye1tas |! 
jo sosipryduresoeyyy — --—-- —-- —--—-. — 


jo sostiprydwiesoeyy - 
pure sosiprydurels1j 
pue sosipryduresoiyy 
jo sosiprydwie pa}e1tag 


jo sosiprydwe payei1aS 


“DID] “Ava 


“q WIOF 
“sinuay “ADA 


cae eee ae 
. —--.. 
eee 
— 


“YW WiIO4 


“sinuay “Ada 


Or 


pue sosipryduesoiyy \ 


) 


260 HYALONEMA (PRIONEMA) AGUJANUM. 


It is different with the amphidises with smooth teeth, stouter shaft, and 
broader anchors. There is a great gap in the length frequency-curve of these 
spicules in all the three forms: — in the var. tenuis, form A, curve between 80 and 
225 uw; in the var. tenuis, form B, curve between 78 and 200 u; and in the var. 
lata curve between 64 and 207 uw. This clearly divides these spicules biometri- 
cally into two groups: — macramphidises over 200, and micramphidises under 
80 u in length. 

Besides one well-pronounced main elevation each of the three length fre- 
quency-curves of the macramphidiscs shows only a quite insignificant secondary 
elevation. The macramphidise group can therefore be considered as fairly 
homogeneous. 

The micramphidises on the other hand show clearly pronounced gaps in the 
length frequency-curves; in the var. tenuis, from A, curve between 30 and 51 uy; 
in the var. tenuis, form B, curve between 33 and 47 uw; and in the var. lata curve 
between 26.8 and 47 uw. These gaps divide them into two distinct groups, one 
comprising the micramphidises over 47 u in length, the other the micramphidises 
under 33 uw in length. For this reason, and because the former are also distin- 
guished from the latter by their shafts, which in the larger ones are provided 
with a relatively very large central tyle, and which in the smaller ones are not 
thickened at all, or only slightly so at or near the centre, I divide the micram- 
phidises into two secondary groups: — large micramphidises with well-developed 
central tyle, and small micramphidises with no central thickening or only a 
slight one. 

Thus four kinds of amphidises are to be distinguished: — macramphidises, 
serrated amphidises, large micramphidises, and small micramphidiscs. 

The normal macramphidiscs (Plate 73, figs. 1-7; Plate 75, figs. 3-21; Plate 
77, figs. 1,9, 10; Plate 78, figs. 12-15) havea straight and stout cylindrical shaft, 
slightly thickened at or near the middle to a central tyle. A verticil of stout 
and short, distally attenuated, truncate spines arises from this tyle. The 
number of spines forming the verticil is variable but never great, most frequently 
four to eight. The verticil is regular or irregular. Its irregularity is usually 
slight, rarely considerable. In the latter case there are more than eight spines. 
The remaining parts of the shaft are either quite smooth or they bear only a few 
scattered spines nearly as broad as the spines of the central tyle, but usually 
much shorter. 

The terminal anchors are composed of eight teeth quite uniformly curved 
throughout (Plate 73, figs. 4, 6) or more strongly bent at the ends than elsewhere 
(Plate 73, fig. 5). Their curvature is such that the end-parts of the teeth are 


HYALONEMA (PRIONEMA) AGUJANUM. 261 


either parallel, or slightly convergent or divergent. The teeth have the usual 
T-shaped transverse section. Their upper (outer) band-shaped part arises 
from the margin of a transverse circular dise situated at the end of the shaft. 
The diameter of this disc is a little less than a third of the anchor-breadth. In 
apical views of the anchors, the basal parts of adjacent teeth appear connected 
by the interdental parts of this dise as by a web (Plate 77, fig. 10). The upper 
band-shaped part of the teeth is 22-27 » broad at the base and in the middle. 
It is attenuated distally and pointed at the end. The contour of the tip of the 
tooth has the shape of a gothic arch (Plate 73, figs. 1-3; Plate 77, fig. 9). 

The macramphidises have on the whole narrower anchors and attain a 
considerably larger size in var. tenuis, form A, than in var. tenuis, form B, and 


in var. lata. Their dimensions are as follows: — 


NORMAL MACRAMPHIDISCS. 


Hyalonema (Prionema) agujanum 
var. tenuis 
= — = var. lata. 
form A. | form B. 
limits 225-440 200-350 207-370 
Total Oe 
length most frequently 387 320 320 
about wu 
Shaft, thickness p» 20-27 18-22 19-25 
diameter yp 28-43 26 24-34 
Central difference between 
tyle diameter of tyle and 4-19 5 2-11 
adjacent parts of 
shaft py 
: —- 9 47 
Snitesior length yu 7 5-15 
central tyle| cal thickness 8-11 | 10 5-9 
| 
length, limits 63-110 | 55-83 | 65-95 
Anchor 
breadth, limits p 116-172 119-160 112-168 
| 
Proportion of limits 100 : 143-221 ees iid=236 155-211 
anchor-length to —— 
anchor-breadth. average 100: 169 | 196 186.8 
Proportion of 2 : | a = 
anchor-length to limits 1: 3.9-5.4 4.2-4.9 | 3.1-5 
total length of 
whole spicule average 1: 4.7 4.7 4.2 


262 HYALONEMA (PRIONEMA) AGUJANUM. 


In var. tenuis, form A, I found a remarkable abnormal amphidisc (Plate 75, 
figs. 35-37), 224 » long with a straight shaft 20 1 thick. One of the terminal 
anchors is quite regular, 90 1 long and 1124 broad; the other is somewhat 
irregular, and partly spirally twisted. Two large protuberances about 50 y» 
long arise from the rather eccentrically situated “‘central”’ tyle of the shaft. 
One of these terminates in a broad and thin lamella extending in a radial plane 
which passes through the axis of the spicule. The distal part of this lamella is 
strongly and abruptly bent, so as to become parallel to the shaft (Plate 75, fig. 35). 
The other protuberance of the central tyle terminates in a stout oblique spine. 

If we mentally construct an ovoidal (rotation-ellipsoidal) surface following 
the outer sides of the teeth of both anchors and entirely enclosing the whole 
spicule, we find that the large protuberances of the central tyle reach this surface 
and abruptly bend on reaching it. This indicates that such an ideal rotation- 
ellipsoidal surface formed a real limit to their radial growth. This limit may very 
likely be the surface of a cell ovoidin shape. If this be so, we might assume that 
the amphidise was formed and grew within this cell, and that the outer band- 
shaped parts of its anchor-teeth and the distal bent parts of the protuberances 
of the central tyle were developed in the superficial part of the protoplasm of 
this cell. Thus the appearance of this abnormal macramphidisc is in favour of 
the view that each amphidisc is produced, like the sigms and cheles of the monax- 

“onid sponges, in an ellipsoidal cell, the shape of the surface of which determines 
the shape and position of the anchor-teeth, which are formed and which grow in 
its superficial part. 

The serrated amphidiscs (Plate 74, figs. 1-9; Plate 75, figs. 1, 2, 22, 23; 
Plate 76, figs. 33, 35, 36; Plate 77, figs. 2-7) have a rather slender, straight or, 
rarely, slightly bent (Plate 74, fig. 5) shaft. The shaft is considerably thickened 
at or near the middle to a conspicuous central tyle. A verticil of long, more or 
less, often very considerably curved, cylindroconical and truncate or terminally 
rounded spines arises from the central tyle. In an abnormal serrated macram- 
phidise of var. tenuis, form A, the spines of the central tyle are in shape and 
position similar to the teeth of the terminal anchors, only smaller. One of the 
terminal anchors of this spicule (the other is broken off) is 117 » long and 75 u 
broad; the anchor-shaped spine-verticil of the central tyle is 61 » long and 55 yu 
broad. The remaining parts of the shaft are covered rather densely with minute 
spines. These increase in number and in size towards the ends of the shaft. 
The terminal anchor usually consists of eight teeth. The individual teeth are 
generally curved in the same direction, concave to the shaft, throughout their 
length. More rarely a portion of a tooth is curved the other way, convex to the 


HYALONEMA (PRIONEMA) AGUJANUM. 263 


shaft (Plate 74, fig. 3; Plate 77, figs. 2,3). The end-parts of the teeth are often 
bent rather abruptly inward and they generally converge. The teeth have the 
usual T-shaped transverse section. Their outer and upper band-shaped part 
is, in the larger serrated amphidiscs, nearly uniformly (18-22 w) broad throughout, 
attenuated only slightly distally, and rounded at the end. The lateral and termi- 
nal margins of the teeth are bent down shaftwards and serrated. The serration- 
teeth are triangular, sharp-pointed, and usually directed more or less backwards. 
The lateral ones are 1.5—2 » long and 1-2 u broad, the terminal ones smaller. 

In var. tenuis, form A, and in var. lata the serrated amphidises attain a larger 
size than in var. tenwis, form B; and in var. lata the average relative breadth of 
the anchors is considerably greater than in the two forms of var. tenuis. The 
dimensions of the serrated amphidises are: — 


SERRATED AMPHIDISCS. 


var. tenuis. 
var. lata 
form A form B 
limits yu 90-410 100-342 90-415 
Total 
zeneth ose frequently 320 103, 180 149, 198, 264! 
about yu 
Shaft, thickness yu 3-12 5.5-7.5 3.5-8 
diameter 6-17 12-15 6-14 
Central differences between 
tyle diameter of tyle and 2 5-10 6-8 art is 
adjacent parts of 
shaft be 
, 5-15 8-12 5-10 
Spines of length” 4 
era Leyes i paenvehieleness, jt 1.2-4 1.5 1-2 
length, limits 30-159 30-145 60-165 
Anchor 
breadth, limits yp 20-120 25-118 48-154 
Proportion of limits 100: 63-106 55-83 63-105 
anchor-length to — 
anchor-breadth average 100: 71.8 70.4 83 
Proportion of ey m 
anchor-length to limits 1: 2-2.4 2.2-2.4 2.2-2.4 
total length of the 
whole spicule | average Li: | 2.3 2.3 2.3 
1 When there oe ipo eine numbers in this zone it indicates that the length frequency-curve 


pertaining to the spicules of the variety or form has more pronounced elevations than one; in these the 
serrated amphidiscs do not appear to be biometrically homogeneous groups. 


264 HYALONEMA (PRIONEMA) AGUJANUM. 


The rare large micramphidiscs have a stout shaft with an exceptionally 
large, usually somewhat irregular, central tyle. This tyle bears numerous 
minute and slender spines. These are not arranged in a verticillate manner, 
but are scattered over the whole tyle. The remaining parts of the shaft also ~ 
bear minute spines. The anchor-teeth, which arise nearly vertically from the 
end of the shaft, are curved quite uniformly throughout, through an angle of 
about 90°, so that their end-parts are nearly parallel. The dimensions of these 


amphidises are: — 


LARGE MICRAMPHIDISCS. 


var. tenuis 
var. lata 
form A form Bt 

limits yu 51-80 47,78 47-64 
Total 
length most frequently 75 50, 60 

about yu 
Shaft, thickness 1.3-3 ioe 

diameter yp 4-7 3.5 5.5 
Central differences between 
tyle diameter of tyle and 27-4 3-4 

adjacent parts of 

shaft 

length, limits 18-39 13, 35 | 18-24 
Anchor = “- 

breadth, limits 17-31 11, 26 14-20 
Proportion of “limits 100: 67-100 | 74-85 | 78-83 
anchor-length to — SS 
anchor-breadth average 100: 82.5 79.5 | 80.5 
ee | eS ee eee ee, S| | 
Proportion of a | 
anchorlenet ito | limits 1: 2-3 2.2,3.7 2.3-3 
total length of the | ; | 
spicule | average 1: 2.5 2.9 72,0 


The small micramphidiscs (Plate 75, figs. 24-27, 31-34; Plate 77, fig. 8) 
have a straight shaft, which is either simple, cylindrical, and without any trace 
of a central tyle, or, more rarely, slightly thickened at or near the centre to a 
small central tyle. Such central tyles on the shaft are much more frequent in 
the small micramphidises of var. lata than in those of var. tenuis. The shaft is 
covered throughout with more or fewer, sometimes very numerous minute spines. 


1 Only two seen. 


HYALONEMA (PRIONEMA) AGUJANUM. 265 


The spines are vertical, or inclined toward the centre of the spicule. The anchor- 
teeth arise vertically from the end of the shaft, and are uniformly curved through 
an angle of about 90°, so that their end-parts are nearly parallel. The dimensions 
of the small micramphidises are: — 


var. lenuis 
—— $$$ —————— var. lata 
form A form B 

limits yp 20-30 18-33 18-26 .8 
Total —— 
length most frequently 24 5 24.5 20, 24.5 

about pu 
Shaft, thickness 0.8-1.3 1-1.5 

length, limits yp 5-8.5 4-12 | 5-7.5 
Anchor a 

breadth, limits yp 6-9.5 6-9 7-8.5 
Proportion of limits 100: 93-160 75-200 100-160 
anchor-length to }=§=£=————— 
anchor-breadth average 100: 122 107 127 
Proportion of abt 
eG leeth fo limits 1: 2.9-4.9 2.5-5.9 2.9-4.4 
total length of the 
whole spicule | average 1: 3.8 4 3.6 


The above description shows that these sponges are similar enough to be 
considered one species. The greater average relative breadth of the serrated 
amphidises, particularly the larger, and some other peculiarities in one of the 
specimens, call for the recognition of two varieties: — var. tenuis with narrower 
serrated amphidisc-anchors, and var. lata with broader. One of the four speci- 
mens of var. tenwis has much smaller macramphidiscs than the others, and I 
consequently distinguish two forms in it: — A with larger, and B with smaller 
macramphidiscs. 

The nearest ally of Hyalonema (Prionema) agujanum appears to be the 
sponge I describe as Hyalonema (Prionema) pinulifusum (p. 284). From this it 
differs by the shape of the macramphidises and particularly by the pinules; 
in H. (P.) agujanum the distal rays of the largest pinules (together with the 
spines) are rather slender and more or less cylindrical, in H. (P.) pinulifusum 
they are very stout and spindle-shaped. 


266 _ HYALONEMA (PRIONEMA) AZUERONE. 


Hyalonema (Prionema) azuerone, sp. nov. 


Plate 56, fig. 1; Plate 57, figs. 1-23; Plate 58, figs. 1-22. 


One specimen of this species was trawled in the Eastern Pacific at Station 
4621 on 21 October, 1904; 6° 36’ N., 81° 44’ W.; depth 1067 m. (581 f.); it grew 
on a bottom of green mud and rock; the bottom-temperature was 40.5°. The 
Station is off the southern coast of western Panama, southwest of the Azuero 
Peninsula, to which the name refers. 

Shape and size. The specimen (Plate 56, fig. 1) appears as a soft and resilient 
dise with irregular lacerated margin. It is 275 mm. long, 255 mm. broad, 15-25 
mm. thick, and forms (probably the greater) part of a sponge which may have 
been broad and low cup- or vase-shaped, perhaps similar to Hyalonema populi- 
ferum F. E. Schulze.! Fragments of large stalk-spicules, and slight remnants of 
a protuberance indicate that a stalk was present in the living sponge, which arose 
from the face bearing the protuberance. This face must be considered as dermal. 

The sponge consists of a mass of curved lamellae, mostly 2-3 mm. thick, 
and joined to form a labyrinthic structure with elongate cavities or canals, which 
have a maximum width of 11 mm. 

The colour in spirit is reddish brown. 

General structure and canal-system. In those regions of the lower (dermal) 
surface where the superficial parts are intact, broad, oval pores covered by a 
fine network are observed. One of these pores (Plate 58, fig. 4) measures 3.8 
by 3.4mm. The network covering it consists of straight threads 30-40 u thick. 
The nodes are considerably thickened; the meshes are triangular or irregularly 
square, and 30-120 » wide. The flagellate chambers are curved, irregular sac- 
shaped, and 80-140 » wide. They form groups surrounding efferent canals and 
lie, within these groups, close together. The chamber-groups are attached to 
and held in position by a network of threads, spread out between them and the 
superficial membranes of the sponge-lamellae in which they lie. 

The skeleton. The intact parts of the superficial (dermal and gastral) 
membranes are covered by a dense fur of pinules (Plate 58, figs. 3a, 10, 11). 
Small patches of the same pinule-fur also occur at the thickened nodes of the nets 
covering the afferent pores (Plate 58, fig. 4). Pinules are likewise met in the 
walls of some at least of the canals (Plate 58, fig. 1b). These canalar pinules are, 


however, not nearly so densely crowded as the superficial ones. Rhabds extend 


1 Ff. HE. Schulze. Amerikanische Hexactinelliden, 1899, taf. 2, fig. 7. 


HYALONEMA (PRIONEMA) AZUERONE. 267 


paratangentially in the superficial membranes and occupy, singly or in bundles of 
two or three, the axes of the threads of the nets covering the afferent pores. 
Similar rhabds traverse the choanosome, singly or in bundles, in various directions. 
Most of these rhabds are centrotyle isoactine amphioxes. In some, one actine 
is reduced in length and terminally thickened; these resemble tylostyles. Pentac- 
tine megascleres occur in the superficial parts of the lamellae. In the interior 
a few hexactine forms are found. Very numerous microhexactines and a few 
pentactine and diactine-derivates of these spicules are also found in the interior. 
Seven kinds of amphidises occur in this sponge: — not very numerous macramphi- 
dises with serrated anchor-teeth; very rare large mesamphidises with smooth 
teeth; very numerous medium mesamphidises, which, in places (Plate 58, fig. 2), 
form quite dense masses; a few similar small mesamphidises; numerous slender- 
shafted regular micramphidiscs; and two kinds of micramphidiscs, a larger and a 
smaller, which are stout-shafted, and generally more or less irregular. 

The superficial (dermal and gastral) pinules (Plate 58, figs. 3a, 10, 14, 15, 17, 
18, 20-22) observed were all pentactine. The distal ray is straight, 190-390 u 
long, and 5-9 u» thick at the base. It ends with a very slender sharp-pointed 
terminal cone, and the whole of it, with the exception of its proximal and distal 
end-parts, is beset with spines. These spines are numerous, rather crowded 
and longest in the middle-part of the ray; they decrease in size both proximally 
and distally. The lowest arise nearly vertically; distally they become more 
and more inclined towards the tip of the ray. The longest spines of the middle- 
part of the ray usually enclose angles considerably less than 45° with the axis of 
the ray. These spines are conic, sharp-pointed, attain 25 uw in length, 3 u in 
thickness, and are slightly curved, concave towards the tip of the ray. They 
are either simple, or bear one or two outwardly directed branch-spines, which 
sometimes reach a very considerable size (Plate 58, fig. 18). The maximum 
thickness of the distal ray, together with the spines, is 22-36 ». The basal half 
of the lateral rays (Plate 58, figs. 14, 15) is nearly cylindrical and smooth, the 
distal half conic and provided with somewhat sparse, quite large, broad, and low 
spines. The end is blunt. The lateral rays are 25-55 » long. They appear to 
be longer in the gastral than in the dermal pinules; in the former they are usually 
about 40 u long, in the latter about 30 u. 

The canalar pinules (Plate 58, figs. 1b, 16, 19) are on the whole similar to 
the superficial ones but have more slender rays, a shorter distal ray, and fewer 
and smaller spines on the latter. It is also to be noted that they are not all 


pentactines, a few hexactine forms occurring among them. The measurements 


268 HYALONEMA (PRIONEMA) AZUERONE. 


of these spicules are: — distal ray, length 134-290 », basal thickness 4-5 y, 
maximum thickness together with the spines 13-28 »; lateral rays, length 26- 
52 uw; proximal ray (when present), length 35-38 y. 

The hexacline megascleres measured were 0.7—2.4 mm. in diameter, and had 
smooth, conic, blunt-pointed rays, 17-45 y» thick at the base. 

The pentactine megascleres measured had straight rays, 10-25 u thick at 
the base. The proximal ray is 0.1-0.6 mm. long; the lateral rays, which enclose 
angles of about 80° with the proximal, are 150-300 u long. 

The fairly tsoactine centrotyle amphiox rhabds are more or less, often very 
considerably curved, particularly the long ones. They are usually blunt-pointed, 
near the end sometimes wavy in outline, 0.6—-2.8 mm. long, and 9-25 y» thick in 
their middle-part. The central tyle is 12-28 in transverse diameter, the 
proportion between the thickness of the adjacent parts of the spicule and the 
thickness of the tyle being 100 to 108-151, on an average 100 : 120.6. 

The tylostyle-like anisoactine centrotyle rhabds are 1—2.5 mm. long, usually 
slightly curved, and 13-15 u thick near the morphological centre. Their central 
tyle measures 14-16 » in diameter. The terminal thickening (tyle) of the 
reduced ray is 17-20 » in diameter. Besides the intact tylostyle-like spicules, 
the measurements of which are given above, some fragments of them with a 
terminal tyle sometimes 23 » in diameter were observed. 

The muicrohexactines (Plate 57, figs. 18-23; Plate 58, fig. le) measure 
50-160 w in diameter, usually 70-110 u. The rays of the same spicule are gen- 
erally equal. They are smooth, at the base 1-3.5 » thick, usually about 1.8 u, 
straight in their proximal part and generally slightly curved in their distal part. 
Their curvature appears to be, on the whole, in inverse proportion to the size 
of the spicule; the largest microhexactines, that is those more than 125 yu 
in diameter, having nearly straight rays. One of the microhexactines observed 
had a bifureate ray (Plate 57, fig. 20). 

The rare micropentactines measured were 94-150 » in diameter, and had 
rays 1.5-3 p» thick at the base. 

One of the rare diactine microhexactine-derivates measured consisted of two 
straight rays forming an angle of 85°. Its rays are 3 » thick at the base; one 
is simple and 60 yu long, the other bifurcate and 50 yu long. 

The amphidiscs. According to their shape, four kinds of amphidises are to 
be distinguished: — A large amphidiscs with relatively short anchors and 
serrated’ anchor-teeth; B medium amphidises with relatively long anchors and 


smooth anchor-teeth; C small amphidiscs with slender shafts and relatively 


HYALONEMA (PRIONEMA) AZUERONE. 269 


small regular anchors; and D small amphidises with stout shafts and relatively 
large, usually more or less irregular anchors. Biometrically, according to 
the length frequency, A is a well-defined, simple, and homogeneous group. 
B overlaps C and D somewhat, and C and D are about equal in length. B 
is biometrically composed of three secondary groups represented by (a), large, 
(b), medium sized, and (c), small amphidises. C is biometrically a simple 
and homogeneous group. JD is biometrically composed of two well-defined 
secondary groups represented by larger amphidises (a), and smaller amphi- 
dises (b). Thus if both their shape and the biometric character of their length- 
frequencies are taken into consideration seven kinds of amphidises are to 
be distinguished:— macramphidises (A); large mesamphidises (B a); medium 
mesamphidises (B 6b); small mesamphidises (Be); slender-shafted micram- 
phidises (C); stout-shafted large micramphidises (D a); and stout-shafted small 
micramphidises (D b). 

The macramphidiscs (Plate 57, figs. 1-5; Plate 58, figs. 5-9) are 300-356 u 
long, most frequently about 320 4. Their shaft, which is straight and for the 
most part 7-9 u thick, thickens at the ends gradually to a conic extension 10-14 yu 
in diameter, and in or near the middle abruptly to a central tyle of the same 
diameter. The proportion of the thickness of the adjacent parts of the shaft 
to the thickness of the central tyle is 100 to 130-200, on an average 100 : 157.4. 
An irregular verticil of cylindroconic, truncate, or terminally rounded spines arises 
from the central tyle. These spines are 1.5-3.5 w thick, usually 1.5-4 uw long, 
sometimes as much as 8», and when long are irregularly curved. They bear 
on their terminal face a cluster of exceedingly minute secondary spinelets. 
Seattered spines, similar to those of the central tyle, but on the whole shorter, 
are met on the remaining parts of the shaft. The terminal anchors are 77— 
119 » long; they are broadest usually a little over a third of the whole spicule, 
somewhere beyond the middle, and attenuated towards the end. Their maxi- 
mum breadth is 85-104 yu, their end-breadth 75-95 ». The proportion of length 
to maximum breadth is 100 to 77-114, on an average 100: 101.5. The maxi- 
mum breadth is 3-11 », on an average 7.1 uw, greater than the end-breadth. The 
anchor usually consists of nine or ten teeth. The individual teeth arise steeply 
from the end of the shaft, and are strongly curved in their basal part. Farther 
on the curvature decreases either gradually or somewhat abruptly. The 
‘decrease of curvature either continues to the end of the tooth, or it increases 
again just before the end. The total curvature is such that the end-parts of 
the teeth converge toward the shaft, with the axis of which they usually enclose 


270 HYALONEMA (PRIONEMA) AZUERONE. 


an angle of 10°-20°. The teeth have the usual T-shaped transverse section. 
The lower, radial part, corresponding to the upright stroke of the T, extends 
to the end of the tooth. The upper, paratangential part, corresponding to the 
upper, horizontal stroke of the T, is 12-16 » broad in its middle-part and grad- 
ually attenuated distally; its end is broad and simply rounded; its lateral 
margins are strongly serrated (Plate 58, figs. 5-9). The individual saw-teeth 
are pointed and usually triangular. In the middle-part of the anchor-tooth 
these saw-teeth are 1-2 » long and close together. Distally they become smaller 
and more distant; at the end they are only about 0.5 » long. The saw-teeth 
are directed obliquely inward. A similar serration of the teeth was found 
also in H. spinosum (p. 276) and in a few others. 

In a few of the macramphidises observed two or three supernumerary 
shaft-rudiments arose from the central tyle. In one of them, two of these 
rudiments bore somewhat reduced and irregular terminal anchors. 

The large mesamphidiscs (Plate 57, fig. 8) are very rare; the one represented 
is 232 ulong. Itsshaft is 5.5 u thick and its central tyle 8 ». A verticil of spines, 
with a maximum length of 4 y, arises from the latter, and numerous short and 
broad spines cover the remaining parts of the shaft. The terminal anchors are 
semioval, 108 » long, and 72 » broad; the proportion of their length to their 
breadth being 100: 67. 

The medium mesamphidiscs (Plate 57, figs. 6, 7; Plate 58, figs. 2, 13) are 
very numerous. They measure 56-130 » in length, most frequently about 85 u. 
Their shaft is 1.3-3 » thick and abruptly thickened in or near the middle to a 
central tyle 1.5-5 » in diameter. The proportion of the thickness of the shaft 
to that of the tyle is 100 to 140-220, on an average 100: 165.4. A verticillate 
bunch of irregularly curved, obtuse spines 1-3.5 » long arises from the tyle. 
Similar, usually much shorter spines are scattered in greater or smaller numbers 
irregularly over the remaining part of the shaft. The degree of spinulation of 
the shaft is correlated with, and in proportion to, the size of the spicule; the larger 
the amphidise the larger and the more numerous the spines. The anchors are 
15-46 u» long, one third to nearly half of the whole spicule, and 12.5-31 u» broad. 
The proportion of their length to their breadth is 100 to 57-83, on an average 
100 : 68.6. This proportion is correlated to the size of the spicule, the anchors 
being on the whole relatively the narrower, the larger the spicule (the anchor). 
The average proportion of length to breadth of the anchors under 20 u in length 
is 100 : 80.5, of the anchors under 30 u in length 100: 72.3, and of the anchors 
over 40 » in length 100 : 65.9. The anchors usually consist of twelve or thirteen 


HYALONEMA (PRIONEMA) AZUERONE. 271 


teeth. The individual teeth arise nearly vertically, are strongly and usually 
somewhat abruptly bent a short distance from their point of origin, and only 
slightly curved, concave to the shaft in their distal and middle-parts. The 
curvature is usually such that the end-parts of the teeth diverge from the shaft at 
angles of about 6°. Rarely the teeth are more strongly curved, so that their 
end-parts become nearly parallel to the shaft and to each other. The end-parts 
of such teeth are either straight or slightly curved outwards. 

The small mesamphidiscs are rare. They connect the medium-sized mesam- 
phidises described above with the slender-shafted micramphidises described 
below. The small mesamphidises are usually about 44 » long, have shafts 
about 1.5 » thick, and anchors measuring 15-18 » in length and 11-16 u in breadth. 
The average proportion of anchor-length to anchor-breadth is 100: 81. 

The large stout-shafted micramphidiscs (Plate 57, fig. 9) are 38-68 wu long, 
most frequently about 43 ». The shaft is straight, 1.8—2.5 uw thick, for the greater 
part of its length, and abruptly thickened in or near the middle to a more or less 
irregular central tyle, usually 4-6 » in diameter, sometimes as muchas 8 up. The 
proportion of the thickness of the shaft to that of the tyle is 100 to 160-820, on 
an average 100: 239.8. The whole of the shaft, including the central tyle, is 
more or less spiny. The spines of the tyle are generally larger than the others 
and arranged in a verticillate manner. The anchors are usually irregular, the 
teeth on one side often being considerably longer than those on the other. The 
two anchors of the same spicule usually have the longest teeth on opposite sides, 
exceptionally on the same side. The maximum length of the anchor, that is the 
anchor-length on the side where the teeth are longest, is 15-42 4, sometimes more 
than half the length of the whole spicule. On the opposite side the anchor is 
usually 4-10 uw shorter. The breadth of the anchors is 8.4-21 ». The propor- 
tion of the maximum length to the breadth is 100 to 45-91, on an average 100: 
66.4. The individual teeth arise vertically from the end of the shaft and are 
strongly curved in their basal part. Farther on the curvature decreases and their 
end-parts are curved only slightly, concave to the shaft, or are straight, or even 
curved slightly in the opposite direction. In no case do the end-parts of the teeth 
diverge much from a direction parallel to the shaft, either one way or the other. 
When, as sometimes happens, the longest teeth of the two opposite anchors lie 
on the same side of the spicule and are, both together, longer than the whole 
spicule, their end-parts lie side by side, but do not coalesce. 

The small stout-shafted micramphidiscs (Plate 57, figs. 10-12) are 23-34 u 


long, most frequently about 32 «. They are similar to the large ones, but have 


Za2 HYALONEMA (PRIONEMA) AZUERONE. 


more spiny shafts and relatively smaller and, on the whole, still more irregular 
anchors. The shaft is for the most part 1.2—2 » thick, and abruptly thickened 
in or near the centre to a remarkably large central tyle which measures 2—5 » in 
diameter. The remainder of the shaft is often not quite uniform in thickness. 
The proportion of the thickness of the shaft to that of the tyle is 100 to 133-333, 
on an average 100: 204.8. The whole of the shaft, including the central tyle, 
is beset with very numerous spines. Those on the tyle are either large and ar- 
ranged in a verticillate manner, or small and quite uniformly scattered over the 
whole tyle. Those on the remaining parts of the shaft are always small. The 
maximum length of the anchors is 7-12 uv, about a third of the length of the whole 
spicule, their breadth 8-12 u. The proportion of maximum length to breadth is 
100 to 73-125, on an average 100 :101.3. The individual anchor-teeth are 
curved so that their end-parts do not greatly diverge from a direction parallel to 
the shaft. 

The slender-shafted micramphidiscs (Plate 57, figs. 13-17; Plate 58, fig. 12) 
are 30-58 » long, most frequently about 42 u. The shaft is regularly cylindrical, 
straight or, rarely, slightly curved, 1-1.7 » thick, and thickened at some point, 
sometimes a long way from the middle, to a central tyle 1.4-2.4 u» in diameter. 
The proportion of the thickness of the shaft to that of the tyle is 100 to 114-131, 
on an average 100:121. A few blunt spines, sometimes 0.7 » long, arise from 
the tyle. The remainder of the shaft is usually quite smooth. Ina few, particu- 
larly in the large and slender-anchored ones, the shaft bears minute spines. The 
anchors are regular, 6-10 » long, a quarter to a sixth of the whole spicule, and 
9-10 » broad. The proportion of their length to their breadth is 100 to 105-150, 
on an average 100 : 121.6. The number of teeth in the anchor is about seventeen. 
The individual teeth arise vertically and are considerably curved in their basal 
part. Distally the curvature decreases in a uniform manner. The end-parts 
of the teeth diverge more or less from the shaft. 

The large slender-anchored forms above referred to connect these amphi- 
dises with the small mesamphidisces. 

The nearest ally of the sponge above described among the species hitherto 
made known appears to be Hyalonema validum F. E. Schulze. With this species 
it coincides in respect to the shape and size of all the spicules, with the excep- 
tion of the stout-shafted more or less irregular micramphidises, which are present 
in H. (P.) azuerone and absent in H. validum; the microhexactines, which have 
more strongly bent rays in the latter than in the former; and the dermal 
pinules, the distal rays of which are bushy and have a thick, abruptly pointed 


HYALONEMA (PRIONEMA) SPINOSUM. 273 


terminal cone in H. validum, and are slender and have a very slender and fine- 


pointed terminal cone in H. (P.) azuerone. 


Hyalonema (Prionema) spinosum, sp. nov. 


Plate 48, figs. 1-31; Plate 49, figs. 1-23; Plate 50, figs. 1-5. 


Three specimens of this species were trawled nearly under the equator in the 
Eastern Pacific at Station 4742 on 15 February, 1905; 0° 3.4’ N., 117° 15.8’ W.; 
depth 4243 m. (2320 f.); they grew on very light, fine Globigerina ooze; the 
bottom-temperature was 34.3°. 

The microhexactines bear unusually large spines. To this the specific 
name refers. 

Shape and size. The largest specimen (Plate 48, fig. 12) is a lamella or 
plate, roughly round in outline when spread out flat. It is 46 mm. long, 37 mm. 
broad, and has a fairly uniform thickness of 8-10 mm. The margin is rounded. 
The lamella is folded along a straight line passing nearly through its centre. 
The two parts on either side of the fold are flat, and enclose an angle of about 
70°. On the convex side of the fold a rounded protuberance arises near the 
margin. In life, the stalk, which is now, however, entirely absent, arose from 
this. At the opposite end of the fold the margin is slightly incised. On the con- 
vex surface of the lamella, which is the dermal, the covering (dermal) membrane 
is lost in many places, and this side consequently appears rough and porous. On 
the opposite, concave side, which is the gastral, meandric branching grooves are 
observed, which, on the whole, radiate from a point in the fold near the centre 
of the lamella. At this point a small and slender gastral cone arises from the 
concavity of the fold. 

One of the smaller specimens (Plate 48, fig. 11) is lenticular in shape. It 
measures 35 mm. in horizontal diameter and is 16 mm. thick. Near the middle 
of one (the lower, dermal) face a rounded protuberance arises. From this, in 
life, the stalk, which is now absent, protruded. In respect to the structure of 
the surface this specimen resembles the large one. The other small specimen is 
fragmentary and measures 25 by 22 by 8 mm. 

The colour of the two better preserved specimens is, in spirit, light brown; 
of the fragmentary one, whitish. 

The lamellar or lenticular sponge-body is traversed by wide canals (Plate 48, 
fig. 13), most of which extend in a more or less vertical direction. Some of these 


canals are afferent and open out below, others are efferent and open out above 


274 HYALONEMA (PRIONEMA) SPINOSUM. 


in the gastral surface. The gastral membrane exhibits, in many places, a 
reticulate structure; in life the mouths of the efferent canals were probably 
covered with nets. 

The skeleton. The surface is, so far as the dermal and gastral membranes 
are intact, covered by a dense pinule-fur (Plate 48, fig. 23). The dermal pinules 
on the outer (lower, convex) side, and the gastral pinules on the inner (upper, 
concave) side are very much alike. The gastral pinule-fur extends quite down 
to the bottom of the grooves above referred to. Lateral, paratangentially 
situated, rays of large (hypodermal and hypogastral) pentactines extend just 
below the level occupied by the lateral pinule-rays. In the gastral membrane 
numerous paratangential amphioxes accompany them. The proximal rays of 
the pentactines point radially inward. Large numbers of stout acanthophores, 
tetractine to monactine, occur in the protuberance from which, in life, the stalk 
arose. 

The interior of the sponge is occupied by dense masses of relatively large 
microhexactines, which evidently form the main support of the whole sponge- 
body. Besides these spicules, rhabd and hexactine megascleres and amphidiscs 
occur in the choanosome. 

The dermal pinules (Plate 48, figs. 17-22) are mostly pentactine, rarely 
hexactine (Plate 48, fig. 20). The distal ray is 100-154 » long, usually 117- 
138 uw, and 3.5-4.5 uw thick at the base. It is straight, regularly conic, and not 
thickened in the middle. The distal end-part of the ray is, for a considerable 
distance, free from spines. The basal part is also smooth. The remaining parts 
of it are covered with sparse spines directed obliquely upward. The spines are 
largest on the middle-part of the ray; they are sometimes 11 » and more long, 
slender, usually only 1-1.3 4 thick, basally cylindrical, distally conical, and 
sharp-pointed. The maximum transverse diameter of the distal ray, together 
with the spines, is 10-17 ». The lateral rays are straight, sparsely spined in their 
distal part, and 20-50 u long, usually 25-40 ». The proximal ray of the hexac- 
tine forms is smooth and rarely more than 15 u long. 

The gastral pinules (Plate 48, figs. 23-27) are similar to the dermal and, like 
these, for the most part pentactine. The distal ray is 100-142 u long, usually 
105-135 yu, and 3.5-5.5 w thick at the base. Its maximum transverse diameter, 
together with the spines, is 11-17 ». The lateral rays are 22-35 u long. 

The hypodermal and hypogastral pentactines (Plate 49, figs. 12-14) have 
smooth, blunt, conic rays. The lateral rays enclose angles of 90° or a little less 
with the apical (proximal) ray. The apical ray is straight, or slightly curved, 


HYALONEMA (PRIONEMA) SPINOSUM. 275 


0.5-2.8 mm. long, and 20-100 u thick at the base; the lateral rays are straight, 
and 0.2-1 mm. long. The length of the lateral rays is not in proportion to the 
length of the apical ray, pentactines with a very long apical ray often having 
comparatively short lateral rays and vice versa. 

The hexactine megascleres (Plate 49, fig. 19) have smooth, generally fairly 
straight, conic rays. The intact ones measured have a maximum diameter of 
0.5-1.5 mm. and rays 12-43 u thick at the base. Some fragments with rays 
43 » thick, which I observed, indicated that these spicules occasionally attain 
considerably larger dimensions. 

The acanthophores (Plate 48, figs. 1-10) have one to four straight or, more 
rarely, curved rays, smooth in their basal part, but covered with spines in their 
end-part. The rays are conic or, more rarely, cylindrical and blunt-pointed or 
rounded, and not infrequently thickened at the end. These spicules measure 
110-430 » in maximum diameter (length); their rays are 10-30 uw thick at the 
base. The rays of the tetractine and triactine forms lie in one plane. In the 
tetractine forms, which are the most frequent, either all four rays are fairly equal 
(Plate 48, figs. 1, 3) or only three, the fourth being more or less reduced in length 
(Plate 48, figs. 2,4,5). In some of these spicules one ray is altogether suppressed. 
These are the triactines (Plate 48, fig. 6). The diactines usually appear as 
straight centrotyle rods (Plate 48, figs. 7-9). The rare monactines are tylostyles 
(Plate 48, fig. 10). Their terminal tyle is obviously homologous to the central 
tyle of the diactines. 

The rhabds. The rhabds of the gastral membrane are more or less curved, 
slightly centrotyle amphioxes, and mostly about 1 mm. long and 8-9 uw thick. 
The central tyle measures 10-13 y in transverse diameter. In the interior simi- 
lar and also much larger rhabds are met. The largest intact ones observed 
measured 2.9 mm. by 40 u; the stoutest rhabd-fragment was 130 yu thick. 

The six rays of the microhexactines (Plate 49, figs. 14-18, 20-23) are, in 
the same spicule, fairly equal and regularly arranged, each one enclosing an 
angle of 90° with its neighbours. The microhexactines measure 108-180 yu 
in total diameter, usually 117-148 ». Their rays are straight, 50-90 » long, at 
the base 4.5-6 » thick, usually about 5 uw, conic and sharp-pointed. They bear 
large and conspicuous, backwardly directed spines. On the proximal half of 
the ray the spines are 1.2-2.6 » long, stout, and sparse; on its distal half they are 
smaller and much more crowded. 

Among the amphidiscs four kind are to be distinguished :— large macram- 
phidises, small macramphidises, large micramphidises, small micramphidiscs. 


276 HYALONEMA (PRIONEMA) SPINOSUM. 


The abundant normal large macramphidiscs (Plate 48, figs. 14-16; Plate 49, 
figs. 7-9, 11; Plate 50, figs. 1-5) are 180-298 u long, most frequently about 255 u. 
The shaft is usually straight, rarely slightly curved, for the most part nearly 
cylindrical, 3-8 » thick, and abruptly thickened at or near the middle to a 
central tyle 6.5-17 » in transverse diameter. The proportion of the diameter 
of the adjacent parts of the shaft to the diameter of the tyle is 1 :1.38—1 :3.2, 
most frequently about 1:2. From the central tyle a verticil of about eight 
large spines arises; these are slightly and irregularly curved but on the whole 
vertical (Plate 48, figs. 14-16; Plate 49, figs. 8,9, 11). These spines are cylin- 
drical, rounded or abruptly pointed at the end, and always quite smooth and 
destitute of secondary spinelets. They are 8-23 » long and 2-3.5 u thick at the 
base. The parts of the shaft outside the central tyle and its vicinity bear nu- 
merous low, cylindrical and truncate, wart-like spines, 0.5-1.5 « high, 1-2 » broad, 
and circular in outline (Plate 48, figs. 15, 16; Plate 49, figs. 8,9, 11). From the 
terminal face of each of these spines a cluster of exceedingly minute secondary 
spinelets arises. 

The terminal anchors are 68-107 u» long, considerably more than a third of 
the whole spicule, and 61-117 » broad. The proportion of length to breadth is 
100 : 73-100 : 114, on an average 100: 94. A correlation between the anchor- 
proportion and the size of the spicule was not noticed. All the anchors counted 
were composed of eight teeth. 

The individual teeth are considerably curved near the base. Distally the 
curvature decreases. The end is slightly and somewhat abruptly bent inward 
towards the shaft. The teeth have a T-shaped transverse section. ‘The upper 
part is band-shaped, 9-13 » broad near the base, very slightly attenuated distally, 
and rounded at the end. The lower part is a crest projecting towards the shaft. 
This crest is 5 » high near the base; distally it gradually becomes lower, and it 
appears to vanish altogether about 10 « from the end of the tooth. The anchor- 
teeth bear, on their lateral margins, secondary teeth and consequently appear 
serrated (Plate 49, fig. 7; Plate 50, figs. 1-5). These secondary teeth stand 
quite close together and extend from the base to within a short distance of the 
end of the primary tooth, leaving only the rounded end free. The secondary 
teeth are triangular in outline, 0.5-1.2 » long, 1-1.5 u broad, sharp-pointed, and 
directed more or less backwards. They resemble shark’s teeth. 

Besides the normal spicules above described a few young and also a few 
abnormally large macramphidiscs have been observed. The young forms have a 
slender shaft, a relatively stout central thickening, and short and thin anchor- 


HYALONEMA (PRIONEMA) SPINOSUM. 277 


teeth. One of the abnormal forms is represented on Plate 49, fig. 10. This 
spicule is 235 uw long, its shaft is 5 » thick, central tyle 9» thick. A verticil of 
short, laterally compressed, distally broadened and truncate, band-shaped 
spines arises from the tyle. The remainder of the shaft bears short, truncate, 
cylindrical spines. The anchors are about 54 u long, 33 » broad. - The anchor- 
teeth have serrated margins, are strongly curved in their basal part, but nearly 
straight in their middle- and end-parts. The latter are nearly parallel to the 
shaft. Another similar spicule observed was only 180 wlong. Ihave also seen a 
few large macramphidiscs in which the spines on the central tyle were similar 
to the teeth of the terminal anchors, and all curved in one direction, so that the 
verticil formed by them was like a terminal anchor, only smaller. 

The rare small macramphidiscs (Plate 49, figs. 5, 6) differ from the large 
macramphidises — apart from their smaller size — chiefly by being destitute 
of long central spines. The small macramphidises are 45-126 » long. The shaft 
is 1-3 » thick, and either simply cylindrical (Plate 49, fig. 5) or gradually thick- 
ened at or near the middle (Plate 49, fig. 6) to a tyle sometimes 5.5 uw in transverse 
diameter. The proportion of the thickness of the adjacent parts of the shaft to 
the diameter of the tyle is 1:1 (when there is no tyle); 1:2.2 (when the 
tyle is most highly developed). The whole of the shaft is uniformly and densely 
covered with small spines. The spines on the tyle are not larger than the 
others. The anchors are 13-56 » long, a third or less of the whole spicule, and 
12-43 » broad. The proportion of the length to the breadth of the anchors 
is 100 to 77-92, on an average 100 :86. The individual teeth appear to differ 
from those of the large macramphidiscs only by being smaller. 

The large micramphidiscs are very rare. In fact only two could be measured. 
These are 51 and 56 yu long, and have anchors 16 and 19 uv long and 8.5 and 9 u 
broad respectively. The proportion of length to breadth of their anchors is 
100 : 56 and 100 : 44. 

The small micramphidiscs (Plate 48, figs. 28-31; Plate 49, figs. 1-4) are, 
although much more abundant than the other amphidise-forms, still not nearly 
so frequent asin other hyalonematids. They are 13-29 wlong, usually 17-27 u, 
and have a shaft 0.8-1.7 » thick. The shaft generally bears a larger or a smaller 
number of minute, cylindrical, truncate, vertical or oblique spines. These 
spines are irregularly distributed; often they form a little cluster near the centre 
of the shaft. The anchors are 4-7.5 u long, a fifth to a third of the whole spicule, 
and 5-8 » broad. The proportion of their length to their breadth is 100 to 87- 
175, on an average 100 : 134.8. The individual anchor-teeth are strongly curved 


278 HYALONEMA (PRIONEMA) CRASSUM. 


in their basal part, but only slightly curved or straight in their distal part. 
The latter is either parallel to the shaft or diverges from it only slightly. 

Among the known species Hyalonema solutum F. E. Schulze! appears to be 
the nearest ally of the sponges above described. From this they differ by 
having much smaller pinules, stouter microhexactine rays, spined macramphi- 
dise-shafts, and serrated macramphidisc-teeth. The nearest ally appears to be 
H. (P.) crassum (infra). From this it differs chiefly: — by the absence of 
macramphidises with short and broad anchors and smooth teeth; by the 
anchors of the serrated macramphidises being somewhat differently shaped; 
by the presence of small macramphidises; by the smaller size of the largest 
micramphidises; by the absence of stout paratangential rhabds (tignules) in the 
superficial membranes; and by having smaller pinules. 


Hyalonema (Prionema) crassum, sp. nov. 


Plate 106, figs. 4-37; Plate 107, figs. 1-20; Plate 108, figs. 1-17. 


A larger and two smaller specimens of this species were trawled nearly under 
the equator at Station 4742 on 15 February, 1905; 0° 3.4’ N., 117° 15.8’ W.; depth 
4243 m. (2320 f.); they grew on very light, fine Globigerina ooze; the bottom- 
temperature was 34.3°. They possess macramphidises with remarkably stout 
shafts and thick superficial amphioxes. To these peculiarities the specific name 
refers. 

Shape and size. The largest specimen (Plate 107, fig. 16) has the shape of a 
low, thick-walled cup, irregularly circular in outline. The cup measures 36 mm. 
in transverse diameter and is 21 mm. high. Its wall is at the base about 9 mm. 
thick, near the margin about 6 mm. Its convex, outer, dermal face is fairly 
smooth. On the inner, concave, gastral face longitudinally (radially) extending 
grooves make their appearance. The margin of the cup is rounded. Just out- 
side this rounded margin, where it passes into the outer convex face, a slightly 
protruding but very distinct crest makes its appearance. This crest, which 
forms a complete ring round the cup, probably marks the boundary between the 
dermal and gastral parts of the surface. 

The two smaller specimens are similar, but more cake-shaped and respec- 
tively 24 and 21 mm. in maximum diameter. 

The colour of the sponge in spirit is light dirty brown. 

The skeleton. All the intact parts of the surface are covered with a dense 


1 F. HE. Schulze. Uexactinellida. Ergeb. Deutsch. tiefsee-exped., 1904, 4, p. 77, t. 31, fig. 14-22. 


HYALONEMA (PRIONEMA) CRASSUM. 279 


spicule-fur composed of the distal rays of the superficial (dermal and gastral) 
pinules. The dermal and gastral membranes are supported by the lateral 
rays of these pinules and of the hypodermal and hypogastral pentactines. Very 
numerous paratangentially extending amphioxes are also found in them. Many 
of these spicules are very stout and appear as tignules. Hexactine megascleres, 
amphioxes, microhexactines, and amphidises occur in the interior. The micro- 
hexactines are exceedingly abundant and appear as dense masses in the sections. 
They form the chief support of the whole sponge. Of amphidises four kinds 
can be distinguished : — macramphidiscs with smooth teeth, macramphidises with 
serrated teeth, and large and small micramphidises. The first two are not 
frequent and appear to be confined to the superficial parts of the choanosome. 
The large micramphidises are also rather rare. The small micramphidises, on 
the other hand, are exceedingly abundant and form continuous layers in the 
walls of some of the canals. 

The pinules (Plate 106, figs. 26-30) of the dermal and gastral faces of the 
sponge agree so closely in shape and size that I shall here describe them together. 
All the pinules observed were pentactine. Their distal ray is straight, 110- 
200 u long, most frequently 140-165 », and 4—-5.5 » thick at the base. The spines 
it bears are small and not numerous. The longest usually arise from the middle- 
part of its length, and here the distal ray, together with the spines, attains a maxi- 
mum diameter of 14-19». The lateral rays are spiny, particularly in their 
distal half, and generally conical and pointed, more rarely cylindroconical and 
terminally rounded. They are 20-30 u long, rarely as much as 35 u. 

In the spicule-preparations I found a few fragments of diactine pinules and 
one whole pinule. Possibly such spicules occur in the above mentioned crest 
separating the dermal and gastral parts of the surface. I, however, failed to 
find any such spicules in situ, so that it appears very doubtful whether the few 
observed are proper to the sponge. 

The hypodermal pentactines (Plate 108, figs. 1, 3-5, 8, 9) have a conical, 
rather blunt-pointed, usually straight, rarely bent apical proximal ray 1-1.7 mm. 
long, and 27-62 » thick at the base. The lateral, paratangential rays are also 
blunt conical. Those of the same spicule are often markedly unequal; the length 
of the largest is 300-510 u. , 

The hypogastral pentactines (Plate 108, figs. 2, 6, 7) are similar to the hypo- 
dermal but have on the whole shorter and somewhat stouter rays. Their 
dimensions are: — length of apical ray 0.75-1.35 mm.; basal thickness of apical 
ray 30-70 u; length of lateral rays 230-320 uy. 


280 HYALONEMA (PRIONEMA) CRASSUM. 


The hexactine megascleres (Plate 108, figs. 10-13) are 0.7-2.5 uw in diameter, 
and have straight or slightly curved, blunt, conical rays 20-55 u thick at the base. 

Three kinds of amphioxes can be distinguished: — large ones, confined to the 
choanosome; intermediate and smail ones, found both radially situated in the 
choanosome and paratangentially situated in the dermal and gastral membranes; 
and small stout paratangentially situated ones, confined to the dermal and 
gastral membranes. 

The large amphioxes of the choanosome measured are 2.5-8.5 mm. long and 
18-80 » thick. These spicules are 90-140 times as long as thick. 

The intermediate and small slender amphioxes of all parts of the body are 
0.67—2.5 mm. long and 10-35 u thick. These spicules are 40-160 times as long as 
thick. 

The small stout amphioxes (tignules) of the dermal and gastral membranes 
are 410-980 » long and 13-50 » thick. These amphioxes are 17-39 times as long 
as thick. A good many of them are distinctly centrotyle, the central tyle being 
sometimes 9 » more than the adjacent parts of the spicule in transverse diameter. 
The gastral small stout amphioxes (Plate 107, fig. 11) are, on the whole, 
relatively considerably thicker than the dermal, the former being on an average 
23.7 times, the latter 28.4 times as long as thick. 

Taking all the amphioxes of the sponge together we find that all those 
under 650 u in length are less than 40 times as long as thick, while all those 
over 940 u in length measured are, with a single exception, more than 40 times 
as long as thick. 

The microhexactines (Plate 106, figs. 4-12, 31-37) are 108-175 u in diameter, 
on an average about 140 4. The rays of the same spicule are generally equal 
and regularly arranged, but are exceptionally unequal in length. The rays are 
straight, conical, sharp-pointed, at the base 4.5-7 » thick, usually 5-6.5 uw, and 
spined. The spines of the proximal part of the ray are sparse, vertical, broad 
conical, sharp-pointed, and 1.5-2 4 high. Distally the spines become more 
numerous and crowded, smaller, more slender, and more and more inclined back- 
wards towards the centre of the spicule. 

From the morphological point of view four kinds of amphidiscs can be dis- 
tinguished: —1, large ones with thick shaft, broad and short anchors, and 
smooth teeth; 2, large ones with slender shaft, medium anchors, and serrated 
teeth; 3, small ones with long and slender anchors; and 4, still smaller ones with 
medium anchors. 

Examined biometrically, according to their length frequency, the amphidises 


15 


10 


Number 


Length (x). 


HYALONEMA (PRIONEMA) CRASSUM. 281 


fall into two groups, large and small ones. These two groups are very clearly 
distinguished, there being no amphidiscs 62-159 » long. This absence of inter- 
mediate amphidiscs finds its expression in the adjoined graph in the large gap of 
the curve between 72.89 and 129.13. The amphidiscs the lengths of which are 
represented by the curves to the right of the gap belong to the morphological 
groups 1 and 2. The two curves overlap considerably. The amphidiscs to 


Smooth \ Mtacramphidiss 


-—----—-- Serrated 
poconscreseese Micramphidiscs 
Micramphidiscs Macramphidiscs 
———_ AS oor "eo Oo 
Small Large Serrated 
oe i 
Smooth 
—_——_- 


--4-----/--------------- 


--------;--- po np rt rt nn ee tenes: 
' ' 
' ra 
' i] 
~ u yal - 
See a= eee pee ee eee ere a Se eR eee ow ales Ses em omen eee 
ai 1 A 
se SS a eT ee 
fibene atin 
Bie ate it 
cf es fie a ' 
ecient eaten ened a ae hed ap a ee SRS ta Tae ey Ta EOS RPE Ee a ee 
Be rhea ' 
== ma et as a i 
pod Oe heen aii 
mart Ze 
eet a a a ae Soi ae Se oa ey ol ee eee eee Ne a = 
Hee cae Sie! ies eat ee alee ra 
ee nnrE Pen Me ee ee ee atl 2 Ne ee ns Se is 
a NS ES A+ 
: He ihe Se i aa ass : 
a a a a ag eh ein 
ON SCN DHANMOnTDAOCOoHOMWMWOMODWOAAO DTW & 
AY OPYHANHAASTAANREANQTAASCHRASCNH 
NYT MO HMAMMNDNMOOOHEOTrMODAtTOONCWOHeROM-ONO HH 
An AH ANNAN YOM THT MOOONRDARDOAAN TOL 
| | eee 
1 
pre lt tok EP I we okt lel 
OADNGMOAAMNDNOCHDOYHTODOAORMWDOAANINYNYTWHM 
BN MOM AANMAROTMIANREAANAMANSCHE OMASCN 
Ae HMO OHMNMNOODWOHAHAKO HNO DADONOCALKR OFAN WS 
al OT St PIV ISRIUSN TNINS OSC G.e) sists stl ill Doda SS) SoTL GeO) i2 SOP ASS Kes NI oy Ze 


Fig. 13.— Amphidises. 


which the curve to the left of the gap pertains are those of the morphological 
groups 3 and 4. There is a conspicuous depression in this curve at 37.40- 
41.14, corresponding to the absence of amphidiscs 37-41 » long. This depres- 
sion may be taken as the limit dividing the (smaller) amphidises of the mor- 


phological group 4 from the larger ones of group 3. 


282 HYALONEMA (PRIONEMA) CRASSUM. 


I designate the four groups of amphidiscs: — smooth macramphidises (group 
1); serrated macramphidises (group 2); large micramphidises (group 3); and 
small micramphidises (group 4). 

The smooth macramphidiscs (Plate 108, figs. 14-17) are 290-370 » long, most 
frequently about 337 4. Their length frequency-curve is narrow and simple, 
and has a single summit. The shaft of these spicules is straight, cylindrical, 
18-30 » thick, usually 20-26 u, and thickened at or near the middle of its length 
to a central tyle 4-12 » more in transverse diameter than its adjacent parts. 
Several broad, terminally rounded spines 3-8 » long arise from the central 
tyle. The remaining parts of the shaft are smooth. 

The terminal anchors are 55-78 uw in length, usually one sixth to one fourth 
of the whole spicule, and 105-140 » broad. The proportion of their length to 
their breadth is 100 to 155-236, on an average 100 : 174.3. The individual 
teeth attain their maximum breadth of 20-30 u in their distal part, and are very 
abruptly pointed, the contour of their end-part having, when seen en face, the 
shape of a broad gothic arch. The teeth are uniformly curved; the outer con- 
tour of the anchor when seen in profile is generally nearly semicircular. 

The serrated macramphidiscs (Plate 107, figs. 1-5, 17-20) are 150-328 yu long. 
Their length frequency-curve is rather broad and irregular, and has three distinct 
summits. The middle one is quite insignificant; the other two, situated at about 
164 and 240 u respectively, are very pronounced. The shaft of these amphi- 
dises is straight, 3-6 » thick, and thickened at or near the middle of its length 
to a central tyle 2-6 » more in transverse diameter than its adjacent parts. 
The central tyle bears a verticil of cylindrical, terminally rounded, straight or 
curved spines 5-14 u long. The remaining parts of the shaft are covered with 
numerous low protuberances (very short spines). 

The terminal anchors are 61-105 » long, the whole spicule being 2.5 to 3.5 
times as long as the anchor. The maximum anchor-breadth is 45-100 ». The 
end-parts of the teeth of some of these anchors are nearly parallel; in these anch- 
ors the end-breadth is equal to the maximum breadth; the end-parts of the 
teeth of others are convergent,— in these anchors the end-breadth is 2-6 yu less 
than the maximum breadth. The proportion of anchor-length to anchor-breadth 
is 100 to 72-102, on an average 100 : 83.6. 

The individual teeth arise vertically from the shaft, are strongly bent in 
their basal part, and straight or only slightly curved in their distal part. Their 
tips are, as mentioned above, parallel or slightly convergent. The teeth attain 


their maximum breadth of 12-15 u in their middle-part, and are attenuated 


HYALONEMA (PRIONEMA) CRASSUM. 283 


both towards the base and towards the tip. The end of the tooth is simply 
rounded. From the lateral margins of the teeth pointed triangular protuberances 
arise, which stand close together and render these margins serrated. The saw- 
teeth are, in the middle-part of the tooth, about 1 « high, 2 » broad, and vertical. 
Distally they become narrower and smaller and more and more directed back- 
wards (Plate 107, figs. 17-20). The rounded distal ends of the teeth are smooth. 

The large micramphidiscs are 42-61 » long, most frequently about 52 x. 
Their length frequency-curve is rather broad and irregular in so far as it exhibits, 
besides the main summit at about 52 u, another insignificant one at about 63 yu. 
The shaft of these amphidises is straight, spiny, sometimes centrotyle, and 1.5— 
2.3 w thick. 

The terminal anchors are 17-22 » long. The whole spicule is 2.2-3 times 
as long as its anchors. The maximum anchor-breadth is 9-14 ». The end- 
breadth is equal to the maximum breadth or slightly smaller, sometimes as much 
as 4y. The proportion of anchor-length to anchor-breadth is 100 to 53-72, 
on an average 100 : 62. 

The individual teeth, which arise vertically from the shaft, are strongly 
bent in their basal part and only slightly bent or nearly straight in their distal 
part, so that their tips are nearly parallel or slightly convergent. 

The small micramphidiscs (Plate 106, figs. 13-25) are 13.5-36 » long. Their 
length frequency-curve is rather broad and irregular. It exhibits two equally 
high main summits at about 18.4 and 22.1 u, and one insignificant summit at 
about 27 4. The shaft of these amphidiscs is straight, cylindrical, 0.8-1.2 u 
thick, rough or smooth, and usually centrotyle. The tyle, which exceeds the 
adjacent parts of the shaft 0.2—1 ,» in transverse diameter, is often a good distance 
away from the middle of the length of the spicule. 

The terminal anchors are 3.5—-14 u in length, a fifth to a third of the whole 
spicule, and 5-9 broad. The proportion of anchor-length to anchor-breadth 
is 100 to 61-162, on an average 100 : 119.4. The largest of these small micram- 
; phidises, that is those over 30 u in length, are transitional to the large ones above 
described, not only in respect to size, but also in respect to anchor-shape. The 
proportion of anchor-length to anchor-breadth is in these spicules on an average 
100 :65. In all the small micramphidiscs, that is in those under 30 u in length, 
the anchors are broader than long, the average proportion of anchor-length to 
anchor-breadth being in these spicules 100 : 125.6. 

The anchor-teeth of these spicules are generally strongly and rather abruptly 
bent at a point a third of their length from the base, and only slightly curved 


284 HYALONEMA (PRIONEMA) PINULIFUSUM. 


in their distal and proximal portions. A more or less conspicuous conical spine 
with a maximum height of 0.5 u arises from the centre of the apex of the 
anchor. The anchors are very frequently irregular in so far as some teeth are 
considerably longer than the opposite teeth (Plate 106, figs. 21-23, 25). 

The nearest ally to H. (P.) crassum is H. (P.) spinosum (p. 273). From this 
H. (P.) crassum differs chiefly: — by possessing macramphidises with short and 
broad anchors and smooth teeth; by the anchors of the serrated macramphidiscs 
being somewhat differently shaped; by the absence of the spicules there described 
as small macramphidises; by the largest micramphidiscs attaining a much larger 
size; by the presence of stout paratangential rhabds (tignules) in the superficial 
membranes; and by having longer pinules. 


Hyalonema (Prionema) pinulifusum, sp. nov. 


Plate 70, figs. 11-24; Plate 71, figs. 1-11; Plate 72, figs. 1-15. 


I establish this species for a fragment trawled off the south coast of western 
Panama at Station 4621 on 21 October, 1904; 6° 36’ N., 81° 44’ W.; depth 1067 
m. (581 f.); it grew on a bottom of green mud and rock; the bottom-temperature 
was 40.5°. It possesses large pinules with distal rays greatly thickened in the 
middle and markedly fusiform in shape. To these the name refers. 

Shape and size. The specimen is a flat fragment, 14 cm. long, 8 em. broad, 
and with a maximum thickness of 1 em. The margin is lacerated. The speci- 
men is composed of lamellae about 1 mm. thick, separated by wide cavities. 
It probably formed part of a lamellar or cup-shaped sponge. 

The colour in spirit is brown. 

The skeleton. On many parts of the surface the pinule-fur is still more or 
less intact. A number of small wart-like protuberances, 0.5-1.5 mm. broad 
and high, arise on one side of the lamellar body. These bear on their summits 
dense masses of medium-sized pinules. Much larger scattered pinules with 
stout, spindle-shaped distal ray arise from the walls of the wide depressions be- 
tween these protuberances. Pinules of the same kind densely cover the margins 
of some of the lamellae on the other side of the sponge. Other parts of the thin 
lamellae bear sparse, small pinules, with relatively few and small spines on the 
slender distal ray. Besides these three kinds of pinules, a fourth kind, with distal 
rays terminating in a rather long and slender terminal cone and with large second- 
ary spinelets on the primary spines of the distal ray, has been found quite 
frequently in the preparations. These pinules are identical with certain pinules 


HYALONEMA (PRIONEMA) PINULIFUSUM. 285 


of Hyalonema (Prionema) azuerone, a large specimen of which was contained 
in the same bottle as the fragment of Hyalonema (Prionema) pinulifusum. I 
am therefore inclined to consider these pinules as spicules of the H. (P.) azuerone 
which got into the H. (P.) pinulifuswm accidentally. 

Of the three kinds of pinules which I consider proper to the sponge, the small 
ones with short and sparse spines on the distal ray are doubtlessly canalar. The 
two other kinds are probably dermal and gastral, but the fragmentary condition 
of the specimen renders it impossible to say which are which. In the follow- 
ing description I name these three kinds of pinules: — large pinules; medium 
pinules; and small, canalar pinules, respectively. 

Pentactines have been found under various parts of the surface of the 
lamellae. Some hexactine and tylostyle megascleres and dense masses of diac- 
tine rhabds occur in the interior. The microscleres are numerous microhexac- 
tines, few micropentactines transitional between the microhexactines and the 
small canalar pinules, and amphidiscs. Of the latter seven kinds can be dis- 
tinguished: — macramphidises; large and small mesamphidises with serrated 
teeth; large and small mesamphidises with smooth teeth; and large short- 
anchored, and small long-anchored micramphidiscs. 

The large pinules (Plate 70, figs. 15-19; Plate 71, fig. 11) are generally pent- 
actine, only very few hexactine ones having been observed. The distal ray 
is straight, fusiform, 200-400 uw long, generally 230-370 u, on an average 358 un, 
and 8-16, thick at the base. Above it thickens very considerably and it 
measures, without the spines, 18-50 » in transverse diameter at the point of 
maximum thickness, which les a short distance above the middle of its length. 
Farther on it again becomes thinner, and it ends in a rather broad and short, 
blunt- or sharp-pointed terminal cone. Its profile without the spines is elongate 
oval, drawn out at one end to the nearly cylindrical basal part and at the other 
to the terminal cone. The nearly cylindrical basal part and the distal cone are 
quite smooth, the remaining parts of it are covered with numerous large spines. 
The spines are usually all directed upwards and slightly curved, concave to the 
ray. The very lowest are quite divergent, the others strongly inclined, and in 
their end-parts nearly parallel to the adjacent part of the surface of the ray. 
Exceptionally (Plate 70, fig. 19) some of the lowest spines are directed down- 
wards. The spines are generally 12-40 u long, 3-8 uw thick at the base, simple, 
conical, and sharp-pointed; they rarely bear one or two secondary spinelets on 
the outer, convex side. The maximum diameter of the distal ray, together 
with the spines, is 40-63 xu. 


286 HYALONEMA (PRIONEMA) PINULIFUSUM. 


The lateral rays are straight, in the same spicule equal or somewhat unequal, 
and either nearly cylindrical throughout and terminally rounded, or cylindrical 
in their proximal part, conical in their distal part, and blunt-pointed. They 
generally bear a small number of rather larger spines on their distal part. The 
lateral rays are, at the base, considerably thinner than the basal part of the 
distal ray, and attain a length of 34-52 u, on an average 44.5 uy. 

The proximal ray of the hexactine forms is about as long as the laterals. 

The medium pinules (Plate 70, figs. 20-24) are pentactine. Their distal 
ray is straight, 165-216 » long, generally 167-205 yu, on an average 189 u, and 
5.5-9 » thick at the base. Their basal part is for a considerable distance free 
from spines, and they end in a very short likewise spineless terminal cone. 
Their remaining parts bear somewhat sparse and rather divergent spines which 
are slightly curved, concave to the ray. The spines are conical, sharp-pointed, 
about 3 u thick at the base, and attain 30 » in length. They are usually simple; 
occasionally one or two bear a small secondary spinelet. The maximum thick- 
ness of the distal ray, together with the spines, is 33-48 u. The lateral rays are 
conical, terminally rounded, and 35-48 » long. Their distal part bears a small 
number of rather large spines which sometimes form an irregular verticil below 
the end of the ray. 

The small canalar pinules (Plate 70, figs. 11-14) are generally pentactine, 
very rarely hexactine. The distal ray is 110-240 u long, generally 120-206 yu, on 
an average 167 uw, and 3.5-8.3 » thick at the base. Its basal part and its long 
and slender terminal cone are smooth; its middle-part bears a small number, 
generally about a dozen or so, of sparse, small, straight or slightly curved spines 
which are directed obliquely upwardly. The maximum thickness of the distal 
ray, together with the spines, is 9-25 4. The lateral rays are cylindrical and 
smooth in their basal, conical and spiny in their distal part. They measure 
28-62 » in length. The proximal ray (of the hexactine forms) is about as long 
as the laterals. 

The superficial (hypodermal and hypogastral) pentactines have straight, 
conical, terminally rounded rays. The dimensions of the few I was able to 
measure are: — basal thickness of rays 10—23 yu, length of proximal ray 300-410 u, 
length of lateral rays 177-430 yu. 

The hexactine megascleres observed were 0.6-1 mm. in diameter, and had 
straight conical rays, 10-24 » thick at the base. 

Most of the rhabd megascleres are rather long blunt amphioxes with hardly 
a trace of a central tyle. Besides these spicules, which form the bulk of the 


HYALONEMA (PRIONEMA) PINULIFUSUM. 287 


supporting skeleton, smaller amphioxes with distinct central tyle, tylostyles, 
and, exceptionally, amphityles are met. : 

The ordinary amphiozes are fusiform, very blunt at the ends, 0.8-2.5 mm. 
long, 10-33 » thick in their middle-part, and generally curved. In a good many 
of them, particularly the long ones, the curvature is very considerable. A few 
angularly bent spicules of this kind have also been observed. 

The small centrotyle amphioxes are generally 390-620 u long; but larger 
ones, connecting them with the amphioxes above described, have also been 
observed. The small centrotyle amphioxes are straight or only slightly curved, 
and 7-14 » thick near the middle. The central tyle is 12-30 u in transverse 
diameter, that is 5-16 » more than the adjacent parts of the spicule. 

The tylostyles are amphiox-derivates with one ray reduced in length and 
terminally thickened. Their dimensions are:—total length 1.2-1.7 mm.; 
maximum thickness 16-22 4 at morphological centre, which lies somewhere 
between the middle of the length and the terminal tyle; transverse diameter 
of terminal tyle 13-24 4; thickness just below terminal tyle 10-16 uw, that is 
3-8 uw less than the diameter of the terminal tyle. The terminal tyle is more 
or less spherical, and usually bears one or two small, stout, truncate or terminally 
rounded spines. Occasionally a rather large spine arises from it. 

The amphityles are amphiox-derivates with both rays reduced in length 
and terminally thickened. One that I measured is 1.7 mm. long, and 27 u thick 
_ in the middle and just below one of the terminal tyles. Towards the other 
tyle it is attenuated to 15 4. The two terminal tyles are respectively 41 and 
22 » in diameter. 

The microhexactines (Plate 71, figs. 1-4, 9) are regular, the six rays of the 
same spicule usually being fairly equal. These spicules measure 80-120 uw in 
total diameter. The rays are straight or slightly curved, conical, fine-pointed, 
1.5-2.2 » thick at the base, and just perceptibly roughened by exceedingly 
minute spines. 

A few micropentactines (Plate 71, fig. 10) have been found, which appear 
to connect the regular microhexactines with the small canalar pinules. These 
spicules are 80-140 y» in diameter and have rays 2-3.7 u thick at the base. 

The amphidiscs, which are 15-470 uw long, exhibit a remarkable degree of 
diversity. I have measured 178 of them. Their length frequencies are repre- 
sented in Figure 14. 

The figure shows that the lengths of the amphidiscs*form a nearly uninter- 


rupted series. At one point only we find the next largest amphidise more than 


HYALONEMA (PRIONEMA) PINULIFUSUM. 


288 


Parts of the curve comprising more than 
one kind of amphidiscs. 


2 
a 
af 
—-—+--»—Macramphidiscs. : 
corrgerated Mesamphidises. g 
So Large, short-anchored | y,. cn & 
ee: Small, long-anchored } Micramphidiscs. 3 
fe 
n 
a 
& 
H 


Small, long-anchored 
Large, short-anchored 
micramphidiscs. 


micramphidiscs. 


Number of 
spicules observed. 


8 
' 
7 1 ' ray iN tae. an We A 
6 Wa apa oe eee fates Fre Ra ater ae ee ae ta et SL ia a EIEIO PETS IN eT 
Faery Ml te a en es Se Ena eee ee Bee ie pat Sey 
fe) (pea ey Grane eo ae ree 
(Al ney ec a ates Oe ee ee 
Jing game eae te testaresin eG [Oa NOR a es ale yal) 
Dale see a? wi ara ‘Tasca 
1 Tan Geib yen ene tecipale tc 
: ae vamed 
S) ISS SN ew 
tb © NO a 
aS YRR 
ei Se ee | 
al Pi 
on om st LO 
as aS 
& Ct DN O 
S QS 
eto rd 


4--- 
\ 


Large, smooth mesamphidiscs, 


Small, serrated mesamphidiscs. 


me baie ake 


28.76 


2 


Large, serrated mesamphidiscs. 


Macramphidiscs. 


Fig. 14.— Amphidises, length frequencies. 


‘ 
a 


——— 


HYALONEMA (PRIONEMA) PINULIFUSUM. 289 


1.1 times longer than the next smallest. This point lies between 62 and 84 u. 
The amphidises 62 » long and shorter, that is those 15-62 u in length, I consider 
as micramphidises. Some of these micramphidises have relatively longer, others 
relatively shorter anchors. The relatively long-anchored are 15-35 u long, the 
relatively short-anchored 33.5-62 ». The length frequency-curve of the micram- 
phidises exhibits two marked principal elevations which correspond respectively 
to the most frequent sizes of the long- and short-anchored forms. Within the 
micramphidiscs two groups can therefore be distinguished, both from a mor- 
phological and biometrical point of view: — smaller long-anchored micramphi- 
discs, and larger short-anchored micramphidiscs. 

Of the amphidiscs 84 « long and longer, that is those 84-470 yu in length, 
some have slender, others broad anchors. The slender-anchored are 84-380 yu 
long, the broad-anchored 370-470 u. The part of the length frequency-curve 
pertaining to these amphidiscs exhibits one pronounced main elevation situated 
at about 425 yu, close to its maximum end. The amphidises represented by this 
main elevation are all broad-anchored. These spicules form a homogeneous 
group, which I name macramphidisc because it comprises the largest amphidises 
of the whole series. Some of the slender-anchored amphidises have smooth, 
others serrated teeth. Those with smooth teeth are 84-292 u long, those with 
serrated teeth 214-380 ». Since the slender-anchored amphidises with serrated 
teeth are on the whole much larger than those with smooth teeth; since all the 
slender-rayed amphidises over 292 u in length are serrated ones; and since the 
morphological difference of teeth serrated and teeth smooth is of considerable 
importance, I propose to consider these two kinds of slender-anchored amphidises 
as belonging to two distinct groups; although biometrically, judged merely by 
the length frequency-curve of the amphidises in general, they are not differen- 
tiated. I name these two groups, which are, in size, intermediate between the 
micramphidises and the macramphidises, smooth mesamphidiscs and serrated 
mesamphidiscs respectively. The length frequency-curve of each exhibits, 
when taken by itself, a depression, particularly well-marked in the case of the 
curve of the latter. In the curve of the smooth mesamphidises this depression 
lies at 121 u, in the curve of the serrated mesamphidises at 260 4. As shown 
by the two depressions of these two curves, a large and a small kind of spicule 
can be distinguished in both of them. 

The amphidiscs of Hyalonema (Prionema) pinulifusum can accordingly be 


arranged in seven groups: — 


290 HYALONEMA (PRIONEMA) PINULIFUSUM. 


I. Macramphidises (1) 
II. Mesamphidises 
A serrated mesamphidises 
a large serrated mesamphidises (2) 
b small serrated mesamphidises (3) 
B smooth mesamphidises 
a large smooth mesamphidises (4) 
b small smooth mesamphidises (5) 
III. Micramphidiscs. 
A larger short-anchored micramphidises (6) 
B smaller long-anchored micramphidises (7) 

The macramphidiscs (Plate 71, figs. 5-8) are 370-470 » long, most frequently 
about 425 ». The shaft is straight, for the greater part of its length cylindrical, 
and 15-22 4 thick. It is gradually thickened towards the ends, and generally 
also slightly and somewhat abruptly thickened near the middle to a central 
tyle. The ends usually exceed the thinnest part of the shaft by 9-12 u in thick- 
ness. The central tyle is small, or absent altogether, and measures, when 
present, 18-29 » in transverse diameter, that is 1-9.5 1 more than the adjacent 
parts of the shaft. The shaft is very poor in spines. Sometimes it bears no 
spines at all. Usually one to three cylindrical and truncate, or cylindroconical 
and terminally rounded spines arise from the central tyle, or, when it is absent, 
from a corresponding point of the shaft. These spines are 4-11 4 long and 
3-9 » thick. The remaining parts of the shaft are either quite smooth or bear 
one or a few spines similar to the central ones. 

The anchors are 126-162 » long, about a third of the whole spicule, and 153- 
177 » broad. The proportion of their length to their breadth is 100 to 103-138, 
on an average 100: 115.3. They are composed of eight teeth. The individual 
teeth have the usual T-shaped transverse section. The upper (outer) part of 
the teeth, which corresponds to the upper stroke of the T, is band-shaped, 24— 
29 » broad, and abruptly pointed or rounded at the end. The margins of these 
bands, that is the lateral margins of the teeth, are either smooth throughout, 
or they exhibit slight irregularities, sometimes even an indication of a serration, 
in their distal part. The lower (inner) part, which corresponds to the lower 
stroke of the T, is, at the base of the tooth, usually 19-22 y high. The teeth 
arise nearly vertically from the shaft, and are curved downward in such manner 
that their ends are either parallel or convergent. In the latter case the anchor is, 


at the end, sometimes 17 » narrower than in its broadest part, above. 


HYALONEMA (PRIONEMA) PINULIFUSUM. 291 


The large serrated mesamphidiscs (Plate 72, figs. 1, 2) are 280-380 u long, 
most frequently about 295 4. The shaft is straight, for the greater part of its 
length cylindrical, and 8-15, thick. It is gradually thickened towards the 
ends, and abruptly thickened at or near the middle to a central tyle 14-22 » 
in transverse diameter, that is 5-7 » more than the adjacent parts of the shaft. 
The central tyle bears a verticil of spines, which is either regular and situated 
in a plane vertical to the axis of the shaft or irregular and oblique to the axis 
of the shaft. The individual spines are 2-13 » long, and 2-6 u» thick at the base. 
Their end-parts are generally more or less, sometimes very considerably, curved. 
The remaining parts of the shaft bear a smaller or larger number of similar but 
smaller and less curved spines. 

The terminal anchors are usually regular, more rarely irregular, with longer 
teeth on one side than on the other. The tips of the teeth of such anchors lie 
in a plane oblique to the axis of the shaft. If one anchor is thus oblique, the 
other anchor of the same spicule is generally oblique to the same extent, but in 
the opposite direction, so that the two planes passing through the tips of the 
teeth of the two anchors are approximately parallel. In a large serrated mes- 
amphidise in which this obliqueness of the anchors was particularly pronounced, 
I found the spine-verticil on the central tyle oblique also, but in a direction 
opposite to that of the two planes passing through the tips of the anchor-teeth. 
The anchors are 111-155 » long, a little over two fifths of the whole spicule, 
and 67-116 » broad. The proportion of their length to their breadth is 100 to 
56-75, on an average 100 : 66.5. The upper (outer) band-shaped parts of the 
individual anchor-teeth are 15-23 » broad in their middle-part. They taper 
gradually to the rounded or abruptly pointed end. The teeth are curved down- 
ward (inward); more strongly in their basal part, and often at a point lying near 
the end; less strongly in their other parts. This curvature is, on the whole, 
such that the ends of the teeth converge considerably. The ends of the anchors 
are generally 9-17 » narrower than their broadest parts, above. The lateral 
margins of the teeth are distinctly serrated. The serration is quite regular in 
the proximal and middle-parts of the teeth, but often irregular in their end-parts. 
The saw-teeth are generally higher than broad, sharp-pointed, and close together. 
They measure 1-3 y in length and 1-2 u in breadth. 

The small serrated mesamphidiscs are similar to the large ones. Their 
principal dimensions are: — total length 214-240 u, most frequently about 215 yu; 
length of anchors 83-110 »; breadth of anchors 52-68 »; proportion of anchor- 
length to anchor-breadth 100 to 59-66, on an average 100 : 62.3. 


292 HYALONEMA “(PRIONEMA) PINULIFUSUM. 


The large smooth mesamphidiscs (Plate 72, figs. 3-6) are 122-292 » long. 
Their length frequency-curve has three nearly equal elevations at about 150, 
180, and 240 u. The shaft is nearly always straight, only in two of the hundreds 
observed was it markedly curved. The shaft is for the greater part of its length 
cylindrical, and 4-9 » thick. It is abruptly thickened at or near the middle 
to a central tyle 7-18 » in transverse diameter, that is 2-11 » more than the 
adjacent parts of the shaft. The tyle bears a number of spines which are gen- 
erally arranged in a more or less verticillate manner, sometimes however scat- 
tered indiscriminately over the whole tyle. When these spines form a verticil, 
this is situated in a plane either vertical or oblique to the axis of the shaft. 
The individual spines are usually strongly curved or abruptly bent in their 
distal part, cylindroconical, and truncate or terminally rounded. They are 
2-11 » long, and about 2 u thick at the base. The remaining parts of the shaft 
generally bear numerous small, and often also several large spines, 4-6 u long, 
exceptionally as much as 10». The small spines usually arise vertically; most 
of the large ones are oblique, directed and also curved in a distal direction 
(towards the adjacent anchors, away from the central tyle). 

The anchors are, as in the large serrated amphidiscs, either regular or irreg- 
ular, oblique, with the teeth on one side longer than the teeth on the other. 
The two anchors of the same spicule are generally fairly equal in size; sometimes, 
however, one is considerably larger than the other. In one of the large smooth 
mesamphidises observed, one anchor measured 133 by 78 u, the other only 
112 by 62,4. The anchors are 47-133 u long, usually over two fifths of the 
whole spicule, and 26-78 » broad. The proportion of their length to their 
breadth is 100 to 49-73, on an average 100 : 57.9. The anchors are composed 
of ten to twelve teeth. The individual teeth are curved, more strongly in their 
basal part and often also in their distal than in their middle-part. Their total 
curvature is such that their ends are either parallel or only slightly convergent 
or divergent. In the forms with terminally convergent teeth the end-breadth 
of the anchor is sometimes 7 u less than its maximum breadth. 

The small smooth mesamphidiscs (Plate 72, figs. 7, 8) are similar to the 
large ones, but have not so sharply defined central tyles, and relatively broader 
anchors. Their dimensions are: — length 84-120», most frequently about 
110 »; thickness of shaft 2-5 4; diameter of central tyle 3.4—9 uy, that is 0.6-4 u 
more than that of the adjacent parts of the shaft; anchor-length 30-46 4; anchor- 
breadth 21-40 »; proportion of anchor-length to anchor-breadth 100 to 60-87, 
on an average 100 :73. The anchors of these spicules are composed of about 
ten teeth. 


HYALONEMA (PRIONEMA) PINULIFUSUM. 293 


The large short-anchored micramphidiscs (Plate 72, fig. 15) are 33.5-62 u 
long, most frequently about 444. The shaft is 0.9-2.8 » thick, and usually 
thickened at or near the middle to a central tyle, which is sometimes 1.1 » more 
than the adjacent parts of the shaft in transverse diameter. In many of these 
spicules the tyle is very insignificant, and in some not a trace of a central tyle 
could be detected. The shaft usually bears minute scattered spines, the most 
conspicuous of which arise from the central tyle. 

The anchors are 5-24 u long, usually about a quarter of the whole spicule, 
and 8-17 » broad. The proportion of their length to their breadth is 100 to 
71-160, on an average 100 :109.3. The individual teeth are curved rather 
uniformly throughout. Their ends are more or less divergent. 

The small long-anchored micramphidiscs (Plate 72, figs. 9-14) have remark- 
ably stout shafts. They are 15-35 » long, most frequently about 20 4. The 
shaft is straight, 1.2-2.5 1 thick, and frequently thickened at one place to a 
spindle-shaped ‘‘central”’ tyle, sometimes 1 » more than the adjacent parts of 
the shaft in transverse diameter. This tyle is usually situated very eccentri- 
cally. In the larger forms the shaft bears numerous conspicuous spines (Plate 
72, fig. 14). In the smaller ones the spines are fewer in number and smaller 
in size; sometimes they are absent altogether. 

The anchors are 5-16 » long, about a third of the whole spicule, and 6-13 u 
broad. The proportion of their length to their breadth is 100 to 77-200, gen- 
erally 100 to 83-140, on an average 100 : 112.3. The anchor-teeth are curved 
towards the shaft quite strongly in their basal part, and less strongly or not at all 
in their distal part. The tips of the teeth (their distal straight parts) are nearly 
parallel to the shaft. 

Its fragmentary nature renders it impossible to say with certainty to which 
genus of the Amphidiscophora this sponge belongs. The chief reason for placing 
it in Hyalonema (Prionema) is the presence of serrated amphidises and the gen- 
eral resemblance of its spiculation to that of some of the species of this genus. 
Its nearest allies appear to be Hyalonema hercules F. E. Schulze,’ and H. (P.) 
agujanum (p. 251). Hyalonema hercules resembles it in its general appearance, 
but differs from it in respect to its macramphidises and gastral pinules. In H. 
hercules the macramphidises have four large spines, arranged crossways, on the 
central tyle, and the gastral pinules have very long and slender distal rays. In 
the sponge above described the tyles of the macramphidiscs bear only from one 
to three quite insignificant spines, and there are no such pinules with long and 


1 FB. Schulze. Amerikanische Hexactinelliden, 1899, p. 9, taf. 1, figs. 19-29. 


294 HYALONEMA (PRIONEMA) FIMBRIATUM. 


slender distal rays as the gastrals of H. hercules. It is also to be noted that 
H. (P.) pinulifusum possesses amphidiscs with serrated teeth, while Schulze 
does not mention the occurrence of such amphidises in H. hercules. From 
H. (P.) agujanum, which agrees with H. (P.) pinulifusum quite well in regard to 
the amphidises, and indeed from all other Amphidiscophora with the exception 
of the above mentioned H. hercules, it differs by possessing large pinules with 
thick spindle-shaped distal ray. It is also to be noted that H. (P.) agujanum 
differs from it in its general appearance. 


Hyalonema (Prionema) fimbriatum, sp. nov. 


Plate 59, figs. 1-6; Plate 60, figs. 1-34; Plate 61, figs. 1-11; Plate 62, figs. 1-45; Plate 63, figs. 1-28. 


Four fairly complete and three fragmentary specimens of this species were 
trawled in the Central Pacific: the four well-preserved ones and one of the frag- 
mentary ones at Station 4742 on 15 February, 1905; 0° 3.4’ N., 117° 15.8’ W.; 
depth 4243 m. (2320 f.); they grew on very light, fine Globigerina ooze; the 
bottom-temperature was 34.3°; the two other fragmentary ones at Station 4740 
on 11 February, 1905; 9° 2.1’ S., 123° 20.1’ W.; depth 4229 m. (2422 f.); they 
grew on dark gray Globigerina ooze; the bottom-temperature was 34.2°. 

The anchor-teeth of certain very numerous amphidiscs bear broad, fim- 
briate, marginal frills. To this the name refers. 

Shape and size. The well-preserved specimens from Station 4742 are 
flattened disc- or lens-shaped and regular, broad-oval to circular (Plate 62, 
fig. 30) or slightly irregular, wavy in outline (Plate 62, fig. 29). The largest 
regular specimen appears as a biconvex lenticular disc. It is 31 mm. long, 
28 mm. broad, and 10 mm. thick in the middle. Towards the margin it thins 
out to about 3 mm. One of the faces of the dise bears a rather eccentrically 
situated rounded protuberance 3 mm. in height, from which, in life, the stalk 
arose. Where the superficial membranes are intact the surface is continuous 
and destitute of larger apertures. In other places it is porous. Two of the 
three other well-preserved specimens from Station 4742 are similar. In one 
(Plate 62, fig. 30) the disc measures 25 by 23 by 12 mm., and has one convex, 
broad and low conic face and one flat face. The protuberance from which 
the stalk arose is situated on the flat face; this is the dermal. The third regular 
specimen is 20 mm. in maximum diameter. The slightly irregular specimen 
(Plate 62, fig. 29) is a lamella 35 mm. long, 27 mm. broad, and 6 mm. thick in 
the centre. It thins out distally, the somewhat wavy margin being 1-3 mm. 


HYALONEMA (PRIONEMA) FIMBRIATUM. 295 


thick. The fragment from Station 4742 is a porous lamellar mass 30 mm. long. 
The two fragments from Station 4740 are also porous lamellar masses, and 30 
and 35 mm. long respectively. 

The colour of all the specimens in spirit is very light brown. 

The skeleton. The dermal and gastral surfaces are covered by a dense 
pinule-fur. The dermal and gastral pinules appear to be quite similar. The 
lateral rays of these pinules, the lateral rays of large pentactines, and rhabds 
are found in the superficial membranes. The radial, inwardly directed apical 
(proximal) rays of the pentactines and radially or obliquely disposed rhabds 
traverse the space underlying the superficial membrane. In the lower part of 
this region, and in the distal zone of the choanosome, fimbriate amphidiscs are 
met in large numbers. In some parts of this region these spicules form dense 
masses (Plate 60, fig. 24). In the walls of many of the internal canals large 
canalar pinules form a fur, often quite dense. Besides these spicules there 
occur in the choanosome rhabds, often forming bundles, hexactine megascleres of 
various sizes, microhexactines, micropentactines, macramphidises, and micram- 
phidises. The micramphidiscs are not numerous and occur chiefly in the canal- 
walls. In the basal protuberance, from which, in life, the stalk arose, the 
following spicules occur besides those of the choanosome:— numerous slender- 
rayed, long-spined tetr- to hexactine acanthophores; a few monactine-derivates 
of these; numerous di- to pentactine acanthophores with stout rays; numerous 
more slender, modified, sometimes very strongly curved acanthophore rhabds; 
and numerous anchor-spicules. 

Besides these spicules which are doubtlessly proper to the sponge, various 
others, which I take to be foreign, are found, sometimes in large numbers. 
These are: — pentactines with a very stout, spindle-shaped proximal ray some- 
times 100 » thick; large amphidises of various kinds, most of which are similar 
to, and probably identical with, the large macramphidises of Hyalonema agassizi; 
giant pentactine pinules as much as 1.2 mm. long; and other kinds of pinules. 
The large foreign amphidiscs usually occur in clusters. 

The superficial (dermal and gastral) pinules (Plate 62, figs. 1-4, 16-18) are 
always pentactine. They have a straight distal ray 63-87 u long, on an average 
(of 27 measurements) 71.8 u, and 3.2-4.8 uw thick at the base. It is thickened 
in or near the middle, and is here 4.5-6 uw in transverse diameter. It ends with a 
regular or somewhat irregular terminal cone. Its irregularities appear to be 
caused by the concrescence with it of the distal spines, which lie nearly parallel 
to it. The distal ray bears sparse, irregularly distributed spines. The basal 


296 HYALONEMA (PRIONEMA) FIMBRIATUM. 


and distal spines are short, the middle ones have a maximum length of 15-28 u. 
These long spines point obliquely upwards and usually enclose an angle of 30°— 
40° with the axis of the distal ray. The maximum diameter of the distal ray, 
together with the spines, is 27-45 4. The spines are conic, sharp-pointed, and 
straight or curved, concave towards the tip of the ray. They are usually simple, 
but occasionally bear small secondary spinelets. The lateral rays (Plate 62, 
figs. 16-18) are straight, nearly cylindrical in their basal and middle-parts, 
abruptly pointed, and 23-36 » long, on an average (of 42 measurements) 28.3 y. 
They bear, along their whole length, with the exception of base and tip, rather 
sparse conspicuous spines about 24 long. The proximal spines are vertical, 
the distal ones inclined towards the tip of the ray. 

Among these pinules I found an abnormal one with a reduced distal ray 
only 20 » long, bent and rounded at the end, and destitute of large spines. 

The canalar pinules (Plate 62, figs. 19, 32-41) are also nearly always pentac- 
tine. I found only a single hexactine one among them. This had a proximal 
ray 53. long. The distal ray is straight, 80-122 » long, exceptionally as much 
as 138 », on an average (of 29 measurements) 103.6 u» long, 3-6.5 » thick at the 
base, and thickened in the middle, where it measures 4-8 y» in transverse diameter. 
Its end appears as a slender, sharp-pointed cone. The distal ray bears irregu- 
larly arranged spines. The number of these spines is never great. Sometimes 
there are only three or four (Plate 62, figs. 32,41). The largest spines generally 
arise from the middle-part of the ray; proximally and distally they become 
smaller. The spines are conic, sharp-pointed, straight or curved, usually concave 
towards the tip of the ray. They are generally simple, only very rarely they 
bear small secondary spinelets. The large spines of the middle-part of the ray 
are usually 10-52 » long, strongly divergent and generally inclined towards the 
tip of the ray. Occasionally, however, some of them are vertical (Plate 62, 
fig. 38) or inclined towards its base (Plate 62, fig. 41). The maximum diameter 
of the distal ray, together with the spines, is 20-77 ». The lateral rays are 
conic, 40-88 » long, and bear numerous small spines. 

These spicules are connected with the micropentactines described below 
by transitional forms, in which the spines of the distal ray are much smaller, 
only 1-3 » long. The maximum transverse diameter of the apical (distal) ray, 
together with the spines, of these pinules (pinule-derivates) is only 7-9 u. 

The pentactine megascleres underlying the superficial membrane (Plate 63, 
fig. 7-9) have straight or only very slightly curved, usually conic rays, 13-60 u 
thick at the base. Occasionally a ray is reduced in length and terminally 


HYALONEMA (PRIONEMA) FIMBRIATUM. 297 


rounded. The apical (proximal) ray is 0.6—2.1 mm. long; the lateral rays are 
0.18-0.7 mm. The latter are inclined inward and enclose with the axis of the 
proximal (apical) ray an angle of 75°-89°, usually about 80°. 

The hevactine megascleres (Plate 63, figs. 1-5) measured were 0.5—2.2 mm. 
in diameter and had rays 10-55 u thick at the base. Some fragments of such 
spicules observed, which were up to 62 u thick, indicate that considerably larger 
hexactines also occur. The rays of the hexactine megascleres are straight or 
slightly curved, and usually conic and pointed. One (Plate 63, figs. 4, 5) or 
two (Plate 63, fig. 1) of the rays may be reduced in length and terminally rounded. 
The rays of the same spicule are either about equal in size (Plate 63, fig. 3) or 
unequal. The inequality is usually due to two rays lying opposite being longer 
than the other four (Plate 63, figs. 1, 2). 

Most of the rhabds of the body proper are centrotyle amphioxes, but diactines 
with one ray reduced, and rounded and thickened at the end, also occur. These 
spicules resemble tylostyles. z 

The centrotyle amphioxes (Plate 63, figs. 10, 11) are nearly straight or slightly 
curved, 1.2-1.8 mm. and more long, and 9-21 » thick near the centre. The 
central tyle measures 12-26 in transverse diameter. The relation between 
its thickness and the thickness of the adjacent parts of the spicule is 106-163, 
usually about 120 : 100. 

The tylostyle-like rhabds with one ray reduced and terminally thickened 
(Plate 63, figs. 12-14) are 1-1.5 mm. and more long and usually 12-24 y thick. 
Their terminal tyle is 18-36 u in diameter. 

The slender-rayed, long-spined acanthophores of the protuberance, from which 
in life the stalk arose (Plate 62, figs. 20-26), have four to six rays, and are con- 
nected by transitional forms with the pinules. They measure 130-220 u in 
diameter, and have straight or slightly curved, pointed rays 3-4.5 » thick and 
beset with numerous spines. The spines on the middle-parts of the rays are 
usually the largest, and are 3-21 w long. Proximally and distally they decrease 
in size. The spines are either all directed obliquely outward, or only the distal 
ones are thus inclined, the proximal ones arising vertically. The rays of the 
same spicule are usually unequal in respect to their spinulation and for a certain 
extent also in respect to their size. Sometimes (Plate 62, figs. 20, 21, 28, 25) 
this inequality is inconsiderable, sometimes (Plate 62, figs. 22, 24, 26) it is very 
marked. In the latter case one of the rays is usually longer and provided with 
longer spines than the others. These spicules, which often resemble pinules 


quite closely, connect the more regular slender-rayed long-spined basal spicules 


298 HYALONEMA (PRIONEMA) FIMBRIATUM. 


with the true pinules. The slender-rayed long-spined basals may therefore be 
considered as pinule-derivates. 

The acanthophores with stout rays are monactine to pentactine. 

Among the tri- to pentactine acanthophores (Plate 63, figs. 15-19) the tetrac- 
tines with four rays extending in one plane (stauractines) greatly predominate. 
The maximum diameter of these spicules usually is 330-670 », but much smaller 
forms only 100-300 » in diameter (Plate 63, fig. 15) also occur. The rays are 
equal or unequal, fairly straight, 10-28 u thick at the base, and slightly attenu- 
ated distally. They often have a somewhat wavy outline. Their end-parts 
are usually thickened, densely covered with rather short, broad spines, and 
blunt-pointed, or, particularly in the cases where the rays are reduced in length, 
terminally rounded. The thickened, spiny end-parts of properly developed 
long rays are accordingly usually spindle-shaped, those of reduced, short rays 
usually more or less spherical. 

Of the diactine or monactine forms, that is the rhabd acanthophores, various 
kinds can be distinguished: — slender, long-spined tylostyles; angularly bent 
centrotyle diactines; straight or slightly curved, stout, centrotyle diactines; 
stout, strongly curved, not centrotyle rhabds with thickened ends; slender, 
slightly curved, long rhabds with thickened ends; and strongly curved rhabds 
of the last mentioned sort. 

The slender tylostyle monactine acanthophores with long spines are very rare. 
A spicule of this kind measured was 220 u long and 8 » thick; its terminal tyle 
measured 18 » in diameter. I am inclined to consider these spicules as monac- 
tine-derivates of the slender-rayed long-spined basal tri- to hexactines above 
described. 

The angularly bent centrotyle diactine acanthophores are also very rare. They 
have a spiny tyle and two straight rays enclosing an angle of about 90°. In one 
of these spicules measured, the two actines were quite straight, and respectively 
13 » thick and 430 and 500 » long. The spiny central tyle was 28 u in diameter. 

The stout, straight or slightly curved, centrotyle diactine acanthophores (Plate 
63, figs. 20-23) are usually 550-920 u long, and 14-30 » thick near the centre. 
The central tyle is 20-54 » in diameter. The proportion of the thickness of the 
tyle to the thickness of the adjacent parts of the spicule is 114-300 : 100. When 
the tyle is large, it is spiny (Plate 63, fig. 20); when it is small, it is smooth 
(Plate 63, figs. 21-23). The two rays of these spicules have the same shape as 
the rays of the tri- to pentactine stout-rayed basals above described, but are 
on the whole longer. I think there can be no doubt about these spicules being 


diactine-derivates of the stout-rayed tri- to pentactine acanthophores. 


HYALONEMA (PRIONEMA) FIMBRIATUM. 299 


The stout, strongly curved, not centrotyle rhabd acanthophores (Plate 63, 
figs. 27, 28) are rare. They are cylindrical, thickened at both ends, and uni- 
formly or irregularly curved. Their middle-part is smooth; their thickened ends 
are spiny. These spicules are, measured along the chord connecting their 
ends, usually 300-400 u long, and about 18 thick. The terminal thickenings 
(tyles) are spherical and measure 35-50 u» in diameter. 

The slender rhabd acanthophores (Plate 63, fig. 24) are usually slightly and 
uniformly curved, 0.9-1.3 mm. long, and 5-15 u thick near the middle. Their 
ends are more or less spiny and usually thickened. The terminal thickening is 
sometimes 25 u» and more in transverse diameter. A central tyle, 2-4 » thicker 
than the adjacent parts of the spicule, is usually present. 

The strongly curved, slender rhabd acanthophores (Plate 63, figs. 25, 26) are 
rare. They are destitute of a central tyle and appear as strongly and irregularly 
curved slender rods about 7 » thick. They are usually thicker at one end than 
at the other, and thickened at both ends to unequal terminal tyles which are 
spined, more or less spherical, and have a maximum transverse diameter of 
25 u. The maximum diameter (length) of the curve formed by these spicules 
is usually 300-500 u. 

The basal anchor-spicules (Plate 62, figs. 5-11) are spined rods with an anchor 
at the distal end. These rods have near the middle a maximum thickness of 
72 4, and are attenuated both proximally and distally; proximally to a fine 
point, distally to a thickness of 9-32 » just above the anchor. The distal and 
middle-parts of these rods are covered with straight, strongly inclined, inwardly 
directed spines 10-25 long. Proximally these spines become smaller and 
finally disappear, so that the inner end-part of the spicule appears quite smooth. 
The rod is traversed by an axial thread which terminates distally in the middle 
of the anchor. The end is thickened, and from this thickening four short branch- 
threads arise, which form a cross lying in a plane vertical to the rod or 
anchor-shaft. The terminal anchor is 22-128 uw high and 43-140 u broad. It 
consists of a stout, spherical centrum from which a number of anchor-teeth arise. 
The centrum appears as a terminal tyle of the rod forming the anchor-shaft. 
The teeth extend at various angles obliquely backward (upward) and outward. 
They are sometimes 40 » long, blunt, and very irregular and variable in position, 
shape, curvature, and size. Some are bifurcate or otherwise branched. 

All the anchors observed lay altogether within the sponge. The stalk, 
which no doubt was present in life, is absent in all the specimens. Probably 
anchors of the kind described above take part in its formation. A few smooth 


300 HYALONEMA (PRIONEMA) FIMBRIATUM. 


and very stout spicule-fragments found within the stalk-protuberance make 
it probable, however, that either these anchors are not the sole stalk-spicules, 
or that the proximal, smooth end-parts of the anchor-shafts are very greatly 
increased in length and in thickness during the process of further growth, which 
leads to their distal parts being pushed out from the body to form the protruding 
stalk. 

The six rays of the microhexactines (Plate 60, figs. 25-30; Plate 62, figs. 
42-45) are usually fairly equal; more rarely two opposite ones exceed the other 
four markedly in length. The microhexactines with equal rays measure 56-95 u 
in total diameter, most frequently 65-85 y», on an average (of 44 measurements) 
75.3 uw. Their rays are 1.8-2.8 » thick at the base, usually about 2 », conic, and 
attenuated to fine points at the end. They bear rather sparse, minute spines. 
The spines of the basal and middle-parts of the ray are usually 0.2-0.5 u long; 
distally they become smaller. The basal half or so of the ray is quite straight, 
the distal part curved. Where the straight basal part passes into the curved 
distal part an abrupt, sometimes quite angular bend is often discernible. The 
curvature of the distal part is very considerable, the direction of the end-part 
diverging up to 120° and more from the direction of the basal part. The direc- 
tion of curvature of opposite rays is usually opposite, so that any two opposite 
rays together generally form an S-shaped curve. 

The rare microhexactines with two opposite rays exceeding the other four 
in length measured were 80-90 » long and 40-50 4 broad. In these spicules 
the two opposite, longer rays are not so strongly curved as the four shorter ones. 

In a spicule-preparation I found a monactine microhexactine-derivate 
which appeared as a minutely spined tylostyle with strongly bent pointed end. 
Its measurements were: — chord 57 uw; thickness 2.5 uw; tyle 4.5 u. 

A few microhexactines 110-120 » in diameter with straight rays, 4-5 u 
thick at the base, were also observed. These rare spicules were perhaps foreign. 

The muicropentactines (Plate 60, figs. 31-34; Plate 62, fig. 28) consist of 
one slightly longer apical and four shorter lateral rays, which latter are fairly 
equal in size and extend in a plane vertical to the apical ray. The rays of these 
spicules are straight in their proximal and curved, generally very considerably, 
in their distal part. Opposite lateral rays are curved either in the same or in 
different directions. The rays are, measured along the chord, 35-79 u long, 
conic, pointed, and 2.8-3.7 u thick at the base. They bear conic, pointed spines, 
which, in the proximal part of the ray, attain a length of 0.7 4. Distally the 
spines become smaller. These spicules are connected by transitional forms with 
the canalar pinules. 


| 
| 
| 
| 
| 


301 


HYALONEMA (PRIONEMA) FIMBRIATUM. 


In a 


Occasionally smaller micropentactines with straight rays are met. 


spicule of this kind the rays measured were 4 u thick at the base, the apical ray 


was 54 » long; the laterals were 34 u long. 


Of amphidiscs several kinds can be distinguished: — A, large ones, with 


medium anchors the teeth of which are smooth, and have straight or outwardly 


curved, diverging ends; B, large, medium-sized, and small ones with slender 


anchors, the teeth of which bear frill-like, fimbriate membranes on their margins 


and have inwardly curved, convergent ends; and C, small ones with broad 


anchors, the teeth of which appear smooth and have end-parts more or less 


parallel to the shaft. 


The frequency of the various lengths is repre- 


I measured 202 amphidiscs. 


sented in the following exponential graph (Fig. 15). 


Macramphidiscs 


Large 


Fimbriate. amphidiscs. 
Small 


SCS, 
' 


Micramphidi 


ee eee ee ee ee ee ee 


Number, 
30 
25 
20 


' 


me alba 


oP GES — 8E 06F 
8E 06h — 08 SPF 
08’ Shr — Z2'SOP 
LOSOV — EV 89E 
EV 89E — €6 PEE 
€6 VEE — 6 POE 
6 POE — 189% 
18'9L¢ — V9 TSe 
v9 TSC — 91866 


“192 866 — L6 L0G 


26 £02 — 90°68T 
90°681 — Z8°TZT 
is} \)L ASG ISit 
Gc 9ST — F0'Ch 
FO'CVI — €1 6c1 
€L 6¢L — 6E ZIT 
6€° ZIT — éZ 901 


6Z 901 — 60°26 
60'26 —02'88 
0288 —8108 
8l08 —é68°cL 
68'cL — 9299 
9299 — #209 
¥609 —9L¥S 
9LVS —8l 6P 
8L6v —9dSP 
9¢SP —TIIP 
VI Ivy —OVZé 
OV ZE —O00TE 
OO rE — 16 0€ 
Se LOOG ea OESG 
--O1'8q —sSo'SZ 
CCS Cais GGISG 
SGSC wea LG 
LlGe— 6Ler 
616L —SP LI 
GV ZL —98'SI 
O8iSl Creu 
AMAL nse 
yysuaT 


= 
n 


1SC 


Length of Amphid 


‘ig. 15.— Amphidiscs. 


302 HYALONEMA (PRIONEMA) FIMBRIATUM. 


The part of the curve between 304.49 and 490.38 w pertains to the large 
amphidises with smooth, divergent anchor-teeth, A; the part between 34.00 and 
334.93 » to the amphidiscs with fimbriate, convergent anchor-teeth, B; and the 
part between 14.42 and 41.14 » to the amphidises with smooth anchor-teeth with 
parallel end-parts, C. There is no dimensional overlapping of A and B and only 
a slight overlapping of B and C, 14.42 and 34.00. The dimensionally transitional 
forms of B and C causing this overlapping are, however, rare, so that the part 
of the curve between 14.42 and 34.00 pertaining to them lies quite low. The 
three differently shaped amphidise-forms (A, B, and C) are differentiated accord- 
ingly not only in regard to their shape but also in regard to their size (length). 
Fig. 15 further very clearly shows that the amphidises A and C vary 
only slightly in size and form biometrically homogeneous groups, and that the 
amphidise B has a very wide range of dimensional variation and does not 
form a biometrically homogeneous group. The part of the frequency-curve 
pertaining to this group exhibits one high and rather broad and three smaller 
elevations. This shows that the main-group B consists of four secondary groups, 
the amphidises belonging to one of which are frequent, those belonging to the 
three others, rare. It is therefore advisable to distinguish six groups (three 
main-groups, one of which, B, comprises four secondary groups) of amphidises 
in the sponges here described:— A, macramphidises, Ba, largest fimbriate 
amphidises, Bb, large fimbriate amphidises, Be, small fimbriate amphidises, 
Bd, smallest fimbriate amphidises, and C, micramphidises. 

The macramphidiscs (Plate 59, figs. 1-6; Plate 62, fig. 31) are 335-446 » long, © 
most frequently about 400 u. The shaft is cylindrical, straight, 8-16 u thick, 
most frequently about 12 yu, and abruptly thickened in or near the middle to a 
central tyle 11-22 » in transverse diameter. The proportion of the thickness 
of the adjacent parts of the shaft to the thickness of the tyle is 100 to 121-167. 
From the tyle a verticillate bunch of spines arises. The number of the spines 
forming this bunch is variable. Sometimes they are few in number and small 
in size (Plate 59, fig. 2), sometimes numerous and large (Plate 59, fig. 1). Forms 
intermediate between these extremes are the most frequent. The spines form- 
ing these bunches are irregularly distributed and, when few in number, fre- 
quently confined to,one side of the shaft. The individual spines are 7-26 u 
long, 4-5.5 uw thick at the base, cylindrical throughout and terminally rounded, 
or attenuated distally, truncate, and provided with a cluster of exceedingly 
minute secondary spinelets on the terminal face. The primary spines arise 
vertically or steeply from the central thickening of the shaft and are, farther on, 


HYALONEMA (PRIONEMA) FIMBRIATUM. 303 


curved, usually all more or less in the same direction. In short spines this 
curvature is insignificant, in long spines, very pronounced. The long spines 
are usually strongly curved in their basal part and straight or slightly curved, 
not infrequently in the opposite direction, in their distal part. The plane of the 
main curvature either passes through the axis of the shaft, or it is oblique to it. 
Since, as above stated, all the spines on the tyle are usually curved in the same 
direction, the verticillate bunch formed by them appears — when the spines are 
long — bent, straight or spirally, toward one end of the spicule. The remain- 
ing parts of the shaft are smooth. The axial thread passes through the central 
tyle without being thickened, and there is no trace of an axial cross. I noted, 
however, a few small dots in the central part of the tyle, near the axial thread, 
which appeared to have the same refractive index as the axial thread. 

The two anchors of the same spicule are fairly equal, or rather unequal, in 
size. The anchors are 80-180 u» long, a third to two fifths of the whole spicule, 
and 70-113 4 broad. The proportion of anchor-length to anchor-breadth is 
100 to 46-84, usually 100 to 63-80, on an average (of sixteen calculated individual 
proportions) 100 : 70. 

The individual anchor-teeth are near the base 10-14 u high, and a little 
farther out, at their widest point, 12-22 4 broad. They are attenuated distally 
and at the end simply rounded (Plate 59, figs. 5, 6; Plate 62, fig. 31) or, more 
rarely, divided, by a slight indenture, into two terminal lobes (Plate 59, fig. 4). 
They arise steeply or vertically from the end of the shaft and are curved in their 
basal part through an angle of about 80°. Then they become nearly or quite 
straight and remain so to within a short distance of the end. This long straight 
part of the tooth ses an angle of about 10° with the continuation of the axis 
of the shaft. The end-part of the tooth is slightly bent outward or more rarely 
straight and excended in the same direction as the middle-part. The plane of 
the normal curvature of the tooth passes through the axis of the shaft. Occa- 
sionally the end-part of a tooth is bent also in a plane vertical to this, paratan- 
gentially as it were, to one side (Plate 59, fig. 6). 

The fimbriate amphidiscs are all very similar. The only differences between 
the four biometric groups of them, that is the largest, large, small, and smallest, 
are those due to the relative anchor-breadth decreasing and the relative size of 
the central tyle of the shaft increasing with the size of the spicule. Their anch- 
ors are from a little less than two fifths to nearly half the whole spicule in 
length. 

The largest fimbriate amphidiscs (Plate 60, figs. 1-6, 24; Plate 61, figs. 1-11; 


304 HYALONEMA (PRIONEMA) FIMBRIATUM. 


Plate 62, fig. 27) form a biometrically homogeneous and well-defined group, 
entirely separated dimensionally from the (larger) macramphidises on the one 
hand and the (smaller) large fimbriate amphidises on the other. 

The largest fimbriated amphidiscs are 200-323 4 long, most frequently 
about 250 » long. The shaft is straight, on the whole cylindrical, and 4—7.5 u 
thick. Its thickness is fairly proportional to the length of the spicule. The 
shaft is thickened slightly and gradually towards the ends, and considerably 
and abruptly somewhere in its middle-part. The latter thickening, the central 
tyle, is usually some distance, occasionally (Plate 60, fig. 5) very far away from 
the real (geometrical) centre of the shaft, and measures 8-14 uw in transverse 
diameter. The proportion between the thickness of the adjacent parts of the 
shaft to the thickness of the tyle is 100 to 160-325. From the central tyle a 
verticillate bunch of spines arises. These spines (Plate 62, fig. 27) are 5-15 u 
long, at the base 2-2.8 » thick, cylindrical, and terminally simply rounded, or 
attenuated distally and truncate with a cluster of exceedingly minute secondary 
spinelets on the terminal face. The (primary) spines are curved. The curva- 
ture is irregular, and a rather abrupt angular bend usually occurs somewhere 
near the middle of the length of the spine. Generally all the spines of the bunch 
are, as in the macramphidises, curved in the same direction longitudinally or 
obliquely (spirally). The parts of the shaft outside the central tyle bear very 
numerous spines, the largest of which are 1 » long, 1.5 » broad, cylindrical, and 
provided with a cluster of exceedingly minute secondary spinelets on their flat 
or rounded terminal face (Plate 60, figs. 5, 6; Plate 62, fig. 27). The degree 
of development of these scattered (primary) spines is very variable; often they 
are reduced to hardly perceptible protuberances en the, syrface of the shaft 
(Plate 60, fig. 3). 

The two anchors of the same spicule are fairly equal, or rather unequal, in 
size. They usually consist of eight teeth. The anchors are 72-136 u long, and 
43-67 uw broad at their broadest point and attenuated distally, their ends meas- 
uring only 32-60 u in transverse diameter. The difference between the maxi- 
mum and end-breadth of the anchors is 3-18, on an average (of 29 measure- 
ments) 7.8 4. The proportion of the length to the maximum breadth of the 
anchors is 100 to 42-72, on an average (of 29 calculated proportions) 100 : 52.2. 
The largest (longest) anchors are on the whole narrower than the smaller (shorter) 
ones. The average proportion of length to maximum breadth is in the anchors 
over 120 » in length 100 : 47.8, in those under 100 u in length 100 : 55.7. 

The individual anchor-teeth arise nearly vertically from the end of the 


HYALONEMA (PRIONEMA) FIMBRIATUM. 305 


shaft, are strongly curved, concave to the shaft, for a short distance quite at the 
base, and slightly and quite uniformly curved in the same direction for the 
remainder of their length. The total curvature is such that the ends of the 
teeth converge towards the shaft, and enclose with it angles of about 8°-16°. 
The body of the tooth has the usual T-shaped transverse section. The lower 
(radial) part increases in height proximally to 5-9 u. The upper (paratangen- 
tial) part is 6-10 » broad near the middle of the length of the tooth and attenu- 
ated both proximally and distally. The distal end of the body of the tooth is 
narrow and blunt-pointed. 

The two margins of the outer part of the tooth (which corresponds to the 
horizontal upper stroke of the T) are continued in fine, frill-like, fimbriate, 
siliceous membranes, which diverge from the plane through tooth- and shaft- 
axis and extend obliquely inward. The tooth, together with its two fimbriate 
marginal membranes, has a transverse section (Fig. 16). 


Upper (paratangential) part of the tooth. 


Marginal fimbriate membrane. 


Lower (radial) part of the tooth. 


Fig. 16.— Anchor-tooth. Section. 


The fimbriate marginal membranes extend from the base (Plate 61, figs. 
4, 5, 8, 9) to the tip (Plate 61, figs. 6, 7, 10) of the tooth and even slightly beyond 
it. They are at the base of the tooth quite narrow, only about 1 u broad (Plate 
61, figs. 4,5, 8,9); in the middle of the tooth (Plate 61, figs. 1-3) they broaden 
distally and attain a breadth of about 7 4. Beyond they again become slightly 
narrower and are, at the end of the tooth, about 4 u broad. Narrow and deep 
incisions, extending down to the body of the tooth, divide these membranes into 
lobes, which are, in the distal and middle-part of the tooth, on an average about 


306 HYALONEMA (PRIONEMA) FIMBRIATUM. 


2. broad; proximally they become considerably narrower. Secondary inci- 
sions subdivide the marginal parts of these primary into secondary lobes, so 
that they attain a somewhat dendritic appearance (Plate 61, figs. 1-3). 

I am not aware that such fimbriate marginal membranes have hitherto 
been observed in the amphidiscs of the Hexactinellida Amphidiscophora. They 
may be compared with the thin marginal parts of the cladomes of the phyllo- 
and discotriaenes of certain lithistid Tetraxonida. 

The large fimbriate amphidiscs (Plate 60, figs. 7-11) are 122-185 u long, 
most frequently about 163 4. Their shafts are 2-4 4 thick. Their thickness 
is fairly proportional to the length of the spicule. The central tyle is 3-7 u 
in diameter, two thirds to twice as thick as the adjacent parts of the shaft. 
The spines arising from the tyle are similar to those of the largest fimbriate 
amphidises but proportionately smaller and usually not all curved in the same 
direction (Plate 60, figs. 8, 10). The remainder of the shaft usually is more 
spiny than in the largest fimbriate amphidises. The anchors are 39-80 u long; 
their maximum breadth is 26-55, their end-breadth 20-50 u. The difference 
between maximum and end-breadth is 3-6 uw, on an average (of ten measure- 
ments) 5.2 4. The proportion of the length to the maximum breadth of the 
anchors is 100 to 50-78, on an average (of ten calculated proportions) 100 : 58.8. 
A correlation between amphidisc-length and relative anchor-breadth is not 
discernible in the amphidises belonging to this subgroup. 

The small fimbriate amphidiscs (Plate 60, figs. 12-14) are 64-99 » long, most 
frequently about 77 u. The shaft is 1.5-1.8 u, the central tyle usually 2-3 » 
thick. Strongly bent spines usually arise from the latter. Smaller short 
and broad spines cover the remaining parts of the shaft quite densely. The 
anchors are 23-36 » long and have a maximum breadth of 13-21 ». The end- 
breadth is usually 1-2 uw less than the maximum breadth. The proportion of 
length to maximum breadth of the anchors is 100 to 52-72, on an average (of 
six calculated proportions) 100 : 59. 

The smallest fimbriate amphidiscs (Plate 60, fig. 15; Plate 62, fig. 15) are 
36-54 uw long, most frequently about 52 and 384 long. The shaft is 1.2-1.8 u 
thick. A central thickening, as much as 2.8 » in diameter, is sometimes dis- 
cernible. Often, however, there is hardly any trace of such a tyle.. The 
shaft is covered with spines about 0.5 u long. The anchors are 16-24 u long, 
and have a maximum breadth of 9.5-13 ». The end-breadth is 1—2 u less than 
the maximum breadth. The proportion of the length to the maximum breadth 
of the anchors is 100 to 55-75, on an average (of eight calculated proportions) 
100 : 63.1. 


OONEMA. 307 


The micramphidiscs (Plate 60, figs. 16-23; Plate 62, figs. 12-14) are 15-40 yp 
long, most frequently about 20 4. The shaft is cylindrical, straight or, very 
rarely, slightly curved, and 0.7-1.7 u thick. Sometimes it is slightly and gradu- 
ally thickened near the middle up to 2 4; more frequently no trace of a central 
thickening can be detected. The shaft is covered by blunt or truncate spines 
about 0.5 1 long. These spines are often very numerous. The anchors are 
4-14 » long, usually a little less than a third of the whole spicule, and 5-12.5 » 
broad. The proportion of their length to their breadth is usually 100 to 68- 
130, rarely up to 100 : 156, on an average (of thirty calculated proportions) 
100 :111.5. The larger micramphidiscs have relatively narrower (more slender) 
anchors than the smaller. In the micramphidises with anchors under 7.5 u 
in length the proportion of anchor-length to anchor-breadth is generally 100 to 
100-130, rarely up to 100 : 156, on an average 100 :118.9. In the micramphi- 
dises with anchors over 7.5 » in length this proportion is 100 : 68-114, on an 
average 100 :86.6. In consequence of the slenderness of their anchors the 
larger micramphidises appear as transitional forms connecting the smaller 
micramphidises with the smallest fimbriate amphidisecs. The individual anchor- 
teeth of the micramphidiscs are uniformly and considerably curved, concave 
to the shaft, in their basal part. Distally this curvature decreases and their 
end-parts are nearly straight. The total curvature is such that the (nearly 
straight) end-part of the teeth come to lie parallel or nearly parallel to the 
shaft and to each other. j 

| The above sponges differ from all the species of Hyalonematidae hitherto 

described by the anchor-teeth of their fimbriate amphidiscs bearing marginal 
frills. In some respects, particularly in respect to the basal anchors and the 
microhexactines, they resemble Hyalonema depressum F. E. Schulze. In respect 
to other characters, particularly in the various kinds of amphidiscs, they differ, 
however, fundamentally also from this sponge. 


OONEMA, subgen. nov. 


Species of Hyalonema of which the amphidiscs of one of the kinds have 
relatively very large and broad, usually more or less semispherical, anchors 
about half of the whole spicule in length. 

The collection contains six specimens of this subgenus, which belong to 


five species, four of which are new. 


308 HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 


Hyalonema (Oonema) bianchoratum pinulina, var. nov. 


Plate 82, figs. 1-34; Plate 83, figs. 1-68; Plate 84, figs. 1-32; Plate 85, figs. 1-8. 


Two fine specimens of this variety were trawled off the coast of northern 
Peru at Station 4651 on 11 November, 1904; 5° 41.7’ S., 82° 59.7’ W.; depth 
4063 m. (2222 f.); they grew on a bottom of sticky, fine, gray mud; the bottom- 
temperature was 35.4°. In the following description one of them is designated 
a, the other b. 

With other characteristics these sponges differ from the typical Hyalonema 
(Oonema) bianchoratum Wilson by the distal rays of their pinules attaining not 
nearly so great alength. To this the name of the variety refers. 

Shape and size. Both specimens are upright, cylindrical, widened above 
to form a shallow cup, and rounded at the lower end, from which a rather eccen- 
trically situated stalk arises. From the bottom of the cup a cylindroconical 
terminally rounded gastral cone protrudes. Specimen a is 111 mm. long, the 
longest and shortest diameters of its upper end being respectively 49 and 31 
mm. Specimen b (Plate 82, fig. 1) is 141 mm. long. The longest and shortest 
transverse diameters of the central cylindrical part of its body are 49 and 42 mm., 
those of its upper, cup-shaped extension respectively 66 and 48 mm. The 
stalk of specimen a is broken off at a distance of 40 mm. from its point of origin, 
that of b close to the body of the sponge. An isolated stalk, in the same jar 
as the body of specimen b, which fits the stump at the lower end of the body, 
apparently belongs to it. This stalk, which was attached to the stump before 
the specimen was photographed (Plate 82, fig. 1), is 230 mm. long, and, near 
its point of origin, circular in transverse section, and 3.8 mm. in diameter. 

Surface. Pores could not be found where the choanosome extends up to 
the superficial membrane. These poreless tracts appear as broad bands which 
form a network with irregular meshes, the maximum diameter of which is rarely 
more than 1 mm. on the dermal face, but is sometimes as much as 10 mm. on the 
gastral face. In the meshes of this primary network are spread out reticular sieve- 
membranes (Plate 82, fig. 1; Plate 83, figs. 60-62) composed of narrow bands 
of superficial (dermal or gastral) tissue. The meshes of the dermal secondary 
reticulations are usually 100-300 » wide, those of the gastral usually 300-500 uy. 
The nodes of these nets are much thickened. In the meshes of the dermal 
pore-sieves (Plate 83, fig. 62) some remnants of what seems to have been a ter- 
tiary network were observed. In the meshes of the gastral pore-sieves (Plate 
83, fig. 61) no such remnants could be found. 


HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 309 


Canal-system. The pores of the dermal sieves on the outer side of the body 
lead into wide canals extending into the interior. Other still wider canals extend 
up to the gastral sieves on the inner face of the cup. Between these wide canals, 
the former of which are, no doubt, afferents and the latter efferents, a tissue is 
found containing narrow canals, and rather densely packed small flagellate 
chambers (Plate 84, fig. 2). The sections of these flagellate chambers (Plate 
84, fig. 2a) are mostly circular or broad-oval and 50-120 » in maximum diameter. 

The colour of both specimens in spirit is greenish brown. 

The skeleton. The poreless parts of the surface and the strands forming 
the pore-sieve nets are, both on the dermal and the gastral face, covered by 
a dense pinule-fur (Plate 83, figs. 45b, 61, 62). Under the poreless tracts of 
both faces paratangential, more or less centrotyle amphioxes and the lateral 
rays of pentactine megascleres form a superficial (hypodermal, hypogastral) 
skeleton. The strands of the dermal pore-sieve nets are supported by the 
lateral rays of hypodermal pentactines and a few centrotyle amphioxes (Plate 
83, fig. 62). The centra of the pentactines are here usually about 700 » apart. 
In the gastral pore-sieve nets no pentactines have been found. Here centrotyle 
amphioxes, congregated in dense bundles, alone occupy and support the strands 
of the reticulation (Plate 83, fig. 61). 

Numerous centrotyle amphioxes, rather scarce hexactine megascleres, 
and masses of microhexactines occur in the choanosome. Some of the micro- 
hexactines have straight, others curved rays. I think it not improbable that 
the former, which are much the scarcer, line the walls of the wide main canals, 
and are to be considered as canalaria; while the latter are imbedded in the 
choanosomal tissue, and are to be considered as parenchymalia. 

Four kinds of amphidiscs can be distinguished: — large and small macram- 
phidises, and large and small micramphidises. The large macramphidises are 
rather scarce in both specimens and confined to the choanosome, where they 
appear to be irregularly scattered. The small macramphidises are very numer- 
ous on and in the gastral membrane of specimen a, where most of those seen 
in situ in the sections were found to lie between the distal rays of the pinules 
wholly outside the sponge, with their shafts vertical to the surface (Plate 83, 
fig. 45c), while only a few are scattered irregularly in the gastral membrane. 
On the dermal face of this specimen small macramphidiscs have also been 
observed, but they are here not nearly so numerous. In specimen } these amphi- 
dises are similarly situated but much less abundant. The large micramphidiscs 


are very rare in both specimens, the small very numerous in 6, but somewhat 


310 HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 


scarce in a. I observed a large number of these small micramphidiscs in situ 
in the gastral membrane of specimen b, where they lie in large part paratangen- 
tially with their shafts parallel to the surface; and I found a great many also 
in the centrifuge spicule-preparations of specimen b, both in this membrane 
and in the choanosome. One- to six-rayed acanthophores with terminally 
or, much more rarely, entirely spined rays are abundant in both specimens in 
the vicinity of the point of origin of the stalk. In specimen a these spicules 
are on the whole stouter than in specimen b. The skeleton of the stalk extends 
through the body of the sponge up to the gastral cone. Its upper, imbedded 
part consists of centrostyle amphioxes and the upper end-parts of the large 
spicules forming the free part. The latter, provided it really belongs to the 
sponge, is in specimen b (Plate 82, fig. 1) composed of five stout and about a 
dozen more slender spicules twisted spirally together. The free part of the 
stalk of specimen b is composed of about a dozen stout and a small number of 
slender spicules. 

The symbiotic zoantharian polyps. To the proximal end-part of the stalk 
of specimen a is attached a tubular Palythoa colony, enclosing the stalk like 
a tight-fitting mantle for a distance of 17 mm. The individual polyps arising 
from this tubular colony are about 3 mm. high and 4 mm. broad. Polyps 
and coenenchym are provided with a stout skeleton composed entirely of acan- 
thophores of the sponge, to the stalk of which the colony is attached (Plate 84, 
fig. 1). In the polyps longer and more slender spicules lying radially in the 
radii of the septa occupy the oral plate, and perhaps also the upper parts of 
the septa. In the superficial parts of the lateral walls of the polyps and the 
coenenchym shorter, stouter, and on the whole more spiny spicules, lying close 
together, form a dense cortex. Still shorter, stouter, and more spiny spicules 
are found near the axis around the mouth and in the wall of the stomatodeal 
funnel. 

On the stalk which probably belonged to specimen b no polyps were 
observed. Its proximal end-part is, however, enveloped by a thin mantle 
(Plate 82, fig. 1) brown in colour, chitinous in nature, and entirely destitute of 
spicules; this mantle may be the basal part of the coenenchym of a zoantha- 
rian polyp-colony. In the body of specimen a no symbiotic polyps were 
observed; the dermal region of the body of b on the other hand contains a 
large number of such polyps (Plate 82, fig. 1; Plate 83, fig. 60a). These polyps 
(Plate 84, fig. 14) are Zoanthidae. They contain no spicules at all and are, 
in their present contracted state, nearly spherical, and 1.3-1.8 mm. in diameter. 


HYALONEMA (OONEMA) BIANCHORATUM PINULINA. dll 


The polyps lie in excavations of the sponge-body just large enough for them. 
Their distal ends are flush with the surface of the sponge. In life, when 
expanded, they probably protruded more or less beyond its surface. These 
polyps form groups within which they are about 4.5 mm. apart (Plate 83, fig. 
60). The coenenchym-like mantle enclosing the upper end of the stalk, which 
has been referred to above, may have formed part of a colony of polyps similar 
to those in the body of the sponge. Some of the polyps in the sponge-body which 
I examined bore a short thread-like protuberance on their lower (inner) end. 
Probably all the polyps of a group, possibly all the polyps of the whole sponge, 
are connected by such threads. I did not make sure of this, however, because 
for this purpose it would have been necessary to cut up the fine and unique 
specimen. 

The pinules (Plate 82, figs. 21-34; Plate 83, fig. 45b). The dermal pinules 
of the upper and middle-parts of the body in both specimens resemble, as radial 
sections show, the gastral pinules, but differ from the dermal pinules on the 
basal part of the sponge, the latter being larger and having distal rays with more 
divergent spines. In the spicule-preparations of different parts of the surface 
besides the pinules shown by the sections to be truly proper to the region in 
question, I always found a few others; in the spicule-preparations of the gastral 
membrane and the upper and middle-parts of the dermal membrane were typi- 
cally basal spicules; and in the spicule-preparations of the basal part of the 
dermal membrane were pinules of the type found in situ on the upper parts 
of the sponge. 

The principal dimensions of the pinules are tabulated on p. 312. 

The gastral pinules (Plate 82, figs. 29, 30; Plate 83, fig. 45b) and the dermal 
pinules on the upper and middle-parts of the sponge (Plate 82, figs. 22, 31-33) are 
nearly always pentactine, very rarely hexactine. Their distal ray is straight 
and 120-280 »! long. It ends with a terminal cone free from spines. Its proxi- 
mal part is also spineless, and it arises with a trumpet-shaped extension from the 
cross formed by the lateral rays. Farther up the distal ray becomes thinner, 
and it attains its minimum thickness at a distance of about 30 u from its base 
(the centrum of the spicule). Beyond that it again becomes thicker. At its 
thinnest point the smooth proximal part of the distal ray is 7-11 » thick. The 
basal thickening is variable. The distal ray of a typical upper dermal pinule is 
17 » in diameter at its thickened base, 30 » higher up, and 11 u at its thinnest 
point. The whole of the distal ray, with the exception of its proximal and distal 


1This and the following measurements refer to the pinules of both specimens together. 


312 HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 


Thickness | Maximum 
| of the thin- | thickness of 
| Length of distal ray nest partof| the distal | Length of the lateral rays 
Pinules Le the distal ray to- Bw 
ray nearits | gether with | 
base “| the spines 
limits average limits 7 limits limits average 
gastral 165-265 219.5 9-10.5 20-26 35-08 43.1 
from the 
upper and 
of middle- 170-250 211.2 7-10 21-23 30-50 38.7 
Picea parts of 
a the body 
2 dermal 
from the | 
eee ©! 130-330 | 234.5 9.17 30-65 40-80 | 56 
body 
gastral 120-280 214.2 feos 17-33 28-52 37.5 
from the 
upper and 
of middle- 180-266 217.9 8-10 20-26 32-60 | 40.1 
fj parts of 
a aig theiedy, 
dermal 
from the 
gay 150-305 | 240.7 10-16 35-65 35-62 | 48.5 
body 


end-parts, bears rather strongly inclined spines, which are slightly curved, 
concave to the ray. These spines attain their largest size at, or some distance 
above, the middle of the ray. Here the distal ray, together with the spines, 
attains a maximum thickness of 17-33 ». The lateral rays of the same spicule 
are usually equal, 28-60 » long, straight, cylindroconical, abruptly and bluntly 
pointed. They are smooth in their proximal part, and in their distal part are 
covered with rather sparse broad spines, usually up to about 1 » long. Some- 
times one ray is reduced in length, nearly cylindrical, and terminally rounded. 
Of hexactine forms (with a proximal ray) I have found (and measured) six, four 
of which were found among the gastral pinules of specimen a. The proximal 
ray is conical, pointed, covered with spines in its distal part, and 10-40 u long. 

The basal dermal pinules (Plate 82, figs. 21, 23-28, 34) are, like those above 
described, nearly always pentactine, very rarely hexactine. Their distal ray 
is straight, 130-330 » long, and spineless in its proximal part. It ends in a 


likewise spineless terminal cone. In these pinules the smooth proximal part is 
a 


HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 313 


also somewhat hour-glass-shaped, and is at its thinnest point 9-17 yw thick. 
Its spines are usually quite strongly divergent, and markedly curved, concave 
towards the ray. They attain their greatest size one half to two thirds of the 
length of the distal ray from the centrum, or still higher up, and here the distal 
ray, together with the spines, attains a maximum thickness of 30-65 u. The 
lateral rays are similar to those of the pinules of the upper part of the sponge, 
above described, but stouter and provided with larger spines. They attain a 
length of 35-80 ». Of hexactine forms I found (and measured) only two, with 
proximal rays 12 and 20 » long respectively. One of these is conical and pointed, 
the other (Plate 82, fig. 26) cylindrical and terminally rounded. 

The hypodermal pentactines (Plate 83, figs. 65-67) have very blunt, conical 
rays. The proximal ray is often somewhat curved; the lateral rays are usually 
straight, occasionally curved in the plane, vertical to the proximal, in which they 
lie. The proximal ray is 0.4-1.3 mm. long, and 15-70 u» thick at the base. The 
lateral rays are 260-610 » long. Those of the same spicule are usually fairly equal, 
more rarely conspicuously unequal. In a hypodermal pentactine with particu- 
larly unequal laterals the longest is 610 4 in length, the shortest only 390 uz. 

The hypogastral pentactines (Plate 83, fig. 68) are similar to the hypodermal, 
but much smaller. Their proximal ray is 210-800 » long, and 12-46 » thick 
at the base. Their lateral rays are 150-460 u long. 

The hexactine megascleres (Plate 83, figs. 63, 64) are 0.35-5.5 mm. in maxi- 
mum diameter. Their rays are straight or slightly and irregularly curved, 
7-120 u thick at the base, attenuated distally, at first more gradually, then more 
rapidly, and pointed at the end. In all the larger and in many of the smaller 
ones two opposite rays are considerably longer than the other four. Some of 
these spicules are nearly twice as long as broad. 

The dermal, gastral, and choanosomal amphiozes are straight or more or less 
curved, rarely angularly bent, centrotyle, 0.5-2.8 mm. long, and 7-59 » thick 
near the tyle. The tyle is 9-60 u in diameter, that is 1-23 u, usually 2-6 », more 
than the adjacent parts of the spicule. The dimensions of the different kinds 
of these spicules (dermal, gastral, and choanosomal) in the two specimens are 
given in the table on page 314. 

The amphioxes of the dermal and gastral membranes are in both specimens 
considerably shorter, stouter, and less curved than those of the choanosomal. 
The gastrals are in both specimens stouter than the dermals. The amphioxes 
of specimen b are on the whole slightly stouter than those of a. This difference 
is particularly well-pronounced in the gastrals. The two limbs of the angularly 


314 HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 
of specimen of specimen 
a 
Amphioxes 
dermal gastral | choanosomal dermal gastral choanosomal 

Length limits mm. 0.56-1.7 0.6-1.9 0.7-2.6 0.5-1.6 0.46-1.8 | 0.75-2.8 
thickness limits yu 11-32 0.45 8-30 12-34 7-59 8-29 
Relative . a 

limits 28-120 24-150 58-173 23-87 22-91 83-137 
length 
(length: 
thickness = average 66.9 59.6 116.8 63.2 44.3 103.3 
10000 :) 
“Lransvetee Gitieter On alae 1-50 | 1433 | 1442 9-60 11-32 
central tyle, limits | 
SS SSS SSS SS Se el 
The tyle exceeds the | | | 
adideent sparisicheene 2-6 iio. | 268 7). Seete Be en i = 
spicule in thickness, by 
(limits) yu 

| 


bent amphioxes usually enclose an angle of 130°-140°. Their bend is generally 
situated so much nearer one end than the other that one limb is six to eight 
times as long as the other, the spicule consequently having the appearance of a 
promonaen. Rarely the bend lies in the middle. The tyle is, as stated above, 
generally only 1-6 » thicker than the adjacent parts of the spicule, and in that 
case simply oval. Occasionally, however, much stouter tyles are observed, 
and in these cases it is clearly to be seen that the tyle is composed of from 
one to four rounded knobs representing rudimentary rays. A few spicules 
of this kind were triactine, a perfectly developed ray occupying the place of one 
of the knobs. Such triactines were observed both among the superficial and the 
choanosomal amphioxes. 

The proportion of length to thickness is in-the choanosomal amphioxes 
of both specimens together 10000 to 58-173, on an average 10000 : 109.3. 
As the curve 


(Fig. 17), in which the reciprocal proportions (thick- 
ness < 10000: length) are represented, shows, there is no great difference 
in the average relative thickness of the smaller and the larger choanosomal 
amphioxes. 

In the superficial (dermal and gastral) amphioxes (Plate 82, figs. 13-19) the 
proportion of length to thickness is 10000 to 74-447, on an average 10000 : 
241.3. Among these the shorter are, on the whole, as the following table shows, 
relatively much thicker than the longer. 


wn 
nO 
ux 
are 
25 
Sie 
nce 38} 
o 2 
Lore 
SS 
a=) 

A 
vo 

2 bo 
p=) 

35 
=o 
ba ce 
cob) 

oS 
BS 
hs 
Sssteal 
<x 


— — — Superficial (dermal and gastral) amphioxes. 


Choanosomal amphioxes 


of these sizes of both specimens 
gether. 


w to 
on 


(ph). 


cool = 
fo @) oO 
S — 


1.41 
1.61 


Fig. 17.— Amphioxes. 


316 HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 


The relative thickness (thickness x 10000:length) of the superficial 
(dermal and gastral) amphioxes of different lengths of both specimens together 
is shown in the following table: — 


O:41— | (0,61 avers 
0 


4 
Length, ; 
ength, mm 6 08 


ee 
aot 
CO & 


1.81-2 


bo 


Relative thick- | limits | 177-356 | 109-447 | 09-39 | 075-445 | 084-346 | 08-393 | 082-159 | 074-147 
ness (thickness | | 
x 10000: ——— 


length) | 


average | 279.3 | 309.3 | 231.7 217.3 156.2 | 202.4 | 118.7 101.5 


This correlation between length and relative thickness comes out very clearly 
in the curve -------- in the graph., Fig. 17. 

To ascertain whether the superficial amphioxes of varying relative thickness 
form a continuous series I arranged the 94 measured according to this relation 
and the result is represented in Figure 18. 

The frequency-curve of the different relative thicknesses in this figure 
clearly shows that, biometrically, two kinds of superficial amphioxes must be 
distinguished: — more slender ones, in which the proportion of length to thick- 
ness is 10000 : 74-210, most frequently about 10000 :112, and stouter ones 
in which this proportion is 10000 : 210-447, most frequently about 10000 : 
312. Among the superficial amphioxes 

0.41-0.8 mm. long 82 % belong tothe stout and 18% to the slender kind. 


ORT ce cc 49 % (a OG % a (a 51% Ce he 6c 66 
116 cc a D7 % 6c (She 4h (ats 6c 73% (te 5 a a 
A (a3 (3 0 % (a3 GS 15 (a3 (a3 100% i 35 “ 66 


It is to be noted that the shortest superficial amphioxes observed, that is 
those 0.41—0.6 mm. long, are on the whole relatively not quite so stout as those 
0.61-0.8 mm. long, which are on the whole the stoutest. These smallest am- 
phioxes are probably young forms. Also among the spicules 0.61-1.6 mm. 
long there are, no doubt, some young forms of larger ones. And since the 
larger ones are all the slender kind these young forms will probably for the most 
part be young forms of the slender ones. 

The distal ends of the spicules of the free part of the stalk are all broken off. 
The parts present have a maximum thickness in specimen a of 0.8 mm., in b 
of 1.3mm. The spiral twist, which all the long fragments exhibit, is such that 
there is one whole turn in about 23 em. of length. The spicules forming the 


HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 317 


upper part of the stalk imbedded in the sponge-body are not centrotyle am- 
phioxes. The largest one observed was 7 mm. long. 

The acanthophores (Plate 83, figs. 1-35) are normally composed of one 
to six rays. One quite abnormal one (Plate 82, fig. 24), which I found in speci- 


men a, has two long and six more or less reduced rays. 


oS on S _& Number of spicules of this relative 
thickness. 
ei 50 ! 
50.1— 75 . 
75.1—100 
100.1 — 125 
= 125.1—150 
Q, 
= 150.1 —175 
oO 
=: 175.1—200 
® 200.1225 


275.1 — 300 


(-yI3uay : QOOOT x SseUyxoIYL) 


375.1 — 400 
400.1 — 425 
425.1 — 450 


450.1 — 475 


Fig. 18.—Amphioxes. 


318 HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 


The rare monactine and frequent diactine rhabd-forms are in specimen a 
270 p-1.3 mm. long and 17-37 u» thick, on an average 25.4 uw; in b 145 p-1.4 mm. 
long and 9-40 uw thick, on an average 16 ». The more slender ones, 20 u or less 
thick, are, in both specimens together, 420 u-1.4 mm. long, the stouter ones, over 
20 w thick, only 270-740 » long. The rare triactine and frequent tetractine 
forms are in specimen a 120-420 » long, with rays 20-44 » thick, on an average 
31 w; in b they are 110-500 » long, with rays 12-34 » thick, on an average 22.4 u. 
The pentactine and hexactine forms, both of which are not numerous, are in 
specimen a 180-350 » long, with rays 15-24 » thick; in b they are 80-390 u 
long, with rays 8-25 yu thick. 

The rays of the tri- to hexactines usually differ in length more or less, often 
very considerably. The rays of the tri- and tetractines always extend in one 
plane, whilst the pentactine and hexactine forms resemble, in respect to the 
position of their rays, the pentactine and hexactine megascleres above described. 
The rays are more or less, exceptionally (Plate 82, figs. 11, 12) very considerably, 
curved and nearly always simple, very rarely branched (Plate 82, fig. 17). They 
are cylindrical or cylindroconical, not infrequently somewhat uneven, and 
rounded and usually thickened at the end. The terminal thickenings are 
particularly well-developed in the rhabd-forms, and these usually also have a 
central tyle. In a fairly typical diactine spicule of this kind, 1 mm. long and 
16 « thick, the central tyle is 18» in transverse diameter, and the terminal 
tyles 30 » and 34 u respectively. The central tyle is either well-defined (Plate 
83, fig. 5) or not (Plate 83, fig. 1). In all the larger and a good many of 
the smaller basal spicules, the proximal and middle-parts of the rays are 
smooth, apart from the occasional slight undulations of their surface. The 
end-parts are nearly always densely spined, or exceptionally smooth (Plate 82, 
figs. 19, 20, 34). A good many of the smaller basal spicules (Plate 82, figs. 10, 
18, 28-30) are entirely spined, the spines on their proximal parts being usually 
slightly smaller than those on their distal parts. The entirely spined forms are 
much more frequent among the basal spicules of specimen a than among those 
of b. The spines are broad and conical. Those measured were 2-6 u long, 
rarely up to 10 u. 

The spicules forming the skeleton of the Palythoa attached to the stalk of 
specimen a (Plate 83, figs. 36-44, 46-59) are monactine to tetractine. The 
rare monactine and frequent diactine rhabd-forms are 122-520 4 long and 
20-40 u thick, on an average 32.4 ». The rare triactine and frequent tetractine 
forms are 90-290 » long and 20-40 u thick; the average thickness is 31.6 u. 


HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 319 


These spicules are similar to the corresponding basal spicules of specimen a, 
and differ from these only by being thicker and more spiny. While in the 
majority of the acanthophores in the sponge the proximal and middle-parts of 
the rays are smooth and only the distal part spiny, we find among the (similar) 
spicules of the Palythoa skeleton relatively many fewer with rays smooth in their 
proximal part, the majority being here entirely spined. It is to be noted also 
that the spicules of the Palythoa skeleton have, on the whole, larger spines than 
the corresponding spicules in the basal part of the sponge. In the larger spicules 
of the Palythoa skeleton the spines are on the distal parts of the rays very much 
larger than on their proximal parts. In the smaller forms this difference is not 
nearly so conspicuous, and in the smallest all the spines appear to be fairly equal 
in size. The largest spines measured were 15 u» long, and 14 uw broad at the base. 
The average thickness of the rays 


of the rhabd acanthophores of specimen....................0...... bis 16.0 u 
ae i gi ue PES DRE eR Pear MIR De oud We oP a“ 25.4 
were oe : “ the Palythoa on the stalk of specimen. .a “ 32.4 u 
“© tri- to tetractine acanthophores of specimen................. bb 22.4 pu 
Mattie ose 4k s os 4 Ae WR FERS a ier tse: a S31.0%5 


te as s = “the Palythoa on the stalk of 
specimen a“ 31.64 

Thus these spicules are in a much stouter than in b, and in the Palythoa 
attached to the stalk of a thicker than in the sponge itself. 

The fact that the Palythoa spicules are, on the whole, stouter and more 
spiny than those of the sponge is, no doubt, due to the Palythoa selecting for the 
purpose of building its skeleton the stoutest and most spiny of the spicules shed 
by the sponge. That these spicules are in a (on the stalk of which Palythoa 
polyps with sponge-spicule skeletons grew) much stouter than in 6 (the symbio- 
tic polyps of which have no skeleton) either may have nothing to do with their 
symbiotic polyps, and be in respect to them accidental; or it may be due to 
an influence of the spicule-requiring Palythoa on the sponge, comparable to 
that of a gall-wasp clutch on the vegetable tissue surrounding it; an influence 
which, in this case, might cause the sponge to produce abnormally stout and 
spiny acanthophores. 

The microhexactines (Plate 82, figs. 2-11, 20), which are the same in both 
specimens, have equal, regularly arranged rays and measure 57-152 u in total 
diameter. The rays are 2-3.8 » thick at the base, conical, and attenuated distally 
to a fine point. They are straight in their proximal part and usually curved 


320 HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 


in their distal part, more rarely straight throughout. The curvature is such 
that the tangents of the end-parts of the rays enclose angles of 120°-150°, excep- 
tionally only 90°, with the continuation of the axis of their proximal parts. 
The proximal end-part of the rays is smooth for a short distance, the distal end- 
part for a considerable distance. The remaining, middle-part bears spines as 
much as 0.7 » long, which are generally vertical. As stated above, I think it 
probable that the straight-rayed microhexactines are canalaria, and only the 
curved-rayed ones true parenchymalia. 

In specimen b I found a microhexactine-derivate with only one ray. This 
monactine spicule appears as a spined tylostyle curved towards its pointed end. 
Its measurements are:— length 1054; basal thickness of single ray 4.5 u; 
tyle 8.5 pu. 

Morphologically two kinds of amphidiscs can be distinguished : — those with 
stout shaft and relatively broad anchors; and those with slender shaft and rela- 
tively narrow anchors. 

To study them biometrically I measured 275 (134 of specimen a and 
141 of specimen b) and drew Figure 19, in which the length frequency-curves of 
the amphidises are represented as follows:— of specimen a (- -- ----- - ); of speci- 
men b (-—-—); and of both specimens together (———). 

In specimen a the amphidiscs are 18-480 » long. Their length frequency- 
curve (---------- ) exhibits two main elevations at about 33 » and about 164 u, 
a number of small elevations, and three large gaps between 54 and 79 y», between 
90 and 110 uw, and between 200 and 220». The amphidises 18-54 » and 79- 
90 » long are all thin-shafted and narrow-anchored; those 110-200 » and 220- 
480 » long are all thick-shafted and broad-anchored. 

The amphidises of specimen b are 21.5-492 u long. Their length frequency- 
curve exhibits two main elevations corresponding exactly to the two main 
elevations of the curve for specimen 6; a number of small elevations, some 
of which correspond to the small elevations of b, and some of which do not so 
correspond; and three principal gaps between 66 and 79, 87 and 118 uz, 
and 187 and 2124. The amphidises 21.5-66 » and 79-87 uw long all belong 
to the thin-shafted slender-anchored kind, those 118-187 » and 212-492 u 
long to the stout-shafted, broad-anchored kind. 

In both specimens therefore two main groups of amphidiscs can be dis- 
tinguished both morphologically and biometrically: — macramphidiscs with 
stout shaft and broad anchors, in both specimens together 110-492 » long, and 
micramphidises with thin shaft and slender anchors, in both specimens together 


321 


MA) BIANCHORATUM PINULINA. 


~| 
vi 


HYALONEMA (OONT 


Number of Amphidiscs 
Small Micramphidiscs 
Large Micramphidiscs 
Small Macramphidiscs 
Large _Macramphidiscs. 


rs 
i=) 


ioe) 
on 


(Se) 
c=) 


29 


20 


= 


Riz === 3r 


-\- by 


ONAN OMT HMHOLY 
NOR VMAene 
aorworoanvon 
ODOnANWTNO CX 

aod 
| lS ees ape I 
WOONNANOMDTWHM 
Tas NRO CO te ON 
SOnoran sd 
DODWRAOANTHN 

| 


> 


of Amphidiscs (). 


both specimens 
together. 


ssrocoasanecoacs specimen a 
————= specimen b 


445.80 — 490.38 


490.38 — 539.41 
5a9Al 593.30 


Fig. 19.— Amphidises 


322 HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 


18-90 »long. It is to be noted that the macramphidises are much more numer- 
ous in a than in b, while the micramphidiscs are much more numerous in b than 
ina. In consequence of this the number of macr- and micramphidiscs measured 
and plotted in the figure are very different in the two specimens, and the sum- 
mits of the two main elevations of the a- and b-curve are very different in height. 

The larger (longer) macramphidises differ from the smaller (shorter) ones 
morphologically by having relatively shorter anchors. The length frequency- 
curves of the macramphidises show that these spicules by no means represent 
a biometrically homogeneous group in respect to their length. The parts of 
the macramphidise curves below (to the left of) the above mentioned gaps 
between 200 and 220 u in a and between 187 and 212 » in b are very regular 
and obviously pertain to biometrically homogeneous groups; the parts of these 
curves above (to the right of) the gaps are on the other hand very irregular * 
and in no way in harmony with the others below (to the left) of them. I there- 
fore think that the group macramphidises should be subdivided into two 
secondary groups: — large macramphidises with relatively short anchors, in 
both specimens together 212-492 » long; and small macramphidises with 
relatively long anchors, in both specimens together 110-200 u long. 

The length frequency-curves of the micramphidises of both specimens 
exhibit, besides the single main elevation, a number of small elevations. Most 
of these are, as in the case of the large macramphidises, probably due to the 
scarcity of the micramphidises of these sizes, which made it impossible to meas- 
ure a larger number of them. Some of these elevations (two in the a-curve; 
and one in the b-curve, corresponding to one of the former) pertaining to the 
largest micramphidises are, however, separated from the rest of the micramphi- 
dise curves by very conspicuous gaps (between 54 and 79 u in the a- and between 
66 and 79 » in the b-curve). I therefore think it well to divide the micramphi- 
dises according to these gaps into two subgroups: — large micramphidises, in 
both specimens together 79-90 » long; and small micramphidises, in both speci- 
mens together 18-66 yu long. 

The chief dimensions of the large macramphidiscs (Plate 85, figs. 1-7) are 
tabulated on page 323. 

In these amphidises the shaft is straight and usually centrotyle. It is 
either quite smooth (Plate 85, fig. 7) or bears a few low rounded knobs (Plate 
85, figs. 2, 4-6), sometimes also a single, straight, cylindrical, terminally rounded 


spine (Plate 85, fig. 1), which arises from its centre (central tyle). Occasionally 


1 These irregularities are partly at least probably due to the rarity of these spicules, which made it 
impossible to measure a larger number of them. 


HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 


323 


of specimen of specimen of both speci- 
a b mens together 
limits 220-480 212—492> 212-492 
Length u 
most frequently about 240, 320, 468 | 277, 387, 468 468 
Shaft, thickness, limits yu 17-26 19-28 17-28 
transverse diameter of tyle, » limits 17-31 19-32 17-32 
Central 
tyle the tyle thicker than the shaft by u, 0-8 0-9 0-9 
limits 
‘length, limits 90-122 94-140 90-140 
| breadth, limits yp 148-195 140-210 140-210 
. proportion of anch-| limits 100 to 141-177 131-189 131-189 
Terminal 
h or-length to anchor- 
anchors | breadth average 100 to 161.4 158.6 160.1 
proportion of anch-|,._. ; ee 
or-length to total aes Ue ee 
length of whole spi- 
cule average 1: 3.2 


a stout knob or two are observed also on other parts of the shaft (Plate 85, 
pes: 1; 2). 


macramphidises, sometimes 21 » long and 14 w thick. 


The single large spine on the central tyle is, in the normal large 
I have never seen more 
than one such large spine on a normal spicule of this kind. In a few abnormal 
large macramphidises I observed (Plate 85, fig. 3) one or two clusters of verticils 
of projections arising some distance from the middle of the shaft. These had a 
maximum length of 45 », and were inclined or curved towards the centrum. 
They appear to be supernumerary anchor-teeth. 

The proportion of the terminal anchor to the total length of the whole spicule 
is (in both specimens together), as stated above, 1 to 2.1-3.9, an average of 1 : 3.2. 
The difference between total length and anchor-length is the greater the larger 
the spicule. In the large macramphidiscs 400 » and more in length the above 
proportion is 1 : 3.2-3.9, in those under 300 » in length 1 : 2.1—8. 

The anchor-teeth are about 30 » broad and pointed at the end. They arise 
nearly vertically from the shaft and are quite strongly curved in their proximal, 
and straight in their distal part. Their total curvature is such that their end- 
parts diverge at an angle of 12°-22° from the shaft. 

The chief dimensions of the small macramphidiscs (Plate 83, fig. 45c; 


Plate 84, figs. 3-13, 26-32) are: — 


324 HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 
of specimen of specimen of both speci- 
a b | mens together 
limits 110-200 118-187 110-200 
Length » | 
most frequently about 164 164 164 
Shaft, thickness, limits p 13-20 14-20 13-20 
length, limits yp 46-87 50-81 46-87 
breadth, limits yu 74-135 85-126 74-135 
Terminal | proportion of anchor- | limits 100 to 153-185 130-172 130-185 
anchors |length to  anchor- 
breadth average 100 to 167.5 153.6 161.1 
proportion of anchor- | limits 1: 2-2).5 
|length to total length 
of the whole spicule | average 1: 2.3 


In these amphidises the shaft is straight, regularly cylindrical, destitute of 
a central tyle, and perfectly smooth. 

The proportion of the length of the anchors to the total length of the whole 
spicule is in both specimens together, as stated above, 1 to 2—2.5, on an average 
1:2.8. The difference between total length and anchor-length is in the small 
macramphidises, in contradistinction to that of the large, on the whole the 
greater the shorter the spicule. In the longer small macramphidises, over 
180 » in length, the above proportion is 1 to 2.2—2.3, in the shorter, under 130 » 
in length, 1 to 2.4-2.5. 

The terminal anchors are composed of from eight to twelve teeth. Eight 
is the most frequent number, but small macramphidises with from nine to 
The position of the teeth 
of the two terminal anchors of the same spicule is alternate. The individual 
teeth have a T-shaped transverse section. The upper band-shaped part is, 
in its middle-part, 22-30 » broad and attenuated both distally and proximally 
(Plate 82, fig. 26). 
concave to the shaft (Plate 84, fig. 27), and usually rounded, very rarely pointed, 


twelve are by no means rare and in no way abnormal. 


It is not only longitudinally, but also transversely curved, 
at the end. The keel, that is the part corresponding to the lower stroke of the 
T, is low distally but attains a great height and thickness proximally (Plate 84, 
figs. 26, 28, 32). The outer contour of the tooth, when seen in profile, appears 
as a line strongly curved near the base and at the tip, but only slightly curved 
in its middle-part. The middle-part of this line diverges at an angle of 20-80° 


from the shaft; its end-part is convergent to the shaft. The end-parts of the 


HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 320 


inner contour (the inner margin of the keel) and the lateral margin, on the 
other hand, diverge from the shaft. 

In specimen a I found a remarkable abnormal small macramphidise (Plate 
85, fig. 8) 190 » long, with terminal anchors respectively 80 and 100 » long and 
about 100 broad. In this spicule each anchor is composed of two partly 
incomplete and somewhat irregular verticils of anchor-teeth, instead of a regu- 
lar single one. This duplication is much more pronounced in one (the upper one 
in the figure) than in the other terminal anchor. Some of the teeth belonging 
to the inner (supernumerary) verticils are nearly straight, extend obliquely 
backwards, and are widened at the end to irregularly oval terminal discs. The 
position of these terminal discs is such that if the whole amphidiscs were assumed 
to be enclosed in a tight-fitting ovoid mantle or shell, the outer faces of the 
terminal discs would come to lie exactly in the (inner) surface of such mantle 
or shell. This observation seems to me to be of similar import as the one on 
an abnormal amphidise found in Hyalonema (Prionema) agujanum var. tenuis 
(p. 262, Plate 75, figs. 35-37); both favor the view that each amphidisc is 
formed within a single ovoid cell. 

The chief dimensions of the large micramphidiscs are: — 


of specimen of specimen of both speci- 
a i) mens together 
limits 79-90 79-87 79-90 
Length «_, —-22 
most frequently about 85 82 84 
Shaft, thickness, limits yu 4 3) 55 3.5-4 
Gentral transverse diameter of tyle, limits p» 4 4 
uyle thereple thicker teanithe shaft by, Wits 0.5 0.5 
length, limits pu 26-35 26-29 26-35 
breadth, limits uw 23-40 23-25 23-40 
Terminal | proportion of anchor- | limits 100 to 80-114 83-88 80-114 
anchors |length to anchor-|——— 
breadth average 100 to 79 86.3 OW 2 
proportion of anchor- | limits 1: 2.4-3.2 
length to total length -————_——. 
of whole spicule average 1: 2.8 


In these amphidises the shaft is straight. The central tyle is not defined 
and passes gradually into the adjacent part of the shaft. Tyle and shaft are 


very spiny. 


326 HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 


The chief dimensions of the small micramphidiscs (Plate 84, figs. 15-25) 


eS = 
of specimen of specimen of both speci- 
a b mens together 
limits 18-54 21.5-66 18-66 
Length yu SSS e ae 
most frequently about 33 33 33 
Shaft, thickness, limits yp 1-1.7 1-2.5 1-2.5 
transverse diameter of tyle, limits 1-3 1-4.5 1-4.5 
Central 
is the tyle thicker than the shaft by, limits 0-1.6 0-2.5 02.5 
length, limits yp 7-20 6.5-23.5 6.5-23.5 
breadth, limits 7-17 8.5-23 7-23 
Terminal | proportion of anchor- | limits 100 to 77-128 80-146 77-146 
anchors |length to anchor-|——— 
breadth average 100 to 97.4 102.6 100.6 
proportion of anchor- | limits 1: 2.7-4 
length to total length 
of whole spicule average 1: 3.2 


In these amphidises the shaft is usually straight, rarely curved. In some 
place at or near the middle it is thickened, gradually in the larger, more abruptly 
in the smaller, to a rather stout central tyle. In the larger forms the tyle and the 
adjacent parts of the shaft, about one third of its total length, are densely cov- 
ered with spines sometimes 1 u long. The end-parts of the shaft of these am- 
phidises are smooth or only roughened by exceedingly minute spines. In the 
smaller forms the spines on the shaft are so small that they can hardly be made 
out as such, and merely render the shaft somewhat rough in appearance. 

The anchor-teeth are curved rather strongly in their proximal part, but 
only slightly or not at all in their distal part. Their end-parts are generally 
slightly divergent. 

A few abnormal small micramphidises were found in specimen 6. In one 
of these, 26 » long, a straight cylindrical branch arises very obliquely from 
the shaft. This branch is as thick (1.6 ») and half as long as the shaft, and 
broken off at the end. In another small micramphidise (45 » long, with termi- 
nal anchors 19 » long and 22 » broad), two opposite rays lying in the same 
straight line and both vertical to the shaft arise from the centrum of the spi- 
cule. These rays are straight, as thick as the shaft (2), and, like the shaft, 


HYALONEMA (OONEMA) HENSHAWI. 327 


covered with spines. One of them is broken off short; the other, which is 
intact, is 23 » long and bears on the end a narrow and pointed anchor-rudiment 
10 » long and 8 u broad, similar in appearance to a half closed umbrella. 

There can be no doubt that the two sponges above described belong to 
the same systematic unit. There can also be no doubt that they are very 
nearly related to the sponge described by Wilson! as Hyalonema bianchoratum. 
Indeed the similarity between them is so great that the Albatross specimens 
must be considered as a variety of the species described by Wilson. 

The distal ray of the largest pinules is in the typical Hyalonema bianchora- 
tum Wilson very much longer than in the sponges above described. Also in 
shape the pinules do not quite agree, and while all the pinules of the former are 
pentactine, some of the pinules of the latter are hexactine. The hypodermal 
and hypogastral pentactines are larger in the former than in the latter. The 
microhexactines of Wilson’s type do not attain so large a size and have stouter 
rays than those of the variety pinulina. The shafts of the large macramphi- 
discs are in the former stouter than in the latter. The small macramphidises 
have in the former a centrotyle shaft and eight anchor-teeth; in the latter 
a simple cylindrical shaft without tyle and quite often more than eight, some- 
times as many as twelve, anchor-teeth. 

These differences, although insufficient for specific distinction, are quite 
sufficient for varietal distinction. I therefore divide Wilson’s Hyalonema 
bianchoratum into two varieties: — var. typica (for Wilson’s type) and var. pinu- 


lina (for the sponges above described). 


Hyalonema (Oonema) henshawi, sp. nov. 


Plate 97, figs. 1-36; Plate 98, figs. 1-7. 


One specimen of this species was trawled in the Eastern Tropical Pacific 
at Station 4649 on 10 November, 1904; 5° 17’ S., 85° 19.5’ W.; depth 4086 m. 
(2235 f.); it grew on a bottom of sticky, gray mud; the bottom-temperature 
was 35.4°. 

I name it after the Director of the Museum of Comparative Zodlogy, 
Mr. Samuel Henshaw. 

Shape and size. The single specimen (Plate 97, fig. 15) has the shape of 
a deep, conical cup, rounded off below. The upper margin is lacerated. The 
stalk, which, in life, doubtlessly projected from its lower end, has been com- 


1H. V. Wilson. Mem. M.C. Z., 1904, 30, p. 22, pl. 2, figs. 1-11. 


328 HYALONEMA (OONEMA) HENSHAWI. 


pletely torn off. The cup is 123 mm. long and above, at the margin, 80 mm. in 
transverse diameter. The wall of the cup is only 6 mm. thick. A great part 
of the dermal membrane is lost; of the gastral membrane extensive tracts are 
present. The lower part of the gastral membrane, which lines the deeper 
parts of the cavity of the cup, appears to contain but few efferent pores. Exten- 
sive pore-sieve nets, with pores sometimes 1.7 mm. in diameter (Plate 97, fig. 
32), occur in its upper part. 

The colour in spirit is rather dark dirty brown. 

The skeleton consists of dermal, gastral, and canalar pinules; hypodermal 
and hypogastral pentactines; superficial paratangential and choanosomal 
more or less radial amphioxes; choanosomal hexactine megascleres; abundant 
microhexactines in all parts of the body; and three kinds of amphidises, macram- 
phidises and large and small micramphidiscs. 

The dermal pinules (Plate 97, figs. 2, 31) are nearly always pentactine, hex- 
actine forms being met only exceptionally. The distal ray is straight, 180 u— 
600 » long, most frequently about 390 yu, and 10-22 » thick at the base. It ends 
in a terminal cone and bears spines, which are short, conical, and vertical on its 
basal part, but strongly inclined and large, sometimes 25 u long, fartherup. The 
maximum thickness of the distal ray, together with the spines, is 15-68 »; in 
those rays over 500 u long this thickness is always over 40 u. The lateral rays 
are 37 »-70 » long; in the dermal pinules with a distal ray over 500 u» in length 
the lateral rays are always over 50 u long. These rays are cylindroconical or 
nearly cylindrical, and rounded at the end. They bear a few scattered spines, 
which usually congregate a little beyond the middle of the length of the ray. 
The proximal ray of the few hexactine forms is 15-75 » long. The dermal pinules 
of the lower part of the body appear to be on the whole shorter than those of 
the upper part. Among the former a fair number with distal rays only 260- 
280 » long have been observed, while the distal ray of the latter is only quite 
exceptionally less than 320 u long. 

The gastral pinules (Plate 97, figs. 1, 3-5, 29, 30) are similar to the dermal, 
and like them nearly always pentactine, exceptionally hexactine. Their distal 
ray is straight, 142-710 u long, generally 342-650 », and at the base 12-27 u 
thick; in those over 600 » long, always 20 u or more thick. The spines on the 
distal ray of these gastral pinules appear to be stouter, shorter, and less inclined 
than those on the distal ray of the dermal. The maximum thickness of the 
distal ray, together with the spines, is 25-85 »; in those over 600 u in length 
this thickness is always over 64 » and usually about 80.4. The lateral rays 


HYALONEMA (OONEMA) HENSHAWI. 329 


are similar to those of the gastrals and 42-70 yu long. The proximal ray of 
the single hexactine form observed is 30 u long. 

The canalar pinules (Plate 97, fig. 6) are pentactine or, more rarely, hexac- 
tine. The distal ray is 120-220 long and 6-10 4 thick at the base. The 
lateral rays are 53-110 » long; the proximal ray is, when present, 28-65 » long. 
All the rays are pointed, conical, and spined. The spines are very small, so that, 
even with the spines, the distal ray is nowhere thicker than at its base. 

The hypodermal and hypogastral pentactines. A large number of hypodermal 
pentactines were observed, but few hypogastral. The hypogastrals and hypo- 
dermals appear to be quite similar. Their rays are straight, smooth, conical, 
and blunt. The proximal ray is 550-900 uw long and 26-47 u» thick at the base. 
The lateral rays are 320-650 y long. 

The hexactine megascleres are 0.6-1.4 mm. in diameter, and have fairly 
straight, conical, and blunt rays, 13-32 » thick at the base. 

The amphioxes are centrotyle, nearly straight or curved, rarely angularly 
bent near one end. They are 0.9-1.6 mm. long and 8-23 y thick near the 
middle. The central tyle is 12-27 u» in transverse diameter, that is 1-6 « more 
than the adjacent parts of the spicule. 

The rays of the microhexactines (Plate 97, figs. 33-386) are nearly always 
perfectly straight; only quite exceptionally one of the rays exhibits a slight 
curvature. The microhexactines are 108-230 4 in diameter, generally 110- 
190 uw, and their conical, pointed rays are 3.5-7 uw thick at the base. The rays 
bear spines, the largest of which are 0.7—1.5 » long. Generally the spines are 
sparsely scattered over the greater part of the length of the ray, leaving the 
distal end-part free for a distance of about 104. The proximal spines are 
vertical, the distal inclined backwards. 

Among the amphidiscs two kinds can be clearly distinguished morphologi- 
cally: — A, a stout kind with large anchors, about half the length of the whole 
spicule; and B, a slender kind with small anchors, much less than half, usually 
about a third, of the whole spicule in length. 

The length frequency-curve (Figure 20) has three main elevations sepa- 
rated by deep depressions. The part of the curve to the right of 106.72, the 
summit of which lies at about 179, pertains to the morphological group A, 
and comprises all amphidises of this kind. The deep depression (down to 0) 
between this part of the curve and the other parts shows that the amphidiscs 
it pertains to form a distinct group. This coincides with their morphological 


character, and so a special group must doubtlessly be established for these 


300 HYALONEMA (OONEMA) HENSHAWI. 


Number Micramphidiscs Macramphidiscs 


30 


10 


i 
I 
| 
! 
| 
| 
! 
\ 
' 
' 
{ 
\ 
i 
I 
| 
f 
| 
| 
! 
! 
\ 
| 
| 
1 
! 
{ 
if 
! 
! 
! 
I 


( 
t 
( 
‘ 


4 ! 
Jp KH ey — de | — Be + = = = = ep ee er re i i 
1 
I 
i} 
( 
i 


! 
{ 
' 
\ 
1 1 
—_<|-=—--- ! ' 
=> ' } 
| 
! 


=e say = 


i) 

! 

LES) QoS | 
(ae) = st SO OO) SO fC. |.) GO (DN (GN SS? (9) St LG KO 9S 
ANBARSTAARRRANRKZAASKRHASAKSERS 
LTMHMASCHKHRHMIORDRYTOSOONSOAKNHOKAANASHSBKR OD 
2 Smet RS TH NNSA 

FS | 

Bo ili jlie lathes Wood dealt NeedliMtlApslitsisal lmyllen 28st geld a Nn A 
anmoocnmoo tO woo =! OOO ON NN & OO = 10 ~~ Oe 
SARBSRSFANRRANHANSRSGSAKHSSEL 
SsHeMMmOoowtrernMOontoewWoInoeworoOnroan © nak 
NAANKDONTSTHTHOSGRGZHDHASHANSHERDON 
ee a 


Fig. 20. — Amphidises. 


amphidises, which, as they are the largest forms, I name macramphidises. All 
the other amphidises differ morphologically from these but are similar among 
themselves. They can, as they comprise the small forms, be named micramphi- 
discs. The part of the curve pertaining to these micramphidiscs is divided by 
the deep depression at about 63.2 into two parts, one comprising the larger, 
the other the smaller forms. Although the larger of these amphidiscs are very 
similar morphologically to the smaller, there could, after their biometrical 
study had pointed the way, be found certain morphological differences between 
them, particularly in the curvature of the anchor-teeth, which corroborate their 
biometrical distinction, and which, although slight, in my opinion justify a 
division of the micramphidises into two subgroups: — large micramphidises 
over 63.2 uw in length, and small micramphidiscs under that. 


HYALONEMA (OONEMA) HENSHAWI. bol 


I do not think that any importance is to be attached to the minor irregu- 
larities of the curve, although some of these, particularly those in the part 
of it pertaining to the small micramphidiscs, are not inconsiderable. 

According to the above three kinds of amphidises are to be distinguished :-— 
macramphidises, larger forms with relatively large anchors; large micramphi- 
dises, forms of medium size with rather small anchors; and small micramphi- 
dises, small forms with rather small anchors. 

The macramphidiscs (Plate 97, figs. 7-14; Plate 98, figs. 1-7) are 114— 
227 » long, most frequently about 179». The shaft is cylindrical, smooth, 
straight, and 12-20» thick. The terminal anchors are 50-111 » in length, 
about half of the whole spicule, and 70-169 u broad. The proportion of the 
length to the breadth of the anchors is 100 to 123-187, generally 100 to 136— 
178, on an average 100 : 156.8. The number of the teeth in an anchor is usually 
eight. The teeth of the two anchors of the same spicule are situated alter- 
nately, but this alternation is often somewhat irregular, the adjacent anchor- 
teeth planes (of opposite teeth) not intersecting at exactly 22.5°. The outer 
contour of the individual teeth is curved considerably in its basal part for about 
0.4 part of the length of the tooth, curved only slightly beyond that up to 
about 0.8 of this length, and curved again strongly at the end, so that the tips 
of the teeth become strongly convergent. The outer band-shaped part of the 
tooth attains its maximum width somewhere beyond the middle of its length, 
and here measures 20-31 » in transverse diameter. The tip of the tooth is 
rounded or, more rarely, somewhat pointed, like a gothic arch. The keel, 
in the larger forms, is over 30 uw high at the base, and becomes gradually lower 
distally. It terminates before reaching the end of the tooth. 

Somewhat irregular forms are not infrequent among these amphidiscs. 
Considerable inequalities in the two anchors of the same spicule (Plate 98, 
fig. 6) or in the teeth of the same anchor (Plate 98, fig. 4) are often met, and some- 
times irregularities occur on the apices of the anchors (Plate 98, fig. 7). 

The large micramphidiscs (Plate 97, figs. 16-20) are 67-91 » long, most 
frequently about 69.5. The shaft is straight, centrotyle, and 2-4 y thick. 
The tyle passes gradually into the adjacent parts of the shaft. It is 3.5-6 
in transverse diameter, that is 0.5-3 » more than the adjacent parts of the 
shaft. With the exception of its end-parts, the whole shaft is covered with 
spines. The spines on the tyle are much larger than the others, sometimes 3 
long, and often strongly curved. The terminal anchors are 20-35 uy, usually 
a little more than a third of the whole spicule in length. Their breadth is 18- 


332 HYALONEMA (OONEMA) CRASSIPINULUM. 


30 4. The proportion of anchor-length to anchor-breadth is 100 to 69-100, 
on an average 100 :89.5. The teeth arise nearly vertically from the ends of 
the shaft, and are curved strongly at the base and decreasingly towards the 
end. The tips of the teeth are usually parallel or slightly divergent. 

The small micramphidiscs (Plate 97, figs. 21-28) are 24-57 » long, most 
frequently about 32.4 uw. The shaft is 0.8-2 » thick, and generally centrotyle. 
The central tyle is 1.8-2.6 uw in transverse diameter, that is 0.38-1 » more than 
the adjacent parts of the shaft. Small spines are scattered over tyle and shaft 
in the larger forms; in the smaller these spines are so minute that it is diffi- 
cult to make them out, often they appear to be absent altogether. The anchors 
are 7-22 w long, usually about a third of the whole spicule. The anchor-breadth 
is 7-19 w. The proportion of anchor-length to anchor-breadth is 100 to 71-121, 
on an average 100 :89.7. The teeth are sometimes remarkably numerous. 
They arise vertically from the ends of the shaft and are more strongly curved 
some distance from the base than proximally; beyond the strong bend, they 
decrease in curvature, so that their end-parts are nearly straight and parallel. 
The teeth are pointed at the end. . 

The nearest allies of the above sponge are the species Hyalonema (Oonema) 
densum, H. (O.) sequoia, and H. (O.) crassipinulum described in this Report. 
From these it differs by being destitute of the large macramphidises. From 
H. (O.) densum also it differs by having straight-rayed micramphidises, and 
from the other two also by its superficial pinules being smaller and their distal 


rays much more slender. 


Hyalonema (Oonema) crassipinulum, sp. nov. 


Plate 92, figs. 1-23; Plate 93, figs. 1-10; Plate 94, figs. 1-33. 


One specimen of this species was trawled in the Central Pacific at Station 
3684 (A.A. 17) on 10 September, 1899; 0° 50’ N., 137° 54’ W.; depth 4504 m. 
(2463 f.); it grew on a bottom of light yellow-gray Globigerina ooze. 

It possesses pinules with large, remarkably divergent spines on the proximal 
part of the distal ray. To this the name refers. 

Shape and size. The single specimen (Plate 93, fig. 9) has the shape of an 
inverted bell, 105 mm. long, 95 mm. broad, and now strongly compressed later- 
ally and only about 18 mm. thick. In life the sponge was probably laterally eom- 
pressed much less, or not at all. A stalk, 2.5 mm. thick and broken off rather 


short, protrudes from the lower rounded end. The lower and lateral surfaces, 


HYALONEMA (OONEMA) CRASSIPINULUM. 333 


which are the dermal, are continuous and fairly smooth. The upper surface, 
which is the gastral, now appears rugose. In life wide cavities, separated by 
upright walls, probably occupied the upper part of the interior. Reticulate 
pore-sieves are observed on some parts of the surface. Indications of flagel- 
late chambers about 140 » in diameter were noticed in some of the sections. 

The colour in spirit is light dirty brown. 

A small colony of Palythoa polyps is attached to the upper part of the 
stalk. 

The skeleton. A fur composed of distal rays of large pinules covers the 
whole sponge. The gastral pinules, particularly those on the pore-sieves, are 
very large, the dermal considerably smaller. Very numerous large micramphi- 
dises lie in and on the surface. Microhexactines, paratangentially extending 
amphioxes, and the lateral rays of pentactines occur just below the lateral rays 
of the superficial pinules. Some hexactine and abundant rhabd megascleres, 
very numerous microhexactines, a few monactine microhexactine-derivates, 
eanalar pinules, and amphidises are found in the interior. The internal amphi- 
dises are of four kinds: — 1, very scarce large macramphidises; 2, not numer- 
ous small broad-anchored macramphidises; 3, very scarce small macramphi- 
dises; and 4, very numerous micramphidises. It is possible, but not probable, 
that 1 and 3 are foreign spicules. Numerous acanthophores for the most part 
diactine and tetractine occur in the basal part of the sponge-body. The canalar 
pinules are rare, and found only here and there in the canal-walls. In the walls 
of some of the canals masses of micramphidises are observed. The remnant 
of the stalk consists of a few stout and several slender spicules. 

In the superficial part of the coenenchym and in the lateral and oral walls 
of the individual polyps of the Palythoa, spicules occur in large numbers; these 
are similar to the smaller and stouter acanthophores of the basal part of the 
sponge. 

The gastral superficial pinules have a distal ray 250-1130 uw long (measured 
in the case of the curved ones along their chord). The length frequency-curve 
of the distal ray has two distinct elevations, at about 600 and 850 u. This 
indicates that two kinds of gastral pinules, a large and a small, should be dis- 
tinguished. 

The large gastral pinules (Plate 92, figs. 1-4, 20, 22, 23), which greatly 
preponderate in the reticulate pore-sieves, are all pentactine. Their distal ray 
is straight or, comparatively very frequently, curved in its distal part. The 


curvature is usually not great but sometimes very marked. In one of these 


334 HYALONEMA (OONEMA) CRASSIPINULUM. 


pinules the distal part of the axis of the distal ray enclosed an angle of nearly 
90° with its proximal part. The distal ray is (measured in the case of the 
curved ones along the chord) 680-1130 » long, most frequently 800-950 u, 
20-35 » thick at the base. Above it thickens considerably, and attains at its 
point of maximum thickness, which lies a little above the middle of its length, 
without the spines, a transverse diameter usually a little more than twice as 
great as that of its base. At its distal end the ray is attenuated very abruptly 
to a blunt point or is, exceptionally, rounded and dome-shaped. The proximal 
part of the distal ray bears short and very stout, vertical, conical spines, which 
extend quite down to its base. Farther on the spines become longer, curved, 
concave towards the shaft and more and more inclined towards its distal end. 
The longest spines attain a length of 20-40 u. The spines are usually regularly 
arranged; only occasionally an irregular arrangement of those occupying the 
concave side of curved distal rays is observed. The maximum diameter of the 
distal ray, together with the spines, is 75-115 u. The lateral rays are, at the 
base, slightly thinner than the proximal end of the distal ray. They are nearly 
cylindrical in their proximal and conical in their distal part, very blunt, 64- 
150 » long, and spined. The spines are quite numerous, very stout, vertical, 
conical, and generally up to about 6 » long. 

The small gastral pinules (Plate 92, figs. 5, 18, 21) are likewise all pentac- 
tine. The distal ray is generally straight, 250-640 » long, most frequently 
500-640 u, and 12-28 uw thick at the base. Above it thickens very consider- 
ably and attains without the spines, at the point of maximum thickness, which 
lies a little above the middle, a transverse diameter two to five times as great 
as that of its base. Distally the ray is attenuated more gradually than in the 
large gastral pinules, so that its end appears more slender. The distal ray is 
covered with spines down to its base. The spines increase in length up to a 
point a little beyond the middle of the ray, where they are sometimes 20-30 u 
long. Beyond they again decrease in size. The lowest spines are, like those 
of the larger gastral pinules, short, stout, conical, and vertical; but as we pro- 
ceed in a distal direction and the spines become longer, their tips curve upwards 
more and more, and a short distance below the middle of the ray they pass, 
often quite abruptly, into spines inclined and bent towards the end of the 
ray to such an extent that their end-parts are very strongly inclined, parallel, 
or even convergent. The distal part of the ray consequently has an appear- 
ance very different from that of its proximal part, the former looking nearly 
smooth, the latter bristling with large spines. The lateral rays are similar in 


shape to those of the large gastral pinules, but only 50-125 u long. 


HYALONEMA (OONEMA) CRASSIPINULUM. 335 


The dermal superficial pinules have distal rays 250-790 u long. Their 
length frequency-curve exhibits, like that of the gastrals, two very distinct 
elevations, so that also among these pinules two kinds, a large and a small one, 
must be distinguished. 

The large dermal pinules (Plate 92, fig. 6) are pentactine. Their distal ray 
is usually straight and 500-790 u long, most frequently 600-650 yu. It is 15-24 pu 
thick at the base, and thickened above. At its point of maximum thickness, 
which lies a little above the middle, it attains a transverse diameter about twice 
as great as its basal thickness. The distal ray ends with a low and broad termi- 
nal cone. Its spinulation is similar to that of the gastral pinules. The spines 
are proportionately smaller. The maximum diameter of the distal ray, together 
with the spines, is 50-90 u. The lateral rays are cylindroconical, and 45-95 pu 
long. They bear small, sparse, broad, and low, conical spines. 

The small dermal pinules (Plate 92, figs. 7, 18) are rather similar to the 
larger ones and, like them, all pentactine. Their dimensions are: — distal 
ray, length 250-440 u, basal thickness 10-17 4, maximum thickness together 
with the spines 28-65 y; lateral rays, length 45-70 up. 

The canalar pinules (Plate 92, figs. 16, 17) are pentactine or hexactine. 
The distal ray is straight, 120-150 uw long, and 5-9 uw thick at the base. It is 
slightly thickened above, gradually attenuated to a fine point, and bears rather 
sparse, small, straight spines directed obliquely upwards. Its maximum thick- 
ness, together with the spines, is 7-30 uw. The lateral rays are 45-95 uv long; the 
proximal, when present, is 50-70 u. Both the lateral rays and the proximal 
are spiny. 

There seems to be no great difference between the hypodermal and hypo- 
gastral pentactines. Both have straight, conical, blunt rays. The lateral 
rays are 230-550 u» long; the proximal ray is 400-700 » long and 15-60 y» thick 
at the base. 

The hexactine megascleres generally have fairly equal rays. In some, two 
opposite rays are a little longer than the others, but the difference never appears 
to be great. The hexactine megascleres observed are 0.8—1.2 mm. in diameter. 
The basal thickness of their rays is 25-80 u. 

The amphioxes of the dermal and gastral membranes (pore-sieve reticula- 
tions) and the choanosome are centrotyle, straight or curved, sometimes very 
considerably, and 0.7-1.7 mm. long. Near the middle they are 8-29 w thick. 
The central tyle is 10-34 » in diameter, that is 2—5 » more than the adjacent 


parts of the spicule. 


336 HYALONEMA (OONEMA) CRASSIPINULUM. 


In the axial part of the sponge a few much larger amphiozes were observed; 
they had a maximum length of 8 mm. and were 160 4 thick. These appear to 
take part in the formation of the upper end-part of the stalk, which is imbedded 
in the body of the sponge. 

The spicules of the stalk are broken off rather short. Where they arise 
from the body of the sponge they are 50-500 u thick. 

The acanthophores in the sponge-body (Plate 94, figs. 24-33) are mostly diac- 
tines and tetractines, but monactine, triactine, and pentactine forms also occur. 
The monactines are tylostyle, the diactines centrotyle. The monactine and 
diactine rhabd-forms are 160-840 » long, and 13-29 » thick near the tyle. 
The tyle in the longer ones is often very large. The tri- to pentactines are 
85-480 y, on an average 223.6 u, in maximum diameter, and have rays 12-30 
thick at the base. The ends of the fully developed rays are always spiny. 
The same is the case in the rays reduced in length, provided the reduction has 
not gone too far. The rays reduced to mere knobs are smooth. The central 
parts of these spicules are usually smooth (Plate 94, figs. 24, 26, 28-33), more 
rarely covered with sparse small spines (Plate 94, figs. 25, 27). 

The acanthophores of the sponge used by the Palythoa to build its skeleton 
(Plate 94, figs. 14-23) are di- to pentactine. The diactines are not nearly so 
numerous among them as among the basal spicules from the sponge. The 
diactines are centrotyle, 170-400 w long, and 20-30, thick near the central 
tyle. Among the tri- to pentactines, forms with two fully developed and one 
or two partly reduced rays are the most frequent. These spicules are 90- 
260 » in maximum diameter, very rarely as much as 350 uw, on an average 206.7 y, 
and their rays are 14-35 u thick at the base, rarely up to 45 u. 

The average measurements of the tri- to pentactines of the sponge-body 
(223.6 ») and of the Palythoa (206.7 1), given above, show that the former have 
on the whole a larger maximum diameter than the latter. Also the rhabd-forms 
show this, the average length of those of the sponge being considerably greater 
than of those of the Palythoa. Apart from this it is to be noted that the Paly- 
thoa spicules have stouter rays, and are more spiny than those of the sponge. 
These facts seem to indicate: — 1, that the more slender and less spiny acantho- 
phores are young forms of the stouter and more spiny ones; 2, that none, or 
only a few, of these young spicules, but many of the old spicules, are shed by the 
sponge; and 3, that of the old, stouter, and more spiny spicules which are shed 
and thus placed at the disposal of the Palythoa, the latter selects the smaller 


(shorter) ones for building up its skeleton. 


HYALONEMA (OONEMA) CRASSIPINULUM. dot 


The rays of the microhexactines (Plate 92, figs. 9-15) are usually nearly 
equal and all quite straight or nearly so. Only rarely microhexactines are 
found in which one or two of the rays are distinctly curved in their middle-part. 
The rays are 3.5-7 u thick at the base, conical, pointed, and covered with spines. 
The spines on the proximal half of the ray are sparse, vertical or slightly inclined 
towards the centre of the spicule, and up to 2 long. The spines on the distal 
half are more numerous, smaller, and rather strongly inclined towards the centre 
of the spicule. Most of the microhexactines have rather long and slender rays. 
These spicules (Plate 92, figs. 9, 10) are 90-220 u in total diameter, and the 
basal thickness of their rays (3.5-6.5 uw) is fairly in proportion to their size. 
Some microhexactines have much shorter and relatively much stouter rays. 
These spicules (Plate 92, fig. 11) are only 65-80 uw in diameter, and have rays 
as much as 7 u thick at the base. 

The rare monactine microhexactine-derivates appear as strongly spined tylo- 
styles. They are about 130 4 long, and 8 u thick near the tyle. The terminal 
tyle itself is about 9 « in diameter. 

Morphologically four kinds of amphidiscs can be distinguished: — 1, large 
amphidises with fairly smooth shaft and broad and short anchors, about a 
third of the whole spicule in length; 2, medium amphidises with a stout smooth 
shaft and broad and long anchors, usually a little more than half the whole 
spicule in length; 3, medium amphidises with a slightly spined, rather slender 
shaft, and long, narrow anchors, more than a third of the whole spicule in length; 
and 4, small amphidises with slender, spined shaft and rather short anchors, 
only about a third of the whole spicule in length. 

The amphidises belonging to the first kind are 375-480 yu long, those belong- 
ing to the second kind 110-200 u, those belonging to the third kind 112-137 x, 
and those belonging to the fourth kind 31-106 ». The first and the fourth kinds 
are accordingly distinguished both morphologically and biometrically. The 
second and third kinds, although distinguished in the same manner from the 
first and fourth, are distinguished from each other morphologically only, and 
not biometrically. 

As the measurements given above and the adjoined graph show, the gap 
in the length frequency-curve separating the fourth from the second and third 
kinds is much narrower than that separating the second and third from the 
first kind. In spite of the width of this gap, and the entire absence of transi- 
tions between the second and third kinds of amphidises on the one hand and the 


first kind of amphidiscs on the other, I am inclined to combine the first, second, 


HYALONEMA (OONEMA) CRASSIPINULUM. 


338 


Micramphidiscs 


Macramphidiscs 
ay a 
cB) Lo FF 
Q 
E Small, broad-anchored Large 
———._”"I——_-. ina 
A Small, narrow -anchored 
[2 ree ee aaa ee Micramphidiscs. 
Macramphidiscs. 
SIOVARE Psa wie ae a ies aaa 
fates Sete AS cosues ee ae nN 
5 Li. 
0 


Fig. 21. — Amphidises. 


HYALONEMA (OONEMA) CRASSIPINULUM. 339 


and third kinds, because in other closely allied species they are not so clearly 
separated biometrically. I distinguish accordingly two main groups of amphi- 
dises: — macramphidises 110-480 » long, and micramphidises 31-106 y» long. 

The macramphidises comprise the first, second, and third kinds of amphi- 
dises. As shown above, the first kind is very clearly distinguished from the 
second and third both morphologically and biometrically. I therefore divide 
the macramphidises into two groups, large macramphidises 375-480 » long, and 
small macramphidises 110-200 u. 

The length frequency-curve of the large macramphidiscs has two distinct 
elevations. However, in view of the morphological similarity of the largest 
and the smallest, and the smallness of the number of large macramphidises 
observed and measured, I do not attach much importance to this, and consider 
the large macramphidiscs as a simple group. 

The length frequency-curve of the small macramphidises has a single 
elevation, and is remarkably regular biometrically. These spicules accord- 
ingly form a remarkably homogeneous group. Morphologically, however, two 
kinds of small macramphidises are to be distinguished: — those with relatively 
smaller, chiefly narrower anchors; and those with relatively larger, chiefly 
broader anchors. 

The micramphidises form morphologically a nearly continuous series, the 
smallest being connected by intermediate forms with the largest with hardly 
any break. Their length frequency-curve, however, shows four elevations 
and three depressions, one of which (at about 47.5 ») is rather conspicuous. 
In view of the slightness of the morphological differences between the micram- 
phidises to which the four elevations of the curve pertain, I abstain from sub- 
dividing them into subgroups corresponding to these elevations. 

Thus I distinguish four kinds of amphidises in this sponge: — large macram- 
phidises, small broad-anchored macramphidises, small narrow-anchored macram- 
phidises, and micramphidiscs. 

The large macramphidiscs (Plate 93, fig. 10) are very rare. In fact I found 
only seven in all, and although some of these were observed in the sections, it 
is not impossible that they are foreign; the probability is, however, greatly 
in favor of their being proper to the sponge. These spicules are 375-480 u 
long, most frequently about 468 u. The shaft is eylindrical, 22-29 » thick, 
smooth, and slightly thickened in or near the centre. The terminal anchors are 
168-215 uw long, about a third of the whole spicule, and 210-260 » broad. The 
proportion of their length to their breadth is 110 to 107-155, on an average 100 : 


340 HYALONEMA (OONEMA) CRASSIPINULUM. 


129. The individual anchor-teeth are usually not curved quite uniformly, and 
pointed at the end. Their end-parts are parallel or slightly divergent. 

The broad-anchored small macramphidiscs (Plate 93, figs. 3-8; Plate 94, 
figs. 1-3) are very much rarer than in the allied species. They are 110-200 u 
long, and have a smooth cylindrical shaft 8-17» thick. Their anchors are 
57-100 » long, usually 1-6 » more than half the whole spicule, and 58-172 u 
broad. The proportion of their length to their breadth is 100 to 101-179, on an 
average 100 : 144.6. It is to be noted that the smaller of these spicules have 
relatively narrower anchors, the larger relatively broader anchors. Thus the 
proportion of anchor-length to anchor-breadth is in those under 130 » in length 
100 to 101-148; in those over 180 u in length 100 to 150-179. The most fre- 
quent number of anchor-teeth is eight. The teeth of the two anchors of the 
same spicule are usually situated alternately (Plate 93, figs. 5, 7); sometimes, 
however, all the teeth, or at least some of them, lie opposite, and appear to be 
in contact with each other (Plate 93, fig. 3). The outer contour of the teeth 
usually at first slightly ascends. It is uniformly curved, concave to the shaft 
to within a short distance from the tip of the tooth, and abruptly bent inward at 
the end. The keel of the tooth extends as far as the curvature of the outer 
contour continues uniform. At the point of maximum breadth, which lies about 
two thirds of their length from their base, the teeth measure 22-31 » in trans- 
verse diameter. Distally the teeth are slightly attenuated. The end is rounded. 

The narrow-anchored small macramphidiscs (Plate 93, figs. 1, 2; Plate 94, 
fig. 4) are very rare. I observed only five of them, and it is possible that they are 
foreign. These spicules are 112-137 u long. The shaft is 5-7 uw thick, slightly 
centrotyle, and roughened with indications of spines. The central tyle is 1-3 
more in transverse diameter than the adjacent part of the shaft. The terminal 
anchors are usually shorter than half the length of the spicule, rarely a little 
longer. They are 52-70 » long and 52-59 » broad. The proportion of their 
length to their breadth is 100 to 84-104, on an average 100 :95. The anchor- 
teeth are strongly curved in their basal part, but only slightly curved in their 
distal part. Some of these spicules have irregular anchors, composed of teeth 
unequal in length. 

The micramphidiscs (Plate 94, figs. 5-13), particularly the larger ones, are 
very abundant. They are 31-106 » long, most frequently about 844. The 
shaft is straight, centrotyle, and 1.5-4 » thick. The central tyle is 3.5-5.5 u 
in transverse diameter, that is 0.6-2.6 « more than the adjacent parts of the 


shaft. An irregular verticil of spines, up to about 1 u long, arises from the 


HYALONEMA (OONEMA) DENSUM. 341 


central tyle, and a good many similar spines are found also on other parts of 
the shaft. The spines are more abundant in the larger than in the smaller forms, 
and in some of the former (Plate 94, figs. 6, 7, 13) are remarkably numerous. The 
terminal anchors are 9-38 » long and 8-39 » broad. The proportion of their 
length to their breadth is 100 to 81-125, on an average 100 :94. As stated 
above, the micramphidises of different sizes, are very similar in shape, the differ- 
ences in the proportions of their different dimensions being only slight. In 
the micramphidises over 80, in length the proportion of anchor-length to 
anchor-breadth is 100 to 89-114, on an average 100 : 95, and the proportion of 
the anchor-length to the length of the whole spicule 1 to 2.6-3.2, on an 
average 1 :2.9. In the micramphidises under 50 » in length the proportion of 
anchor-length to anchor-breadth is 100 to 78-125, on an average 100 : 90.5; 
and the proportion of the anchor-length to the length of the whole spicule 1 to 
2.8-4, on an average | :3.16. The curvature of the anchor-teeth decreases dis- 
tally. This decrease is more marked in the smaller than in the larger micram- 
phidises. The teeth are 4-7 » broad, and rounded at the end; their tips are 
usually nearly parallel. 

This sponge is obviously most closely allied to Hyalonema (Oonema) sequoia. 
From this it differs by the absence of the smaller kind of small macramphidises 
with numerous anchor-teeth; by the presence of narrow-anchored small macram- 
phidises, and superficial pinules with long strongly divergent spines on the 
proximal part of the distal ray; and by the smaller size of several kinds of its 


spicules, chiefly the superficial pinules. 


Hyalonema (Oonema) densum, sp. nov. 


Plate 94, figs. 34-42; Plate 95, figs. 1-20; Plate 96, figs. 1-14. 


One specimen of this species was trawled in the Eastern Tropical Pacific 
at Station 4649, on 10 November, 1904; 5° 17’ S., 85° 19.5’ W.; depth 4086 m. 
(2235 f.); it grew on a bottom of sticky, gray mud; the bottom-temperature 
was 35.4° 

The name has reference to the remarkable density of the sponge. 

Shape and size. The single specimen (Plate 95, fig. 4) appears as an inverted 
cone cut off obliquely and considerably extended at one side above. The upper 
portion protrudes on this side like a bulging rim for a distance of 8 mm. The 
sponge is 57 mm. high, and the regularly oval upper face 46 mm. long and 39 
mm. broad. This upper face, which is to be considered as the gastral, is convex 


342 HYALONEMA (OONEMA) DENSUM. 


and perforated by numerous broad-oval efferent apertures 0.2-0.9 mm. wide 
(Plate 95, fig. 3). A pointed, very eccentrically situated gastral cone 8 mm. 
high and, at the base, 6 mm. thick arises from it. The conical body is slender 
and has no pores visible with the unaided eye. Its surface is to be considered 
as the dermal face of the sponge. Its lower end is torn off. 

The colour in spirit is dirty light brown. 

Canal-system. Inthe choanosome more or less radial canals, sometimes 0.8 
mm. wide, are observed. Indications of elongate, perhaps tubular, flagellate 
chambers 30-70 » broad are observed in the sections. 

Skeleton. The whole of the surface is covered with a dense pinule-fur 
(Plate 95, figs. 1, 2). Between the proximal parts of the freely protruding 
distal rays of the pinules forming it are met small macramphidiscs, mostly 
with the shaft in a radial position. The dermal and gastral membranes are 
supported by the lateral rays of the superficial pinules, paratangential centro- 
tyle amphioxes, and the lateral rays of hypodermal or hypogastral pentactines. 
Masses of microhexactines and some small macramphidises occur in and just 
below these membranes. A good many large micramphidises, dense masses 
of microhexactines, and a few canalar pinules occur in the canal-walls. The 
micramphidises appear to be restricted to the efferent canals. Apart from these 
canalar spicules, one finds in the interior a few large macramphidises, hexactine 
megascleres, and small micramphidiscs, numerous ordinary small choanosomal 
amphioxes, and some large axial amphioxes forming the upper continuation 
of the stalk. In the lower part of the sponge-body numerous acanthophores 
are added to these spicules. These extend remarkably far up. The upper 
acanthophores have long, slender, and usually fairly straight and not very spiny 
rays. In the lower acanthophores the rays are either reduced in length, stout, 
and very spiny, or long, slender, not particularly spiny, and more or less, often 
considerably curved. 

The dermal pinules have a distal ray 230-855 wp long. The length frequency- 
curve of their distal rays has a very marked depression at about 530 y, and two 
perfectly distinct elevations at 370 and 650 y». I therefore distinguish two kinds 
of dermal pinules, a large and a small. 

The large dermal pinules (Plate 95, figs. 1, 15, 19, 20) are pentactine. Their 
distal ray is straight, 560-855 » long, most frequently about 650 u, and 12-23 4 
thick at the base. It ends with a short and stout terminal cone, and bears spines 
which extend quite down to its base, or nearly so. The lowest spines are very 
short, stout, conical, and vertical; distally the spines become larger and more 


HYALONEMA (OONEMA) DENSUM. 343 


inclined and curved concave towards the tip of the ray. The largest spines 
usually attain a length of about 27 u. The maximum diameter of the distal 
ray, together with the spines, is 32-85». The lateral rays are 40-77 y» long, 
nearly cylindrical in their proximal, and conical in their distal part. Their 
middle and sometimes also their proximal parts bear broad and low spines. 
The end-parts are smooth and sharply or bluntly pointed. 

The small dermal pinules are similar to the large ones. They are nearly 
always pentactine. Exceptionally a remnant of a proximal ray, sometimes 
15 w long, is present. The distal ray is straight, 230-505 » long, most frequently 
about 370 », and 6-10 u thick at the base. Its maximum diameter, together 
with the spines, is 12-47 ». The lateral rays are 40-68 u long. 

The gastral pinules (Plate 95, figs. 2, 11-14, 16-18). Although the length 
frequency-curve of the distal rays of these spicules is irregular and exhibits no 
less than five elevations, these are separated by depressions so shallow that 
differently sized kinds of gastral pinules cannot be distinguished. The gastral 
pinules are generally pentactine, rarely hexactine. The hexactine forms are, 
however, not so rare among these pinules as among the dermal. Apart from 
this the gastral pinules are quite similar in shape to the dermal. The distal 
ray is straight, 300—930 u long, most frequently 400-650 u, and 10-28 uw thick 
at the base. Its maximum thickness, together with the spines, is 25-80 u. 
The spines are sometimes 35 u long. The lateral rays (Plate 95, figs. 11, 12) 
are 35-82 » long. The proportion of the length of the distal to that of the 
lateral rays of the same spicule is 7-13 to 1, on an average 9:1. The proximal 
ray, when present, is, in shape and spinulation, similar to the laterals and 20- 
68 uw long. 

The searce canalar pinules are mostly pentactine. The distal ray is 150- 
200 » long, and 7-10 » thick at the base. Its maximum transverse diameter, 
together with the spines, is 12-22 ». The lateral rays are 50-60 u long. 

The hypodermal and hypogastral pentactines are very similar. Both have 
a straight, conical, terminally rounded proximal ray 540-860 u» long, and 20-48 u 
thick at the base. The lateral rays are also straight, conical, and rounded. 
Those of the same spicule are often very unequal in size. Their length is 250- 
530 pu. 

The hexactine megascleres are 1.1-3.5 mm. long and 1.1—1.8 mm. broad. 
In the larger, two opposite rays are longer than the other four. In the smaller 
the six rays are usually fairly equal in size. The rays are 40-90 u thick at the 
base, straight, generally regularly conical, and rounded at the end. Occasion- 


344 HYALONEMA (OONEMA) DENSUM. 


ally the thickest part of the ray does not lie at its proximal end but farther out, 
some distance from the centre of the spicule. The largest hexactine observed 
was of this kind. In this spicule the two longer opposite rays measured 1.1 mm. 
and 2.4 mm. in length respectively. The longer of the two is 70 u thick at the 
base. Its point of maximum thickness is 0.4 mm. from the centre of the spicule, 
and here the ray measures 80 u in transverse diameter. At the rounded end 
it is 15 u thick. In the proximal part of the ray the axial thread is simple and 
quite thin (0.5 » in diameter); distally it gradually increases in thickness to 
5 » at the end of the ray. In its distal and middle-parts it is not simple but 
provided, at frequent intervals, with verticillate groups of strongly inclined 
branches with a maximum length of 15 uz. 

The superficial and ordinary choanosomal amphioxes are centrotyle, usually 
0.6—2.2 mm. long, and 7—27 uw thick near the middle. The central tyle, which not 
infrequently protrudes much more on one side of the spicule than on the other, 
is 13-37 uw in transverse diameter, that is 1-18 » more than the adjacent parts 
of the spicule. 

The large axial amphioxes and rod-shaped fragments found in the central 
part of the sponge are 25-1304 thick. The largest intact one observed is a 
fusiform amphiox, blunt at both ends, 5 mm. long, and 28 yu thick. 

The acanthophores (Plate 94, figs. 34-36) have from two to six, most fre- 
quently two or four rays. The dimensions of these spicules are tabulated 


below. 


ACANTHOPHORES. 
from higher up in the from the lower end of the 
sponge sponge 
Number of Nl 
rays more or| total length | total length 
less developed (maximum (maximum 
diameter) of | basal thick- diameter) of basal thick- 
spicule | ness of rays spicule ness of rays 
a | M Me Me 
2 620-1560 7-19 100-790 12-30 
3 390-490 12-15 170-300 28 
4 390-610 | 13-29 120-565 11-388 
5 615 21 217-540 20-26 
6 300-400 14-19 600 21 


HYALONEMA (OONEMA) DENSUM. 345 


The table shows that, apart from the few hexactine forms, which appear 
only partly to conform to the rule, the acanthophores situated farther up are 
larger and have more slender rays than those situated farther down. The rod- 
shaped diactine acanthophores are longer than any of the others. Apart from 
this the size (ray-length) of these spicules is by no means in inverse preportion 
to the ray-number; the triactines, for instance, are shorter than the tetractines. 
The thickest rays are met in the tetractines. This applies both to the upper 
and the lower tetractines. The diactines have a central and often also two ter- 
minal tyles. The latter sometimes attain remarkably large dimensions. Ina 
spicule of this kind 7804 long and 154 thick, the two terminal tyles were 
respectively 50 and 60 in diameter. The small acanthophores are often spined 
throughout; in the large ones the spines are confined to the ends of the rays. 
The spines are low and broad, and attain 10 u in length and 16 u in breadth. 
They are conical and pointed or, more rarely, rounded at the end and dome- 
shaped. The acanthophores with rounded spines are characteristic of the spe- 
cies. The rays are straight or curved. Strongly curved rays are met particu- 
larly among the larger tri- to hexactines situated below. The rays of all the 
small acanthophores, of all the diactine acanthophores, and of all kinds of 
acanthophores situated farther up, are usually fairly straight. 

The microhexactines (Plate 94, figs. 37-40) are 60-165 » in diameter, usually 
95-160 u. The rays are equal, conical, finely pointed, 3-6 » thick at the base, 
and curved slightly but quite distinctly and quite uniformly throughout their 
length. They bear spines which are rather sparse, vertical, and sometimes 1 yu 
high in their proximal part, and which are more numerous, smaller, and directed 
backwards in their distal part. Toward the ends of the rays the spines decrease 
in size to such an extent that the end-parts themselves merely appear rough, 
even under the highest power. 

From a morphological point of view four kinds of amphidiscs can be dis- 
tinguished: — A, large ones, with broad, short anchors, less than a third of 
the whole spicule in length, and no protuberance, or only one or two, on the 
shaft; B, middle-sized ones with long and broad anchors, about half the length 
of the whole spicule; C, middle-sized ones with short elliptical anchors, about a 
third of the length of the whole spicule, and a shaft spined throughout; and D, 
small ones with short U-shaped anchors, less than a third of the whole spicule 
in length. 

The length frequency-curve of the amphidises, shown in Figure 22, exhibits 
four very distinct elevations separated by deep depressions or gaps. These 


346 HYALONEMA (OONEMA) DENSUM. 


° on S on SS oe Number 
Length, («). 
DAT — 93°98 
23123 — 25.554-7s= 
25.55— 28.10 4-44 
28.10 — 30.91 ¥ 
30.91 — 34.00 B. 
34.00 — 37.40 z 
37.40— 41.14 5 
41.14— 45.26 S 
45.26—- 49.78 3. 
49.78 — 54.76 me 
54.76— 60.24 S go 
60:24-==66.26-— === is 
66.26 — 72.89-4- 
72.89 — 80.18 
80.18 — 88.20 
88.20 -— 97.02 
97.02 — 106.72 
106.72 — 117.39 
117,39 — 129.13 Y 
129.13 — 142.04 B. 
142.04 — 156.25 
156.25 — 171.87 
171.87 — 189.06 2 
189.06 — 207.97 BS 
207.97 — 228.76 i 
228.76 — 251.64 3 
251.64 — 276.81 . B: 
276.81 — 304.49 B 
304.49 -— 334.93 | B 
334.93 — 368.43 
368.43 — 405.27 ] 
405.27 — 445.80 =< 
445.80 — 490.38 Re % 
490.38 — 539.42 35 & 
539.42 — 593.36 a e 
593.36 — 652.70 So 
a 
n Do 


Fig. 22. — Amphidises. 


four elevations coincide with the four morphological groups above referred to. 
There can be no doubt, therefore, that we have here to deal with four distinct 
kinds of amphidises. The group A is very clearly distinguished from all the 
others, both morphologically and biometrically. The group B is clearly dis- 
tinguished morphologically from all other groups, but distinguished biometri- 


HYALONEMA (OONEMA) DENSUM. 347 


cally by a wide gap in the length frequency-curve only from group A. Groups 
C and D differ morphologically greatly from A and B but not nearly so much 
from each other. Biometrically, that is judging from the width of the depres- 
sion separating the two elevations of the curve pertaining to them, they are 
also less clearly distinguished from each other than A is from B. 

Thus C and D together form a main group, which is to be named micramphi- 
dises, as it comprises the smallest amphidises. Although separated by a wide 
gap in the curve, and differing also morphologically, I am inclined to combine 
A and B in a like manner in one main group, which is to be named macramphi- 
dises, as it comprises the largest amphidises. Within each of these main groups 
I distinguish two subgroups differing in size, and thus divide the amphidises 
into the four groups: — large macramphidises (morphological group A); small 
macramphidises (morphological group B); large micramphidises (morphologi- 
eal group C); and small micramphidises (morphological group D). 

The large macramphidises (Plate 96, figs. 8, 9, 14) are rare. They are 
450-540 » long, most frequently about 476 », and have a straight shaft, 21- 
29 » thick. The shaft is either quite simple and cylindrical throughout (Plate 
96, fig. 9), or it bears a rounded protuberance or two, about 10 u high, in its 
middle part (Plate 96, figs. 8, 14). The terminal anchors are 125-140 u long, 
less than a third of the whole spicule, and 190-230 » broad. The proportion of 
length to breadth of the anchors is 100 to 145-174, on an average 100 : 162. 
The anchors are composed of eight teeth. The individual teeth are throughou} 
curved fairly uniformly and sharply pointed at the end. 

The small macramphidiscs (Plate 96, figs. 1-7, 10-13) are present in fair 
numbers, but are not nearly so abundant as in the allied species. They are 90- 
184 » long, most frequently about 135.6 u. The shaft is straight, simply cylin- 
drical, and 9-15 uw thick. The terminal anchors are 45-92 u» long, usually a little 
more than half the whole spicule. Their breadth is 60-136 ». The proportion 
of anchor-length to anchor-breadth is 100 to 125-157, on an average 100 : 146.2. 
The anchors are usually composed of eight, more rarely of seven teeth. The 
teeth of the two anchors of the same spicule are usually situated so that those 
of the one anchor alternate regularly with those of the other. The individual 
teeth consist of an outer band-shaped part, up to 30 « broad, and simply rounded 
at the end, and an inner keel, high at the base and uniformly narrowing dis- 
tally. The outer contour is more strongly curved in its proximal and distal 
than in its middle-parts. At the end of the tooth it is always strongly bent 


inwards. 


348 HYALONEMA (OONEMA) DENSUM. 


The large micramphidises (Plate 95, figs. 5-8) are abundant. They are 44- 
86 » long, most frequently about 69.5 ». The shaft is straight, centrotyle, and 
1.5-4 » thick. The central tyle is 2-5 » in transverse diameter, that is 0.5-2.5 u 
more than the adjacent parts of the shaft. The shaft bears rather numerous 
scattered spines, the largest of which arise from the central tyle. These spines 
are 1-4 » long and, if long, generally considerably curved. The terminal anchors 
are 13-31 » long, usually about a third of the whole spicule, and 15-35 y» broad. 
The proportion of anchor-length to anchor-breadth is 100 to 78-123, on an aver- 
age 100 : 102.3. The individual teeth are curved rather strongly in their basal 
part. Distally the curvature decreases so that their ends are slightly divergent 
or nearly parallel. 

The small micramphidiscs (Plate 95, figs. 9, 10) are not numerous. They 
are 24-40 » long, most frequently about 26.8 u. The shaft is straight, usually 
distinctly centrotyle, and 1—1.7 » thick. The tyle is 1.5-2.3 » in transverse 
diameter, that is 0.2-1.2 » more than the adjacent parts of the shaft. The termi- 
nal anchors are 7—16.5 « long, usually less than a third of the whole spicule, 
and 7-14 » broad. The proportion of anchor-length to anchor-breadth is 100 
to 75-143, on an average 100 : 97.8. The individual teeth arise vertically from 
the ends of the shaft, are straight in their basal part, curved through a quadrant 
in their middle-part, and straight again in their distal part. Their ends are 
parallel. 

Among the small micramphidises I found several irregular ones with asym- 
metric anchors. One of these is 16 u« long, has a shaft 1.5 » thick, and possesses 
apparently only two teeth, one in each anchor. These two teeth stand opposite 
each other and are not very much shorter than the whole spicule, which is 
consequently similar to a depressed 8. 

The nearest allies of the above sponge are the species Hyalonema (Oonema) 
sequoia, H. (O.) crassipinulum, and H. (O.) henshawi described in this Report. 
From these it differs by the smaller size, and the distinct curvature of the rays 
of its micramphidises; by the possession of acanthophores with terminally 
rounded spines; by differences in the dimensions of its pinules; and by the shape 


and general density of its body. 


HYALONEMA (OONEMA) SEQUOIA. 349 


Hyalonema (Oonema) sequoia, sp. nov. 
Plate 85, figs. 9-21; Plate 86, figs. 1-36; Plate 87, figs. 1-7; Plate 88, figs. 1-13; Plate 89, figs. 1-36; 
Plate 90, figs. 1-10; Plate 91, figs. 1-6. 

One specimen of this species was trawled in the Central Tropical Pacific, 
at Station 4740 on 11 February, 1905; 9° 2.1’ S., 123° 20.1’ W.; depth 4429 
m. (2422 f.); it grew on a bottom of dark gray Globigerina ooze; the bottom- 
temperature was 34.2°. Most of its superficial pinules attain a very large size, 
exceeding the ordinary pinules of other hexactinellids in dimension as Sequoia 
gigantea does the other conifers. To this the name refers. 

Shape and size. The single specimen is much torn (Plate 86, fig. 8). It 
appears to be part of a wall, 4-6 mm. thick, of a wide tube or funnel. The 
specimen is without the stalk, and when laid down flat is 105 mm. long (high) 
and 116 mm. broad. A stalk, 84 mm. long and broken off at the end, arises 
from one end. The upper part of the specimen, that is the part opposite the 
stalk, is composed of lamellae, between the free margin of which remnants of 
reticulate pore-sieves are spread out. 

The colour in spirit is light brownish yellow. 

The skeleton. The pore-sieves (Plate 86, fig. 7) are supported by para- 
tangential amphioxes, most of which are small, but a few are large. The latter 
obviously correspond to the tignules of other hexactinellids. The pore-sieves 
also contain microhexactines and micramphidises. Numerous small macram- 
phidises and large pinules rest on the outer side of the amphioxes support- 
ing the strands of these reticulate sieves. Although now partly irregularly 
disposed (Plate 86, fig. 7), I do not doubt that, in life, the axes of the shafts of 
these small macramphidises and of the distal rays of the pinules were vertical 
to the surface. In the few places where the outer surface of the sponge is intact 
I found the same spicules, with the exception of the large amphioxes (tignules), 
and in addition hypodermal pentactines. Numerous slender amphioxes, some 
hexactine megascleres, masses of microhexactines, and a few large macramphi- 
dises have been observed in the choanosome of the upper and middle-parts of 
the body. In the spicule-preparations of these parts have been observed also 
pinule-like microhexactines, with one ray longer than the other five, and large 
numbers of micramphidises. The pinule-like microhexactines doubtlessly line 
the canal-walls. The position of the micramphidiscs may be the same. Atcan- 
thophores with one to six stout and terminally interiorly spined rays occur in 
the basal part of the sponge-body, from which the stalk arises. The stalk con- 
sists of three thick and a number of slender spicules, all broken off distally. 


350 HYALONEMA (OONEMA) SEQUOIA. 


Besides these spicules which will be described below, a number of others, 
chiefly amphidiscs (Plate 89, fig. 15e) and pinules, were found in the sponge. 
Since, however, some of these kinds of spicules are very rare, and since the 
other, more frequent ones are identical with spicules of Hyalonema (Hyalonema) 
agassizi and Hyalonema (Prionema) fimbriatum trawled at the same Station 
and contained in the same jar, I consider them as foreign. 

The superficial pinules (Plate 86, figs. 8, 13-26; Plate 87, figs. 1-7; Plate 
88, figs. 7-13; Plate 89, fig. 15c) are nearly all pentactine, hexactine forms 
being very rare. These pinules are very unequal in size, the largest attaining 
quite unusual dimensions. The distal ray is straight and 0.18-1.4 mm. long, 
most frequently about 0.9 mm. The length frequency-curve of the distal 
pinule-rays is simple, with a single elevation at 0.9 mm., which shows that these 
pinules form, in spite of their great dimensional differences, a simple, biometri- 
cally harmonious group. The distal ray is 5.5-55 » thick at the base, and 
together with the spines is 19-160 » thick at the thickest point. The maximum 
thickness is two to four times as great as the basal thickness. The point of 
maximum thickness lies rather far up, being usually three times as far from 
the base as from the tip of the ray. The distal ray ends in a terminal cone free 
from spines. This in the large pinules (Plate 87, figs. 3a, 5, 7; Plate 88, figs. 
12a, 13a) is broad, rather blunt, and traversed by a remarkably thick axial 
thread; in the smaller (Plate 88, figs. 7-10, lla) it is either stout or slender, 
and not infrequently sharp-pointed (Plate 88, fig. 10). In the large pinules 
the distal ray is covered with spines quite down to its base (Plate 87, fig. 3b; 
Plate 88, figs. 12b, 13b); in the smaller its basal part, for a short distance, is 
quite smooth (Plate 88, figs. 7-10, 1lb). The length of this smooth basal zone 
is, on the whole, in inverse proportion to the size of the spicule. The basal 
spines of the distal rays of the large pinules are short, broad, conic, sharp-pointed, 
and vertical. Distally they become more and more inclined towards the tip 
of the ray. At the same time they increase in length up to the point of maxi- 
mum thickness of the ray. From here up to the tip of the ray their length 
remains about the same. In typical large pinules the basal spines are up to 
7 » long, and 10-14 » broad at the base. The upper spines are equally thick but 
attain 35 » in length. Most of the inclined spines on the upper and middle- 
parts of the ray extend longitudinally, in planes passing through the axis of 
the distal ray. In a good many of the large pinules, however, irregularities 
occur in the position of the spines. Either the spines on part of the ray are all 
spirally twisted and directed obliquely to one side (Plate 87, fig. 2), or there is, 


HYALONEMA (OONEMA) SEQUOIA. 351 


somewhere near the tip, an umbilicus-like spot around which they are disposed 
quite irregularly (Plate 87, figs. 4-7). Very frequently a difference in the posi- 
tion of the spines on opposite sides is observed in the distal part of the ray, 
which renders it asymmetrical in appearance (Plate 87, fig. 3a; Plate 88, fig. 13a). 
These irregularities are so frequent that they can hardly be considered as 
abnormities. In some places the spines are isolated and irregularly scattered ; 
in others they are arranged in spiral rows and appear to rise from the crests of 
scale-like protuberances of the central solid part of the ray. : 

The lateral rays are conical, blunt, at the base slightly thinner than the 
distal ray, and 33-195 » long; they are usually one tenth to one third of the dis- 
tal ray in length. In the smaller pinules they are on the whole relatively much 
longer than in the larger ones. In the latter I have never found them more 
than a seventh of the distal ray in length. In the large pinules the lateral rays 
are spined more or less densely throughout their whole length. Their spines 
are vertical, and similar in shape and size to those on the basal part of the distal 
ray (Plate 87, fig. 3b; Plate 88, figs. 12b, 13b). The lateral rays of the smaller 
pinules are spined only in their distal part, and their spines are very small. 

The proximal ray of the rare hexactine superficial pinules is similar in 
shape and size to the laterals. The proximal rays measured are 57—95 u long. 

The hexactine megascleres (Plate 85, figs. 20, 21) have smooth, usually 
somewhat curved, rarely angularly bent, cylindroconical, terminally rounded 
rays. In the smaller forms the six rays are usually fairly equal in size, in the 
larger two opposite rays are generally considerably longer than the other four. 
The hexactine megascleres are usually 0.5-5.5 mm. in maximum diameter, and 
their rays are 20-140 uw thick at the base. But smaller forms with correspond- 
ingly thinner rays also occur. 

The hypodermal and hypogastral pentactines have a straight, cylindroconical, 
terminally rounded proximal ray, usually 0.5-1.2 mm. long, and 20-40 u» thick 
at the base. The lateral rays are much shorter, usually only 0.3-0.6 mm. long. 

The amphiozes are of three kinds: — 1, small and slender, 2, small and stout, 
and 3, large. 

The small and slender amphioxes (Plate 89, fig. 15a), which predominate in 
the interior, are centrotyle, straight or curved, sometimes very considerably 
bent, usually 0.6-2 mm. long, and 6-20. thick near the middle. The pro- 
portion of length to thickness is in these spicules 1000 :7 to 1000 :13. The 
central tyle is 10-21 » thick, that is 1-4 « more than the adjacent parts of the 


spicule. 


302 HYALONEMA (OONEMA) SEQUOIA. 


The small and stout amphioxes (Plate 89, fig. 15b) are centrotyle, fairly 
straight, 0.6-2.5 mm. long, and 22-70 » thick near the middle. The proportion 
of length to thickness is in these spicules 1000 :17 to 1000 :31. The central 
tyle is 24-75 u thick, that is 1-7 » more than the adjacent parts of the spicule. 

The large amphiozes (tignules) (Plate 89, figs. 1-5) are slightly and irregularly 
curved, not centrotyle, and not exactly cylindrical in the middle or uniformly 
thickened toward it; the outline is slightly wavy. They are 5-8 mm. long and 
100-140 uw thick. The proportion of length to thickness is in these spicules 
1000 : 15 to 1000 : 20. 

The acanthophores (Plate 85, figs. 9-19) have one to six, most frequently 


four rays. The diactines are centrotyle. The forms with 


5-6 rays are 140-224 win maximum diameter and have rays 10-28 u thick, 


3-4 ce ce 95-435 cc Ge a3 ec “e igs ce 15-36 “‘ ing 
2 ‘“ “ 212-1050 “ long and near the central tyle 14-18" “ 
1 ray is) 108-180" _* © © ~ “ terminal tye 20-30 “ 


The central tyle of the long diactines is usually 5-7 » more in transverse 
diameter than the adjacent parts of the spicule. In the smaller tetractines the 
four rays are usually fairly equal; in the larger one ray, or two opposite rays, 
are often longer than the others. All the long-rayed (diactine) forms and a 
few of the short-rayed (mon- to hexactine) ones have rays smooth in their proxi- 
mal and middle-parts and spined only in their end-parts. Most of the mon- 
to hexactine forms are spined throughout, the terminal spines being, as a rule, 
considerably larger than the more proximal ones. The spines are vertical, 
broad, low, conical, and pointed. 

The stalk-spicules are ail broken off at the distal end. The parts present 
have a maximum thickness of 0.2-1.2 mm. 

The microhexactines (Plate 86, figs. 9, 11, 12, 35, 36; Plate 88, figs. 1-4) 
are 60-200 u in diameter, generally 95-170 uw, and have equal, regularly arranged 
rays. The rays are perfectly straight, 4-6 » thick at the base, conical, and sharp- 
pointed. Everywhere except at the extreme tip they bear spines. The spines 
on their proximal half arise vertically; beyond that they incline more and more 
backward, towards the centrum of the spicule. The largest spines are those 
arising at a distance of about a third of the length of the ray from the centrum. 
Here they are about 1.5 » long, and from here they decrease in size, both distally 


and proximally. 


HYALONEMA (OONEMA) SEQUOIA. 353 


In the centrifuge spicule-preparations (Plate 86, fig. 10) I found a few monac- 
tine microhexactine-derivates. This spicule appears as a tylostyle and is spined 
throughout. Its dimensions are:— length 167 y», basal thickness of ray 6 yu, 
diameter of tyle 9 u. 

The true choanosomal microhexactines have, as above stated, equal rays. 
In the spicule-preparations, however, a large number of small spined hexactines 
are found, in which one ray is considerably larger than the other five. These 
spicules I consider as pinule-like derivates of the regular microhexactines, which 
line the canal-walls, and are therefore to be considered as canalaria. 

These pinule-like microhexactine-derwate canalaria (Plate 88, figs. 5, 6) 
have a longer (distal) ray, 115-300 » long, and 5-11 4» thick at the base, and 
five shorter (proximal and lateral) rays, 40-95 u long. The proximal ray may 
be longer or slightly shorter than the laterals. All the rays are spined. The 
spines on the distal ray are longer than the spines on the other rays — the more 
so, the more the distal exceeds the other rays in length. They are also for the 
most part directed obliquely upwards towards the tip of the ray. 

The amphidiscs. Morphologically two main kinds of amphidises can be 
distinguished: — amphidises with broad terminal anchors and a shaft which 
is either quite smooth or provided only with one or a few terminally rounded 
protuberances or spines, and amphidises with slender terminal anchors and 
generally spiny shaft. The former are large, 90-550 » long; the latter are 
small, 17.5-122 » long. I consider the former as macramphidiscs, the latter 
as micramphidiscs. 

Among the macramphidiscs two subgroups can be distinguished both 
morphologically and biometrically. In one the anchors are much shorter 
than half the length of the whole spicule, and the anchor-teeth pointed; in the 
other the anchors are about half as long as the whole spicule, and the anchor- 
teeth terminally rounded. The former are larger, 370-550 » long; the latter 
smaller, 90-195 uw long. The differences in their anchors, and the absence of 
intermediate forms between 195 and 370 u in length, which finds its expres- 
sion in a wide gap in the length frequency-curve, Figure 23, very clearly 
distinguish these two kinds of macramphidises from each other. I accord- 
ingly divide the macramphidises into two subgroups:— large and = small 
macramphidiscs. 

The length frequency-curve of the micramphidises also shows a great 
depression, which lies at about 57 w and reaches down to the O-line. Thus also 


among these spicules a larger and a smaller kind can be distinguished. The 


354 HYALONEMA (OONEMA) SEQUOIA. 


larger ones, to which the part of the curve to the right of this depression refers, 
and which are 63-122 » long, have anchor-teeth distally rather divergent. The 


smaller ones, to which the part of the curve to the left of the depression refers, and 
which are 17.5—52 uw long, have anchor-teeth distally nearly parallel. I therefore 
also divide the micramphidises into two subgroups: — large and small micram- 
phidises. It is to be noted that these two kinds of micramphidises do not 
differ so much from each other as the two kinds of macramphidises. I distin- 


Length | as | ron) | ror) | = IS | ‘ Number 
15.86— 17.45 ea aed 
17.45— 19.19 eens | 
1ONG =) 2140 Siete Math 1 
21.11— 23.23 le a ta 
232325108 SI be ae Pst ad 
25.55— 28.10 A Siediape anotiah 
28.10 — 30.91 ee et i (YP 
30.91— 34.00 Si fias aes ac RS 
34.00-— 37.40 ee ieee a 2 
37.40 — 41.14 i (ota aa ' ! Ee 
AVIA -45.26%}--t=4-steaT Pl S 
AD26— AQ WS —t-5 1 Nf at kt 3 
ZS) sey fa atl tr =. 
SAO COATS Ie ay en Sas a 
r 60.24— 66.26+-47, 1 st rr tas Z 
3 66.26 — 72.894--t-Li it iif 
& 72.89— 80.18 i aces eo ea! 
2 80.18 — 88.20 Soe By 
> 88.20-- 97.02 eee | (og 
B 97.02 —106.724--<- is a 
=: 106.72 117.394 - ie 
a 117.39— 129.13 i elec 
& 129.13 — 142.0447 4--1---Ns faa 
Sas l= 
"156.25 — 171.87 -+ -+-=- ropot ab --------5 
171.87 — 189.06-4--+-+-----=rateot z 
189.06 — 207.97 3 
20797 — 228, 16— s 
228.76 — 251.64 Ss l 
251.64 — 276.81: E. | 
276.81 — 304.49 a 
304.49 — 334.93 a 
334.93 — 368.43 
368.43 — 405.27 = = 
405.27 — 445.80 es e § 
445.80 — 490.38: fo a 8 
490.38 — 539.42 0 a 
539.42 —573.33-4 ---> ee 
573.33 — 630.66 g 8 


Fig. 23-— Amphidises. 


HYALONEMA (OONEMA) SEQUOTA. 355 


guish four kinds of amphidises in this sponge: — 1, large macramphidises, 2, 
small macramphidises, 3, large micramphidiscs, and 4, small micramphidiscs. 

Although the length frequency-curve of the large macramphidiscs has two 
summits, I do not distinguish two distinct groups among these spicules, because 
the depression between the two summits is but slight and because there are 
no notable morphological differences between the spicules to which the two 
parts of the curve on each side of the depression refer. 

The large macramphidiscs (Plate 86, figs. 1-6; Plate 89, figs. 31, 32; Plate 
91, figs. 1-6) are 370-550 uw long, most frequently about 425 4. The shaft is 
straight, cylindrical, and 19-27 » thick. It usually bears a few broad and low 
quite insignificant tubercles. Some of these are often arranged in an irregular 
verticil situated in the middle-part of the shaft, which is, at this point, usually 
slightly thickened to an inconspicuous central tyle, only 1-3 u, exceptionally 
as much as 6 », more than the adjacent parts in transverse diameter. Rarely 
the shaft bears a larger, cylindrical, terminally rounded spine, sometimes 28 yu 
long, and 10 u thick (Plate 86, fig. 4). I have never observed more than one 
such spine on the shaft of the large macramphidiscs. 

The terminal anchors are 120-170 » long and 200-256 » broad. The 
proportion of their length to their breadth is 100 : 139 to 100 : 196, on an average 
100 : 171.3. The proportion of the anchor-length to the total length of the 
spicule is 1 to 2.64.7, on an average 1 : 3.6. The anchors are usually composed 
of eight teeth. The teeth of the two anchors of the same spicule lie opposite 
each other in the same planes passing through the axis of the shaft. The indi- 
vidual teeth are about 25 » broad near the base, and pointed at the end (Plate 
89, figs. 31, 32). Their curvature is usually greater at the base and at the end 
than in the middle. The tip of the tooth is sometimes abruptly bent either 
inward (Plate 91, fig. 4) or, more rarely, outward (Plate 91, fig. 1). The teeth 
occasionally bear conspicuous, somewhat branch-like protuberances on their 
convex outer (Plate 91, fig. 3) or concave inner side (Plate 91, fig. 2). A well- 
marked depression can be made out, sometimes very clearly, on the apex of the 
anchor (Plate 91, fig. 4). 

The length frequency-curve of the small macramphidises has two summits 
separated by a rather conspicuous gap. The smaller ones, to which the part 
of the curve to the left of the depression refers, have a larger number of anchor- 
teeth than the larger ones, to which the part of the curve to the right of the 
_ depression refers. Two kinds of small macramphidises could therefore be 


distinguished. Since, however, the differences between them are not great and 


356 HYALONEMA (OONEMA) SEQUOIA. 


since the extreme forms are connected by numerous transitions, I shall here 
describe both together. 

The small macramphidiscs (Plate 86, figs. 7, 27-34; Plate 89, fig. 15d; 
Plate 90, figs. 1-10) are 90-195 » long, most frequently about 1644. The 
shaft is straight, smooth, cylindrical, and 5.5-16.5 4 thick. The terminal 
anchors are 39-100 » long, and 55-174 » broad, usually 70-150 u. The pro- 
portion of anchor-length to anchor-breadth is 100 :120 to 100:178, on an 
average 100: 149. As has been stated above, these anchors are about half as 
long as the whole spicule, sometimes a little shorter than that, more frequently 
a little longer. Each anchor is composed of five to thirteen teeth. The larger 
amphidises of this kind, that is those to which the part of the length frequency- 
curve culminating at 164 » refers, have five to ten, usually eight teeth; the 
smaller, to which the part of the curve culminating at 93 u refers, have eight to 
thirteen, usually eleven teeth. The two terminal anchors of the same spicule 
are composed of the same number of teeth. The teeth of the terminal anchors 
extend in planes passing through the axis of the spicule. The anchor-teeth 
planes of one anchor enclose equal angles with their neighbours, each 360 degrees 
divided by the number of teeth. The anchor-teeth planes of the other anchor 
of the same spicule allernate regularly with these in such manner that they 
divide each angle into two equal parts (halves). Thus the tips of the teeth of 
the two opposite anchors are not opposite but alternate. 

The individual anchor-teeth are curved, either uniformly or, more fre- 
quently, less in the middle-part than at the base and at the tip. The outer 
contour of each tooth is abruptly curved inwards at the distal end. The teeth 
are T-shaped in transverse section. Their outer (upper) part, which corresponds 
to the upper stroke of the T, has the shape of a curved band increasing in breadth 
distally to a point three quarters of the length of the tooth from its base. Here 
the tooth is 9-30 » broad. The end-part of the tooth, lying beyond this point 
of maximum breadth, is simply rounded (Plate 90, figs. 1, 3, 7, 9). The inner 
(lower) part of the tooth, which corresponds to the lower stroke of the T, is a 
thick keel, uniformly decreasing in height distally. The end-part of the upper 
(outer) band-shaped portion of the tooth bends down around the end-part of 
the keel on all sides except the axial, so that, viewed in profile, the end-part of 
the whole tooth becomes strikingly similar to a crow’s beak (Plate 90, figs. 4, 6, 
8, 10). 

Slightly abnormal small macramphidiscs with one or more somewhat irregu- 
lar teeth, like the one represented (Plate 90, figs. 5, 6), have repeatedly been met. 


HYALONEMA (OONEMA) SEQUOIA. 357 


More strongly aberrant forms are much rarer. A small macramphidisce of this 
kind (Plate 89, figs. 35, 36) is 112 » long, and has a shaft 14 » thick. The termi- 
nal anchors are very irregular, spirally twisted, and on one side much longer than 
on the other. The chords of the longest anchor-teeth are more than three 
quarters of the whole spicule in length. 

The length frequeney-curve of the large micramphidises also has two 
summits, but as the depression separating them is slight, and as the spicules to 
which the two parts of the curve on the two sides of it refer, are very similar in 
shape, I do not consider this irregularity of the length frequency-curve sufficient 
for dividing the large micramphidiscs into two groups. 

The large micramphidises (Plate 89, figs. 6-14) are 63-122 » long, most 
frequently about 93 u. The shaft is 2.5—4 uv thick, and generally thickened in its 
middle-part to a central tyle 5-6 » in diameter. Rarely it is of uniform thick- 
ness throughout and without a tyle. With the exception of its end-parts, which 
are smooth, the whole of the shaft is covered with spines. The spines arising 
from the tyle are usually arranged in an irregular oblique verticil. These spines 
are larger than the others. The terminal anchors are 29-43 u long and 25—40 u 
broad. The proportion of their length to their breadth is 100 : 75 to 100 : 105, 
on an average 100 : 87.9. The proportion of the anchor-length to the length of 
the whole spicule is 1 to 2.4-3.6, on an average 1 : 2.7. The individual anchor- 
teeth are curved strongly at the base, but curved only slightly in their middle- 
part. The tip of the tooth is frequently abruptly bent inwards. Apart from 
this abruptly bent end-part, the distal half of the tooth diverges from the shaft 
at an angle of 6°-12°. 

I found an abnormal large micramphidisc with strongly reduced terminal 
anchors. This spicule (Plate 89, figs. 16-19) is 100 wlong. Its shaft is straight, 
8 » thick, and covered with numerous scattered tubercles and a verticil of short, 
stout, cylindrical, terminally rounded spines. The terminal anchors are rudi- 
mentary, only 17 » long and 23 » broad, and composed of a terminal tyle enclosed 
by thin leaf-like teeth, most of which terminate with two terminal spines. 

The length frequeney-curve of the small micramphidiscs has three sum- 
mits. The two depressions separating them are inconsiderable, and the small 
micramphidises of different sizes differ only in that the smallest generally have 
a smooth shaft, the larger generally a spiny one. Although the smallest of these 
amphidises, belonging to the elevation of the curve to the extreme left, might 
therefore be separated from the others, I think it best to consider them all as 


forming a single group, and describe them together. 


308 HYALONEMA (PHIALONEMA) BREVANCORA. 


The small micramphidiscs (Plate 89, figs. 20-30, 34) are 17.5-52 » long, 
most frequently about 32.5 u. The shaft is 0.8-2 » thick, and thickened in the 
middle-part to a central tyle 2-3.3 » in transverse diameter, that is 0.5-1.3 u 
more than the adjacent parts of the shaft. In most of the larger and some 
of the smaller forms the shaft is spined. In most of the small and a few of the 
larger it is smooth. The terminal anchors are 5-20 » long and 5.5-15 » broad. 
The proportion of anchor-length to anchor-breadth is 100 :75 to 100 : 110, 
on an average 100 :90. The proportion of the anchor-length to the total length 
of the spicule is 1 to 2.5—4.5, on an average 1 : 3.1. The anchor-teeth are strongly 
curved in their proximal and nearly straight in their distal part. Their straight 
distal parts are slightly divergent, or nearly parallel to the shaft. 

The nearest allies of this sponge are Hyalonema (Oonema) henshawi, H. (O.) 
densum, and H. (O.) crasstpinulum. From all of them it differs by its super- 
ficial pinules attaining a much larger size; H. (O.) densum is further distinguished 
from it by having slightly curved microhexactine rays; H. (O.) henshawi by 
apparently being destitute of the large macramphidises; and H. (O.) crassi- 
pinulum by having smaller spicules, by being destitute of the smaller small 
macramphidises with numerous anchor-teeth, and by possessing small narrow- 
anchored macramphidises and pinules with large, strongly divergent spines on 


the proximal part of the distal ray. 


PHIALONEMA, subgen. noy. 


Species of Hyalonema, whose amphidiscs of one kind (the largest) have 
small, very short, and relatively broad terminal anchors. 
The collection contains four specimens and two fragments of this sub- 


genus. These belong to two species, one of which is new. 


Hyalonema (Phialonema) brevancora, sp. nov. 


Plate 55, figs. 1-37. 


There are in the collection two fragments of this species, both from the 
Central Tropical Pacific, Station 3684 (A.A. 17), on 10 September, 1899; 0° 50’ 
N., 137° 54’ W.; depth 4504 m. (2463 f.); they grew on a bottom of light 
yellow-gray Globigerina ooze. 

The large macramphidises have small, particularly low terminal anchors. 


To this the name refers. 


HYALONEMA (PHIALONEMA) BREVANCORA. 009 


Shape and size. The larger fragment (Plate 55, fig. 1) is an irregular, porous, 
flattened mass measuring 47 by 38 by 8 mm. The smaller one is only 22 mm. 
long. 

The colour in spirit is dirty white. 

The skeleton consists of pinules; hexactine, pentactine, and rhabd mega- 
scleres; microhexactines; and amphidiscs. In most of the pinules in the 
preparation the distal ray bears relatively very long spines; these pinules are 
probably hypodermal or hypogastral. In some pinules these spines are very 
short; these may be canalar. The hexactine megascleres are found in the 
innermost part of the specimens; the pentactines are no doubt hypodermal or 
hypogastral. The rhabd megascleres for the most part form bundles. The 
microhexactines are numerous, and all of the same kind. Macramphidises and 
large and small micramphidises can be distinguished among the amphidiscs. 
The small micramphidises are abundant, the other amphidisc-forms rare. 

The (probably dermal and gastral) pinules with long-spined distal ray 
(Plate 55, figs. 19-28, 30, 32, 33) are nearly always pentactine, very rarely 
hexactine. The distal ray is straight, 70-89 » long, and 3-4 u thick at the base. 
It bears spines along its whole length. The spines on the proximal third or so 
of its length are very small, straight, and directed obliquely upwards. The 
distal and middle-parts of the ray are covered with spines very unequal in 
length and in curvature, the large and the small ones being here irregularly 
intermingled (Plate 55, fig. 19). Some of these spines attain a relatively very 
considerable size, the largest being 18-54 » long and about 2. thick at the 
base. The lower spines, both large and small, are usually nearly straight, and 
very divergent (Plate 55, figs. 22, 25, 28). Farther up the short spines only are 
like this, most of the longer ones being curved, concave to the ray. This curva- 
ture is not infrequently so great that their ends become inclined towards the 
distal part of the ray (Plate 55, figs. 19, 21, 23). Thespines are conic and sharp- 
pointed. Some of the larger ones bear one or two, rarely more, secondary spine- 
lets, usually 2-3 » long, and inclined towards the end of the spines from which 
they arise. The maximum thickness of the distal ray, together with the spines, 
generally is 22-37 y, rarely as much as 54 uw. The lateral rays are usually 22-37 pu 
long, sometimes longer. They are cylindrical proximally, conic distally, pointed, 
and beset with numerous oblique spines inclined towards the end of the ray. 
These spines attain a very considerable size, particularly in the distal and 
middle-parts of the ray. The lateral spines of these rays seem to be larger than 


the others; they give to the contour of the ray, when seen from above, a markedly 


360 HYALONEMA (PHIALONEMA) BREVANCORA. 


serrated appearance (Plate 55, figs. 32, 33). The proximal ray, when present, 
is similar to the laterals, and attains a length of 27 » (Plate 55, fig. 30). 

The (probably canalar) pinules with short-spined distal ray (Plate 55, fig. 29) 
observed by me were all pentactines. The distal ray is 66-85 u long, and about 
5 » thick at the base. Its spines are straight, conic, small, and directed obliquely 
upwards towards the tip of the ray. They are largest in the middle of the ray 
and decrease in size both distally and proximally. The distal end-part of the 
ray is often, for a considerable distance, quite free from spines. The maximum 
diameter of the distal ray, together with the spines, is usually about 14». The 
lateral rays are pointed, spiny, and usually 28-45 u long. 

The pentactine megascleres (Plate 55, figs, 2, 3) have straight, conic rays, 
20-40 » thick at the base, and rounded at the end. The proximal ray is usu- 
ally 0.8-1.1 mm. long; the laterals are 0.25—-0.6 mm. long, and slightly inclined 
towards the proximal, with which they enclose angles of 78°-84°. 

The hexactine megascleres (Plate 55, fig. 31) observed measured 0.4—0.9 mm. 
in diameter, and had somewhat unequal, straight, conic, and blunt rays 7-16 u 
thick at the base. 

The rhabd megascleres (Plate 55, figs. 4, 6) observed are for the most part 
more or less curved centrotyle amphioxes. These spicules are 0.4—4.5 mm. 
long and 4-20 » thick near the centre. The proportion of the thickness of the 
spicule to the diameter of the tyle is 100 : 125 to 100 : 225, most frequently 
about 100: 150. There are besides these spicules centrotyle amphioxes angu- 
larly bent in the middle (Plate 55, fig. 4) and centrotyle rhabds with one of the 
actines reduced in length and thickened at the end to a terminal tyle. In some 
of the latter a kind of terminal spine arises, from the thickened end (Plate 55, 
fig. 6). 

The microhexactines (Plate 55, figs. 34, 37) measure 85-184 » in diameter, 
most frequently about 1504, and have six equal, perfectly straight, conic, 
sharp-pointed rays, usually 2-3 » thick at the base. The rays bear oblique, 
outwardly directed spines. These are numerous and very small, usually under 
0.5 w in length. 

Of amphidiscs three kinds are to be distinguished: — macramphidiscs, large 
micramphidiscs, and small micramphidises. 

The macramphidiscs (Plate 55, figs. 5, 14-18) are 285-349 u long, most fre- 
quently about 315 4. The shaft is straight and near the centre, where it is 
thinnest, 6-9 » in transverse diameter. It is generally thickened abruptly in 
the middle to a central tyle 10-13 » in diameter. Toward the ends it is always 


HYALONEMA (PHIALONEMA) BREVANCORA. 361 


gradually thickened to about double its minimum thickness near the middle. 
The central thickening bears a verticil of conic, truncate spines, 5-10 » long, 
and 3-4 » thick at the base. The truncate ends of these spines bear clusters 
of very minute, short, secondary spinelets. One of the large macramphidises 
observed was destitute alike of the central tyle and the central spine-verticil. 
Apart from this spine-verticil, the shaft is, in all the large macramphidises 
observed, entirely smooth. The terminal anchors are 25-41 » long, about a 
tenth of the whole spicule, and 5.3-72 » broad. The proportion of the length 
to the breadth of these anchors is 100 : 145 to 100 : 240, on an average 100 : 203. 
The anchor usually consists of eight teeth. The individual teeth are either 
uniformly curved, concave to the shaft throughout, or thus curved only in their 
basal and middle-part, and abruptly bent down at the end. The end-parts of 
the teeth enclose angles of about 25° with the axis of the shaft. The basal parts 
of the teeth appear to be massive; distally they thin out to rounded, spoon-like 
lamellae about 15 u broad. 

The micramphidiscs range from 18 to 38 » in length. In the frequency- 
curve pertaining to this dimension there is a marked depression at about 33 u. 
The micramphidises shorter than this have, as a rule, nearly smooth shafts; 
those as large or larger than this, very spiny shafts. I consider the former as 
small, the latter as large micramphidiscs. 

The large micramphidiscs (Plate 55, figs. 10-12) are 33-38 u long, most 
frequently about 36 yu. The shaft is cylindrical, 1.6-1.8 » thick, and covered 
with numerous irregularly scattered spines. The ‘terminal anchors are 7-11 yu 
long, a sixth to a fourth of the whole spicule, and 8-10.5 » broad. The propor- 
tion of anchor-length to anchor-breadth is 100 : 90 to 100 : 114, on an average 
100 :104. The individual teeth are rather strongly and uniformly curved in 
their basal part; distally the radius of curvature increases. Their nearly 
straight end-parts are approximately parallel to the shaft. 

The small micramphidiscs (Plate 55, figs. 7-9, 13) are 18-32 » long, most 
frequently about 26 u. The shaft is straight, cylindrical, and 1.2-1.6 uw thick. 
It is smooth, or bears a few small spines in its middle-part. The anchors are 4-8 
long, a sixth to nearly a third of the whole spicule, and 7-9.5 1 broad. The 
proportion of anchor-length to anchor-breadth is 100 : 100 to 100 : 180, on an 
average 100 : 131. The anchor-teeth of the small micramphidiscs are, in respect 
to their curvature, similar to those of the large micramphidises above described. 

Although the fragmentary condition of the specimens renders it difficult 
to decide to which genus of Amphidiscophora they belong, the probability is 


362 HYALONEMA (PHIALONEMA) PATERIFERUM. 


that they are Hyalonemas, and if so they must be placed in the subgenus 
Phialonema. 

Of the known species of Hyalonema H. globus F. E. Schulze’! appears to 
be most nearly allied to the sponges above described. With this species they 
agree fairly well in respect to the pinules, the shape of the shaft, and the short- 
ness and breadth of the anchor-teeth of the large macramphidises. They differ, 
however, from H. globus by having secondary spinelets on some of the primary 
spines of the distal rays of their pinules, by their small micramphidises being 
much larger and by the anchors of their large macramphidises having an alto- 
gether different shape. 


Hyalonema (Phialonema) pateriferum Wilson. 
Plate 50, figs. 6-15; Plate 51, figs. 1-28; Plate 52, figs. 1-29. 


Mem. M. C. Z., 1904, 30, p. 28, Plate 1, figs. 1-13. 


Six specimens of this species were collected during the expeditions of 1899- 
1900 and 1904-1905 in the Central and Eastern parts of the Tropical Pacific. 
Two of these, found at Station 3684 (A.A. 17), together with two other specimens 
and three fragments of the same species previously collected in the Gulf of 
Panama at Stations 3363 and 3376, were described by Wilson as Hyalonema 
pateriferum. Among the sponges of the expeditions of 1899-1900 and 1904— 
1905 placed at my disposal for description, there are four specimens, all from 
different stations, which belong to this species. Two of these were trawled off 
the coast of northern Peru at Stations 4651 and 4656, and two in the Eastern 
Tropical Pacifie at Stations 4721 and 4742. 

For the reasons given below I distinguish six forms within this species: — 
the two specimens and three fragments described by Wilson from Stations 

3363 and 3376 
the two specimens described by Wilson from Station 3684 (A.A. 17) 
the specimen examined by me from Station 4651 
the specimen examined by me from Station 4656 
the specimen examined by me from Station 4721 


—~e oases 


and the specimen examined by me from Station 4742 
Shape and size. One of the specimens of form A is, according to Wilson 
(loc. cit.), obconical, irregular, 65 mm. high, 90 mm. broad, and provided with a 


1 F. EB. Schulze. Rept. Voy. Challenger, 1887, 21, p. 221, pl. 40, figs. 1-16. 


HYALONEMA (PHIALONEMA) PATERIFERUM. 368 


stalk 330 mm. long, and 6 mm. thick at the base. Another is saucer-shaped, 
40 mm. deep, 85 mm. long, and 65 mm. broad. The dermal membrane and the 
central part of the gastral membrane are reticulate. The marginal part of the 
latter is perforated by efferent pores 1.5 mm. wide. The specimens of form B 
are, according to the same author (loc. cit.), flattened. One is saucer-shaped, 
15 mm. deep, 80 mm. long, and 60 mm. broad; the other a fragment, probably 
of a similar sponge. The surface is continuous and smooth, not reticulate. 
The specimen of form C (Plate 52, fig. 20) appears as a broad and low, conic cup. 
It is 52 mm. high, 61 mm. long, and 54 mm. broad. The central part of the 
cup-wall is very thick. Distally it thins out to a sharp margin. The lower 
truncate end, from which in life the stalk probably arose, is lacerated. No trace 
of a stalk or a gastral cone can now be detected in the specimen. The outer 
(dermal) surface of the cup-wall is much damaged, and appears irregular and 
very porous. The inner (gastral) surface is, for a considerable extent, still 
covered by the gastral membrane. This is perforated by rather large broad- 
oval apertures. The specimen of form D (Plate 52, fig. 21) is a slightly curved 
lamella with rounded margin, 45 mm. long, 36 mm. broad, and uniformly 10 mm. 
thick. The larger part of the surface is smooth. On the concave (gastral) 
face the superficial (gastral) membrane is preserved. There is no gastral cone. 
A portion of the margin of the sponge is much lacerated. From this part the 
now missing stalk probably arose. The specimen of form EH (Plate 51, fig. 1) 
is a porous, lacerated, lamellar fragment, and measures 60 by 32 by 8 mm. 
The specimen of form F is likewise very fragmentary. It appears as an irregular, 
porous lamella and measures 33 by 29 by 4 mm. 

The colour of the specimens of forms C and D in spirit is brown with a 
greenish tinge, that of form H# reddish brown, and that of form F whitish. 

Canal-system. The efferent canal-systems are, according to Wilson (loc. cit.), 
in form A 5-10 mm. wide, and traceable quite down to the basal part of the 
sponge. In form D the flagellate chambers appear to be elongated, sac-shaped, 
irregularly curved, and 70-90 u broad. 

The skeleton. The surface of the body is covered with a dense pinule-fur 
(Plate 52, figs. 22,23). In the forms A and B examined by Wilson (loc. cit.) the 
fur of the dermal face is composed of pinules with distal rays of moderate and 
fairly equal length. On the gastral face pinules with much longer distal rays 
lie scattered between the masses of pinules with moderately long distal rays. 
In the forms C and D, pinules with long distal rays are scattered among the ordi- 


nary ones also in the fur of the dermal face. So far as the fragmentary state 


364 HYALONEMA (PHIALONEMA) PATERIFERUM. 


of the specimens allows one to judge, this is also the case in the forms EF and F. 
It is certainly true in some forms, probably in all, that from the margins which 
mark the boundary between the dermal and the gastral faces there arise centro- 
tyle amphioxes, diactine pinules, and spicules transitional between these forms. 
Besides the lateral rays of the pinules, amphidises, paratangentially extending 
centrotyle amphioxes, and the lateral rays of pentactine megascleres are found 
in the dermal and gastral membranes. According to Wilson (loc. cit.) the amphi- 
dises of the superficial membranes are large macramphidiscs, and he says that 
these spicules are very abundant in these membranes of the forms (A and B) 
studied by him. In the specimens of forms D and EF, examined by me, where 
the superficial membranes are more or less preserved, I found them occupied 
by micramphidises in places very abundant, but nearly destitute of macram- 
phidises. Below the superficial membranes, the apical (proximal rays of the 
pentactines, centrotyle amphioxes, and a few transitions between them.and diac- 
tine pinules, occur. All these spicules (spicule-rays) are situated radially. 
Hexactine megascleres, canalar pinules, microhexactines, transitions between 
these and the pinules, and amphidises are met in the interior of the body rhabds, 
which are, for the most part, centrotyle amphioxes. In the vicinity of the point 
of origin of the stalk stout-rayed acanthophores occur. Many of the rhabds 
of the interior form bundles which traverse the choanosome. The hexactine 
megascleres appear to increase in size toward the central part of the sponge. 
In the forms C, D, HE, and F the canalar pinules are scarce, and irregularly 
and sparsely scattered over the walls of some of the canals only, the walls of 
other canals appearing to be destitute of these spicules. The microhexactines 
vary considerably in respect to their size, their spinulation, and the curvature 
of their rays. Wilson (loc. cit.) considers the large, straight-rayed, and strongly 
spined ones (in the forms A and B) as canalaria. In the forms D, EH, and F 
these spicules do not appear to be restricted to the canal-walls. In form C I 
failed to find any of the large, straighter-rayed microhexactines. The hexactine 
and pentactine transitions between the microhexactines and the pinules are, 
in the forms D, E, and F true canalaria. The amphidises, among which four 
forms can be distinguished, are exceedingly abundant. Micramphidiscs, chiefly 
large ones, clothe the walls of the efferent canals of form D in dense masses. 
In the forms C, D, EL, and F macramphidiscs are scattered in very large numbers 
through the choanosome. According to Wilson (loc. cit.) only few macramphi- 
discs occur in the interior of forms A and B. The large macramphidises are 


much more numerous than the small ones. The stout-rayed acanthophores 


HYALONEMA (PHIALONEMA) PATERIFERUM. 365 


were chiefly observed by Wilson (loc. cit.) in one of the specimens of form A, 
and by me in the specimen of form ?. They probably occur in equal abundance 
also in the others, and in all they envelop the parts of the stalk-spicules lying 
just below the surface, within the body of the sponge. The stalk is preserved 
only in one of the specimens of form A. It consists here, according to Wilson 
(loc. cit.), of about fifty spicules, broken off below. 

The marginal pinules are diactine; the dermal, gastral, and canalar mostly 
pentactine, more rarely hexactine, and still more rarely diactine. I was unable 
to find any marked difference between the dermal, gastral, and canalar pinules. 
The slight difference in the length of the distal ray of the canalar and the other 
pinules, noticed by Wilson (loc. cit.) in the forms A and B, is not pronounced in 
the forms examined by me. I shall, therefore, in describing the pinules, not 
take their position into account. 

By far the most frequent form of pinule is a pentactine with rays of moderate 
length. In the other, much less frequent forms, a sixth (proximal) ray is devel- 
oped, or the distal or lateral rays are elongated, or the latter reduced to mere 
rounded knobs. The pentactine (and hexactine) pinules are connected by trans- 
itions with each other and with the large straight-rayed microhexactines. The 
pinules with well-developed proximal and reduced lateral rays appear as diac- 
tines. These are connected by transitional forms with the centrotyle amphioxes 
but hardly at all with the other pinule-forms. 

The pentactine or (rarely) hexactine pinules with a distal ray of moderate 
length (Plate 50, figs. 6-8; Plate 52, figs. 11-14) and well-developed laterals 
have a conical distal ray, very gradually attenuated to an exceedingly slender 
and sharp-pointed terminal cone. The distal ray is, in the pinules with moderate 
laterals, generally straight; in those with long laterals, which usually also have 
a long sixth proximal, and which appear as transitions to the microhexactines, 
often curved. The basal and terminal parts of the distal ray are smooth; its 
central part bears small spines. The distal spines are always rather strongly 
inclined towards the tip of the ray. The proximal spines are either also so 
inclined (Plate 50, figs. 6-8), or more divergent, often even vertical, or inclined 
slightly in the opposite direction (Plate 52, figs. 11-13). The distal ray is in 
forms A and B, according to Wilson (loc. cit.), 100-220 u long, in form C 65-217 un, 
in form D 85-240 u, in form E 85-137 pu, and in form F 93-220 u. The basal 
and maximum thicknesses (together with the spines) of the distal ray are in forms 
A and B, according to Wilson (loc. cit.), base 5 4, maximum ?; in form C base 


3-5 w, maximum 7-20 uw; in form D base 2.5-5 », maximum 3-22 uy; in form EH 


366 HYALONEMA (PHIALONEMA) PATERIFERUM. 


base 4-6 », maximum 8-27 »; and in form F base 3.5-6 4, maximum 7-16 u. 
The maximum thickness of the distal ray, together with the spines, is in the 
ordinary pinules with laterals of moderate length usually 8-16 u; distal rays 
with a maximum thickness of only 6 u or less are found only among those forms 
with long laterals, which pass into the microhexactines. The lateral rays are 
in the forms A and B, according to Wilson (loc. cit.), pointed and nearly or quite 
smooth. In the forms C, D, H, and F they are also usually pointed, but smooth 
only exceptionally; as a rule they are provided with sparse, but rather large and 
conspicuous spines. Sometimes I observed lateral rays with much larger and 
more numerous spines which, in respect to spinulation, resembled the distal ray. 
The lateral rays are in the forms A and B, according to Wilson (loc. cit.), 
30-40 yu long, in form C 13-44 u, in form D 16-100 yg, in form EH 24-54 y, and in 
form F 26-63 4. The pinules with lateral rays more than 50 » long are mostly 
transitions to the microhexactines. In the ordinary pinules a sixth proximal 
ray is present only quite exceptionally, and here hardly ever more than 30 
long; in the pinules transitional to the microhexactines a proximal ray is gen- 
erally met, and in these it attains a length of 50-100. In regard to the 
spinulation, the proximal rays usually resembles the laterals. In some of the 
forms transitional to the microhexactines, the proximal ray is spined in a similar 
way to the distal. 

The pentactine pinules with elongated distal ray (Plate 52, fig. 15). The 
distal ray of these spicules is in the forms A and B examined by Wilson (loc. 
cit.) 300-400 » long, in form D 240-315 ». In forms C and F I observed only 
very few pinules of this kind. In these the distal ray was 350 u long. In 
form E I failed to find any pinules of this kind. I ascribe the absence of these 
spicules in this form and their scarcity in the preparations of forms C and F 
to the fragmentary condition of the specimen of these forms. In the forms 
C, D, and F the distal ray is 4.5-6.5 » thick at the base, conic, and generally 
somewhat curved. It terminates in an exceedingly long and slender, spineless 
terminal cone. Its middle-part bears small spines inclined towards the tip. 
Its maximum transverse diameter, together with the spines, is 5-14 4. In 
forms A and B, examined by Wilson (loc. cit.), the distal ray is similar. The 
lateral rays are pointed or, more rarely, rounded at the end. In the forms 
A and B, examined by Wilson (loc. cit.), they are 40 u long, in the forms C, D, 
and F, 15-38 u. 

The diactine pinules (Plate 52, fig. 16) appear as anisoactine, centrotyle 
amphioxes with numerous spines on their distal ray, and occasionally also a few 


HYALONEMA (PHIALONEMA) PATERIFERUM. 367 


spines on their proximal ray. Wilson (loc. cit.) gives the length of one of these 
spicules (of form A or B) as 700 w, and the thickness of its tyle as 124. The 
diactine pinules of the forms examined by me are shorter, not more than 470 y 
long. In form D, where I found the largest number of them, the distal ray is 
140-200 » long, 4-5 u thick at the base, conic, and attenuated distally to a very 
slender terminal cone. This terminal cone and a small region at the base of 
the ray are free from spines; the remaining parts bear small spines strongly 
inclined towards the tip of the ray. The proximal ray in the diactine pinules 
of this form (D) is 80-125 u long. The tyle, which consists of four knob-like 
protuberances (the rudiments of the four reduced lateral rays), measures 9-17 yu 
in transverse diameter. A diactine pinule of form C, which I measured, had a 
distal ray 350 u long, and 5 u thick at the base, a proximal ray 120 » long, and a 
central tyle 15 » in transverse diameter. 

The lateral rays of the (hypodermal and hypogastral) pentactines are, accord- 
ing to Wilson (loc. cit.), in the forms A and B 150-600 » long, and 12-48 uz thick 
at the base. In form D, where alone I could measure a large number of these 
spicules, their lateral rays are 120-360 u long and 12-30 uw thick. The proximal 
ray is generally longer than the lateral rays. The lateral rays are straight, 
smooth, and pointed; the proximal ray is similar, or, rarely, reduced in length, 
and thickened and rounded at the end. 

The hexactine megascleres. Wilson (loc. cit.) gives the measurements of one 
of these spicules (of form A or B) thus: — length of rays 700 yu, basal thickness 
48 ». In form D these hexactines have rays 25-41 uw thick at the base. One 
of the intact ones of this form was 1.2 mm. in diameter. 

The choanosomal rhabds are usually centrotyle amphioxes. In the forms A 
and B they measure, according to Wilson (loc. cit.), 0.5-8 mm. by 8-28 uw. In the 
forms examined by me they appear to be similar. 

The paratangential superficial and the radial subdermal and subgastral 
centrotyle amphioxes are in form D 320-520 u long and, near the middle, 3-10 u 
thick. The central tyle is 11-13 » in diameter. 

The stalk-spicules are in form A, where alone they have been observed, 
according to Wilson (loc. cit.), 0.13-1 mm. thick, attenuated below, and _ pro- 
vided with ‘‘the well-known annular ridges.” 

The acanthophores (Plate 52, figs. 17-19) are, according to Wilson (loc. cit.), 
in form A di- to hexactines, tetractines with unequal rays being most frequent. 
The measurements given by him are 900 u for the length of a diactine, and 250 u 
for the length of a ray of a tetractine. In form F I found di- to pentactine 


368 HYALONEMA (PHIALONEMA) PATERIFERUM. 


acanthophores with rays 15-30 » thick at the base. The diactines are here 
550-720 » long, the tri- to pentactines 290-720 » in maximum diameter. The 
rays of these spicules are somewhat irregular, wavy in outline, and often slightly 
curved. They usually taper distally. The end itself is frequently slightly 
thickened and terminally rounded. The basal and middle-parts of the rays 
are smooth, their end-parts, for a short distance, densely spined. 

Among the microhexactines (Plate 50, figs. 9, 10; Plate 51, figs. 23-28; 
Plate 52, figs. 1, 2) forms with small spines and strongly curved rays, and forms 
with larger spines and only slightly curved or straight rays, can be distinguished. 
The former are usually much smaller than the latter. The larger forms with 
straight rays are connected by transitions with the pinules. The rays of the 
microhexactines are in the forms A and B, according to Wilson (loc. cit.), 
30-80 » long, and in the small ones with curved rays 2 » thick. In the forms 
C, D, E, and F the rays of the microhexactines are, at the base, 1-3.5 u thick, 
usually 1.5-2.5 4. Those measured of form C were 55-80» in diameter, of 
form D 64-128 u, of form EH 55-150 uw, and of form F 59-138 u. The small 
microhexactines with curved rays are regular, the six rays of the same spicule 
being equal in size and curvature, all straight at the base, and uniformly curved 
in their distal part through an angle of 45°-135°. The direction of curvature 
in opposite rays is usually opposite (Plate 51, figs. 23, 24, 26, 28). In the rare, 
large microhexactines with curved rays, the curvature is irregular, and different 
in the different rays of the same spicule (Plate 51, fig. 25). In the large micro- 
hexactines with nearly straight rays, the six rays are generally equal. Any 
curvature observable in them is restricted to their distal part. 

Of amphidiscs four forms can be distinguished: — large macramphidises, 
small macramphidises, large micramphidises, and small micramphidises. The 
large and small macramphidises are not clearly separated biometrically (accord- 
ing to their length frequency) or morphologically. Nevertheless there is, in 
all the four forms examined by me, a deep depression at about 100 4 in the 
frequency-curve pertaining to these spicules, which renders it advisable to dis- 
tinguish them. The macramphidises shorter than 100 4 I consider as small, 
those longer as large ones. The macramphidises under 100 u» in length, that is 
the small ones, have relatively longer anchors and fewer anchor-teeth than 
those over 100 » in length, that is the large ones. The small macramphidises 
are clearly distinguished from the large micramphidiscs morphologically, the 
former having stout and smooth or nearly smooth shafts and broad terminal 
anchors; the latter slender and strongly spined shafts and narrow terminal 


HYALONEMA (PHIALONEMA) PATERIFERUM. 369 


anchors. The large and small micramphidises are distinguished biometrically 
by gaps in the frequency-curves pertaining to their length. These gaps lie in 
the different forms in different places, between lengths of 24 and 49 ». Wilson 
also distinguishes four forms of amphidises: — macramphidises (= large macram- 
phidises), amphidises (Wilson, loc. cit., Plate 1, figs. 10 and 11) (= small macram- 
phidises), mesamphidises (= large micramphidises), and micramphidises (= small 
micramphidises). He thinks it possible that the small macramphidises (with 
4-6 teeth in each anchor) represent young stages of the large macramphidises 
(with 8 teeth in each anchor). I do not think this is so. 

The large macramphidiscs (Plate 50, fig. 15; Plate 51, figs. 2, 16-22; Plate 
52, figs. 3, 4, 9, 10) have a shaft either cylindrical, and of uniform thickness 
throughout (Plate 52, fig. 10) or thickened towards the ends (Plate 51, fig. 18). 
In the smaller and medium-sized large macramphidises the shaft is usually nearly 
quite smooth (Plate 51, figs. 17, 19; Plate 52, fig. 4); in the larger ones it often 
bears a smaller or a larger number of very low and broad, rounded protuber- 
ances which are scattered irregularly over its central part. In the large macram- 
phidises (Plate 51, fig. 18) these protuberances are 64 broad and 2 uw high. 
The axial thread is perfectly simple, not thickened in the centre of the spicule, 
and there is no trace of an axial cross (Plate 50, fig. 15). The anchors are 
remarkably low and composed of from five to twelve teeth, most frequently 
eight. The individual teeth arise nearly vertically from the end of the shaft, 
and are curved concave towards it. The curvature is slight at the base, but 
increases distally, so that the axes of the end-parts of the teeth enclose angles 
of 30°-45° with the shaft-axis. The teeth of the same anchors are usually simi- 
lar (Plate 51, fig. 22); sometimes, however, particularly in the large macramphi- 
discs with more than eight teeth, one (Plate 51, fig. 21) or more of them are 
abnormally small. The teeth are T-shaped in transverse section. The upper 
part (of the T) is band-shaped, distally widened, at its broadest point 19-24 u 
in transverse diameter, and abruptly pointed; seen from above the teeth appear 
mitre-shaped. The lower part (of the T) is broad, low, and rounded below. It 
terminates some distance below the end of the teeth. 

The large macramphidises of form A and B are, according to Wilson (loc. 
cit.), 100-200 » long. In those of form A the shaft is 8-16 4 thick. Their 
anchors are composed of eight teeth. In the large macramphidises of form A 
the anchors are about one fifth of the whole spicule in length. Those of form B 
are about one seventh. Inform C the large macramphidises are 106-186 u long, 
most frequently about 137 u, and have shafts 14-22 » thick, exceptionally only 


370 HYALONEMA (PHIALONEMA) PATERIFERUM. 


8 yu. Their anchors are 17-30 uw long, usually one seventh to one fourth of the 
whole spicule, 68-101 » broad, and composed of from seven to eight teeth. The 
proportion of anchor-length to anchor-breadth is 100 to 273-429, on an average 
100 : 339. The large macramphidises of form D (Plate 52, figs. 3, 4, 9, 10) are 
100-318 » long, most frequently about 200 », and have shafts 10-22 » thick, 
rarely only 8y. Their anchors are 19-47 uw long, usually one ninth to one 
seventh of the spicule, 55-122 » broad, and composed of from six to nine, usually 
eight teeth. The proportion of anchor-length to anchor-breadth is 100 to 222-420, 
on an average 100 :298. The large macramphidises of form H are mostly regu- 
lar, but irregular forms also occur among them. The regular ones (Plate 50, 
fig. 15; Plate 51, figs. 2, 17-22) are 105-265 uw long, rarely as much as 334 yp, 
most frequently about 200 u, and have shafts 14-23 » thick. Their anchors 
are 17-35 » long, usually one tenth to one seventh of the whole spicule, 62-109 
uw broad, and composed of from eight to eleven teeth. The proportion of anchor- 
length to anchor-breadth is 100 to 276-500, on an average 100 : 361. The rare 
irregular large macramphidises of this form (Plate 51, fig. 16) differ from the 
regular by their anchors being longer and composed of less numerous and spirally 
twisted teeth. The irregular large macramphidise (Plate 51, fig. 16) is 116 u 
long and has a shaft 20 » thick and anchors 42 uw long and 54 » broad. The large 
macramphidises of form F are 103-188 » long, rarely as much as 235 u. The 
frequency-curve pertaining to their length has two summits, a higher one at about 
136.5 yw, and a lower one at about 164 u. The shafts of these spicules are 11-18 u 
thick, rarely as much as 22. Their anchors are 17—30 u long, usually one eighth 
of the whole spicule, 66-105 » broad, and composed of from five to twelve teeth. 
The proportion of anchor-length to anchor-breadth is 100 to 320-430, on an 
average 100 : 363. 

The small macramphidiscs (Plate 51, fig. 15; Plate 52, figs. 5-8) are similar 
to the large ones and have, like them, a shaft which is cylindrical and of uniform 
thickness throughout (Plate 51, fig. 15) or thickened towards the ends (Plate 52, 
figs. 5, 7). The shaft is either smooth (Plate 52, fig. 6), or it bears a few low 
tubercles scattered irregularly over its central part (Plate 52, fig. 8). The 
anchors are generally one sixth to one third of the whole spicule in length, and 
composed of from four to seven teeth; in the smallest forms there are four or 
five teeth. The number of teeth in the two anchors of the same spicule is often 
different. The teeth are similar to those of the large macramphidises above 
described, but, particularly in the smallest form, more slender, relatively longer, 


and more strongly curved. 


HYALONEMA (PHIALONEMA) PATERIFERUM. ovl 


The small macramphidises are in the forms A and B, according to Wilson 
(loc. cit.), 60-100 » long; in form C 68-100 yu, most frequently about 76 uw; in 
form D 63-96 u long, most frequently about 804; in form H 87-100 u long, 
most frequently about 954; and in form F 75-100» long, most frequently 
about 93 u. The thickness of their shafts are in form C 9-13 y, in form D 5-9 u, 


in form # 11-17 yn, and in form F 9-13 ». The anchors of these spicules are: 
in form C 18-28 » long and 40-65 » broad, the proportion of anchor-length to 
anchor-breadth being 100 to 143-333, on an average 100: 258; in form D 
(Plate 52, figs. 5-8) 25-31 uw long and 35-60 » broad, the proportion of anchor- 
length to anchor-breadth being 100 to 120-200, on an average 100 : 162; in 
form F (Plate 51, fig. 15) 18-25 w long and 52-70 uw broad, the proportion of 
anchor-length to anchor-breadth being 100 to 256-340, on an average 100 : 306; 
and in form F 14-20 p» long and 30-58 uw broad, the proportion of anchor-length 
to anchor-breadth being 100 to 210-330, on an average 100 : 286. 

The large micramphidiscs (Plate 50, fig. 14; Plate 51, figs. 9-14; Plate 52, 
‘figs. 27-29) have a shaft 1-3 4 thick and cylindrical throughout or slightly 
and gradually thickened in or near the middle. The shaft is beset with irregular 
obtuse spines 0.5-2 u long. These are generally very numerous, and usually 
occupy all parts of the shaft with the exception of its ends. The terminal 
anchors are long, rather narrow, and very obtuse. Sometimes their length 
is sufficient to bring the teeth of the two opposite anchors of the same spicule 
nearly into contact with each other (Plate 50, fig. 14; Plate 51, fig. 9). The 
individual teeth arise steeply from the shaft. They are curved only slightly 
in their basal part, but strongly and more or less abruptly bent down a short 
distance from their origin. Their distal and middle-parts, beyond this bend, 
are only slightly curved or straight and enclose a small angle, 20° or less, with 
the shaft-axis. Sometimes this angle is 0 (Plate 52, fig. 8); then they are 
parallel to the shaft. 

The large micramphidises of forms A and B are generally simple. Excep- 
tionally, however, they have more than two anchor-crowned rays. The ordinary 
simple ones are, according to Wilson (loc. cit.), 50-80 « long, and have anchors 
which are slightly more than a third of the whole spicule in length and com- 
posed of eight teeth. One of the large micramphidises with more than two 
anchor-crowned rays, measured by Wilson (loc. cit.), was 72 «in maximum diam- 
eter, and had five rays, three of which bore terminal anchors. The large 
micramphidises of form C are 49-66 u long, most frequently about 57 », and 


have anchors 15-28 u long, less than a third to nearly half of the whole spicule, 


372 HYALONEMA (PHIALONEMA) PATERIFERUM. 


and 15.5-28 » broad. The proportion of anchor-length to anchor-breadth is 100 
to 76-100, on an average 100 :92. Those of form D (Plate 52, figs. 27-29) are 
535277 uw long, most frequently about 52 », and have anchors 11—27 y» long, one 
third to nearly a half of the whole spicule, and 9.5—-22 » broad. The proportion 
of anchor-length to anchor-breadth is 100 to 62-91, on an average 100 : 76. 
Those of form E (Plate 50, fig. 14; Plate 51, figs. 7-14) are 47-86, most 
frequently about 73 » long, and have anchors 18-33 u, two fifths to nearly half 
of the whole spicule, and 14-29 » broad. The proportion of anchor-length to 
anchor-breadth is 100 to 57-87, on an average 100 :72. Those of form F are 
35-68 « long, most frequently about 53 u, and have anchors 10-25 » long, a 
quarter to nearly half of the whole spicule, and 7-19 u broad. The propor- 
tion of anchor-length to anchor-breadth is 100 to 63-88, on an average 100 : 73. 

The small micramphidiscs (Plate 50, figs. 11-13; Plate 51, figs. 3-6; Plate 52, 
figs. 24-26) have a straight shaft, 0.7-1.5 » thick, which is either cylindrical 
and of uniform thickness throughout, or slightly and gradually thickened in or 
near the middle. It usually bears a few scattered spines up to 1 yw in length 
in its middle-part. The terminal anchors are from under a third to two fifths 
of the whole spicule in length. They are obtuse in shape and composed of about 
eighteen teeth. The individual teeth arise vertically from the shaft, are nearly 
straight in their basal part, and then curve downwards. This curvature decreases 
distally. The ends of the teeth are nearly straight and enclose only small 
angles with the shaft-axis, or are parallel to it. 

The small micramphidises are in forms A and B, according to Wilson (loc. 
cit.), 20-25 » long. In form C they are 22-31 u long, most frequently about 
26 w; in form D 18-31 yu, most frequently about 24 u; in form EF, 15-30 u, most 
frequently about 21 4; and in form F 14—24 yu, most frequently about 20 u long. 
Their anchors are in form C 4-1 uw long and 5.5-12.5 » broad, the proportion of 
anchor-length to anchor-breadth being 100 to 95-178, on an average 100 : 140; 
in form D (Plate 52, figs. 24-26) 4-9 uw long and 7—9.5 uw broad, the proportion of 
anchor-length to anchor-breadth being 100 to 100-200, on an average 100 : 153; 
in form F (Plate 50, figs. 11-13; Plate 51, figs. 3-6) 4.5-9.5 w long and 5-10 pu 
broad, the proportion of anchor-length to anchor-breadth being 100 to 87-150, on 
an average 100 : 114; and in form F 3-6 » long and 4-8 uw broad, the proportion 
of anchor-length to anchor-breadth being 100 to 100-175, on an average 100 : 140. 

Eight specimens and three fragments of this species were collected in the 
central and eastern part of the Tropical Pacific. One specimen and three 
fragments of form A were trawled off Panama at Station 3363, on 26 February, 


HYALONEMA (PHIALONEMA) PATERIFERUM. 373 


1891; 5° 43’ N., 85° 50’ W.; depth 1788 m. (978 f.); they grew on white Globi- 
gerina ooze; the bottom-temperature was 37.5°. One specimen of form A was 
trawled off Panama, at Station 3376, on 4 March, 1891; 3°'9’ N., 82° 8’ W.; 
depth 2070 m. (1132 f.); it grew on gray Globigerina ooze; the bottom-tempera- 
ture was 36.3°. The two specimens of form B were trawled in the Central Tropi- 
cal Pacific at Station 3684 (A.A. 17) on 10 September, 1899; 0° 50’ N., 137° 54’ 
W.; depth 4504 m. (2463 f.); they grew on light yellow-gray Globigerina ooze. 
The single specimen of form C was trawled off northern Peru at Station 4651, 
on 11 November, 1904; 5° 41.7’ S., 82° 59.7’ W., Aguja Point S. 83° E., 206 km. 
(111 miles); depth 4063 m. (2222 f.); it grew on sticky, fine, gray sand; the bot- 
tom-temperature was 35.4°. The single specimen of form D was trawled off north- 
ern Peru W. 8. W. of Aguja Point, at Station 4656 on 13 November, 1904; 
6° 54.6’ S., 83° 34.3’ W.; depth 4063 m. (2222 f.); it grew on fine, ereen mud 
mixed with gray ooze; the bottom-temperature was 35.2°. The specimen of 
form / was trawled in the Eastern Tropical Pacific, at Station 4721, on 15 Janu- 
ary, 1905; 8° 7.5’ S., 104° 10.5’ W.; depth 3811 m. (2084 f.); it grew on 
light brown Globigerina ooze. The single specimen of form F was trawled in 
the Eastern Tropical Pacific at Station 4742, on 15 February, 1905; 0° 3.4’ N., 
117° 15.8’ W.; depth 4243 m. (2320 f.); it grew on very light, fine Globigerina 
ooze; the bottom-temperature was 34.3°. 

There can, I think, be no doubt that the four sponges described above all 
belong to Wilson’s Hyalonema pateriferum. The specimens of this species studied 
by Wilson from the Stations 3363 and 3376 appear to be fairly identical with 
each other, but differ from all the rest. The specimens described by him from 
Station 3684 (A.A. 17) are likewise identical with each other and different from 
all the rest. The four specimens examined by me, which all come from different 
stations, differ from each other and from the specimens described by Wilson. 

The following are the fourteen more important spicule-dimensions, of which 
the averages and the nature of the variation have been ascertained:—a, the 
length of the distal ray of the ordinary pinules; b, the basal thickness of this 
ray; c, the length of the lateral rays of the ordinary pinules; d, the diameter of 
the microhexactines; e, the length of the large macramphidises; f, the thickness 
of the shafts of these spicules; g, the average proportion of the length to the 
breadth of the anchors of these spicules; h, the length of the small macramphi- 
dises; 2, the thickness of the shafts of these spicules; /, the average proportion 
of the length to the breadth of the anchors of these spicules; J, the length of 


the large micramphidises; m, the average proportion of the length to the breadth 


374 HYALONEMA (PHIALONEMA) PATERIFERUM. 


of the anchors of these spicules; n, the length of the small micramphidises; and 
o, the average proportion of the length to the breadth of the anchors of these 
spicules. 

a, The length of the distal ray of the ordinary pinules varies in the forms 
A, B, and F between about the same limits. The other forms differ, in respect 
to this dimension, from these and from each other. 6, The distal rays of the 
ordinary pinules are, in the forms A, B, EH, and F, usually about 5 u thick at the 
base, in forms C and D considerably thinner. c, The shortest lateral rays of the 
ordinary pinules are in the forms A and B 30 u long, in the forms H and F 24— 
26 uw, in form D 16 uw, and in form C only 13 u. d, The diameter! of the micro- 
hexactines varies in the forms A, B, and FE between fairly equal limits (55-160 1). 
In the forms D and F the largest microhexactines are smaller, only 128 » in 
diameter in the former and 138 uw in diameter in the latter. In form C these 
spicules are much smaller still. e, The length of the large macramphidises 
varies between similar limits (100-235 yu) in the forms A, B, C, and F. In the 
forms D and EF the largest large macramphidiscs are 300 » or more long, and 
also have a much greater average size. f, The shafts of the large macramphi- 
dises are thickest in forms C and E, thinner in form D and F, and still thinner in 
form A. In form B this dimension is not known. g, The average proportion 
of anchor-length to anchor-breadth is in the forms # and F 100 : 361 and 100 : 
363 respectively; in form C 100 : 339, and in form D only 100 : 298. In the 
forms A and B studied by Wilson it is not known. Since, however, Wilson 
(loc. cit.) states that in the former the anchor-length is one seventh and in the 
latter one fifth of the length of the whole spicule, which is said to be the same 
in both, it may be assumed that these two forms differ in respect to this anchor- 
proportion from each other. h, The small macramphidises are in the forms A, B, 
C, and D fairly equally long, in the forms # and F they are longer. 7, The thick- 
ness of the shafts of the small macramphidises is greatest in form H, equal and 
smaller in form C and F, and still smaller in form D. In forms A and B this 
dimension is not known. k, The average proportion of anchor-length to anchor- 
breadth of the small macramphidises is In the forms C, EH, and F 100 to over 250, 
in form D only 100 to 162. In the forms A and B this anchor-proportion is not 
known. J, The length of the large micramphidiscs varies in the forms A, B, and 
E between nearly equal limits (47-80 1), and is in form FH most frequently about 
73 ». In form C these spicules are not so large, most frequently 57 » long, and 
in forms D and F nearly equal and still shorter, most frequently 52 and 53 u 


‘In the forms A and B, where only the ray-length is given, the double ray-length is taken as the 
diameter. 


HYALONEMA (PHIALONEMA) PATERIFERUM. 375 


respectively. m, The average proportion of the anchor-length to the anchor- 
breadth of the large micramphidiscs is in form C 100 to 92, in the forms D, EF, 
and F 100 to 72-76. According to Wilson (loc. cit.), the length of the anchors 
of these spicules is, bothin forms A and B, a third of the length of the whole 
amphidise; the anchors of these spicules are in these two forms therefore 
probably also about equal in respect to the proportion between length and 
breadth. n, Informs A and B the length (20-25 ») of the small micramphidises is 
equal. In forms C and D these spicules are larger, most frequently about 26 and 
24 » long respectively. In forms H and F they are smaller, most frequently 
about 20 and 21 u long respectively. 0, The average proportion of anchor- 
length to anchor-breadth of the small micramphidiscs is in form D 100 to 153, 
in.form C and F100 to 140, and in form # 100 to 114. In the forms A and B this 
proportion is not known. 

The affinities of the six different forms in respect to these further qualities 


are tabulated below :— 


| 3684 (A.A. 17) (form B) 9 abedehlmn 


4651 (form C) 2 eh 
3363 and 3376 
ont Ay 4656 (form D) 1 h y 
4721 (form E) 3 bdl 
SS ——————— es 
% | 4742 (form F) 3 abe 
a a 
3S ¢q . 5 
Bs E 4651 (form C) 4 2 fy eh 
g ; . 2 
5 3684 (A.A. 17) q 4656 (form D) 3 1 z h 
oa ‘ 8 a +e 
L (dostile) ‘o> | 4721 (form E) B 3 =} {loclit 
Z e g 5 
n a 
3 2 | 4742 (form F) # 3 © Jabe 
= = E 
© Ss 4656 (form D) 3 bhn 
a e 
4651 (form C) $ | 4721 (form E) 2 ik 
ah 
a 
4742 (form F) 4 eiko 
4721 (form E) 2 em 
4656 (form D) 
4742 (form F) 4 dflm 
4721 (form E) 4742 (form IF) 7 beghkmn 


According to this table the units of all the fifteen possible pairs of forms, 
with the exception of those of two, coincide with respect to only 1-4 of the 


376 SKIANEMA: 


fourteen qualities here discussed, and must therefore, I think, be kept distinct. 
The two pairs A-B and E-F are more similar. The units of the first coincide 
in respect to nine, the units of the second in respect to seven of these fourteen 
qualities. The pair A—B consists of the two forms described by Wilson, and it 
must, in comparing these, be kept in mind that this author does not give the 
measurements of all the dimensions and proportions (a—-o) here discussed, and 
of the dimensions he does give mentions only to limits, but states neither the 
biometric character of the variation nor the averages of the individual measure- 
ments. As his measurements are insufficient for this comparison it is probable 
that these two forms do not coincide in the manner indicated by the figures 
given in the above table. However this may be, there doubtlessly exists a con- 
siderable difference between the large macramphidises of these forms, the 
length of the anchors being one seventh of the length of the whole spicule in 
the one, and one fifth in the other. I think this difference by itself sufficient 
to keep the forms A and B distinct. 

The forms £ and F are certainly very similar. The chief differences between 
them are that the large macramphidiscs and large micramphidiscs are larger, 
and that the breadth of the anchors of the small micramphidises is relatively 
smaller in the former than in the latter. The specimens of both these forms 
are very fragmentary, which renders it doubly difficult to decide whether the 
observed differences between them should be considered sufficient to keep them 
distinct or not. In doubtful cases like this, it is, I think, better to keep similar 
specimens distinct rather than to unite them. 

The differences between these six lots of sponges are slight, not correlated 
to the distance between the stations where they were obtained, and in my 
opinion insufficient for varietal distinction. They render it however advisable 
to describe them as different forms of Hyalonema pateriferum. These forms are 
not equivalent, H and F being much more similar than any other pair, with the 
exception possibly of A and B, . 


SKIANEMA, subgen. nov. 


Species of Hyalonema of which the amphidises of one kind have relatively 
rather large, broad and low, umbrella-shaped terminal anchors. 

The collection contains three specimens of this subgenus, which belong to 
two species, both of which are new. 


HYALONEMA (SKIANEMA) AEQUATORIALE. 377 


Hyalonema (Skianema) aequatoriale, sp. nov. 


Plate 99, figs. 1-37; Plate 100, figs. 1-12; Plate 101, figs. 1-3. 


A single specimen of this species was trawled in the Eastern Tropical Pacific 
at Station 4742 on 15 February, 1905; 0° 3.4’ N., 117° 15.8’ W.; depth 4243 m. 
(2320 f.); it grew on a bottom of very light, fine Globigerina ooze; the bottom- 
temperature was 34.3°. 

The locality where it was found lies nearly under the equator and to this 
the name refers. 

Shape and size. The single specimen is somewhat lacerated and fragmentary. 
It now appears (Plate 99, fig. 17) flattened and elongate. One end is rounded. 
At the other it terminates with a nearly straight margin vertical to the two longer 
sides. It is 71 mm. long, 45mm. broad, and has a maximum thickness of 15 mm. 
In life it was probably not much thinner than broad. The straight terminus is 
the upper gastral face. It is slightly depressed in its middle-part, from which 
a gastral cone arises. This cone is surrounded by thin, more or less vertical, 
radiating lamellae, between which extend extensive cavities, now much com- 
pressed. The rounded end is the lower, and from it doubtlessly arose in life 
a stalk, which has, however, been completely lost. 

The colour in spirit is whitish brown. 

Traces of elongate flagellate chambers about 75 » broad can be made out here 
and there in the sections. 

The skeleton. A dense spicule-fur covers all intact parts of the surface 
(Plate 101, figs. 1, 2a, 3). Between the basal parts of the distal rays of the 
superficial pinules forming this fur are met small macramphidiscs, generally 
with the shaft vertical to the surface of the sponge (Plate 101, fig. 2c). The 
superficial membranes are supported by the lateral rays of the (dermal and 
gastral) pinules, and the (hypodermal and hypogastral) pentactines; paratan- 
gential rhabds also occur in it in considerable numbers (Plate 101, fig. 3). Just 
below the surface numerous large macramphidiscs are found (Plate 101, fig. 2d). 
A loose bundle of large amphioxes occupies the axial part of the sponge. This 
bundle extends completely into the gastral cone. More or less radially extending 
rhabds occur in the choanosome. Most of the rhabds in the superficial mem- 
branes and in these bundles are amphioxes; some diactine styles or tylostyles, 
however, also occur. Microhexactines are scattered throughout the choano- 
some in large numbers. Large and small micramphidises are also found in it. 
These spicules are, however, rather rare. In the interior of the gastral cone 


a good many spheres have been observed. 


378 HYALONEMA (SKIANEMA) AEQUATORIALE. 


Foreign skeletal elements are always met in the deep-sea hexactinellids 
which have, like the specimen here described, been somewhat injured in capture. 
I do not remember, however, ever having seen a sponge so rich in foreign spicules 
as this one. The spicules in question could be determined as foreign because 
they are identical with the pentactines, pinules, hexasters, amphidises, etc., 
of Holascella euonyx, Hyalonema (Hyalonema) agassizi, Hyalonema (Prionema) 
fimbriatum, Hyalonema (Phialonema) pateriferum, and Hyalonema (Prionema) 
spinosum brought up in the same haul together with the sponge here under 
discussion. 

The dermal pinules (Plate 99, figs. 29-31) are generally pentactine, rarely 
hexactine. The distal ray is straight, 200-260 u long, and 5-8 uw thick at the 
base. It ends in a rather slender sharp-pointed terminal cone, and bears every- 
where, except at the base and at the tip, rather slender straight or slightly curved 
spines, which are all strongly inclined towards its tip. The maximum thickness 
of the distal ray, together with the spines, is 25-42 4. The lateral rays are 
cylindroconical, pointed, spiny, and 30-45 » long. The proximal ray of the rare 
hexactine forms (Plate 99, fig. 29) is 9-42 u» long. 

The gastral pinules (Plate 99, figs. 25-28, 36) are a little larger than the 
dermals and appear always to be pentactine. Their straight distal ray is 212— 
275 w long, and 6-9 uw thick at the base. It ends with a long and slender sharp- 
pointed terminal cone and bears everywhere, except at the tip and at the base, 
remarkably sparse spines. These spines are long, slender, straight or slightly 
curved, and strongly inclined towards the tip of the ray. The maximum thick- 
ness of the distal ray, together with the spines, is 23-39 ». The lateral rays 
are 35-48 » long and, like those of the dermal pinules, cylindroconical and 
spined. 

The hypodermal and hypogastral pentactines seem to be quite similar. Their 
rays are conical, straight, and blunt. The proximal ray is generally 0.4-1 mm. 
long, and 16-50 » thick at the base. The lateral rays are 140-800 uz. 

The hexactine megascleres are mostly 360-850 » in diameter, and have coni- 
eal, blunt, and straight rays 9-31 » thick at the base. A few fragments observed 
in the preparations indicate that some of these spicules attain a larger size. 

The ordinary superficial and choanosomal amphioxes are straight or slightly 
curved and usually more or less centrotyle. In some no trace of a central 
thickening could be made out. These spicules are 0.25 u-1.9 mm. long, and 
7-26 » thick near the middle. The central tyle is sometimes 6 » in transverse 
diameter, usually about 0.3 « more than the adjacent parts of the spicule. The 


HYALONEMA (SKIANEMA) AEQUATORIALE. 379 


“central” tyle is often situated a considerable distance away from the middle 
of the length of the spicule, many of these centrotyle amphioxes being markedly 
anisoactine. 

The styles and tylostyles are, like the amphioxes above described, centrotyle 
diactine rhabds. One of their rays is similar to an amphiox-ray, the other is 
reduced in length and rounded, and generally also thickened at the end. These 
spicules are 0.5-2 mm. long. They are slightly thickened at the morphological 
centre, in which the axial cross can always be made out, and are here 8-25 yu 
thick. The rounded end (terminal tyle) is 8-40 4 in diameter and usually 
separated from the remaining part of the spicule by an attenuation. In this 
attenuation, or neck, the spicule is 1-11 « thinner, usually 3-6 uv, than the rounded 
end (terminal tyle). 

The large amphioxes of the rhabd-bundle which forms the skeletal axis of the 
sponge-body and terminates in the gastral cone are 2 mm. and more (the long 
ones are broken) long and 30-60 u thick. 

The spheres are regularly spherical, oval, or irregular, potato-shaped. 
They measure 17-170 » in maximum diameter, most frequently about 30 x. 
All contain a granular centrum round which silica-layers of somewhat varying 
refractory index have been deposited. The surface is in the smaller spheres 
regular, smooth, and continuous, in the larger it is usually irregular. As an 
example I shall describe a typical large sphere. This spicule is 168 » long and 
157 » broad. It has an oval granular centrum 12 4 long and 7 broad. The 
granules in it are numerous, and about 1 » in diameter. In the silica, which is 
perfectly hyaline, a concentric stratification around the centrum can be made 
out very clearly. In one place a watchglass-shaped granular body, which 
appears sickle-shaped in profile (optical section), is interpolated between two 
successive layers of ordinary hyaline silica. A number of groove-like inden- 
tures, sometimes 2 » deep, are visible on the surface of the sphere. Several of 
these radiate from one point. 

The microhexactines (Plate 99, figs. 3-10, 32-35) are 60-96 uw in maximum 
diameter. In some all the rays are fairly equal; in others two opposite rays are 
considerably longer than the other four. The latter are sometimes nearly twice 
as long as broad. The rays are 1.8—2.4 uw thick at the base. They are conical, 
finely pointed, and covered with very minute spines. The basal part, usually 
about half of the total length of the whole ray, is nearly straight, the distal part 
curved. This curvature is usually greater at the point where the basal straight 
part passes into the distal curved part than farther on. The whole curvature is 


380 HYALONEMA (SKIANEMA) AEQUATORIALE. 


such that the directions (tangents) of the proximal and distal end-parts of the 
ray generally enclose an angle of 105°-130°. The tips of opposite rays point in 
opposite directions. 

From a morphological point of view four kinds of amphidiscs are to be dis- 
tinguished: — A, larger forms with low (short) and very broad anchors, about a 
third of the length of the whole spicule; B, forms intermediate in size with rela- 
tively large anchors, about half as long as the whole spicule; C, forms inter- 
mediate in size with small, relatively broad anchors, a fourth to a fifth of the 
whole spicule in length; and D, small forms with more slender anchors. 

As the length frequency-curves in Figure 24 show, these four morpho- 
logically different kinds of amphidises are by no means all clearly separated 
also biometrically. In fact the curve pertaining to the amphidises of the 
groups B and C overlap to a large extent, and only the curve pertaining to 
group D is clearly distinct from the others. 

In view of the great morphological difference between the groups B and C 
and the total absence of intermediate forms connecting these two groups, I 
do not hesitate to consider them as different kinds of amphidises. I distinguish 
altogether four different kinds of amphidises in this sponge: — large (group A) 
and small (group B) macramphidiscs, and large (group C) and small (group D) 
micramphidises. The length frequency-curves pertaining to the first three forms 
are quite simple and without deep depressions; these groups are biometrically 
homogeneous. The curve pertaining to the small micramphidises (group D) 
is complicated, however, by two deep depressions descending to the O-line, which 
divide it into three parts. Since, however, the larger, the medium, and the 
smaller small micramphidises pertaining to the three distinct elevations of this 
curve are quite similar in shape, I do not think it advisable to distinguish sub- 
groups within this amphidisc-group. 

The regular large macramphidiscs (Plate 99, figs. 1, 2, 37; Plate 100, figs. 
5-11; Plate 101, fig. 2d) are 105-298 » long, usually 122-257 », most fre- 
quently about 180 u. The shaft is straight, cylindrical, perfectly smooth, and 
14-27 » thick, generally 19-27 uy. The terminal anchors are 42-87 » long, 
about a third of the whole spicule, and 90-195 » broad. The proportion of the 
length to the breadth of the anchors is 100 to 191-288, on an average 100 : 
236.8. Each anchor consists of from eight to eleven teeth. The teeth of the 
two anchors of the same spicule are generally situated alternately. The teeth 
arise nearly vertically from the ends of the shaft, are curved very slightly in 


their proximal part, but very strongly in their distal part, and their tips converge 


Macramphidiscs 


D 

——————————————— eee 
Fe Large 
Zz Small = 

———xm—_—_—_—"—_.7. 

Micramphidiscs 
30 —_—_— sash 
¢ Small Large — —_Macramphidiscs in general 
25 ee es, es yee Macramphidiscs 
wer \ Micramphidiscs 


LES Gear a RE Se ei er ae nie ay Ua ara 


10 


a ee Oe — —J—\— -—- —-\- —S: 


ae 
1s 


MEMCEna lsc <> > Ss (ime ei ae a 
Meee ois or eee ele PN ee fees eee at 

i Be Nici cra eat Cone teas eat Sat oy Cah St oN OR ON ONC Hat oe Cue eieey ten tae 
mT Coon! rr! ioe) 
BIOTA ANBSRSTARAREARKAASH RAS ASSES SSSE 
YOFTMOn~MDHTMNWMOWOARTRNODAWDTONOCMAHRONn-DAOFROKROnst x 

i] STH TNNNNYNOMABAHIMOOOMnOODOANTOLNn- WOON WMNOCM 

0 re 

ee | ella ee lel a tee lel se tel lel oh ‘be 
NAN OMODAMNMOONRWOOWMOMDWOAODAIOAAN DMD MOKnOR €C D 
HQaAVOetAaNABeaaSGAQARRanSsgagesagsggsgrcsgy 
Fn trtwmoner~nnhRrMW OO ty oa LO GON COR OR ON OTA OreOns 

Bee RA TR TR NNNM 


Length of Amphidiscs (). 


Amphidises 


Fig. 24. 


382 HYALONEMA (SKIANEMA) AEQUATORIALE. 


very markedly. The distances between the ends of opposite teeth are therefore 
smaller than the breadth of the anchor. While the latter is, as above stated, 
90-195 », the former is only 83-164 yu, that is 7-20» less. The outer band- 
shaped part of the tooth attains its maximum width of 17-29 » about two thirds 
of its length from its base. Distally it is simply rounded off. The keel in the 
larger forms is, at the base of the tooth, about 30 » high, decreases in height 
distally, and terminates some distance within the tip of the tooth. 

Besides the regular large macramphidises above described, a good many 
irregular large macramphidiscs (Plate 99, figs. 18-20) have been observed. The 
irregularity most frequently observed is an inequality of the two anchors of the 
same spicule. These may differ in size, in the proportion of their length to their 
breadth, and in the number of teeth composing them. The irregular large 
macramphidises of this kind are about as large as the regular ones. Much more 
rarely smaller forms are met, in which either a large conic protuberance arises 
from the apex of one of the anchors (Plate 99, fig. 18) or the anchors are quite 
irregular. The teeth composing such anchors are exceedingly unequal, some 
being hypertrophied, twisted, or otherwise deformed, others rudimentary (Plate 
99, figs. 19, 20). 

The small macramphidiscs (Plate 100, figs. 1-4, 12; Plate 101, fig. 2c) are 
70-120 uw long, most frequently about 84.2 4. The shaft is straight, cylindrical, 
perfectly smooth, and 6.5-13 » thick. The terminal anchors are 38-50 u long, 
about half the whole spicule, and 37-84 » broad. The proportion of the length 
to the breadth of the anchors is 100 to 120-175, on an average 100 : 146.6. 
Each anchor is composed of from ten to twelve teeth. The teeth of the two 
anchors of the same spicule are generally situated alternately, but this alternation 
is only exceptionally regular, usually it is more or less irregular. The individual 
teeth are curved quite uniformly for the greater part of their length through 
about a quarter of a circle, so that the whole anchor is more or less hemispherical 
in shape. Their extreme tips are strongly bent inward and converge, so that 
the distance between the ends of opposite teeth is usually about 6 u less than 
the breadth of the anchor. The outer band-shaped part of the tooth attains its 
maximum breadth of 10-14 u in its distal half, and is rounded or, more rarely, 
blunt-pointed at the end. 

Differences in the number of teeth of the two anchors of the same spicule, 
differences in the size of the teeth of the same anchor (Plate 100, fig. 3), and other 
irregularities often occur. 


The large micramphidiscs (Plate 99, figs. 11-16) are 54-84 » long, most 


HYALONEMA (SKIANEMA) UMBRACULUM. 383 


frequently about 69.5». The shaft is straight or slightly curved, and of a 
uniform thickness of 2.5-5 » throughout or slightly centrotyle. It bears very 
low and broad, tubercle-like, scattered protuberances (spines). The terminal 
anchors are 12-18 uw long, a fifth to a fourth of the whole spicule, and 19-25 u 
broad. The proportion of the length to the breadth of the anchors is 100 to 
134-167, on an average 100 :148.1. Each terminal anchor consists of from 
twelve to sixteen teeth. The individual teeth are curved only slightly in their 
proximal and distal parts, but rather strongly in their middle-part. Their total 
curvature is such that their nearly straight ends diverge. The anchor-teeth are 
rather slender and pointed at the end. 

The small micramphidiscs (Plate 99, figs. 21-24) are 14—25.5 » long, most 
frequently about 18.3 4. The shaft is straight or slightly curved, generally 
of a fairly uniform thickness of 0.7-1.2 » throughout, and covered with minute 
scattered spines. The terminal anchors are 3.5-8 » long, a quarter to a third 
of the whole spicule, and 4.5-8 » broad. The proportion of the length to the 
breadth of the anchors is 100 to 81-148, on an average 100 :98. The individual 
teeth are rather strongly and uniformly curved in their proximal part, and nearly 
straight in their distal part. The straight distal parts of the teeth of the same 
anchor are more or less parallel. 

The nearest allies of the above sponge are Hyalonema (Skianema) umbra- 
culum and H. (Thallonema) geminatum. From H. (S). umbraculum it differs 
by having smaller large micramphidises, from H. (T.) geminatum by being desti- 
tute of the geminate amphidises and the different shape of the pinules, and from 


both by the possession of spheres. 


Hyalonema (Skianema) umbraculum, sp. nov. 


Plate 101, figs. 4-17; Plate 102, figs. 1-8; Plate 103, figs. 1-36. 


Two fragmentary specimens of this species were trawled in the Central 
Tropical Pacific at Station 4740 on 11 February, 1905; 9° 2.1’ 5., 123° 20.1’ W.; 
depth 4429 m. (2422 f.); they grew on a bottom of dark gray Globigerina 
ooze; the bottom-temperature was 34.2°. 

The terminal anchors of the large macramphidises are very broad and 
low, umbrella-shaped. To this the name refers. 

Shape and size. The larger specimen is an irregular oval lamella with 
lacerated margin, from one of the narrow ends of which a couple of stout stalk- 


spicules protrude. The lamella is 62 mm. long, 39 mm. broad, and about 


384 HYALONEMA (SKIANEMA) UMBRACULUM. 


2mm. thick. It has obviously been strongly compressed during or after capture, 
and I do not think that the living sponge, of which it once formed a part, was 
at all lamellar. The other specimen (fragment) is similar but much smaller. 

The colour in spirit is light brown. 

The skeleton is composed of superficial pinules, hypodermal and hypogastral 
pentactines, hexactine megascleres, choanosomal and superficial rhabds, acan- 
thophores, axial amphioxes forming an upper continuation of the stalk in the 
sponge-body, stalk-spicules proper, microhexactines, diactine microhexactine- 
derivates, and amphidises. The hexactine megascleres are exceedingly scarce. 
The superficial and choanosomal rhabds are for the most part centrotyle am- 
phioxes, but diactine tylostyles also occur among them. The microhexactines 
are abundant, their diactine-derivates very rare. The amphidises are of four 
kinds:— large and small macramphidises, and large and small micramphidiscs. 
The small micramphidises are remarkably scarce. 

The dermal and gastral superficial pinules (Plate 103, figs. 9-13) appear 
to be quite similar. All the pinules observed were pentactine. The distal ray 
is straight, 178-290 » long, most frequently about 240 u, and 4-11 » thick at 
the base. It ends with a rather long and slender spineless terminal cone, and 
its basal part is also free from spines. The middle-part of the distal ray is, for 
about two thirds of its length, covered with straight or slightly curved spines, 
which are strongly inclined towards its tip. The spines situated half way up 
the ray are the largest. The maximum thickness of the distal ray, together 
with the spines, is 27-40 4. The lateral rays are cylindroconical, blunt, spiny, 
and 28-48 u long. 

The rays of the hypodermal and hypogastral pentactines are cylindroconical 
and very blunt. In the intact pentactines observed the proximal ray is 370- 
480 » long, and 14-18 u» thick at the base, while the lateral rays attain a length 
of 120-240 »; however, judging from the fragments of larger ones found in the 
preparations, the rays of these pentactines must frequently attain a much larger 
size. The largest lateral rays of fragmentary pentactines observed attain 1 mm. 
in length and 70 » in thickness at the base. These very large fragments may, 
however, be parts of foreign spicules. 

One of the very rare hexactine megascleres measured is 480 » in maximum 
diameter, and has terminally rounded, cylindroconical rays 12 thick at the 
base. One of the rays of this spicule is considerably longer than the other four. 

The choanosomal and superficial amphiozes are centrotyle, 0.5—2.5 mm. long, 


usually 1-1.5 mm., and 11-264 thick near the centre. The central tyle is 14- 


HYALONEMA (SKIANEMA) UMBRACULUM. 385 


28 » in transverse diameter, that is 1-3 1 more than the adjacent parts of the 
spicule. 

The diactine tylostyles are much more frequent in the smaller specimen 
than in the larger. They are about 1 mm. long, and at the morphological cen- 
trum, where a slight thickening is to be noticed, are 9-16 » in transverse diameter. 
The rounded end is 20-28 y, and the attenuated ‘‘neck,” separating it from the 
rest of the spicule, is 11-15 u thick. 

The rhabds of the axial skeleton, which form the upper continuation of the 
stalk within the body of the sponge, are 50-100 » thick. As nearly all these 
spicules found in the preparations are broken, I could not determine their length. 

The few large spicules of the stalk proper are 540-630 u thick. 

The acanthophores of the basal part of the sponge (Plate 101, figs. 15-17) 
have from two to four rays. The tri- and tetractines are 340-580 » in maximum 
diameter, their rays being 14-40 » thick at the base. The extreme tips of the 
rays are generally spineless, smooth, simply rounded, and dome-shaped. On 
this smooth end-part follows a spiny belt, usually occupying from a quarter 
to a half of the whole ray. Proximally the spines in these belts become smaller 
and smaller until they disappear altogether, leaving from half to three quarters 
of the ray entirely smooth. 

The microhexactines (Plate 101, figs. 4-7, 11-14) are 40-100 » in diameter, 
on an average 64.3 u. The rays are either equal, or two opposite ones exceed 
the other four in length. The basal part of the rays is quite straight, the distal 
part, usually a little less than half of the ray, uniformly curved and so strongly 
that the directions (tangents) of the basal half and the tip of the ray enclose an 
angle often as small as 90° or even smaller. The rays are conical, 1.1—1.8 
thick at the base, and end in fine points. They are fairly smooth or only slightly 
roughened by barely visible spines. 

Besides these regular microhexactines a few diactine microhexactine-derivates 
(Plate 101, fig. 14) have been observed. These spicules appear as centrotyle 
amphioxes with fine, curved end-parts. Their surface is more rough (spiny) 
than that of the regular microhexactines. 

The measurements of a typical spicule of this kind are: — length 91 yu, 
diameter of central tyle 3 u, basal thickness of rays 1.5 u. 

Morphologically two main kinds of amphidiscs can be distinguished: — 
those with relatively large and broad terminal anchors and those with inter- 
mediate or relatively small, not particularly broad anchors. The former, which 

‘are 78-280 u long, I consider as macramphidises; the latter, which are 16-99 u 


long, as micramphidiscs. 


386 HYALONEMA (SKIANEMA) UMBRACULUM. 


The larger macramphidises have very broad and rather short anchors, 
usually about a third of the whole spicule in length. The smaller have rela- 
tively much longer anchors, usually about half the whole spicule in length. 
Forms intermediate in respect to the proportion of the length to the breadth of 
the anchors connect the larger, shorter- and the smaller, longer-anchored 
kinds of these spicules. These intermediate forms are, however, far from 
numerous. 

The length frequency-curve in Figure 25 shows that the larger (short- 
anchored) and the smaller (long-anchored) macramphidises are very clearly 
distinguished biometrically. This biometrical distinction, together with the 
rarity of the forms transitional between the two morphologically, makes a sub- 
division of the macramphidises into two subgroups necessary; namely :— large 
macramphidises, larger forms with anchors usually about a third of the length 
of the whole spicule; and small macramphidises, smaller forms with anchors 
usually about half of the whole spicule in length. 

The part of the length frequency-curve pertaining to the micramphidises 
is divided, by a deep depression extending quite down to the O-line, into two 
parts, one comprising the larger forms, 54-99 u in length, the other comprising 
the smaller forms, 16—38.7 u in length. Although the larger and the smaller 
of these spicules differ morphologically only in so far as the anchors are on the 
whole relatively broader in the former than in the latter; neverthéless I think 
it advisable to distinguish also in this main amphidisc-group two subgroups, 
namely, large micramphidises, comprising the larger forms with broader anchors, 
and small micramphidises, comprising the smaller forms with narrower anchors. 

The length frequency-curves pertaining to the large and small macramphi- 
dises are quite simple and have, each, only one summit; these two amphidisec- 
groups are obviously homogeneous. The curves pertaining to the micramphi- 
dises on the other hand have, each, two depressions, dividing each into three 
parts. Although this division is very well-marked, particularly in the small 
micramphidises, I do not propose further to subdivide these subgroups of amphi- 
dises because I was unable to detect any morphological differences between the 
respective amphidises to which the different elevations of the curves pertain. 
Thus I distinguish four kinds of amphidises in this sponge: —large and small 
macramphidises, and large and small micramphidiscs. 

The regular large macramphidiscs (Plate 102, figs. 1, 2, 7, 8; Plate 103, 
figs. 1-8, 14-23) are 110-280 » long, most frequently about 268.4 u long. The 


shaft is straight, cylindrical, smooth, and 17—26.5 » thick. The terminal anchors 


Macramphidiscs. 


Number 


30 


25 


20 


; 
en es ee ee, ee ey A i eae eee ee E 
PES Pen ee eS Oe Ea I EY ae ON ners eee Pt See i 
Se ey a ' 
ee ae al i ; 
SS SSS SS SS SS SS SS SS SS A i i} 
SSS SS SSS SSS SSS SS SSS SSS SSS SE SSS SSS = ; 
4 va 
wae na a a a a nr a a ee / pall 
SR ie gis I” ee Fe Bae a ie ' WH 8 0 enn 
Tg at mma eg 
= SSS es SSS a ee Se re Sao Soon fi-if\ i earthen LL! 
= Pe = Fas Spee Ns ea teh SH Ee so 
Sea akan eRe Oe ONS La, em ee = IN ' ' } ' ' 
5 aa nana 2 = 22 = = fy --- fe = == === === rd | 4 ' 
ee eee fi ere a Se ee a Se fl ae ‘ } 
ines Se GR ee [1 ‘ t 
— ee ra te eo te er f-gn- - - - - - ---l- 1 i 
---- -- pet eb tee -b A- + - -p- -/- . 7 1 
Se een ee ee SL Someta hop afaln cb wee peat ee ' 
0- oes ry 1 ' 1 1 ipeese ' ' ' H ‘ ' Ky 1 
1 
OumorWMwADMOODADWOWMWOWOMODWDAWOAVAOMAtWMO LY OC 
MOMAANNMARDRSMANEEANARANSHRMASNWS 
MoOn~ DMA MMNOWDOAhnTRMNODAAMDONOCMOALROLKNnDAA OAD 
a MMA NNNNYMYMNMABWHHADIOOOMm-AADOANANMO LR CO 
we} =e SS en 
tp 
ye TET SI TS TUITE Ties Aiea aT eee Oe 
.cO LO =asmMmwWoOoOn oS oO OD DO © wo t& 
SRPTAANRBSRSSARRRANRSARSRRSSAG 
~eonmmmondeo tf ito) on! 
SSSA NRRARSSZSSSSRESSRSESSSRAIHR 
ae 
Length of Amphidiscs (). 


+------- 


189.06 — 207.97---------! 


207.97 — 228.76-} -------: 
poet 304 49-|--—---> 


304.49 — 334.93: 


Macramphidiscs in general 
—-—--—--— Large | 


a a Saal | Macramphidiscs 
a Large ; eg 
ee eta | Micramphidises 


Fig. 25 — Amphidises. 


388 HYALONEMA (SKIANEMA) UMBRACULUM. 


are 51-93 u long, usually about a third of the whole spicule, and 105-190 u broad. 
The proportion of the length to the breadth of the anchors is 100 to 141-316, 
on an average 100 : 225.3. The number of teeth in the anchor is from eight to 
ten. The two anchors of the same spicule are usually composed of the same 
number of teeth, and in this case the teeth of two anchors are generally regularly 
alternate. Sometimes the number of teeth is not the same in the two anchors 
of the same amphidise, and in that case they of course do not alternate regularly. 
The individual teeth arise nearly vertically from the ends of the shaft, and are 
curved only slightly in their proximal half, but strongly in their distal half. This 
curvature is so great, that the tips of the teeth become strongly convergent, and 
the distance between the ends of opposite teeth is 12-32 yu less than the (maxi- 
mum) breadth of the anchor. The outer band-shaped part of the tooth attains 
its maximum breadth a little distance distally from the middle of its length, and 
is here sometimes 32 » broad. At its distal end the tooth is simply rounded off. 

Besides these regular forms several irregular large macramphidiscs (Plate 1041, 
figs. 8-10) have been observed. In these spicules one or both of the terminal 
anchors are irregular, and the shaft bears, besides the terminal anchor-teeth, 
other protuberances which arise — usually in a verticil — from its middle-part. 
All these supernumerary protuberances terminate at the (hypothetical) oval 
wall of the amphidisc-cell, and are here abruptly bent or slightly extended to 
terminal discs. 

The small macramphidiscs (Plate 102, figs. 3-6; Plate 103, figs. 24-26) are 
78-128 » long, most frequently about 112 4. The shaft is straight, cylindrical, 
smooth, and 6-11.54 thick. The terminal anchors are 37-67 uw long, about 
half the whole spicule, and 53-104 u broad. The proportion of the length to the 
breadth of the anchors is 100 to 138-176, on an average 100 : 150.6. The termi- 
nal anchors consist of ten to thirteen teeth. The number of teeth is, as in the 
large macramphidises, not always the same in the two anchors of the same 
spicule. When it is the same the teeth of opposite anchors are usually situated 
alternately; when it is not the same, there is no regular alternation of teeth. 
The teeth arise nearly vertically from the ends of the shaft and are curved quite 
uniformly, approximately through a quarter of a circle, to within a short distance 
of the tip. The anchors are therefore nearly hemispherical in shape. The 
outer band-shaped part of the tooth attains its maximum width of 15-20 
some distance distally from the middle of its length. Sometimes its broadest 
part lies quite close to the distal end, and in this case this end is broad and 
rounded (Plate 102, fig. 3); sometimes it lies some distance from the end, and 


HYALONEMA (SKIANEMA) UMBRACULUM. 389 


then the end is attenuated and bluntly pointed (Plate 102, fig. 5). The distal 
end-parts of the outer band-shaped portions of the teeth are abruptly bent 
inward and strongly convergent, so that the distances between the ends of 
opposite teeth are 5-15 u less than the (maximum) breadth of the anchor. The 
keel retains a considerable height to within a short distance of the’end of the 
tooth, and then terminates more or less abruptly. Seen in profile the tip of 
the tooth therefore resembles an eagle’s beak. 

The large micramphidiscs (Plate 103, figs. 31-36) are 54-99 » long, most 
frequently about 84.2. The shaft is 2.6-4.5. thick, straight, or, rarely, 
curved. Sometimes it is slightly thickened at or near the middle, sometimes 
no trace of a central tyle can be detected. The tyle is, when present, sometimes 
1.4 1 more than the adjacent parts of the shaft in transverse diameter. The 
surface of the shaft is somewhat undulating and spiny. The spines are usually 
very minute; sometimes a few larger ones arise from the central tyle. The 
terminal anchors are 10-23 u long, one fifth to one fourth of the whole spicule, 
and 14-36 » broad. The proportion of the length to the breadth of the anchors 
is 100 to 107-200, on an average 100 : 150.9. The anchor-teeth arise vertically 
from the ends of the shaft, are either strongly bent a short distance from their 
base and slightly curved in their distal and middle-parts, or curved with a 
radius increasing distally in a uniform manner. Their tips diverge. The teeth 
are sharp-pointed at the end, and attain a maximum breadth of about 4 u. 

The small micramphidiscs (Plate 103, figs. 27-29) are 16-38.7 » long, most 
frequently about 19.2, 26.8, and 34.2 u.!_ The shaft is straight or, rarely, some- 
what curved, 1.2-1.9 » thick, spiny, and sometimes slightly thickened in or 
near the centre to a small tyle. The spines are generally very minute; exception- 
ally one or two of the central ones attain a length of 1 4. The terminal anchors 
are similar to those of the large micramphidiscs, but narrower. They are 4.5— 
10 » long, usually a little less than a third of the whole spicule, and 5.3-14 
broad. The proportion of the length to the breadth of the anchors is 100 to 96— 
157, on an average 100 : 128.1. 

The nearest allies of the above sponge are Hyalonema (Skianema) aequatoriale 
and H. (Thallonema) geminatum described in this Report. From H. (S.) aequa- 
toriale it differs chiefly by the absence of spheres and the smaller average size 
of the microhexactines and large micramphidises; from H. (7.) geminatum by 
the absence of geminate macramphidiscs and differences in the shape of the small 
macramphidiscs, the micramphidiscs, and the pinules. 


1 give these three numbers because the length frequency-curve pertaining to these spicules has three 
nearly equally important elevations. 


390 HYALONEMA (THALLONEMA) GEMINATUM. 


THALLONEMA, subgen. nov. 


Species of Hyalonema of which the amphidises of one kind (the largest) have 
anchors which appear as if they were double, because some or most of their 
teeth bear from one to three simple branches. 

The collection contains one fragment of this subgenus. This belongs to a 


new species. 


Hyalonema (Thallonema) geminatum, sp. nov. 


Plate 103, figs. 37-62; Plate 104, figs. 1-14; Plate 105, figs. 1-14. 


There is in the collection one small fragment of this species. It was trawled 
in the Central Tropical Pacific at Station 4740 on 11 February, 1905; 9° 2.1’S., 
123° 20.1’ W.; depth 4429 m. (2422 f.); it grew on a bottom of dark gray 
Globigerina ooze; the bottom-temperature was 34.2°. 

Many of the anchor-teeth of the largest amphidisecs are provided with 
from one to three branches, which makes the anchors of these spicules appear 
doubled. To this the name refers. 

Shape and size. The fragment is an oval lamella, 50 mm. long, 34 mm. 
broad, and has a maximum thickness of 3 mm. 

The colour in spirit is light dirty brown. 

The skeleton. A dense fur, composed of the distal rays of superficial pinules, 
covers the intact parts of both faces of the lamella. Much smaller, probably 
canalar pinules are found in the interior. Besides the lateral rays of the super- 
ficial pinules the lateral rays of pentactine megascleres and paratangentially 
extending amphioxes are found in the superficial membrane. Amphioxes similar 
to the superficial ones, hexactine megascleres, and microhexactines occur in 


large numbers in the choanosome. The sponge possesses four kinds of amphi- 


dises: — large geminate macramphidises, ordinary large macramphidises, small 
macramphidises, and micramphidiscs. All these kinds of amphidises are 
abundant. 


Superficial pinules are, as above stated, found on both sides of the lamella. 
Those on the one side are very similar to those on the other. The only difference 
between them which I could detect is that the basal thickness of the distal ray 
appears to be in those of the one face (the dermal ?) on the whole slightly greater 
than in those on the other (the gastral ?). 

The dermal and gastral superficial pinules (Plate 103, figs. 58-62) are pentac- 


HYALONEMA (THALLONEMA) GEMINATUM. 391 


tine. The distal ray is straight and 178-270 » long, most frequently about 
250 w. It usually ends in a rather stout and sharp-pointed terminal cone (Plate 
103, figs. 59-62). Exceptionally the tip is rounded (Plate 103, fig. 58). The 
basal thickness of the ray is 7-11 ». Apart from small parts of it at the basal 
and distal ends, the ray is quite densely spined. The spines are for the most 
part nearly straight. Those arising from the middle-part of the ray are of 
considerable size, up to 30 4 and more long. The maximum thickness of the 
distal ray, together with the spines, is 832-46 ». The lateral rays are conical, 
blunt-pointed, spined, and 28-43 yu long. 

The small, probably canalar pinules are pentactine. The distal ray is 
straight, usually 90-110 » long, and 4—6 » thick at the base. Its base and its 
sharp-pointed distal end-part are smooth; its middle-part bears very large, 
strongly divergent, sparse spines, which are curved, concave towards the tip of 
theray. The largest spines are found in the proximal part of the spine-bearing 
region. The lateral rays are conical and 32-60 u long, generally 40-50 up. 

The hypodermal and hypogastral pentactines have smooth, straight, and 
very blunt, conical rays. The proximal ray is 0.2-1 mm. long, and 7-22 u 
thick at the base. The lateral rays are 160-450 u long. 

The hexactine megascleres are generally 0.8-1.8 mm. in diameter and have 
smooth, blunt, conical rays 15-45 » thick at the base. 

The superficial and choanosomal amphioxes are usually fairly straight, 
rarely markedly curved, and 0.4-2.6 mm. long. The shorter ones, that is those 
under 1 mm. in length, are distinctly centrotyle with a tyle 1-4 u more than 
the adjacent parts of the spicule in transverse diameter. The medium ones, 
that is those 1-1.5 mm. in length, have only a very insignificant tyle, not more 
than 1.5 » thicker than the adjacent parts of the spicule. In the large ones, 
that is those over 1.5 mm. in length, there is hardly a trace of a central tyle. 

The microhexactines (Plate 103, figs. 39-48) are 37-120, usually 53-100 u 
in diameter (maximum diameter). Most of them have equal rays; in some 
two opposite rays are longer than the other four. The rays are 1.8—2.2 » thick 
at the base, conical, and finely pointed. The proximal part, about the half of 
the ray, is straight, the distal part curved. This curvature is either uniform, 
or, more frequently, at the point where the proximal straight part passes into 
the distal curved part greater than elsewhere. The total curvature is such that 
the directions (tangents) of the proximal and distal end-parts of the ray usually 
enclose an angle of about 120°. The rays bear very numerous, exceedingly 


minute spines, which give them the appearance of being rough. 


392 HYALONEMA (THALLONEMA) GEMINATUM. 


Among the amphidiscs two main kinds can be distinguished morphologi- 
cally : — larger ones with relatively large anchors, and smaller ones with relatively 
medium-sized or small anchors. I consider the former as macramphidises, the 
latter as micramphidises. 

Among the macramphidises three subgroups can be distinguished morpho- 
logically: — a, large ones with short and broad anchors, some to most of the 
teeth of which are branched; 6, middle-sized ones with short and broad anchors, 
and simple teeth; and c, smaller ones with long and broad anchors and simple 
teeth. These three macramphidise groups are connected by transitional forms 
both morphologically and biometrically. The morphological connections be- 
tween b and c are macramphidises under middle size with anchors of medium 
length. The morphological connections between a and b are large macramphi- 
dises in which only one or two anchor-teeth are branched. 

As the length frequency-curve pertaining to the macramphidises in Figure 26 
shows, there is a conspicuous enough depression separating biometrically the 
bulk of 6 from c; on the other hand the depression between the bulk of a and 
the bulk of 6 is very insignificant. Although the three subgroups of macram- 
phidises are thus rather closely connected both morphologically and biometri- 
cally, I think the difference between them sufficient for a separate description. 

The micramphidises are very various in size, their length ranging from 16— 
92 u. They are, however, morphologically all very much alike. The length 
frequency-curve pertaining to them is, as the figure shows, exceedingly irregular 
and has no less than six low elevations in its left part (which pertains to the 
smaller forms) and one high elevation in its right end-part (which pertains 
to the largest forms). According to this one might divide these amphidiscs into 
two subgroups: — large micramphidises for those to which the simple high ele- 
vation in the right-hand end-part of the curve pertains, and small micram- 
phidises for those to which the irregular left-hand and central parts of the 
curve pertain. Since, however, there is but very little morphological difference 
between the former and the latter, I refrain from doing so. 

I accordingly distinguish four kinds of amphidiscs in this species: — 1, 
geminate, 2, large, and 3, small macramphidises; and 4, micramphidiscs. 

The geminate macramphidiscs (Plate 104, figs. 1-5, 8, 11, 12; Plate 105, 
figs. 1-14) are 210-360 u long, most frequently about 278 ». The shaft is 21-31 yu 
thick, straight or slightly curved, and usually quite smooth and simply cylindri- 
cal. Sometimes a large, terminally rounded spine or branch, 20-30 u long, arises 
from the middle-part of the shaft (Plate 105, fig. 3). When such a spine is present 


Macramphidiscs 
EEE SS 


‘Large 
eS 


Small Geminate 


‘Micramphidiscs 


a ee ee ee ee ne a ee ee ee ee ee ee eee eee 


asso 


i 
15 iN 
Vy nas Ss Sag Sieg on Gere amg me Per oe 
: is nese RRO SEEE ERSURRERESSEROMEpeEeaEEIEET iar oak ek eee Me eee = 
' 
a ! 
Sees Ser oN. AS ' 
0 1 ' se. a 
“oic) 2: eet eP ECE ePRE PEER EE EEET EE 
S SHAAN ARSASSSSESSRSSESHSIUSAISE SATIRE 
ep Seer wA AN ANA OM oO = 
Se ee ae ee eeesen el eh eu tee ye et Tey ab sty kod 
YB PAAR BS SSSAKREAKSSSSRSRSRSSHL SIR 
SRS SARRARSSILIRSENSSSSORISA SSR ESS S 
Length of Amphidiscs (,:). 


Macramphidiscs generally 


si eee eo — Geminate 


Peers ena s ee eeensneseseredssece 


Small S 


Micramphidiscs 


Fig. 26.— Amphidises. 


394 HYALONEMA (THALLONEMA) GEMINATUM. 


the shaft is particularly strongly bent, convex towards the spine. The terminal 
anchors are 72-100 » long, a fourth to a third of the whole spicule, and 175-200 u 
broad. The proportion of the length to the breadth of the anchors is 100 to 
182-257, on an average 100 : 223. The anchor is composed of from ten to fifteen 
teeth. The individual teeth are usually more strongly curved in their distal 
than in their proximal part. The extreme tips of the teeth are, if not widened 
to terminal dises (vide infra), generally abruptly bent inward and convergent. 
A larger or a smaller number, most frequently about half, rarely all, of these 
teeth bear from one to three branches. Generally one anchor of the spicule 
is richer in branched teeth than the other. The branched teeth consist of a 
stem similar to an ordinary unbranched anchor-tooth, from the outer convex 
side of which from one to three branches arise. These branches are curved 
conformly with the stem from which they arise, concave towards the shaft, 
and usually end in oval flattened extensions, which appear as terminal dises. 
The end of the stem or main tooth, from which these branch-teeth arise, often also 
terminates with such an extension. The outer faces of the simple teeth and of 
the end-parts or terminal discs of the stem and the branches of the branched 
ones lie in a continuous surface ovoid in shape, which I take to be the inner 
face of the limit or wall of the living unit—%in my opinion a single cell — 
within and by which the amphidise is formed. As stated above, transitional 
forms with only one or two branched anchor-teeth (Plate 105, fig. 14) connect 
these geminate with the ordinary large macramphidises described below. 

The ordinary large macramphidiscs (Plate 104, figs. 6,7) are 133-271 u long, 
most frequently about 198.5 and 204.2 u. The shaft is 15-26 » thick, generally 
straight, cylindrical, and smooth, sometimes slightly bent, and occasionally 
provided with one stout blunt spine about 20 4 long. When such a spine is 
present the shaft is always bent as in the geminate macramphidises. The termi- 
nal anchors are 48-105 u long, a third to two fifths of the whole spicule, and 115— 
203 u« broad. The proportion of the length to the breadth of the anchors is 
100 to 169-274, on an average 100 : 225.5. The anchor is composed of from 
eight to eleven teeth. The number of teeth in the two anchors of the same 
spicule is not always the same. The teeth of the opposite anchors often, but 
by no means always, alternate. The individual teeth arise nearly vertically 
from the ends of the shaft, are straight or only slightly curved in their basal 
part, but strongly curved in their distal part. The outer band-shaped portion 
of the tooth attains, in the larger forms, a maximum breadth of 25-29 u. Its 
distal end is rounded and abruptly bent inward so that the tips of the teeth 


HYALONEMA (THALLONEMA) GEMINATUM. 395 


become strongly convergent, the distance between opposite teeth being 6-20 y, 
rarely as much as 32 y, less than the (maximum) breadth of the anchor. 

The small macramphidiscs (Plate 104, figs. 9, 10, 13, 14) are 88-153 u long, 
most frequently about 112 1. A good many of the largest, that is of those 136- 
153 w long, have anchors of only medium length and are consequently transi- 
tional to the large macramphidiscs above described. The shaft is straight, 
cylindrical, and 6-12 » thick. The terminal anchors are 50-72 u» long, a third 
to half of the whole spicule, and 70-130 » broad. The proportion of the length 
to the breadth of the anchors is 100 to 146-183, on an average 100 : 161.8. The 
anchors are composed of from ten to sixteen teeth. Roughly speaking, the 
number of teeth is in inverse proportion to the size of the spicule. The teeth 
of the two anchors of the same spicule are often, but by no means always, situ- 
ated alternately. The individual teeth are generally quite uniformly curved 
through a quarter of a circle and abruptly bent inward at the end, so that their 
tips are strongly convergent. The outer band-shaped part of the tooth attains 
its maximum breadth in its distal portion, and is here 12-18 » broad. The end 
is broad, rounded off, sometimes nearly truncate. 

The micramphidiscs (Plate 103, figs. 37, 38, 49-57) are 16-92 » long, the 
larger ones, to which the conspicuous elevation near the right-hand end of the 
curve pertains, most frequently about 76.5 1 long. The shaft is straight or 
only very slightly curved, and 0.7—5 » thick. It is simply cylindrical or slightly 
thickened at or near the middle to a central tyle, 0.3-0.6 », rarely as much as 
1.5 uw, more than the adjacent parts of the shaft in transverse diameter. Centro- 
tyle forms are more frequent among the larger than among the smaller micram- 
phidises. A larger or smaller number of small spines are scattered over the 
whole of the shaft. In the centrotyle forms the spines arising from the central 
tyle are usually larger than the others. The terminal anchors are 3.5—24 u 
long, that is one fifth to two fifths of the whole spicule, and 5.5-30 » broad. The 
proportion of the length to the breadth of the anchors is 100 to 100-200, on an 
average 100 : 150.5. The anchors of the larger forms are on the whole relatively 
broader than those of the smaller. The anchor is composed of a considerable 
number of teeth; in one 24 » broad I counted eighteen. The individual teeth 
are, in the larger micramphidiscs, up to 5 » broad, and pointed at the end. 

Besides the regular micramphidiscs above described I observed a few irregu- 
lar micramphidiscs with terminal anchors on one side much longer than on the 
other. In these anchors the tips of the anchor-teeth lie in an oblique plane enclos- 
ing an angle of about 45° with the axis of the shaft. The longest part of one 


396 HYALONEMA (THALLONEMA) GEMINATUM. 


anchor lies on the same side of the shaft as the shortest side of the other. The 
dimensions of a typical amphidise of this kind are: — total length 22 u; thick- 
ness of shaft 1.5 1; length of the longest and shortest parts (sides) of the anchors 
respectively 7.5 « and 4 yw; breadth of anchors 9 yu. 

The nearest allies of the above sponge are Hyalonema (Skianema) aequa- 
toriale and H. (S.) umbraculum described in this Report. From both it is 
distinguished by the possession of large geminate macramphidises and small, 


long-spined canalar pinules, and by other differences in the spiculation. 


IV. LIST OF STATIONS. 


Temperature Depth 
Position Sur- | Bot- | (fath- Bottom 
Station Date Lat Long. | face tom | oms) 
eis: ° , 
3363 26 Feb., 1891 | N. 543 W. 8550 83 BIMAR) 978 | White Globigerina ooze. 
3376 4 March, 1891/}N. 39 W. 828 78 36.3 | 1132 | Gray Globigerina ooze. 
3681 27 Aug., 1899 | N.2823 W.12657 66 34.6 | 2368 | Red clay, light brown voleanic ooze. 
(A.A. 2) 

3684 10 Sept., 1899 | N. 050 W.137 54 79 _— 2463 | Light yellow-gray Globigerina ooze. 
(A.A. 17) 

3685 14 Sept., 1899 |S. 848 W.139 48 80 38 830 | Globigerina and volcanic mud and 
(A.A, 25) fragments. 

3689 28 Oct., 1899 |S. 1806 W.142 24 79 37.6 | 807 | Fine coral-sand and manganese nod- 
(A.A 134) ules. 

4621 21 Oct., 1904 | N. 636 W. 8144 79 40.5 | 581 | Green mud and rock. 

4622 21 Oct., 1904 | N. 631 W. 81 44 81 — 581 | Green sand and rock. 

4630 3 Nov., 1904 IN: 653 W. 8142.5) 81 40.5 | 556 | Green sand, large Globigerina. 

4631 3 Nov., 1904 N. 626 W. 8149 82 38.0 | 774 | Green sand. 

4641 7 Nov., 1904 S. 134.4 W. 89 30.2 74 39.5 633 | Light gray Globigerina ooze. 

4642 7 Nov., 1904 S. 130.5 W. 8935 74 48.6 | 300 | Broken shells and Globigerina. 

4649 10 Nov., 1904 |S. 517 W. 8519.5 70 35.4 | 2235 | Sticky gray mud. Very few Globigerina. 

4651 11 Nov., 1904 |S. 541.7 W. 8259.7] 66 35.4 | 2222 | Sticky fine gray sand. 

4656 13 Nov., 1904 |S. 654.6 W. 8334.3] 69 35.2 | 2222 | Fine green mud mixed with gray ooze, 
mineral particles. Sponge _ spicules, 
many diatoms. 

4662 16 Nov., 1904 | S. 1113.8 W. 8935 69 35.2 | 2439 | Brown Radiolaria ooze, manganese 
nodules. 

4672 21 Nov., 1904 |S. 1311.6 W. 78 18.3 65 35.2 | 2845 | Fine green clay; infusorial earth full of 
diatoms. 

4685 10 Dec., 1904 S. 2136.2 W. 9456 72 35.3 | 2205 | Dark brown clay. 

4695 23 Dec., 1904 | S. 25 22.4 W.107 45 74 _ 2020 | Fine light,brown ooze. 

4701 26 Dec., 1904 | S. 1911.5 W. 102 24 72 35.3 | 2265 | Dark brown chocolate clay. 

4709 30 Dec., 1904 | S. 1015.2 W. 95 40.8 72 Blau || POR Light gray Globigerina ooze. 

4711 31 Dec., 1904 |S. 747.5 W. 94 5.5 75 35.3 | 2240 do. 

4721 15 Jan., 1905 S. 8 7.5 W. 104 10.5 75 —_— 2084 | Light brown Globigerina ooze. 

4732 21 Jan., 1905 S. 1632.5 W.119 59 79 34.8 | 2012 | Light gray Globigerina ooze. 

4736 23 Jan., 1905 S. 19 0:4 W.125 5.4 81 34.8 | 2289 | Dark brown chocolate mud. 

4740 11 Feb., 1905 |S. 9 2.1 W.123 20.1 81 34.2 | 2422 | Dark gray Globigerina ooze. 

4742 15 Feb., 1905 | N. 0 3.4 W.117 15.8 77 34.3 | 2320 | Very light fine Globigerina ooze. 


MEMOIRS 


OF THE 


MUSEUM OF COMPARATIVE ZOOLOGY 


AT 


HARVARD COLLEGE. 


VOle Xeni. 


CAMBRIDGE, MASS: U.S: A. 
PRINTED FOR THE MUSEUM. 
1915. 


7 THE Cosmos Press: 
Epwarp W. Wure.er, Campriper, U.S. A. 


® 
4 
a 
t 
' 
i 
. 2 : F 
vr , = 
” ® ° is 
oe : ; 
7 - ; 


Memoirs of the Museum of Comparative Zodlogyv 
AT HARVARD COLLEGE. 


Von. SULT. 


REPORTS ON THE SCIENTIFIC RESULTS OF THE EXPEDITION TO THE 
EASTERN TROPICAL PACIFIC, IN CHARGE OF ALEXANDER AGASSIZ, 
BY THE U. S. FISH COMMISSION STEAMER “ALBATROSS,” FROM 
OCTOBER, 1904, TO MARCH, 1905, LIEUT. COMMANDER L. M. GARRETT, 
U. S. N., COMMANDING, AND OF OTHER EXPEDITIONS OF THE “ALBA- 
TROSS,” 1891-1899. 


XXIX. 


THE SPONGES. 
3. HEXACTINELLIDA. 


By ROBERT VON LENDENFELD. 


WITH ONE HUNDRED AND NINE PLATES. 


PLATES. 


{Published by permission of Huan M. Smiru, U. 8S. Commissioner of Fish and Fisheries]. 


CAMBRIDGE, U.S. A.: 
Printed for the Museum, 


JUNE, 1915. 


CONTENTS. 


RTS on the Scientific Results of the Expedition to the Eastern Tropical Pacific, 
arge of ALEXANDER Agassiz, by the U. S. Fish Commission Steamer “ Albatross,” 


June, 1915. 


} 


PLATE 1. 


Calycosilva cantharellus LenpENnreLp. 


Figs. 1-8, 20-24 — var. helix Lendenfeld. 
Figs. 9-19, 26, 29 — var. (A) simplex Lendenfeld. 
Figs. 25, 27, 28 — var. (B) simplex Lendenfeld. 


1, 2.— Rhabds of the body-skeleton of var. helix; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6. 
3, 4.— The tyle of a centrotyle rhabd of the body-skeleton of var. helix; magnified 2000; u.v. phgt. 
Zeiss, q. monochr. 1.7, q. oc. 10: 
3, focussed higher; 4, focussed lower. 
5-13.— Hypogastral pentactines; magnified 30; phot. Zeiss, planar 20 mm.: 
5-8, of var. helix; 9-18, of var. simplex (A); 
5-7, 9-11, side-views; 8, 12, 13, apical views. 
14-24.— Hexactines; magnified 30; phot. Zeiss, planar 20 mm.: 
14-19, of var. simplex (A); 20-24, of var. helix. 
25-29.— Large spined rhabds of the stalk and its junction with the body of var. simplex; magnified 30; 
phot. Zeiss, planar 20 mm.: 
25, 27, 28, of (B); 26, 29, of (A). 


HEXACTINELLIDA. 


Fig. 1-29 Calycosilva cantharellus n. sp. ee 
1-8, 20-24 C.c. var. helix; 9-19, 26, 29 C.c. var. simplex (A); 25, 27, 28 C. c. var. simplex (B). 


Lendenfeld photographed 


= 
* 
2 > 
oo 
: 
* 
- 
4 
~ 
' 
o 
. 
- 
- 
. 
7 
- 
= \ 
. 
ve : 
* ’ 
= ‘ 
* 
- 
. 
- 
* 
- 
= 
> - 
> . = 
: 
» ae - 
- 
- 


PLATE 2. 


Calycosilva cantharellus LenpENFELD. 


Figs. 1-2, 4-6, 14, 16 — var. (A) simplex Lendenfeld. 
Figs. 3, 7-138, 15 — var. helix Lendenfeld. 


1.— Part of an axial, longitudinal section through the upper end of the stalk and the adjacent (central) ~ 


part of the body of var. simplex (A); magnified 20; phot. Zeiss, planar 20 mm.: 
a, dermal pinule-fur; b, dense subdermal masses of longitudinal rhabds. 
2.— Part of the surface of a shortened and very strongly spined hexactine ray of var. simplex (A); magni- 
fied 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
3.— Part of a radial section through the choanosome of var. helix; magnified 120; phot. Zeiss, apochr. 8, 
compens. oc. 6: 
a, onychhexasters; b, helonychhexaster. 
4.— Central part of a large hexactine of var. simplex (A); magnified 100; phot. Zeiss, apochr. 16, com- 
pens. oc. 6. 
5.— Central part of a large spined rhabd from the junction of the stalk to the body of var. simplex (A); 
magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
6.— Central part of a large hexactine of var. simplex (A); magnified 100; phot. Zeiss, apochr. 16, com- 
pens. oc. 6. 
7.— Part of a radial section through the choanosome of var. helix; haematoxylin; magnified 100; phot. 
Zeiss, apochr. 16, compens. oc. 6: 
a, flagellate chambers; b, onychhexasters. i 
8.— Part of the surface of the stalk of var. helix; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
a, dermal (peduncular) pinules; b, hypodermal (peduncular) oxypentactines. 
9.— Central part of a large hexactine with one ray reduced in length, of var. helix; magnified 100; phot. 
Zeiss, apochr. 16, compens. oe. 6. 
10.— Apical view of a hypogastral oxypentactine of var. helix; magnified 100; phot. Zeiss, apochr. 16, 
compens. oc. 6. 
11.— Central part of a large hexactine of var. helix; magnified 100; phot. Zeiss, apochr. 16, compens. 
oc. 6. 
12.— Part of a radial section through the gastral layer of var. helix; magnified 300; phot. Zeiss, apochr. 
4, compens. oc. 6: 
a, part of a hypogastral oxypentactine; b, end of arhabd; ec, a plumicome. 
13.— Part of the lower, dermal surface of the body of var. helix; magnified 100; phot. Zeiss, apochr. 16, 
compens. oc. 6: 
a, dermal pinules; b, hypodermal oxypentactines. 
14.— Portion of the central part of a large hexactine with one ray reduced in length, of var. simplex (A); 
magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
15.— Central part of a large hexactine of var. helix; magnified 100; phot. Zeiss, apochr. 16, compens. 
oc. 6. 
16.— Portion of the central part of a large hexactine of var. simplex (A); magnified 100; phot. Zeiss, 
apochr. 16, compens. oc. 6. 


- 


PLATE 2. 


HEXACTINELLIDA. 


Fig. 1-16 Calycosilva cantharellus n: sp. 
1, 2, 4-6, 14, 16 C.c¢. var. simplex (A); 3, 7-13, 15 C.c. var. helix. 


[eae ee er a ee ee | 


~ 
- t¥. 


PLATE 3. 


Calycosilva cantharellus LeNDENFELD. 


Figs. 1-5, 8-30 — var. helix Lendenfeld. 
Figs. 6, 7 —var. (A) simplex Lendenfeld. 


1.— Minute strongylohexaster of var. heliz; magnified 600; phot. Zeiss, H. I. 1/12, compens. oc. 6. 
2, 3.— Irregular elongated onychhexaster of var. helix; magnified 600; phot. Zeiss, apochr. 4, compens. 
oc. 12: 
2, focussed higher; 3, focussed lower. 
4, 5— Onychhexaster-derivate oxyhexaster of var. helix; magnified 600; phot. Zeiss, apochr. 4, compens. 
oc. 12: 
4, focussed lower; 5, focussed higher. 
6, 7.— Irregular onychhexaster of var. simplex (A); magnified 600; phot. Zeiss, apochr. 4, compens. 
oc. 12: . 
6, focussed higher; 7, focussed lower. 
8-20.— Helonychhexaster of var. helix; magnified 600; phot. Zeiss, H. I. 1/12, compens. oc. 6: 
8, 9, side-view of a helonychhexaster with the lateral end-rays uniformly and strongly curved 
throughout: 
8, focussed higher; 9, focussed lower; 
10, 11, side-view of a helonychhexaster with the larger proximal parts of the lateral end-rays strongly 
curved in one direction and their smaller distal parts slightly curved in the opposite direction; 
10, focussed higher; 11, foctissed lower; 
12, 13, oblique view of a helonychhexaster with the proximal parts of the lateral end-rays strongly 
curved, their distal parts nearly straight; 
12, focussed higher; 13, focussed lower; 
14, apieal view of a helonychhexaster with the proximal parts of the Jateral end-rays curved for a 
greater or smaller extent and the distal parts fairly straight; 
15, 16, apical view of a helonychhexaster with the larger proximal parts of the lateral end-rays 
strongly curved in one, and their smaller distal parts slightly curved in the opposite direction; 
15, focussed higher; 16, focussed lower; 
17, apical view of a helonychhexaster with the larger proximal parts of the lateral end-rays strongly 
curved in one, and their smaller distal parts slightly curved in the opposite direction; 
18, apical view of a helonychhexaster with the proximal parts of the lateral end-rays strongly curved, 
the distal parts fairly straight; 
19, apical view of a helonychhexaster with the larger proximal parts of the lateral end-rays strongly 
curved in one direction and their smaller distal parts slightly curved in the opposite direction; 
20, oblique view of a helonychhexaster with the proximal parts of the lateral end-rays strongly 
curved in one direction, their distal parts slightly curved in the opposite direction. 
21-27.— Onychhexasters of var. helix; magnified 600: 
21-26, phot. Zeiss, H. I. 1/12, compens. oc. 6; 
27, u. v. phot. Zeiss, q. monochr. 6, q. oc. 10; 
21, 22, small onychhexasters with a small number of stout end-rays; 
23, small onychhexasters with a larger number of end-rays; 
24, 25, larger onychhexasters with a larger number of end-rays; 
24, focussed higher; 25, focussed lower; 
26, 27, large onychhexasters with a small number of end-rays. 
28-30.— The distal parts of three end-rays of onychhexasters of var. heliz; magnified 2000; u. v. phot. 
Zeiss, q. monochr. 1.7, q. oc. 10: 
28, 29, with three or four terminal lateral spines; 
30, with one terminal lateral spine. 


HEXACTINELLIDA. PLATE 3. 


Fig. 1-30 Calycosilva cantharellus n. Sp. 
I-5, 8-20 C.¢. var. helix; 6,7 C. c. var. simplex (A). 


Lendenfeld photographed 


- >. a 


“4 


PLATE 4. 


Calycosilva cantharellus LENDENFELD. 


Figs. 1-20 —var. megonychia Lendenfeld. 
Figs. 21, 22 — var. (A) simplex Lendenfeld. 
Figs. 23, 24 — var. helix Lendenfeld. 


1.— Onychhexaster-derivate oxyhexaster of var. megonychia; magnified 600; phot. Zeiss, apochr. 4, 
compens. oc. 12. 
2.— Onychhexaster of var. megonychia; magnified 600; u. v. phot. Zeiss, q. monochr. 6, q. oe. 10. 
3, 4— Onychhexasters of var. megonychia; magnified 600; u. v. phot. Zeiss, q. monochr. 6; q. oc. 10: 
3, focussed lower; 4, focussed higher. 
5, 6.— Group of onychhexasters of var. megonychia; magnified 300; u. v. phot. Zeiss, q. monochr. 6, q. 
oc. 5: 
5, focussed lower; 6, focussed higher. 
7.— Group of onychhexasters of var. megonychia; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
8-12.— Ends of end-rays of onychhexasters of var. megonychia; magnified 2000; u. v. phot. Zeiss, q. 
monocehr. 1.7, q. oc. 10: 
8, one with all the spines directed obliquely outward; 
9, 10, one with nearly straight spines, two of which are nearly vertical and one directed obliquely 
outward; 
9, focussed lower; 10, focussed higher. 
11, 12, a similar one, one of the spines of which is curved in an S-shaped manner; 
11, focussed lower; 12, focussed higher. 
13-19.— End-rays of onychhexasters and onychhexaster-derivate oxyhexasters of var. megonychia; 
magnified 600; phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 
13-15, with two or three terminal spines; 
16-18, with one clearly distinguished terminal spine; 
19, with one terminal spine which appears as the tip of a simple oxyhexastrose end-ray. 
20.— The largest of the fragments of var. megonychia; magnified 1.85; phot. Zeiss, anastig. 480/412 mm. 
21-24.— Parts of radial sections vertical to the surface, showing the pinule-fur; magnified 75; phot. 
Zeiss, apochr. 16, compens. oc. 6: 
21, the gastral pinule-fur of var. simplex (A); 
22, the dermal pinule-fur of var. simplex (A); 
23, the gastral pinule-fur of var. helix; 
24, the dermal pinule-fur of var. heliz. 


HEXACTINELLIDA. PLATE 4. 
4 eT a { t 1 


{ i AOI 


—" 


Fig. 1-24 Calycosilva cantharellus n. sp. 
1-20 C. c. var. megonychia; 21, 22 C. c. var. simplex (A); 23, 24 C. cc. var. helix. 


Lendenfeld photographed 


a 


PLATE 5. 


Calycosilva cantharellus LENDENFELD. 


Figs. 1, 2, 4, 5, 7-9, 11-15, 18-20 — var. helix Lendenfeld. 


Figs. 3, 6, 10 —var. (B) simplex Lendenfeld. 
Figs. 16, 17 —var. (A) simplex Lendenfeld. 
Fig. 21 —var. megonychia Lendenfeld. 


1.— Radial section through a part of the body near the margin, of var. helix; magnified 20; phot. Zeiss, 
planar 20 mm.: 

a, gastral pinule-fur; b, hypogastral oxypentactines; c, subgastral rhabd-bundles; d, choano- 
somal rhabds and oxyhexactines; e, subdermal rhabd-bundles; f, hypodermal oxypentac- 
tines; g, dermal pinule-fur. 

2.— The end of arhabd of var. helix; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
3.— The skeleton of the basal end of var. simplex (B); magnified 6; phot. Zeiss, planar 50 mm.: 

a, fragment of a spicule, probably a root-spicule, of Hyalonema sp., to which the Calycosilva is 
attached; b, the basal part of the skeleton of the Calycosilva. 

4,— Radial section through part of the body of var. helix; magenta; magnified 20; phot. Zeiss, planar 
20 mm.: 

a, gastral pinule-fur; b, hypogastral oxypentactines; ec, subgastral rhabd-bundles; d, choano- 
somal rhabds and oxyhexactines; e, subdermal rhabd-bundles; f, hypodermal oxypentac- 
tines; g, dermal pinule-fur. 

5-7.— Parts of the basal skeleton-net; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
5, 7, from the stalk of var. heliz; 
6, from the lattice-work which surrounds the spicule-fragment forming the base of attachment 

of var. simplex (B). 

8, 9.— The central part of two rhabds of var. heliz; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 
8, of a simple rhabd; 
9, of a centrotyle rhabd. 
10.— The sectioned face of var. simplex (B), longitudinally cut in two; magnified 1.7; phot. Zeiss, anastig. 
480/412 mm.: 

a, fragment of a spicule, probably a root-spicule, of a Hyalonema sp., to which the Calycosilva 

is attached; b, the Calycosilva. 
11.— Radial section through the margin of the body of var. helix; magnified 20; phot. Zeiss, planar 
20 mm.: 
a, gastral pinule-fur; g, dermal pinule-fur; h, margin. 
12-15.— Ends of rhabds of var. helix; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 
12, 13, the two ends of a nearly isoactine amphistrongyle rhabd; 
14, 15, the two ends of a tylostyle rhabd. 
16.— Axial, longitudinal section through the upper end of the stalk and the adjacent (central) part of 
the body of var. simplex (A); magnified 6; phot. Zeiss, planar 50 mm. : 

a, gastral pinule-fur; b, choanosome; e, stalk; g, dermal pinule-fur. 

17.— Onychhexaster of var. simplex (A); magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 

18, 19.— Onychhexasters of var. helix; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 

20.— The central part of a diactine the two actines of which enclose nearly a right angle, of var. helix; 
magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 

21.— The central part of a triactine of var. megonychia; magnified 200; phot. Zeiss. apochr. 8, compens. 
oc. 6. 


HEXACTINELLIDA. PLATE 5. 


A 


yd 


id 


Fig.. 1-21 Calycosilva caniharellus n. sp. 
1, 2, 4, 5, 7-9, 11-15, 18-20 C.c. var. helix; 3, 6, 10 C.c. var. simplex (B); 16, 17 C.c. var. simplex (A); 
21 C. ¢. var. megonychia. 


Lendenfeld photographed 


PLATE 6. 


Calycosilva cantharellus LENDENFELD. 


Figs. 1-4, 22, 23 — var. (A) simplex Lendenfeld. 
Figs. 5-21, 24-34 — var. helix Lendenfeld. 


1-12.— Hypodermal pentactines; magnified 30; phot. Zeiss, planar 20 mm.: 
1-4, oblique and side-views of hypodermal oxypentactines of the body of var. simplex (A); 
5, 7, 8, oblique views of hypodermal oxypentactines of the body of var. helix; 
6, apical view of a hypodermal oxypentactine of the body of var. helix; 
9, 10, 12, oblique views of hypodermal pentactines of the lower part of the stalk of var. heliz; 
11, apical view of a hypodermal oxypentactine of the lower part of the stalk of var. heliz. 
13.— Group of spicules from the lower part of the stalk of var. helix; magnified 30; phot. Zeiss, planar 
20 mm.: 
a, hypodermal pentactines; b, part of the skeleton-net of the stalk. 
14, 15.— The outer end of a distal pinule-ray of var. helix; magnified 2000; u. v. phot. Zeiss, q. monochr. 
1.7, q. oc. 10: 
14, focussed higher; 15, focussed lower. 
16, 17.— The outer end of a distal pinule-ray of var. helix; magnified 2000; u. v. phot. Zeiss, q. monochr. 
TAS Cle Wics IOE 3 
16, focussed higher; 17, focussed lower. 
18.— Side-view of var. helix; magnified 1.1; phot. Zeiss, anastig. 480/412 mm. 
19-25.— Dermal pinules of the body; magnified 200; phot. Zeiss, apochr. 16, compens. oc. 6: 
19-21, 24, 25, of var. helix; 
22, 23, var. simplex (A); 
19-22, 24, 25, side-views; 
23, apical view. 
26—34.— Dermal pinules of the lower part of the stalk of var. helix; magnified 200; phot. Zeiss, apochr. 
8, compens. oc. 6: 
26, 28, 33, 34, side-views; 
27, 29-32, apical views; 
(30 and 31 are the same view of the same spicule, 30, focussed high, 31, focussed low). 


HEXACTINELLIDA. .. PLATE 6. 


5 


Vy 
WY 
Ne 


Fig. 1-34 Calycosilva cantharellus n. sp. 
1-4, 22, 23 C. ¢. var. simplex (A); 5-21, 24-34 C. ¢. var. helix. 


Lendenfeld photographed 


PLATE 7. 


Calycosilva cantharellus LunDENFELD. 


Figs. 1-10, 12-14, 16, 17 — var. helix Lendenfeld. 
Figs. 11, 15, 18 —var. (A) simplex Lendenfeld. 
Fig. 19 —var. megonychia Lendenfeld. 


1-3.— Plumicomes of helix; magnified 600: 
1, u. v. phot. Zeiss, q. monochr. 6, q. oc. 10; 2,3, phot. Zeiss, H. I. 1/12, compens. oc. 6. 
4, 5.— Part of a plumicome of var. helix; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
4, focussed higher; 5, focussed lower. bs 
6-19.— Gastral pinules; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 
6-10, 12-14, 16, 17, of var. helix; 
11, 15, 18, of var. simplex (A); 
19, of var. megonychia; 
6-15, 19, side-views; 16-18, apical views. 


Caulophacus schulzei Wilson. 


Figs. 20-22, 24-28 — specimen E. 
Figs. 23, 29 — specimen B. 
Figs. 30, 31 — specimen D. 


20-31.— Hexactines; magnified 30; phot. Zeiss, planar 20 mm.: 
20, 22, 24, 25, 27, with rather smooth, pointed, unequal rays, of specimen H; 
21, with one strongly reduced, pointed, and very spiny ray, of specimen H; 
23, with rather smooth, pointed, nearly equal rays, of specimen B; 
26, with rather smooth, pointed, nearly equal rays, of specimen E; 
28, with one ray angularly bent, of specimen EH; 
29, with one ray reduced in length, terminally thickened, and smooth, of specimen B; 
30, with smooth, pointed, unequal rays, of specimen D; 
31, with rather smooth, pointed, nearly equal rays, of specimen D. 


HEXACTINELLIDA. PLATE 7. 


fig. 1-19 Calycosilua cantharellus n. sp. 
1-10, 12-14, 16, 17 C. ¢. var. helix; 11, 15,18 C.c. var. simplex (A); 19 C. c. var. megonychia. 
Fig. 20-31 Caulophacus schulzec Wilson. 
20-22, 24-28 (E); 23, 29 (B); 30, 31 (D). 
Lendenfeld photographed 


. 
. 
- 


PLATE 8. 


28, 29.— Radial section through the marginal part of the body of specimen C; magnified 10; phot. 


PLATE 8. 


Caulophacus schulzei Witson. 


Figs. 1, 5, 6, 8-12, 15, 21, 22, 27 — specimen E. a 


Figs. 2-4, 13, 16, 18-20, 24 — specimen B. 
Pigsy (aelii2o epee —specimen D. 
Figs. 14, 28, 29 . —sspecimen C. 


1-7.— Side-views of hypodermal and hypogastral pentactines; magnified 30; phot. Zeiss, ere 
20 mm.: 
i 5, 6, of hypodermal or hypogastral pentactines of specimen H; 
2-4, of hypogastral pentactines of specimen B; 7, of a he oeantel pentactine of specimen D. 
8-12.— Group of spicules from a suimilemneenn on of specimen E; magnified 100; phot. Zeiss, apochr. — 
16, compens. oc. 6: 
8, 9, pinules; 
10, a discohexactine; 
a hemidiscohexaster; 
, a hypodermal or hypogastral pentactine with one lateral ray reduced in length and terminally 
thickened. ae 
13-17.— Hypodermal and hypogastral pentactines and parts of such; magnified 100; phot. Zeiss 
apochr. 16, compens. oc. 6: 
13, the lateral rays of a hypogastral pentactine of specimen B; 
14, the lateral rays of a hypogastral pentactine of specimen C; 
15, part of the lateral rays of a hypodermal or hypogastral pentactine of specimen H; 
16, side-view of the central part of a hypogastral pentactine of specimen B; 
17, side-view of a hypodermal pentactine of specimen D. 
18-27.— Apical views of the lateral rays of pentactines; magnified 30; phot. Zeiss, planar 20 mm.: 
18-20, of hypodermal pentactines of specimen B; 
21, 22, 27, of hypodermal or hypogastral pentactines of specimen E; 
23, of a large hexactine-derivate pentactine of specimen D; 
24, of a large hexactine-derivate pentactine of specimen B; 
25, 26, of hypogastral pentactines of specimen D. 


Zeiss, planar 50 mm.: 
28, stained with magenta; 
29, stained with azur; 
a, gastral face; b, margin of sponge-body; ce, dermal face. 


HEXACTINELLIDA. PLATE 8, 


Fig. 1-29 Caulophacus schulzet Wilson. 
1, 5, 6, 8-12, 15, 21, 22, 27 (EB); 2-4, 13, 16, 18-20, 24 (B); 7, 17, 23, 25, 26 (D); 14, 28, 29 (C). 


Lendenfeld photographed 


- 
: 

: . 

. 
‘ 
. 
. 
— 
. 
- 
- 
i 


PLATE 9. 


Caulophacus schulzei Wi.son. = 


Figs. 1-22, 24, 26, 32 — specimen E. 
Figs. 23, 25, 28, 33 —specimen D. 


Chic 27 — specimen F. 
Figs. 29, 31 — specimen C. 
Fig. 30 —specimen A. 


4 


1-7.— Rays and end-parts of such of discohexasters, hemidiscohexasters, or discohexactines of specimen 
E; magnified 600: 
1, phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
2-7, u. v. phot. Zeiss, q. monochr. 6, q. oc. 10. 
8.— The fragmentary specimen E from above; magnified 1.85; phot. Zeiss, anastig. 480/412 mm. 
9-13.— Ends of rays of discohexasters, hemidiscohexasters, or discohexactines of specimen E; magni- 
fied 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
14-16.— Oxyhexaster- and hemioxyhexaster-like young stages of discohexasters and hemidiscchexasters 
of specimen NH; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
17-22.— Discohexasters and hemidiscohexasters of specimen E; magnified 200; phot. Zeiss, apochr. 8, 
compens. oc. 6. 
23-26.— Discohexactines; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 
23, 25, of specimen D; 
24, 26, of specimen E. 
27.— Longitudinal section of the peduncle of specimen F; magnified 2.5; phot. Zeiss, planar 100 mm. 
28.— Side-view of specimen D; magnified 1.2; phot. Zeiss, anastig. 480/412 mm. 
29.— Specimen C seen from above; magnified 1.2; phot. Zeiss, anastig. 480/412 mm. 
30.— Specimen A seen from above; magnified 1.2; phot. Zeiss, anastig. 480/412 mm. 
31.— Part of the gastral surface of specimen C; magnified 4.2; phot. Zeiss, anastig. 167 mm. 
32.— Axial section of specimen EH; magnified 2.5; phot. Zeiss, planar 100 mm.: 
a, peduncle. 
33.— Axial section of specimen D; magnified 2.5; phot. Zeiss, planar 100 mm.: 
a, peduncle. 


PLATE 9. 


HEX ACTINELLIDA. 


I 


; 
‘ a 
nn ee ee 
} 


> 


et Wilson ; 


33 Caulophacus schulz 


1 


Fig. 


30 (A). 


31 (C); 


29 


7 (A); 2 


33 (D); 2 


28; 


25, 


A935 


Lendenfeld photographed. 


Phototype by Charles Bellmann, Prague. 


a 


a 
~~ 7 
a 


> ‘ 
ea 
mt | 
e 
Es 
ats, . 
a > 
U 
ae 
t 
hf 
r od : 
i 
_ 
. Ss | 
a. col 
4 \ 25 
7 \ e 
F \ S 
ra = 


PLATE 10. 


Caulophacus schulzei Witson. 


Figs. 1-3, 5, 6, 9, 10, 15-26, 28, 29 — specimen E 


Fig. 4 — specimen B. 
Fig. 7 —specimen D. 
Figs. 8, 11-14 — specimen F. 
Fig. 27 —specimen C. 


1-7.— Parts of rhabds of the body; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 
1 and 2, the ends, and 3 the central part, of a rhabd of specimen 1; 
4, an end of a rhabd of specimen B; 
5, 6, ends of rhabds of specimen H; 
7, end of a rhabd of specimen D. 
8.— Part of the skeleton-net of the peduncle of specimen F; magnified 200; phot. Zeiss, apochr. 8, 
compens. oc. 6: 
a, pinules embodied in the skeleton-net. ‘ 
9, 10.— Rhabds of the body of specimen E; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6. 
11, 12.— Free ends of rhabds of the skeleton-net of the peduncle of specimen I’; magnified 200; phot. 
Zeiss, apochr. 8, compens. oc. 6. 
13, 14.— Parts of the skeleton-net of the peduncle of specimen F; magnified 30; phot. Zeiss, planar 
20 mm. 
15, 16— The distal end of a main-ray and the proximal parts of the end-rays arising from it, of a large 
discocome of specimen E; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
15, focussed lower; 16, focussed higher. 
17-19.— Discocomes of specimen EH; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 
17, 18, small ones with short, strongly divergent end-rays; 
19, a large one with long, more upright end-rays. 
20-25.— Parts of discocomes of specimen E; magnified 600: 
20, 22, 23, phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
21, phot. Zeiss, apochr. 4, compens. oc. 12; 
24, 25, u. v. phot. Zeiss, q. monochr. 6, q. oc. 10; 
20, 21, of large ones with long, more upright end-rays; 
22, 23, of intermediate ones; 
24, 25, of small ones with short, strongly divergent end-rays. 
26.— The distal part of an end-ray of a discocome of specimen E; magnified 2000; u. v. phot. Zeiss, q. 
monochr. 1.7, q. oc. 10. 
27-29.— Groups of microscleres from spicule-preparations: 
27, of specimen C; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6; 
28, 29, of specimen FE; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6; 
a, discohexasters, hemidiscohexasters, and discohexactines; b, discocomes: 


HEXACTINELLIDA. PLATE 10. 


Fig. 1—29 Caulophacus schulzei Wilson; 1—8, 5, 6, 9, 10, 15—26, 28, 29 (E); 4 (B); 7 (D); 8, 11—14, (FH); 27 (C). 


Lendenfeld photographed. 


Phototype by Charles Bellmann, Prague, 


> 


PLATE 11. 
= ° 


al 
” 


1.6 
é 


PLATE 11. 


Caulophacus schulzei Witson. 


Fig. 1 — specimen B. 
Figs. 2-6, 13-16 — specimen E. 
Figs. 7-9, 11, 12 —specimen D. 
Figs. 10, 17 — specimen C. 


1-12.— Side-views of normal pinules; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 
1, a dermal pinule of specimen B; 
2-6, pinules of specimen E; 
7, 8, gastral pinules of specimen D; 
9, 11, 12, dermal pinules of specimen D; 
10, a dermal pinule of specimen C. 
13.— Side-view of an abnormal pinule with hypertroph proximal ray of specimen H; Ege 200; 
phot. Zeiss, apochr. 8, compens. oc. 6. 
14.— The proximal ray of a pinule of specimen E; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 2. 
15, 16— The distal part of a distal pinule-ray of specimen EH; magnified 600; phot. Zeiss, apochr. 4, 
compens. oc. 12: 
15, focussed higher; 16, focussed lower. 


~ 17.— Part of a radial section of specimen C; eosin; magnified 30; phot. Zeiss, planar 20 mm.: 


a, gastral pinule-fur; b, subgastral cavities; ec, choanosome. 


~* 


> 


PLATE I. 


’ - ARXACTINELLIDA. 


Fig. 1—17 Caulophacus schulzei Wilson ; 
1 (4); 2—6, 18—16 (2); 7—9, 11, 12 (D); 10, 17 (C). 


Lendenfeld photographed. 


Phototype by Charles Bellmann, Prague, 


PLATE 12. 


Caulophacella tenuis LenpDENFELD. i 
Figures 1-19. 


1-8.— Distal parts of distal rays of pinules; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12: 
1, 2, of a large dermal pinule; vd 
1, focussed higher; 2, focussed lower; 
3, 4, of a small gastral pinule with stout distal ray; 
3, focussed higher; 4, focussed lower; 
5, 6, of a small gastral pinule with spirally twisted spines; 
5, focussed higher; 6, focussed lower; 
7, 8, of a small gastral pinule with slender distal ray; 
7, focussed higher; 8, focussed lower. 
9.— Oxyhexaster: magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
10-12.— Parts of end-rays of oxyhexasters; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
10, the tip of an end-ray; 4 
11, 12, central part of an end-ray; 
11, focussed higher; 12, focussed lower. ; 
13.— Surface-view of part of the sponge-lamella, after removal of the soft parts with nitric acid; magni- 
fied 30; phot. Zeiss, planar 20 mm. 
14, 15.— Apical views (the lateral rays) of pinules; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 
14, of a large dermal pinule; 
15, of a small gastral pinule. 
16-18.— Oxyhexasters; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12. 
19.— Side-view of a large dermal pinule; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 


Lanugonychia flabellum LENDENFELD. 


Figures 20-34. 


20.— Part of an irregular discohexaster with primary and secondary end-rays; magnified 600; phot. 
Zeiss, apochr. 4, compens. oc. 12. 
21.— A main-ray and adjacent parts of a plumicome; magnified 600; phot. Zeiss, H. I. apochr. 2, 
compens. oc. 6. ; 
22, 23.— The main-rays and basal parts of end-rays of plumicomes; magnified 600; phot. Zeiss, apochr. 
4, compens. oe. 12. 
24-34.— Hexactines and hexactine-derivates with fewer than six fully developed rays; magnified 200; 
phot. Zeiss, apochr. 8, compens. oc. 6: 
24, 25, with one fully developed ray; 
26-29, with two fully developed rays; 
30-34, with three to six fully developed rays. 


HEXACTINELLIDA. PLATE 12. 


2 = Spee ' : 
— ———— 
ui 33 - — ——S 
H 34 


\) 
i Hy 


i 


Fig. 1—19 Caulophacella tenuis n. sp. 


Fig. 20—84 Lanugonychia flabellum n. sp. 


Lendenfeld photographed. 


Phototype by Charles Bellmann, Prague. 


<< PS - A ns : 
PLATE 13. 
_ “ 8 a : 


PLATE 13. 


Lanugonychia flabellum LrnDENFELD. 
Figures 1-28. 


1.— The distal part of an end-ray of a large discohexaster; magnified 600; phot. Zeiss, apochr. 4, com- 
pens. oc. 12. | 
2.— Part of a large discohexaster; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12. 
3.— Part of small discohexaster; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12. 
4.— Fairly large discohexaster; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
5, 6.— Groups of spicules from spicule-preparations; magnified 200; phot. Zeiss, apochre 8, compens. 
oc. 6: 
a, large discohexasters; b, onychhexasters; c, angularly bent, hexactine-derivate diactine. 
7.— Part of the dictyonal skeleton of the stalk; magnified 30; phot. Zeiss, planar 20 mm. 
8.— View of the specimen; natural size; phot. Zeiss, anastig. 480/412 mm. (The stalk is detached 
from the body proper, there is a complete interruption between them at a). 
9-13.— Megascleres; magnified 30; phot. Zeiss, planar 20 mm.: 
9, side-view of a large pentactine; 
10, apical view of the lateral rays of a small pentactine; 
11, part of a large rhabd; 
12, apical view of the lateral rays of a small pentactine; 
13, side-view of a small pentactine. 
14.— Part of the lamellar sponge-body in transmitted light; magnified 3; phot. Zeiss, anastig. 167 mm. 
15.— Group of microscleres from a spicule-preparation; magnified 200; phot. Zeiss, apochr. 8, compens. 
oc. 6: Fi 
a, discohexasters; b, onychhexasters. 
16.— Group of megascleres from a spicule-preparation; magnified 10; phot. Zeiss, planar 50 mm.: 
a, large, partly broken pentactines; b, small pentactine. 
17-26.— Ends of end-rays of discohexasters; magnified 2000; u. v. phot. Zeiss, gq. monochr. 1.7, q. oc. 10. 
27.— End of an end-ray of an onychhexaster; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
28.— Hexactine-derivate with only one fully developed ray; magnified 600; u. v. phot. Zeiss, q. monochr. 
6, q. oc. 10. 


HEXACTINELLIDA., PLATE 13. 


26 


fig. 1—28 Lanugonychia flabellum n. sp. 


Lendenfeld photographed. 


Phototype by Charles Bellmann, Prague, 


PLATE 14. 


Bathydorus laevis spinosissimus LENDENFELD. 


Figs. 1-6, 16, 17, 19-32 — specimen B. 
Figs. 7-11, 14, 15, 18 —specimen A. 
Figs. 12, 13 — specimen C. 


1—4.— Ends of small rhabds of specimen B; magnified 600: 
1, 3, phot. Zeiss, apochr. 4, compens. oc. 12; 
2, 4, phot. Zeiss, H. I. apochr. 2, compens. oe. 6. 
5, 6.— The central part with tyle of two small centrotyle rhabds of specimen B: 
5, magnified 600; phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
6, magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
7-10.— End-parts of large protruding rhabds (prostalia) of specimen A; magnified 200; phot. Zeiss, 
apochr. 8, compens. oc. 6. 
11.— View of the dermal surface of specimen A; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
12.— View of the gastral surface of specimen C; magnified 200, phot. Zeiss, apochr. 8, compens. oc. 6. 
13.— View of specimen C; magnified 1.6; phot. Zeiss, anastig. 480/412 mm. 
14, 15.— Two transverse sections of specimen A; magnified 10; phot. Zeiss, planar 50 mm. 
16.— An oxyhexaster of specimen B; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
17-23.— Oxyhexasters and parts and groups of such; magnified 600: 
17, 19-23, of specimen B; 
18, of specimen A; 
17, 19, 21-23, phot. Zeiss, apochr. 4, compens. oc. 12; 
18, 20, phot. Zeiss, H. I. apochr. 2, compens. oe. 6. 
24-32.— End-rays and parts of such of oxyhexasters of specimen B; u. v. phot. Zeiss, q. monochr. 1.7, 
q. oc. 10: 
24-29, parts of end-rays of different oxyhexasters; 
30-32, an end-ray of an oxyhexaster; - 
30, focussed higher; 31, focussed lower; 32, focussed still lower. 


HEXACTINELLIDA. 


PLATE 14. 


a a ee etitiieteemetnes anes —— ” Y 


st NN ype, po 


Fig. 1—32 Bathydorus laevis F. E. Sch., subspecies spinosissimus n, subsp. 1—6, 16, 17, 19—32 (B); 7 


Lendenfeld photographed, 


Phototype by Charles Bellmann, Prague. 


a .: - i 
[ll 
AS 
\ 


A, 


PLATE 15. 


Bathydorus laevis spinosissimus LENDENFELD. 


Figs. 1-4, 6-10, 14, 16-22 — specimen B. 
Figs. 5, 11-18, 15 — specimen A. 


1.— Middle-sized, fairly regular, dermal tetractine (stauractine) of specimen B; magnified 600; phot. 
Zeiss, apochr. 4, compens. oc. 12. 
2.— Small dermal tetractine with rudiment of a fifth ray, of specimen B; magnified 600; phot. Zeiss, 
H. I. apochr. 2, compens. oc. 6. 
3.— Part (three upwardly directed rays) of a middle-sized dermal hexactine of specimen B; magnified 
600; phot. Zeiss, apochr. 4, compens. oc. 12. 
4.— Small dermal diactine with a rudiment of a third ray, of specimen B; magnified 600; phot. Zeiss, 
apochr. 4, compens. oc. 12. 
5.— Large dermal diactine with rudiments of two other rays, of specimen A; magnified 600; phot. 
Zeiss, H. I. apochr. 2, compens. oc. 6. 
6.— Large dermal diactine with a rudiment of a third ray, of specimen B; magnified 600; phot. Zeiss, 
apochr. 4, compens. oc. 12. 
7, 8— Two large gastral pinule-like hexactines with considerably differentiated distal ray, of specimen 
B; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12. 
9, 10.— A dermal tetractine with rays considerably shortened and thickened, of specimen B; magnified 
600; phot. Zeiss, apochr. 4, compens. oc. 12: 
9, focussed lower; 10, focussed higher. 
11.— Part of a large dermal tetractine (stauractine) with one strongly bent ray, of specimen A; magni- 
fied 600; phot. Zeiss, apochr. 4, compens. oc. 12. 
12, 13.— Two rather large gastral, somewhat pinule-like hexactines with only slightly differentiated 
distal ray, of specimen A; magnified 600; phot. Zeiss, apochr. 4, compens. oe. 12. 
14-17.— Distal, more or less differentiated, pinule ray-like rays of gastral hexactines; magnified 600: 
14, 16, 17, of specimen B; 
15, of specimen A; 
14, 15, phot. Zeiss, apochr. 4, compens. oc. 12; 
16, 17, phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
18.— Large dermal tetractine (stauractine) with one ray considerably shorter than the others, of speci- 
men B; magnified 600; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
19.— Middle-sized dermal tetractine (stauractine) of specimen B; magnified 600; phot. Zeiss, H. I. 
apochr. 2, compens. oc. 6. 
20.— Large dermal tetractine with somewhat unequally developed rays and a rudiment of a fifth ray, 
of specimen B; magnified 600; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
21.— Middle-sized dermal tetractine with two rays considerably reduced in length, of specimen B; 
magnified 600; phot. Zeiss, apochr. 4, compens. oe. 6. 
22.— Large dermal tetractine with one ray considerably reduced in length, of specimen B; magnified 
600; phot. Zeiss, apochr. 4, compens. oc. 12. 


‘ 
z 


: aoe eee D 
HEX AOTID VELLIDA. : PLATE 15, 


Mh beh 
Sere 
eal 


n 


A hae hte! 


TO ase 


F 
1 Ss: 
a b a m, ¥ { 
> * pons - 4% 
z= 4 <~ x 
= . R 
* = 
ay « y. 
ay = “< 
42 t 


copes 
aie ata rrr 


wo /. 


i 
“a 


sis! 


anitblas 
+ ce Gian 


‘ 


~ 


rt 


sonia Nna las fet Sheed hd bealerulvast = 
SA it ky, a PORTA ON 


Oat The! 
pee 


&. 


Se ed 9 Nos 


19 TE f 
fi EN PERT PR Sor ae 
“> 
Ratna 2¢ i 
zt a1 
£ 


tal Nae il 
ep, 
Disa hem ag heat! 


r 

2 

t 
= 

“i 


Se nth ag 
“Sy, 


Phototype by Charles Bellmann, Prague, 


PLATE 16. 


Bathydorus laevis spinosissimus LENDENFELD. 


Figs. 1-8, 10, 11, 14-24 — specimen A. 
Figs. 9, 12, 13 — specimen B. 


1, 2.— Side-views of pentactines with long proximal and short lateral rays, of specimen A; magnified 50: 
phot. Zeiss, planar 20 mm., compens. oc. 6. 
3.— Side-view of a hexactine of specimen A; magnified 50; phot. Zeiss, planar 20 mm., compens. oc. 6. 
4-8.— Side-views of pentactines with long lateral rays, of specimen A; magnified 50; phot. Zeiss, 
planar 20 mm., compens. oc. 6: 
4-6, 8, with normally developed rays; 
7, with the proximal and two lateral rays reduced in length and terminally thickened. 
9.— Gastral pinule-like hexactine of specimen B; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
10, 11.— Two gastral pinule-like hexactines of specimen A; magnified 200; phot. Zeiss, apochr. 8, 
compens. oc. 6. 
12-14.— Dermal stauractines; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 
12, 13, of specimen B; 
14, of specimen A. 
15.— Part of the apical view of the lateral rays of a pentactine of specimen A; magnified 200; phot. 
Zeiss, apochr. 8, compens. oc. 6. 
16, 17.— Apical views of the lateral rays of pentactines of specimen A; magnified 50; phot. Zeiss, 
planar 20 mm., compens. oc. 6: 
16, of a pentactine in which all the lateral rays are properly developed; 
17, of a pentactine with one lateral ray reduced in length. 
18.— Abnormal hexactine of specimen A; magnified 30; phot. Zeiss, planar 20 mm. 
19.— Rectangular diactine of specimen A; magnified 50; phot. Zeiss, planar 20 mm., compens. oc. 6. 
20, 21— Part of a slightly heated lateral ray of a pentactine of specimen A; magnified 600; phot. 
Zeiss, H. I. apochr. 2, compens. oc. 6: 
20, focussed higher; 21, focussed lower. 
22, 23.— Part near the base of a lateral ray of a pentactine, of specimen A; magnified 600; phot. Zeiss, 
H. I. apochr. 2, compens. oc. 6: 
22, focussed higher; 23, focussed lower. 
24.— End of a lateral ray of a pentactine of specimen A; magnified 600; phot. Zeiss, H. I. apochr. 2, 
compens. oc. 6. ) 


Staurocalyptus hamatus LeNDENFELD. 
Figures 25-43. 


25-28.— Ends of rhabds; magnified 200; phot. Zeiss, apochr. 8, compens, oc. 6: 
25-27, of small rhabds; 
28, of a large rhabd. 
29.— A small rhabd; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
30-33.— A middle-sized stout rhabd, and parts of it: 
30, the rhabd; magnified 30; phot. Zeiss, planar 20 mm.; 
31-33, parts of the rhabd; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 
31, one end; 
32, portion of the middle-part; 
33, the other end. 


34-38.— A large rhabd and parts of it: 13 s 
34, the rhabd; magnified 30; phot. Zeiss, planar 20 mm.; 
a, the part represented more strongly magnified in fig. 36; 
35-38, parts of the rhabd; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6; 
35, one end; 
36, portion near the end (at a, fig. 34) with a thickening of the axial thread; 
37, the other end; 
38, part of the thickest portion near the middle. 
39.— Group of spicules from a spicule-preparation; magnified 30; planar 20 mm.: 
a, large rhabd; b, small rhabd; ec, hemioxyhexasters with straight rays; d, oxyhexactine with 
hook-like rays; e, discoctaster. 
40-43.— Small, spined, dermal rhabds; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 
40, 41, with rudiments of other rays besides the fully developed two; 
42, 43, simple rhabds without such ray-rudiments. = 


PLATE 16, 


* 


Fig. 1—24 Bathydorus laevis F. E. Sch., subspecies spinosissimus n. subsp. 1—8, 10, 11, 14—24 (A); 9, 12, 13 (4). 
Fig. 25—43 Staurocalyptus hamatus n. Sp. 


Lendenfeld photographed, 


re 
has i ' 
i 


Phototype by Charles Bellmann, Prague. 


y= 


\e 


PLATE 17: 


Staurocalyptus hamatus LENDENFELD. 


Figures 1-25. 


1-8.— Hemioxyhexasters and microoxyhexactines; magnified 200; phot. Zeiss, apochr. 8, compens. 
oc. 6: 
1-3, microoxyhexactines with hook-like rays; 
4, hemioxyhexaster with partly straight, partly hook-like rays (end-rays) ; 
5-8, hemioxyhexasters with straight rays. 
9, 10.— Groups of spicules from spicule-preparations; magnified 200; phot. Zeiss, apochr. 8, compens 
oc. 6: 
a, dermal rhabd; b, hemioxyhexasters with straight rays; ce, microoxyhexactine with hook-like 
rays, one of which is abnormally elongated; d, diseoctasters; e, small discohexaster. 
11, 12.— Two regular discoctasters with one main-ray axis parallel to the optical axis of the microscope; 
magnified 600; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
13.— Group of spicules from a spicule-preparation; magnified 600; phot. Zeiss, H. I. apochr. 2, compens. 
oc. 6: 
d, part of an irregular discoctaster; e, small discohexasters. 
14-16.— Diseoctasters with the three main (main-ray) axes oblique to the optical axis of the micro- 
scope; magnified 600: 
14, an irregular discoctaster; phot. Zeiss, apochr. 4, compens. oc. 12; 
15, 16, regular discoctasters; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
17, 18.— Centre of a discoctaster with the three main (main-ray) axes oblique to the optical axis of 
the microscope; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
17, focussed higher; 18, focussed lower. 
19-23.— Centres of two discoctasters with one main-ray axis parallel to the optical axis of the micro- 
scope; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
19, 20, of one discoctaster; 
19, focussed higher; 20, foctaccd lower; 
21-23, of another discoctaster; 
21, focussed higher; 22, focussed lower; 23, focussed still lower. 
24, 25.— End-rays of discoctasters; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
24, of a large discoctaster; 
25, of a small discoctaster, 


leans 


HEXACTINELLIDA. 


Lendenfeld photographed. 


Fig. 1—25 Staurocalyptus hamatus n. sp. 


Phototype by Charles Bellmann, Prague, 


PLATE 17. 


a j 
z 
- 7 
o 
€ 
pe 
7 ‘os 
e 
t 
+ 
* 


PLATE 18. 


Staurocalyptus hamatus LenpENFELD. 


Figures 1-14. 


1—4.— Two small discohexasters; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
1, 2, one small discohexaster ; 
1, focussed higher; 2, focussed lower; 
3, 4, another small discohexaster; 
3, focussed higher; 4, focussed lower. 
5, 6.— Views of the sponge after removal of the Dicranodromia; reduced 1: 9.85; phot. Zeiss, anastig. 
480/412 mm.: 
5, from below; 
6, from above. 
7.— A small discohexaster; magnified 600; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
8-10.— Side-views of hypodermal pentactines; magnified 30; phot. Zeiss, planar 20 mm. 
11, 12.— Part of a spicule-group; magnified 600; phot. Zeiss, H. I. apochr. 2, compens. oc. 6:° 
11, focussed higher; 12, focussed lower; 
a, dermal rhabd; b, small discohexasters. 
13.— Part of a large rhabd of abnormal structure; magnified 600; u.v. phot. Zeiss, q. monochr. 6, q.oc. 10. 
14.— The sponge with the Dicranodromia seen from the front; natural size; phot. Zeiss, anastig. 
480/412 mm. 


Holascus edwardsii LENDENFELD. 
Figures 15-26. 


15.— Group of slender-rayed comital triactines; magnified 30; phot. Zeiss, planar 20 mm. 

16.— Group of slender-rayed comital triactines, tetractines, and pentactines; magnified 50; phot. 
Zeiss, apochr. 16, compens. oc. 4. 

17, 18.— Hypogastral hexactines; magnified 50; phot. Zeiss, apochr. 16, compens. oc. 4. 

19-21.— Hypodermal hexactines; magnified 50; phot. Zeiss, apochr. 16, compens. oc. 4. 

22.— Surface-view of the skeleton of the body-wall. The soft parts and most of the smaller spicules are 
removed. The large choanosomal pentactines are still nearly in their natural position. Magni- 
fied 7.5, phot. Zeiss, planar 50 mm.: 

a, large choanosomal pentactines; b, comitals. : 

23.— The central part of a slender-rayed, comital spicule with two fully developed long rays, one con- 
siderably reduced ray, and two insignificant ray-rudiments which appear as slight protuberances; 
magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12. 

24-26.— The distal part of the distal ray of three hypodermal hexactines; magnified 600; phot. Zeiss, 
apochr. 4, compens. oc. 12. 


HEX ACTINELLIDA. PLATE 18, 


= Bek . ~ a : 
ff , te o. 
= ‘. oy, & 
if . ; 
3 — 6 f 
* i™ | 
: : a ii sty hewt - \ \\\ * 
*. . id & FS x | \ , 
ax owe * 9 |10) : 


OY yw 
. if @ 4 p 1S" 
4 é a < ‘ 


“=< { 
AV Sas | 
| | | ? 
; j mw ay ; 
eae | 
She os ean | I) IN 
. petting” 9. | : Fly : - 
ae ‘ AKA yy | | \ ~ £ ‘e : 
= Ca) ie ; . 
4 ete $oe $ ed } ' - Fema 
J 2 oy i ws 4 : j _ 
ae i wi 


20 


aE 


Pal 


— 19 y { 
17 ' 
\ 
| ‘ » 
| | . ,. | 
| . | 


23 24 25 6 


Fig. 1—14 Staurocalyptus hamatus n. sf 
Fig. 185—26 Holascus edwardsti n. sp. 


Lendenfeld photographed, 


Phototype by Charles Bellmann, Prague 


m a! j 5 Po 
~ = ) 7 @ a 
wu uy vo) 
arin + ito S PAT : : 
2) ny : I ; 
i » | r . 
1 t 
} 
’ 
— : * — 
Z Vv 
. 
I 
PLATE 19. 
ld 
- 
7 
. 


PLATE 19. 


Holascus edwardsii LENDENFELD. 


Figures 1-24. 


1-3.— Oxyhexasters; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12. 
4, 5.— Parts of hemioxyhexasters; magnified 600; 
4, phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
5, phot. Zeiss, apochr. 4, compens. oc. 12. 
6-10.— Oxyhexasters and hemioxyhexasters; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
11.— An end-ray of an oxyhexaster; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
12, 13.— The central part (the main-rays) of a graphiocome; magnified 600; phot. Zeiss, apochr. 4, 
compens. oc. 12: 
12, focussed high; 13, focussed low. 
14.— Part (the two tips) of a ring-shaped sigm; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. 
oc. 10. 
15.— Ring-shaped sigm with the spiral axis obliquely situated; magnified 600; phot. Zeiss, apochr. 4, 
compens. oc. 12. 
16-21.— Ring-shaped sigms with the spiral axis parallel to the optical axis of the microscope; tnagnified 
600: 
16, 19-21, phot. Zeiss, apochr. 4, compens. oc. 12; 
17, 18, phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
22-24.— Centrotyle rhabds; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 


* 


it PLATE 19, 


Fig, 1—24 Holaseus edwardsti, n, sp. 


Phototype by Charles Bellmann, Prague. 


q 


E 20. 


a. 
Ay 


PLATE 20. 


Holascus edwardsii LENDENFELD. 


Figures 1-20. 


1, 2.— Large choanosomal pentactines; magnified 2.3; phot. Zeiss, anastig. 167 mm. 
3.— Inner surface of the body-wall of a specimen cut in half longitudinally; reduced 1: 6.5; phot. . 
Zeiss, anastig. 480/412 mm. 
4.— View of a specimen (outer surface of the body-wall); reduced 1: 6.5: phot. Zeiss, anastig. 480/412 
mm. 
5-10.— The distal end-part of anchoring spicules; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12: 
a (in figs. 5-8), axial cross. 
11-15.— Different parts of one and the same anchoring spicule; magnified 200; phot. Zeiss, apochr. 8, 
compens. oc. 6: 
11, portion of the proximal smooth part; 
12-14, successive portions of the spined distal part; 
15, the distal end-part with its anchor. : 
16-20.— The distal end-part of anchoring spicules; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 


“5 


. 


| 


z= i, Ole x “a ne i>. (ee 


PLATE 20, 


HEXAOTINELLIDA. 


Sp. 


1—20 Holascus edwardsii n, 


Fig. 


Lendenfeld photographed. 


Phototype by Charles Bellmann, Prague, 


» 
- 
” 
x 
. 
. 
: 
— > 
‘ 
= 
° 
“ ~ a és 


TE 21. 


| 


ie 


PLATE 21. 


Holascella taraxacum LENDENFELD. 
Figures 1-13. 


1, 2— A main-ray with its end-rays of an oxyhexaster; magnified 2000; u. v. phot. Zeiss, q. monochr. 
Noy Cl Cres Oe 
1, focussed higher; 2, focussed lower. 
3, 4.— The distal part of an end-ray of a discohexaster; magnified 2000; u. v. phot. Zeiss, q. monochr. 
NGG Ch Ces NOP 
3, focussed higher; 4, focussed lower. 
5-7.— The distal part of end-rays of three different discohexasters; magnified 2000; u. v. phot. Zeiss, q. 
monochr. 1.7, q. oc. 10. “ 
8.— View of the most complete specimen; reduced 1: 0.7; phot. Zeiss, anastig. 480/412 mm. 
9.— Part of an end-ray of an oxyhexaster; magnified 2000; u. v. phot. Zeiss q. monochr. 1.7, q. oc. 10. 
10.— Centrum and main-rays of a discohexaster; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, 
q. oc. 10. 
11, 12.— Large and small discohexasters; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
13.— Small discohexasters; magnified 300; u. v. phot. Zeiss, q. monochr. 6, q. oc. 5. 


HEXACTINELLIDA. 


‘ 
| 
\ : * ~ 
Al ee 4 
| : - 
NY | 
\ > 
. m ; 
rs Se . 
4 + 
: 
: 
\ e ‘ 
\ ‘ 
rd / i \ . 
7 g 7 
4 y 
/ n 
: ‘ . . ~ 
' \ j é 
~” i ” » 
a » be 


Fig. 1—13 Holascella taraxacum n, sp. 


Lendenfeld photographed, 


Phototype by Charles Bellmann, Prague 


or 


i) 


PLATE 21. 


PLATE 22. 


Holascella taraxacum LeNDENFELD. 


Figures 1-41. 


1-4.— Superficial (hypodermal, hypogastral) hexactines; magnified 50; phot. Zeiss, planar 20 1 
compens. oc. 6. 

5-11.— Large choanosomal hexactines, pentactines, and tetractines; magnified 7.5; phot. Zeiss, pl 
50 mm. 

12-17.— The outer protruding ray of superficial (hypodermal, hypogastral) hexactines; magnified 200; 
phot. Zeiss, apochr. 8, compens. oc. 6. 

18, 19.— The distal part of a ray of a microhexactine; magnified 2000; u. v. phot. Zeiss, q. mania 4 
7 cenoca 10: 

18, focussed higher; 19, focussed lower. 
20-25.— Micro-hexactines and -pentactines; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
26.— The lower, distal end of an anchoring spicule; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
27, 28.— Parts of groups of onychhexasters in spicule-preparations; magnified 600; phot. Zeiss, H. 

apochr. 2, compens. oc. 6. 

29-35.— The tyles and adjacent parts of centrotyle rhabds; magnified 200; phot. Zeiss, apoch 

compens. oc. 6. y 

36.— Portion of a ray of a large choanosomal hexactine; magnified 200; phot. Zeiss, apochr. 8, compens. 

oc. 6. 

37.— The lower, distal end of an anchoring spicule; magnified 100; phot. Zeiss, apochr. 16, comet 
oe. 6. 

38-41.— Ends of rhabds: magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 


i 


PLATE 22. 


Fig. 1—41 Holascella taraxacum n. sp. 
Lendenfeld photographed, 


Phototype by Charles Bellmann, Prague. 


_" spit | 


PLATE 23. 


PLATE 23. 


Holascella taraxacum LENDENFELD. 
Figures 1-3. 


1.— Portion of the distal part of a longitudinal ray of a large choanosomal hexactine; magnified 600; 
phot. Zeiss, apochr. 4, compens. oc. 12. 

2, 3.— Two distal ends (anchor-heads) of anchoring spicules; magnified 600; phot. Zeiss, H. I. apochr. 2, 
compens. oc. 6. 


Holascella ancorata LENDENFELD. 


= Figures 4-25. 


4.— A part of a ray of a principal tetractine where regeneration took place; magnified 600; u. v. phot. 
Zeiss, q. monochr. 6, q. oc. 10. 

5.— A microdiscohexactine; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 

6, 7.— The central parts of a microdiscohexactine (fig. 6) and a hemidiscohexaster (fig. 7); magnified 
2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 

8.— A microoxyhexactine; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
9.— View of the specimen; magnified 1.4; phot. Zeiss, anastig. 167 mm. 

10.— Portion of a group of microscleres from a spicule-preparation; magnified 600; phot. Zeiss, H. I. 

apochr. 2, compens. oc. 6: 
a, aray of a microdiscohexactine; b, rays of microonychhexactines. 

11.— The distal part of a ray of a microonychhexactine; magnified 2000; u. v. phot. Zeiss, q. monochr. 
Lengo. 10) 

12, 13.— The distal ray of two superficial hexactines; magnified 200; phot. Zeiss, apochr. 8, compens. 
oc. 6: 

12, of a hypodermal hexactine; 13, of a hypogastral hexactine. 

14.— Group of microscleres from a spicule-preparation; magnified 200; phot. Zeiss, apochr. 8, compens. 

oc. 6: 
a, microdiscohexactines; b, a microonychhexactine. 

15.— Fragmentary onychhexasters; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 

16.— A ray of a microonychhexactine; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12. 

17-25.— Six distal ends of rays of discohexasters, hemidiscohexasters, or microdiscohexactines; magni- 
fied 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 

Of four there is only one view (figs. 19-22). Of one (figs. 17, 18) there are two views (fig. 17, focussed 
lower, fig. 18, focussed higher), and of another (figs. 23-25) there are three views (fig. 23, focussed high, 
fig. 24, focussed intermediate, fig. 25, focussed low). 


oD 
GC 
SS 
oe 
< 
— 
— 


3 Holascella taraxacum n. sp. 


Fig. 1— 


Fig. 4—25 Holascella ancorata n. sp. 


Lendenfeld photographed. 


Phototype by Charles Bellmann, Prague. 


/ 
r 


PLATE 24. 


Holascella ancorata LenpENFELD. 
Figures 1-9. 


1, 2.— Parts of spiny hexactines; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
3.— Group of principal spicules; magnified 4; phot. Zeiss, planar 100 mm. _ 
4.— Two microscleres from a spicule-preparation; magnified 200; phot. Zeiss, apocd: 8, compens. oc. 6: 
a, a microonychhexactine; b, a floricome. 
5-7.— Parts of floricomes; magnified 1000; phot. Zeiss, H. I. apochr. 2, compens. oc. 12: 
5, the end of a main-ray with its verticil of end-rays, all of which are broken off rather short, seen 
from above; 
6, the central part (main-ray cross); 
7, the greater part of a whole floricome. 
8.— The central part of a tetractine principal spicule; magnified 300; u. v. phot. Zeiss, q. monochr. 6, 
q. oc. 5. 
9.— The central part of a triactine comital spicule; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 


Holascella euonyx LeENDENFELD. 


Figures 10-17. 


10, 11.— The central part (main-rays) of two small discohexasters; magnified 2000; u. v. phot. Zeiss, q. 
monochr. 1.7, q. oc. 10. 
12.— A small discohexaster; magnified 600; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
13, 14.— Group of microscleres from a spicule-preparation; magnified 600; phot. Zeiss, H. I. apochr. 2, 
compens. oc. 6: 
13, focussed lower; 14, focussed higher; 
a, part of an onychhexactine; b, small discohexaster. 
15.— The greater part of a small discohexaster; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, 
q. oc. 10. 
16, 17— Group of two small discohexasters from a spicule-preparation; magnified 600; phot. Zeiss, 
H. I. apochr. 2, compens. oc. 6: 
16, focussed lower; 17, focussed higher. 


1—9 Holascella ancorata n. Sp 


Fig. 10—17 Holascella euonyx n. sp. 


i 


Lendenfeld photographed, 


Phototype by Charles Bellmann, Prague. 


_ 


a- 


PLATE 25. 
Holascella euonyx LENDENFELD. 
Figures 1-24. 


1.— The end of a ray of an onyehhexactine; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
2, 3.— The end of a ray of a large discohexactine; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, 


q. oc. 10: 
_& focussed higher; 3, focussed lower. 
4, 5— The end of a ray of a large discohexactine; magnified 2000; u. v. phot. Zeiss, q. signgoue! MEFs, 
q. oc. 10: 


4, focussed higher; 5, focussed lower. 
6.— The end of a ray of an onychhexactine; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
7-9.— Onychhexactines and hemionychhexaster; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6: 
7, 9, onychhexactines; 8, a hemionychhexaster. 
10, 11.— Large discohexactines; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
12.— Apical view of the terminal spine-verticil (end-disc) of the upstanding ray of the large discohexac- 
tine represented in fig. 11; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
13.— Group of microscleres from a spicule-preparation; magnified 300; phot. Zeiss, apochr. 4, compens. 
oc) 6: 
a, small discohexasters; b, onychhexactine. 
14, 15.— Side-view of superficial hexactines; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
16.— The central part of a large tetractine principal spicule; magnified 100; phot. Zeiss, apochr. 16, 
compens. oc. 6. 
17.— View of the specimen; reduced 1: 0.86; phot. Zeiss, Tessar 250 mm. 
18.— A tetractine comital spicule; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
19, 20.— Two groups of comital and other medium-sized spicules; magnified 00; phot. Zeiss, apochr. 
16, compens. oc. 6. 
21, 22.— The distal part of the distal ray of a superficial hexactine; magnified 600: phot. Zeiss, H. I. 
apochr. 2, compens. oc. 6: 
21, focussed higher; 22, focussed lower. 
23, 24.— The distal part of the distal ray of a superficial hexactine;- magnified 600; phot. Zeiss, H. I. 
apochr. 2, compens. oc. 6: 
23, focussed higher; 24, focussed lower. 


Farrea occa scutella LENDENFELD. 


Figures 25-29. 


25-29.— Small hexactines, attached and free; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6; 
25, a hexactine attached to a stout beam of the main network; 
26, a free hexactine; 
27, 28, hexactines attached to slender beams; 
29, hexactine attached to a medium beam. 


Lendenfeld photographed, 


Fig. 1—24 Holascella euonyx n. sp. 


Fig. 25—29 Farrea occa Bwok, var. scutella n. 


Phototype by Charles Bellmann, Prague. 


var, 


PLATE 25, 


’ 


PLATE 26. 


PLATE 26. 


Farrea occa scutella LeNDENFELD. 
Figures 1-21. 


1-3.— Parts of oxyhexasters; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
1, the distal part of a main-ray with the basal parts of the end-rays arising from it; 
2, a whole end-ray; 
3, the centre and one main-ray with its end-rays. 
4-6.— Oxyhexasters; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
7.— Oxyhexaster; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12. 
8.— Surface-view of a dried portion of the marginal part of the body; magnified 30; phot. Zeiss, planar 
30 mm.: 
a, superficial pentactines; b, clavules; c, oxyhexasters. 
9.— The gastral face of a portion of the skeleton-net of the marginal part of the body; magnified 6.6; 
phot. Zeiss, planar 50 mm. 
10.— View of the free upper face of the basal plate of attachment; magnified 6.6; phot. Zeiss, planar 
50 mm. 
11.— View of the previously attached lower face of the basal plate of attachment; magnified 100; phot. 
Zeiss, apochr. 16, compens. oc. 6. 
12, 13.— Portions of the skeleton-net of the upper part of the basal plate of attachment; magnified 100; 
phot. Zeiss, apochr. 16, compens. oc. 6. 
14.— Portion of the skeleton-net of the marginal part of the body; magnified 6.6; phot. Zeiss, planar 
50 mm. 
15.— Apical view of a superficial pentactine; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
16, 17.— Views of the stalk and central part of the body of a small specimen from opposite sides; magni- 
fied 6.6; phot. Zeiss, planar 50 mm. 
18, 19.— A specimen with two stalks (probably produced by the partial concrescence of two specimens 
growing near together); magnified 2.1; phot. Zeiss, anastig. 167 mm.: 
18, seen from the side; 
19, seen from above. 
20, 21.— A regular specimen with a single stalk; magnified 2.1; phot. Zeiss, anastig. 167 mm.: 
20, seen from the side; 
21, seen from above. 


PLATE 26. 


HEXACTINELLIDA. 


Fig. 1—21 Farrea occa Bwobk. var. scutella n. var. 


Lendenfeld photographed, 


Phototype by Charles Bellmann, Prague 


PLATE 27. 


Farrea occa scutella LENDENFELD. 


Figures 1-17. 


1.— A clavule with large teeth; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
2-5.— Centres (anchor-heads) of two clavules with large teeth; magnified 500; phot. Zeiss, apr oc 
compens. oc. 12: Ly 
2, a clavule-head focussed high; 
3, the head of the same clavule focussed lower; 
4, another clavule-head focussed high; 
5, the head of the same clavule focussed lower. 
6.— Group of spicules from a spicule-preparation; magnified 200; phot Zeiss, apochr. 8, » COT 
a, apical view of a pentactine; b, a clavule with large teeth; ¢, oxyhexasters. : 
7, 8.— Centre (anchor-head) of a clavule with large teeth; magnified 500; phot. Zeiss,, apochr. 
pens. oc. 12: 
7, focussed high; 8, focussed lower. 
9, 10.— Centre (anchor-head) of a clavule with large teeth and apical protuberance; magnifi 
phot. Zeiss, apochr. 4, compens. oc. 12: 
9, focussed high; 10, focussed lower. 
11.— A elavule with large teeth; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
12.— The centre (anchor-head) of a clavule with small teeth; magnified 500; phot. Zeiss, | 
compens. oc. 12. 
13, 14.— The centre (anchor-head) of a clavule with large, conspicuously spined teeth; magnified 
u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
18, focussed a little higher; 14, focussed a little lower. 
15.— The apical protuberance of a clavule with large teeth similar to the one whose anchor-h 
is represented in figs. 9, 10; magnified 2000; phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
16, 17— The centre (anchor-head) of a clavule with large teeth hardly perceptibly spined; mag 
2000; phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
16, focussed high; 17, focussed low. 


PLATE 27. 


11 


Fig. 1—17 Farrea occa Bwbk. var. scutella n, var. 


Lendenfeld photographed, 


Phototype by Charles Bellmann, Prague. 


t= 


PLATE 28. 


PLATE 28. 


Hexactinella monticularis LenDENFELD. 
Figures 1-28. 


1—4.— Four scopules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
5-7.— The centres and end-rays of three scopules; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, 
q. oe. 10. 
8, 9.— The centre of a scopule; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
8, focussed higher; 9, focussed lower. 
10.— Part of an uncinate; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
11, 12.— Parts of discohexasters; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
11, the end of an end-ray of a small discohexaster seen obliquely from above; 
12, an entire end-ray of a large discohexaster. 
13, 14.— The centres and end-rays of two scopules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
15, 16.— Two large discohexasters; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
17, 18.— Parts of long-spined hexactines; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
19.— Apical view of a superficial pentactine; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
20.— Part of a small discohexaster; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
21.— Part of the superficial skeleton-net (pentactines soldered together); magnified 200; phot. Zeiss, - 
apochr. 8, compens. oc. 6. 
22.— Part of a beam of the skeleton-net with a spine; magnified 200; phot. Zeiss, apochr. 8, compens. 
oc. 6. 
23.— The skeleton-net of part of a specimen; magnified 3.5; phot. Zeiss, planar 100 mm. 7 
24.— Part of a transverse section through a superficial portion of the skeleton; magnified 20; phot. 
Zeiss, planar 20 mm.: 
a, internal skeleton-net; b, spines protruding towards the surface. 
25.— Group of discohexasters from a spicule-preparation; magnified 300; phot. Zeiss, apochr. 4, com- 
pens. oc. 6. 
26.— Portion of the inner, sectioned face of a skeleton-net cut longitudinally in half; magnified 6.6; 
phot. Zeiss, planar 50 mm. 
27.— Part of the superficial skeleton-net (pentactines soldered together); magnified 200; phot. Zeiss, 
apochr. 8, compens. oc. 6. 
28.— Surface-view of the skeleton-net of one of the monticular protuberances of the surface; magnified 
6.6; phot. Zeiss, planar 50 mm. 


PLATE 28. 


HEX ACTINELLIDA. 


ij * € ¥ 
: 3 t ‘ ws Ff 
- ; : 7 § i. 
° . : J : 13 
: :! ~ 
- 1 4 - 2 
\ i 10 § 12 
_ } | 
& } 
t be) | 
i 1a 
i 
/ Te i : 
1 Dees a4 \ 3 gg 3 4£ | 
4 pe ri 5 : ‘ 14 
n } ’ 
5 PY 
ql al te, 
| f \ 6 i : . 7 1 
. } >» 9 
aS ‘at : I -| 
3 
4 ' a; 
&, 


( 
’ 
| 
. ~\ ~ | JA 4 nn =) aed om | ‘ 
| — Ie 2 we ey a —_ 
Z 4 7 > v No A 
| e ~ ri 
| | | 4 s | 20 
15 16 i 19 | 
f 


: ae —_ — ee ~_ ‘ £ 
* BEE ~~ yi» a 


17 


sp. 


Fig. 1—28 Hexactinella monticularis 1. 


Lendenfeld photographed. 


Phototype by Charles Bellmann, Prague. 


é i ie 
ag . 7 — 0S > Ee a a ere -_ 


iid 


‘ 


PLATE 29. 


he Nt es 


| 


PLATE 29. 


Eurete spinosum LENDENFELD. 


Figures 1-26. 


1, 2.— Scopules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
3-6.— The centres and end-rays of two scopules; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12: 
3, a scopule-centre focussed high; 
4, the centre of the same scopule focussed lower; 
5, the centre of another scopule focussed high; 
6, the centre of the same scopule focussed lower. 
7,8.— The centre and end-rays of a scopule; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
7, focussed higher; 8, focussed lower. 
9.— The central part of a hemioxyhexaster; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
10-13.— Hemioxyhexasters and parts of such; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12: 
10, an ordinary, fairly regular, slender-rayed hemioxyhexaster; 
11, 13, parts of ordinary, fairly regular, slender-rayed hemioxyhexasters; 
12, a stout-rayed irregular hemioxyhexaster. 
14-17.— The distal end-parts of main-rays of hemioxyhexasters with one of the end-rays or part of it; 
magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
18, 19.— The two faces of the skeleton-net; magnified 6.6; phot. Zeiss, planar 50 mm.: 
18, the dermal face; 
19, the gastral face. 
20, 21.— Apical views of two superficial pentactines (the crosses formed by their lateral mye) ; Magni- 
fied 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
22.— A lateral ray of a superficial pentactine; magnified 200; phot. Zeiss, apochr. 8, compens. oc.6. 
23.— Part of the dermal zone of the skeleton-net; magnified 50; phot. Zeiss, apochr. 16, compens. oc. 4. 
24.— Part of the gastral zone of the skeleton-net; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
25.— Part of the gastral zone of the skeleton-net; magnified 50; phot. Zeiss, apochr. 16, compens. oc. 4. 
26.— Group of spicules from a spicule-preparation; magnified 200; phot. Zeiss, apochr. 8, compens. 
oc. 6: 
a, a scopule; b, hemioxyhexasters. 


HEXACTINELLIDA. 


4 NS 
4 y 
py i 
\ 
tar 
\ Z 
ay a — 4 ‘ 
= y =F “~ 
fo ‘J 10 f 
y” ~ j \ ; * 
AN ‘ 
y | ee ( 
st 
“2 


"Hy 


mann SOY sg bate 


~ey 


Lendenfeld photographed 


; 


26 


Fig. 1-26 Eurete spinosum n. Sp. 


Lichtdruck von Werner & Winter, Frankfurt a. M. 


to 
or 


PLATE 29. 


ur i b es _ i 
. a, oot et ‘ Ae i . | 
: 7 ae -~ 
a a . H 
Ae ” 
oe 
’ 


PLATE 30. 


ihe] \ 


PLATE 30. 


Eurete erectum ScuHuuze. 
Figures 1-17. 


1-3.— Side-views of gastral pinules (pinule-derivates); magnified 200; phot. Zeiss, apochr. 8, compens. 
oc. 6. 
4.— The dermal face of the skeleton-net; magnified 6.6; phot. Zeiss, planar 50 mm. 
5.— The gastral face of the skeleton-net; magnified 2.1; phot. Zeiss, anastig. 167 mm. 
6.— The gastral face of the dictyonal skeleton-net; magnified 6.6; phot. Zeiss, planar 50 mm. 
7.— Transverse section through the dermal zone of the tube-wall; magnified 100; phot. Zeiss, apochr. 
16, compens. oc. 6: 
a, lateral rays of dermal pinules; c, flagellate chambers; d, distal ray of a dermal pinule; e, 
dermal spine of the skeleton-net; f, skeleton-net. 
8.— Apieal view of a gastral pinule-derivate; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
9.— Side-view of a gastral pinule; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
10.— Transverse section through the dermal zone of the tube-wall; methyl-violet; magnified 100; 
phot. Zeiss, apochr. 16, compens. oc. 6: 
a, lateral rays of dermal pinules; c, flagellate chambers; d, distal ray of dermal pinule; e, 
dermal spine of the skeleton-net; f, skeleton-net. 
11.— View of portion of the gastral face of the skeleton-net; magnified 20; phot. Zeiss, planar 20 mm. 
12.— Transverse section through the tube-wall; magnified 30; phot. Zeiss, planar 20 mm.: 
a, lateral rays of dermal pinules; b, lateral rays of gastral pinules; d, distal ray of dermal 
pinules; f, skeleton-net; g, gastral spines of the skeleton-net; h, distal rays of gastral see 
13, 14.— Apical views of eoetea pinules ((pinule-derivates); magnified 200; phot. Zeiss, apochr. 8, 
compens. oc. 6. 
15.— Transverse section through the gastral zone of the tube-wall; magenta; magnified 100; phot. 
Zeiss, apochr. 16, compens. oc. 6: 
b, lateral rays of gastral pmules; i, gastral scopules. 
16.— View of the sponge; magnified 1.2; phot. Zeiss, anastig. 480/412 mm. 
17.— Transverse section through the tube-wall; magenta; magnified 30; phot. Zeiss, planar 20 mm.; 
a, lateral rays of dermal pinules; b, lateral rays of gastral pinules; c¢, flagellate chambers; d, 
distal rays of dermal pinules; f, skeleton-net; g, gastral spines of the skeleton-net; h, distal 
rays of gastral pinules; i, gastral scopules. 


HEXACTINELLIDA. 


Lendenfeld photographed 


= 


YS, Sri 


Fig. 1-17 Eurete erectum FP. E. Sch. 


Lichtdruck von Werner & Winter, Frankfurt a. M. 


PLATE 30. 


@ e 
ni 
’ 
- 
- 
- 
- 
. 
' 
. 
‘ 
tl 
‘ 
rr 


ae 


' 


PLATE 31. 


PLATE 31. 


Eurete erectum Scuuuze. 


Figures 1-28. 


1.— Centres and end-rays of two gastral scopules with large-headed, strongly divergent end-rays; 
magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
2-5.— Side-views of dermal pinules; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
6-9.— The distal ends of end-rays of two rather large-headed gastral scopules; magnified 1200; phot. 
Zeiss, H.1. 1/12, compens. oc. 12: 
6, an end-ray head focussed high; 
7, the head of the same end-ray focussed lower; 
8, the head of another end-ray focussed high; 
9, the head of the same end-ray focussed lower. 
10-12.— The centre and the end-rays of a gastral scopule with large-headed, fairly divergent end-rays; 
magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6: 
10, focussed high; 11, focussed lower; 12, focussed still lower. 
13.— Part of a large uncinate; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12. 
14.— A small uncinate; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
15.— Part of a discohexaster; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12. 
16.— Group of scopules from a spicule-preparation; magnified 100; phot. Zeiss, apochr. 16, compens. 
oc. 6: 
a, two gastral scopules with strongly divergent, large-headed end-rays; b, a dermal scopule 
with nearly parallel, terminally not thickened end-rays. 
17.— The centre and end-rays of a dermal scopule with fairly divergent, terminally only very slightly 
thickened end-rays; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
18.— An end-ray of a discohexaster; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
19.— The centre and end-rays of a dermal scopule with nearly parallel, terminally not thickened end- 
rays; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
20.— A gastral scopule with fairly divergent, large-headed end-rays; magnified 100; phot. Zeiss, apochr. 
16, compens. oc. 6. 
21.— A discohexaster; magnified 600; phot. Zeiss, apochr. 4, compens. oc. 12. 
22.— Part of the gastral membrane with the crosses formed by the lateral rays of the gastral pinules and 
pinule-derivates in situ; magnified 30; phot. Zeiss, planar 20 mm. 
23.— Two gastral scopules with fairly divergent, large-headed end-rays; magnified 100; phot. Zeiss, 
apochr. 16, compens. oc. 6. 
24,— Transverse section through the gastral zone of the tube-wall; magnified 100; phot. Zeiss, apochr. 
16, compens. oe. 6: 
b, lateral rays of gastral pinules; f, skeleton-net; g, gastral spines of the skeleton-net; h, distal 
rays of the gastral pinules; i, gastral scopules. 
25-28.— Parts of gastral scopules; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
25, basal part of an end-ray; 
26, distal part of an end-ray; 
27, 28, centres of two different scopules. 


‘ 


PLATE 31. 


Fig. 1-28 Eurete erectum F. E. Sch. 


| photographed 


us, 


PLATE 32. 


Farrea sp. Station 4631. 


Figures 1-3. 


1.— View of the skeleton-net; magnified 2; phot. Zeiss, anastig. 167 mm. 
2, 3.— The two faces of the skeleton-net of the wall of the tubular sponge; magnifie 
planar 50 mm.: 

2, the dermal face; 

3, the gastral face. 


Euretid. Station 4651. 
Figures 4-6. 


4.— View of the skeleton-net; natural size; phot. Zeiss, anastig. 480/412 mm. 
5, 6.— The two faces of the skeleton-net of the wall of the funnel-shaped sponge; magnifi 
Zeiss, planar 50 mm.: 
5, the inner, concave (gastral?) face; 
6, the outer, convex (dermal?) face. 


Chonelasma sp. Station 3689. 
Figures 7-9. 
7.— View of the skeleton-net; natural size; phot. Zeiss, anastig. 480/412 mm. - 
8, 9.— The two faces of the skeleton-net of the thick, curved, lamellar sponge; magnified ore 
planar 50 mm.: > 


8, the convex (dermal?) face; 
9, the concave (gastral?) face. _ < 


, 


Caulophacid. Station 3689. 
Figures 10-12. 


10.— View of the skeleton-net; natural size; phot. Zeiss, anastig. 480/412 mm. 
11, 12.— The two faces of the skeleton-net of the wall of the tubular specimen; aed 
Zeiss, planar 50 mm.: 
11, the inner, concave (gastral?) face; 
12, the outer, convex (dermal?) face. 


Hexactinella sp. Station 4631. 
Figures 13-15. 


13.— View of the skeleton-net; natural size; phot. Zeiss, anastig. 480/412 mm. 

14, 15.— The two faces of the skeleton-net of the thick-walled, funnel-shaped sponge; ma gnii ‘fi 
phot. Zeiss, planar 50 mm.; ; 

14, the outer, convex face; 

15, the inner, concave face. 


PLATE 32. 


HEXACTINELLIDA. 
ww: BRN 2 a ts VG 


rahe SE Patel 


4? 
. 


it 
pas ia 


MER g Me . pt et 
I ey 


my 


. 


-, 


‘ 

4 
t 
«a 


id (Euretid °) from station F054 


Fig. 1-3 Hexactinellid B (Farrea sp.?) from station 4631. Fig. 4-6 Hexactinellid 


Fig. 7-9 Hexactinellid B (Chonelasma?) from station 3689 Fig. 10-12 Hexactinellid A (Cauloph 
Fig. 13-15 He xactinellid A (He xactinella>) from station 4631 


Lendenfeld photographed 


PLATE 33. 


PLATE 33. 


Hyalonema (Hyalonema) obtusum gracilis LENDENFELD. 
’ Figures 1-24. 


1, 2.— Centrotyle amphioxes; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
3.— Group of small hypodermal amphioxes; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
4.— Small hypodermal amphiox; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
5-14.— Side-views of hypodermal pentactines; magnified 50; phot. Zeiss, achr. aa, compens. oc. 2. 
15.— View of the sponge; magnified 1.1; phot. Zeiss, anastig. 480/412 mm. 
16.— View of the sectioned face of the sponge cut in half longitudinally and axially; magnified 2; phot. 
Zeiss, anastig. 167 mm.: 
a, oral cone; b, lower end (place where the stalk is broken off). 
17.— The tip of a lateral ray of a hypodermal pentactine; magnified 300; phot. Zeiss, apochr. 4, compens. 
oc. 6. 
18-23.— Rhabds of the supporting skeleton; magnified 50; phot. Zeiss, achr. aa, compens. oc. 2: 
18, 19, small, slightly centrotyle amphioxes; 
20, tylostyle; 
21, medium centrotyle amphiox; 
22, medium amphiox; 
23, large amphiox. 
24.— Oblique apical view of a hypodermal pentactine; magnified 50; phot. Zeiss, achr. aa, compens. 
oc. 2. 


a 


HEXACTINELLIDA. PLATE 33. 


ee ————— @- 


_ — , 2 —:!2 ~ . 
‘ 
= —— 
a se —S — 


\ 
. = \ 
: \ 10 11 
Q “—— aes ; 
“a = — 3 — i 


: 205s 
ny D1 A 
= ee 
23 


Fig. I-24 Hyalonema obtusum n. sp. var. gracilis. 


Lendenfeld photographed 


PLATE 34. 


PLATE 34. 


Hyalonema (Hyalonema) obtusum gracilis LENDENFELD. 


Figures 1-19. 


1.— Section vertical to the surface, through a superficial part of the sponge; magnified 30; phot. Zeiss, 
planar 20 mm.: 
a, dermal membrane; b, subdermal cavities; c, a hypodermal pentactine with reduced ‘and 
terminally rounded apical ray. 
2.— Radial section through the choanosome; magenta; magnified 100; phot. Zeiss, apochr. 16, ‘compens. 
oc. 6. 
3.— Axial section through the oral cone and the adjacent parts of the upper end of the sponge; magenta; _ 
magnified 5; phot. Zeiss, planar 50 mm.: 
a, outer surface (dermal membrane); b, narrow fissure-like gastral cavity between the oral cone 
and the oral frill; ce, summit of the oral cone. 
4.— Axial section through the lower part of the sponge; magenta; magnified 5; phot. Zeiss, planar 50 mm. 
5-18.— Choanosomal hexactines of the supporting skeleton; magnified 50; phot. Zeiss, achr. aa, oc. 2: 
5-7, 10, 12, situated with one axis (two rays) parallel to the optical axis, and two axes (four rays) in 
a plane vertical to the optical axis; 
8, 9, 11, 13-18, situated with the tips of three of the rays in a plane vertical to the optical axis; 
5-7, 11, 15, 16, 18, medium-sized hexactines; . 
8, 10, 13, 17, large hexactines; 
9, 12, 14, small hexactines. 
19.— Radial section through the superficial part of the sponge; magnified 100; phot. Zeiss, apochr. 16, 
compens. oc. 6: 
a, dermal membrane; b, group of small.macramphidises: c, subdermal cavity; d, hexactines 
of the supporting skeleton. 


PLATE 34. 


HEXACTINELLIDA. 


Fig. 1-19 Hyalonema obtusum n. Sp. var. gracilis. 


Lendenfeld photographed 


=? 


PLATE 35. 


_” 
— 


PLATE 35. 


Hyalonema (Hyalonema) obtusum gracilis LENDENFELD. 


Figures 1-37. 


1.— Radial section through the gastral membrane on the outer wall of the gastral cavity; magnified 100; 
phot. Zeiss, apochr. 16, compens. oc. 6: 
a, pinule-fur. 
2.— Apical view of the lateral rays of a gastral pentactine pinule; magnified 300; phot. Zeiss, apochr. 4, 
compens. oc. 6. 
3.— Radial section through the gastral membrane on the oral cone; magnified 100; phot. Zeiss, apochr. 
16, compens. oc. 6: 
a, pinule-fur. 
4-9.— Side-views of gastral pinules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6: 
4, a hexactine gastral pinule; 
5-9, pentactine gastral pinules. 
10-13.— Diactine pinules of the oral frill; magnified 100; phot. Zeiss, apochr. 16, compens. oe. 6. 
14, 15.— The end-part of a ray of a microhexactine; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, 
q. oc. 10: 
14, focussed higher; 15, focussed lower. 
16.— The surface of the oral cone viewed from above; magnified 100; phot. Zeiss, apochr. 16, compens. 
oc. 6. 
17.— Group of microscleres from a centrifuge spicule-preparation; magnified 300; phot. Zeiss, apochr. 
4, compens. oc. 6: 
a, microhexactines; b, small micramphidiscs. 
18-22.— Microhexactines and microhexactine-derivates; magnified 500; phot. Zeiss, H. I. apochr. 2, 
compens. oc. 6: 
18, 19, regular microhexactines; 
20-22, microhexactine-derivates with two well-developed and four less (20) or more (21) or quite 
(22) reduced rays. 
23.— Apical view of the lateral rays of a dermal pentactine pinule; magnified 300; phot. Zeiss, apochr. 
4, compens. oc. 6. 
24.— Radial section through the dermal membrane on the outer surface; magnified 100; phot. Zeiss, 
apochr. 16, compens. oc. 6: 
a, pinules; b, small macramphidisc. 
25.— Dermal pentactine pinule with angularly bent apical (distal) ray; magnified 300; phot. Zeiss, 
apochr. 4, compens. oc. 6. 
26-28.— The distal part (centrum and distal ray) of diactine pinules of the oral frill; magnified 300; 
phot. Zeiss, apochr. 4, compens. oc. 6. 
29-37.— Side-views of dermal pinules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6: 
29, 30, hexactine dermal pinules; 
31-37, pentactine dermal pinules. 


HEXACTIN 


| 
| 
| 


| 


t 
RLLIDA. 


me 


, AV el, "tun G 
% 47 a P vé 
Wea pier t aay 
> ee : ¢ 

; | 
z ey | I 
2 
fs = 


Se RO 


7 & 
[oo 


NY hr ied, ys 
7 ee 


Fig, 1-37 Hyalonema obtusum n. sp. var. gracilis. 


=, 


PLATE 35. 


PLATE 36. 


_- =. — 


PLATE 36. 


Hyalonema (Hyalonema) obtusum gracilis LENDENFELD. 


Figures 1-45. - 


1-25.— Tetractine acanthophores of the sheaths enclosing the large stalk-spicules in the basal part of 
the sponge-body; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
1-13, forms with rays not very different in size; 
14-25, forms in which one or two of the rays are markedly reduced. 
26.— Part of an axial section through the basal part of the spongesvoy; magnified 30; pee Zeiss, 
planar 20 mm.: 
a, Space previously occupied by a large stalk-spicule. 
27, 28.— Ray-ends of the tetractine acanthophore of the sheaths enclosing the large stalk-spicules in 
the basal part of the sponge-body; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
29-36.— Rhabd-acanthophores of the sheaths enclosing the large stalk-spicules in the basal part of the 
sponge-body; magnified 100; phot. Zeiss, apochr. 16, compens. oe. 6: 
29, 32-36, tylostyles; 
30, amphistrongyle; 
31, centrotyle style. 

37, 38.— The two ends of the amphistrongyle acanthophore represented in fig. 30; magnified 300; phot. 
Zeiss, apochr. 4, compens. oc. 6. 7 
39-44.— Diactine acanthophores of the sheaths enclosing the large stalk-spicules in the basal part of the 

sponge-body; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
39, an angularly bent, slender, centrotyle diactine; 
40-44, slightly curved, stout, centrotyle diactines. 
45.— Strongly curved style acanthophore of the sheaths enclosing the large stalk-spicules in the basal 
part of the sponge-body; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 


PLATE 36. 


t 

< 

<a Nes 
3 - 


Fig. I-45 Hyalonema obtusum n. sp. var. gracilis. 


no] 
vu 
= 
a 
5 
2 
° 
= 
a 


PLATE 37. 


Pow 


SS. 


PLATE 37. 
Hyalonema (Hyalonema) obtusum gracilis LENDENFELD. 
Figures 1-22. 


1—5.— Small micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
6-11.— Large micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 


12, 13.— A small macramphidise; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 


12, focussed higher; 13, focussed lower. 
14-19.— Small macramphidises; magnified 500: 

14, 16, 18, 19, phot. Zeiss, H. I. apochr. 1, compens. oc. 6; 

15, 17, phot. Zeiss, apochr. 4, compens. oc. 12. 
20.— A large macramphidise; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12. 
21, 22.— A large macramphidise; magnified 500: 

21, u. v. phot. Zeiss, q. monochr. 6, q. oc. 10, and focussed higher; 

22, phot. Zeiss, apochr. 4, compens. oc. 12, and focussed lower. 


PLATE 37. 


Fig. 1-22 Hyalonema (Hyalonema) obtusum n. Sp. var. gracilis. 


ru 


o* 


PLATE 38. 


PLATE 38. 


Hyalonema (Hyalonema) obtusum gracilis LenpENFELD. 
Figures 1-8. 


1-3.— A small micramphidise; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
. 1, focussed high; 2, focussed lower; 3, focussed still lower. 
4, 5.— The central part of the shaft of a small macramphidise; magnified 2000; u. v. phot. Zeiss, q. — 
monochr. 1.7, q. oc. 10: ; 
4, focussed lower; 5, focussed higher. = 
6.— Part of the tooth-verticil of a small macramphidise, focussed high to show the two uppermost 
anchor-teeth: magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. _ 
7, 8— Part of the tooth-verticil of the small macramphidise, the central part of the shaft of which i HS} 
shown in figs. 4 and 5; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
7, focussed higher; 8, focussed lower. 


oe on. es 


HEXACTINELLIDA. : PLATE 38. 


Fig. 1-8 Hyalonema (Hyalonema) obtusum n. Sp. var. gracilis. 


Lendenfeld photographed. 


a 
oO 
a 
< 
4 
Ay 


PLATE 39. 


Hyalonema (Hyalonema) obtusum gracilis LunpENreLp. 
Figures 1-10. 


1.— An intermediate acanthophore with large spines, from the basal felt; magnified 300; phot. Zeiss, 
apochr. 4, compens. oc. 6. 
2-4.— Slender-rayed acanthophore with long spines and parts of such, from the basal felt; magnified 
300; phot. Zeiss, apochr. 4, compens. oc. 6. 
5.— A very young hexactine; magnified 300; phot. Zeiss, apochr. 4, compens. oc: 6. 
6.— Part of lean acanthophore from the basal felt; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
7-10.— Pachymicrohexactines from the basal part of the sponge; magnified 300; phot. Zeiss, apochr. 
4, compens. oc. 6: 
7, a small one with stout, nearly straight rays; 
8, a large one with more slender rays; 
9, 10, a large one with very stout rays; 
9, focussed higher; 10, focussed lower. 


Hyalonema (Hyalonema) obtusum robusta LENDENFELD. 


Figures 11-41. 


11, 12.— Parts of intermediate acanthophores with large spines, from the basal felt; magnified 500; 
phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 
11, a central part of a triactine; 
12, the tip of a ray. Z 
13-16.— Parts of slender-rayed acanthophores with large spines, from the basal felt; magnified 500; 
phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 
13-15, tips of rays; 
16, the central part of a triactine. 
17-21.— Stout-rayed tetractine and tetractine-derivate acanthophores from the cement surrounding 
the upper parts of the large stalk-spicule imbedded in the sponge-body; magnified 100; phot. 
Zeiss, apochr. 16, compens. oc. 6: 
17, an angularly bent diactine; 
18-20, tetractines; 
21, a triactine. 
22-24.— Parts of the felt, composed chiefly of the slender-rayed acanthophores with long spines, in the 
basal part of the sponge: 
22, 23, magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6; 
24, magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
25, 26.— Uncinate amphioxes; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
27-29.— Parts of the uncinate amphiox represented in fig. 26; magnified 500; phot. Zeiss, H. I. apochr. 
2, compens. oc. 6: 
27, the end from which the spines diverge; 
28, the central part; 
29, the end towards which the spines are inclined. 
30.— Part of an uncinate amphiox; magnified 2000; phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
31, 32— Two small, fairly regular hypodermal pentactines; magnified 50; phot. Zeiss, apochr. 16, 
compens. oc. 4: 
31, a side-view; 
32, an apical view. 
33.— View of the specimen; reduced 1: 0.85; phot. Zeiss, anastig. 480/412 mm. 
34-38.— Rhabd-acanthophores; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
39.— An angularly bent diactine; magnified 100; phot. Zeiss, apochr, 16, compens. oc. 6. 
40, 41.— Larger hypodermal pentactines; magnified 50; phot. Zeiss, apochr. 16, compens. oc. 4: 
40, side-view of a fairly regular one; 
41, apical view of an irregular one with one of the lateral rays reduced. 


PLATE 39. 
HEXACTINELLIDA. : ; 


4 


—t_ 
ge la 


30 
Fig. 1-10 Hyalonema (Hyalonema) obtusum n. sp. var. gracilis. Fig. 11-41 Hyalonema (Hyalonema) oblusum n. sp. var, 1001 


Lendenfeld photographed 


S 
ea) 
i= 
< 
= 
Ay 


PLATE 40. 


= 


Hyalonema (Hyalonema) cbtusum robusta LENDENFELD. 
Figures 1-22. 


1, 2.— Large macramphidises; magnified 500; phot. Zeiss, apochr. 4, compens. oe. 12. 
3-5.— Pinules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6: 
3, a gastral hexactine pinule; 
4, a dermal pentactine pinule with reduced lateral rays; 
5, a dermal pentactine pinule. ; 
6-15.— Microhexactines and ah crore oe ena magnified 500; phot. Zeiss, H. I. apochr. 2, 
compens. oc. 4: 
6, 7, regular microhexactines; 
8, a pentactine microhexactine-derivate; 
9, a microhexactine with two opposite rays much longer than the others; 
10, a diactine microhexactine-derivate, the fully developed rays of which are not opposite; 
11, a triactine microhexactine-derivate; - 
12, 13, diactine (centrotyle), inicroheneenne-denvare the fully developed ae of which are 
opposite; 
14, 15, monactine (tylostyle or tyle) microhexactine-derivates. 
16, 17.— Small micramphidiscs; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 4. 
18.— A young micramphidise; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oe. 4. 
19.— Part of an irregular macramphidise; magnified 500; phot. Zeiss, apochr. 4, compens. oe. 12. 
20.— Group of microscleres from a centrifuge spicule-preparation; magnified 500; phot. Zeiss, H. I. 
apochr. 2, compens. oe. 4: 
a, small micramphidises; b, microhexactine; c, microhexactine-derivate with only two 
opposite, fully developed rays. 
21, 22.— Parts of the upper end of a large stalk-spicule; magnified 300; phot. Zeiss, apochr. 4, compens, 
oc. 6. ‘ 


:. 


Fig. 1-22 Hyalonema (Hyalonema) obtusum n. sp. var. robusta. 


ee” 


PLATE 41. 


PLATE 41. 


Hyalonema (Hyalonema) agassizi LenpENFELD. 


Fig. 1 — form B, Station 4651. 
Figs. 2-11 —form A, Station 4656. 
Fig. 12 —form D, Station 3684 (A. A. 17). 


Figs. 18, 14 — form C, Station 4740. 


1.— Side-view of the specimen of form B; natural size; phot. Zeiss, anastig. 480/412 mm. 
2.— Side-view of the specimen of form A; reduced 1: 0.83; phot. Zeiss, anastig. 480/412 mm. 
3-6.— Oblique view of hypodermal pentactines of form A; magnified 50; phot. Zeiss, achr. aa, compens. 
oc. 6: 
3, 4, 6, larger ones; 
5, a small one. 
7.— Side-view of a small hypodermal pentactine of form A; magnified 50; phot. Zeiss, achr. aa, 
compens. oc. 6. ’ 
8.— Apical view of the lateral rays of a large hypodermal pentactine of form A; magnified 50; phot. 
Zeiss, achr. aa, compens. oc. 6. 
9.— The end-part of a lateral ray of a large hypodermal pentactine of form A; magnified 300; phot. 
Zeiss, apochr. 4, compens. oe. 6. : 
10, 11.— Smaller hypodermal pentactines of form A; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6: 
10, apical view of the lateral rays of one; : 
11, side-view of another. 
12.— The specimen of form D seen from above; natural size; phot. Zeiss, anastig. 480/412 mm. 
13, 14— A specimen of form C; reduced 1: 0.83; phot. Zeiss, anastig. 480/412 mm.; 
13, seen from below; 
14, seen from above, 


LA] 


PLATE 41. 


HEXACTINELLIDA. 


AAA pee oe oe erat 


SNA 


Fig, 1-14 Hyalonema agassizt Nn. Sp. 


1 form B; 2-11 form A; 12 form D; 13,14 form G. 


Lendenfeld photographed. 


te amet ~ epee ps Pee a ty Xf 


- . 
oe 
- 
, 
a ~ 
i 
“-* 
—. 
: 
~ 
- - 
= 
‘ 
A = 
, 
; - 
. 
\ - 
A 
el 
. 
» 
© 


PLATE 42. 


| 


PLATE 42. 


Hyalonema (Hyalonema) agassizi Lenpenreip. * 


Figs. 1-13, 25-28, 35, 36, 38-41, 49, 51, 52 — form A, Station 4656. 


Figs. 14, 15, 29, 37, 47, 48, 50, 58, 54 —form B, Station 4651. 

Figs. 16-23, 43, 44, 55, 56, 58 —form C, Station 4740. 7 

Figs. 24, 30-34, 42, 45, 46, 57, 59 —form D, Station 3684 (A. A. 17). 
ye 


1-8.— Side-views of gastral pinules from the surface of the gastral cone of form A; magnified 300; phot. 
Zeiss, apochr. 4, compens. oc. 6: 
1, normal hexactine pinule with long proximal ray; 
2, normal hexactine pinule with short proximal ray; 
3-7, normal pentactine pinules; 
8, abnormal penttactine pinule. 
9.— Minute pentactine from the surface of the gastral cone of form A; magnified 300; phot. Zeiss, 
apochr. 4, compens. oc. 6. 
10-12.— Apical view of the lateral rays of gastral pinules from the surface of the gastral cone of form A; 
magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
13.— A diactine gastral pinule from the surface of the gastral cone of form A; magnified 300; phot. 
Zeiss, apochr. 4, compens. oe. 6. 4 
14-19.— Side-views of gastral pmules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6: 
14, 15, from the surface at he gastral cone of form B; 
16, 17, from the surface of the gastral cone of form C; 
18, 19, from the surface of one of the radial walls separating the canalicular diverticula of the gastral 
cavity of form C. . Z 
20-23.— Side-views of dermal pinules from the outer surface of form C; magnified 300; phot. Zeiss, 
apochr. 4, compens. oe. 6. 
24. — Side-view of a gastral pinule from the surface of the gastral cone of form D; magnified 300; phot. 
Zeiss, apochr. 4, compens. oc. 6. 
25-34.— Side-views of dermal pinules from the outer surface; magnified 300; phot. Zeiss, apochr. 4, 
compens. oc. 6: 
25-28, of form A; e 
29, of form B; 
30-34, of form D. 
35, 36.— Apical views of the lateral rays of two dermal pinules from the outer surface of form A; magni- 
fied 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
37.— Surface-view of the dermal membrane on the basal part of form B; magnified 50; phot. Zeiss, 
achr. aa, compens. oc. 6: 
a, hypodermal pentactines; b, dermal pinules. 
38-41.— Modified, slender-rayed, long-spined pinules of the basal part of form A; magnified 300; phot. 
Zeiss, apochr. 4, compens. oc. 6: 
38, 39, hexactine forms; 
40, 41, pentactine forms. 
42.— Group of spicules from a spicule-preparation of the basal part of form D; magnified 300; phot. 
Zeiss, apochr. 4, compens. oc. 6: ; 
a, microhexactines; b, dermal pinules. 
43-45.— Modified, slender-rayed, long-spined pinules from the basal part of the sponge; magnified 300; 
phot. Zeiss, apochr. 4, compens. oe. 6: 
43, 44 of form C; 
45, of form D. 
46.— Spined, slender-rayed hexactine acanthophore of form D; magnified 300; phot. Zeiss, apochr. 4, 
compens. oc. 6. 
47, 48.— Modified, slender-rayed, long-spined pinules from the basal part of form B; magnified 300; 
phot. Zeiss, apochr. 4, compens. oc. 6. 
49.— A slender-rayed, long-spined tetractine acanthophore of form A; magnified 300; phot. Zeiss, 
apochr. 4, compens. oe. 6. 
50.— Minute pentactine of the basal part of form B; magnified 300; phot. Zeiss, apochr. 4, compens. F 
oc. 6. 
51-59.— Slender-rayed, long-spined tetractine and pentactine acanthophores; magnified 300; phot. 
Zeiss, apochr. 4, compens. oc. 6: 
51, 52, tetractine ones of form A; 
53, 54, tetractine ones of form B; 
55, 56, tetractine ones of form C; 
57, a pentactine one of form D; 
58, a pentactine one of form C; 
59, a tetractine one of form D. 


ae 


WEXACTINELLIDA. = 
° s 


PLATE 42. 


pee 


=~ 


Fig. 1-59 Hyalonema (Hyalonema) agassizi n. Sp. 
Sorm A; 14, 15, 29, 37, 47, 48, 50, 53, 54 form B; 16-23, 43, 44, 55, 56, 58 Jorm C; 
24, 30-34, 42, 45, 46, 57, 59 form D. 


“< 41-13, 25-28, 35, 36, 38-41, (AY, Ils eV 


Fate: 
Lend a Photographed. 


he 


a 


Lichtdruck von Werner & Winter, Frankfurt a. M. 


v 
i . 
a ’ 
<p _ , . 
- 7 } 
’. 
- ® a 

oo 
ies 

‘ i 

V~. 

vies 
x = 


PLATE 43. 


PLATE 43. S 


Hyalonema (Hyalonema) agassizi LenpENFELD. 


_ Figures 1-7— form A, Station 4656. 


1.— The upper part of a stalk-spicule; reduced 1: 0.5; phot. Zeiss, anastig. 480/412 mm.: 
a, the portion represented in fig. 2; b, the portion represented in fig. 5; ¢, the portion SSPE 
sented in figs. 6 and 7; d, the soyton represented in figs. 3 and 4. 
2-7.— Parts of the stalk-spicule represented in fig. 1; magnified is phot. Zeiss, apochr. 16, compens. 
a oc. 6: ah 
2, 1 em. from the upper end (at a in fig. 1) focussed on the axial thecal : 
3, 4, 41 em. from the upper end (at d in fig. 1); 
3, focussed lower, on the axial thread; 4, focussed higher, on the upper surface; 
5, 20 em. from the upper end (at b in fig. 1) focussed on the axial thread; 
6, 7, 29 cm. from the upper end (at ¢ in fig. 1); ss 
6, focussed lower, on the axial thread; 7, focussed higher, on the upper surface. = 
Le 
a 


HEXACTINELLIDA. PLATE 43. 


Fig. 1-7 (Hyalonema) agassizi n. sp. form A. 
Lendenfeld photographed. 


: ? Lichtdruck von Werner & Winter, Frankfurt a. M. 


PLATE 44. 


PLATE 44. 


Hyalonema (Hyalonema) agassizi LeENDENFELD. 


Figs. 1-20, 22-24, 30 —form A, Station 4656. 


Rigs, 21 25, 27 —form B, Station 4651. 
Fig. 26 —form O, Station 4740. 
Figs. 28, 29 —form D, Station 3684 (A. A. 17). 


1—5.— Marginal diactine pinules of form A: 
1, 2, two smaller ones; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6; 
3, 4, the distal parts of two larger ones; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6; 
5, a larger one; magnified 100; phot. Zeiss, apochr. 16, compens. oe. 6. 
6-10.— Parts of the stoutest portions of uncinate amphioxes of form A; magnified 2000; u. " phot. 
Zeiss, q. monochr. 1.7, q. oc. 10: 
6, part of an uncinate focussed lower; 7, the same focussed higher; 8, part of another uncinate 
focussed lower; 9, the same foctiseed higher; 10, part of a third uncinate. 
11, 12.— The distal end-parts of two uncinates of form A; magnified 500; phot. Zeiss, H. I. apochr. 2, 
compens. oc. 4. 
13, 14.— Two uncinates of form A; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
15.— A microhexactine with fairly straight rays of form A; magnified 500; u. v. phot. Zeiss, q. monochr. 
( Ch, Cs Wo 
16.— The central part of a microhexactine of form A; magnified 2000; u. v. phot. Zeiss, q. monochr. 
17, Geocy 10; 
17.— Group of spicules from a centrifuge spicule-preparation of form A; magnified 200; phot. Zeiss, 
apochr. 8, compens. oc. 6: 
a, uncinate amphioxes; b, regular microhexactines; c, irregular microhexactine with two 
rays much longer than the others; d, micramphidiscs. 
18, 19.— Part (three rays and centre) of a regular microhexactine of form A; magnified 2000; u. v. 
phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
18, focussed higher; 19, focussed lower. 

20.— A microhexactine with nearly straight rays of form A; magnified 500; u. v. phot. Zeiss, q. monogla 
(Cl OG te > 
21-23.— Microhexactines with more or less curved rays; magnified 500; phot. Zeiss, H. I. apochr. = 

compens. oc, 4: 
21, of form B; 
22, 23; ot form A. 
24.— Microhexactine-derivate diactine of form A; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. 
oc. 4. 
25-28.— Microhexactines; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 4: 
25, 27, of form B; 
26, of form C; 
28, of form D. 
29.— Part of a microhexactine of form D; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oe. 4. 
30.— Part (one ray and centre) of a microhexactine of form A; magnified 2000; u. v. phot. Zeiss, q. 
monochr. 1.7, q. oc. 10. 


ee _ 
ee es et 


SE NS ete atid ee ie 


ot on. Sp. 
28, 29 form D. 


Fig. 1-30 Hyalonema (Hyalonema) 4, Z 
1-20, 22-24, 30 form AN 2, 20) aul form B; 26 form (Os 


ASST 


ndenfeld photographed. 


SS 


2 
oe _ 
fo? 
. rs ry 7 
\ 
PLATE 45. 


PLATE 45. 


Hyalonema (Hyalonema) agassizi LENDENFELD. 
Figs. 1-38, 40-49 — form A, Station 4656. 

Figs. 39, 62-64 —form D, Station 3684 (A. A. 17). 
Figs. 50-53 —form B, Station 4651. 

Figs 54-61 —form C, Station 4740. 


1-4.— Stout-rayed tetractine acanthophores of the spicule-cement in the basal part of form A; magnified 
100; phot. Zeiss, apochr. 16, compens. oc. 6. ; 
5.— Part of a rhabd acanthophore of the spicule-cement of the basal part of form A; magnified 100; 
phot. Zeiss, apochr. 16, compens. oc. 6. : 
6-13.— Hexactine megascleres of form A; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6: 
6-8, 11, small ones; 
9, 10, large ones; 
12, 13, medium-sized ones. 
14-17.— Stout-rayed acanthophores of the cement in the basal part of form A; magnified 100; phot. 
Zeiss, apochr. 16, compens. oc. 6: 
14, 15, tetractines with one ray strongly reduced; 
16, 17, diactine tetractine-derivates. 
18.— Section vertical to the surface through a superficial part of form A; magnified 20; phot. Zeiss, 
planar 20 mm.: j 
a, dermal membrane with pinule-fur. 
19-22.— Rhabds of the choanosome of form A; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6: 
19, 21, 22, amphioxes; 
20, a tylostyle. 
23.— Section vertical to the surface through a superficial part of form A; magenta; magnified 100; 
phot. Zeiss, apochr. 16, compens. oc. 6: 
a, dermal pinule-fur. 
24, 25.— Stout-rayed tetractines, with rays strongly reduced in length, of the spicule-cement in the basal 
part of form A; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
26-34.— Spheres of the basal part of form A; magnified 300; phot. Zeiss, apochr. 4, compens. oe. 6. 
35, 36.— Stout-rayed tetractine acanthophores of the spicule-cement of the basal part of form A; magni- 
fied 300; phot. Zeiss, apochr. 4, compens. oc. 6: 
35, a young one; 
36, an adult one. 
37.— A stout-rayed triactine acanthophore from the spicule-cement of the basal part of form A; magni- 
fied 300; phot. Zeiss, apochr. 4, compens..oc. 6. 
38.— A stout-rayed pentactine acanthophore with rays reduced in length, from the spicule-cement in 
the basal part of form A; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
39.— A stout-rayed tetractine acanthophore from the spicule-cement in the basal part of form D; magni- 
fied 30; phot. Zeiss, apochr. 4, compens. oe. 6. 
40-64.— Amphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 4: 
40-45, small micramphidises of form A; 
46-49, large micramphidises of form A; 
50-52, small micramphidises of form B; 
53, small macramphidise of form B; 
54-58, small micramphidises of form C; 
59-61, large micramphidises of form C; = 
62, small micramphidise of form D; 
63, 64, large micramphidises of form D. 


PLATE 45. 


Fig. 1-64 Hyalonema (Hyalonema) agassizi n. Sp. 
1-38, 40-49 form A; 39, 62-64 form D; 50-53 form B; 54-61 form C. 


) 
x 


PLATE 46. 


' PLATE 46. 


Hyalonema (Hyalonema) agassizi LmenpENFELD. 


J Figs. 1-5,.9, 12, 13 —form A, Station 4656. | 


Figs. 6-8, 16 —form D, Station 3684 (A. A. 17). 
Figs. 10, 11 —form C, Station 4740. 


Figs. 14, 15 —form B, Station 4651. 


1-16.— Macramphidises; magnified 500: 

1, 3-11, 14-16, phot. Zeiss, apochr. 4, compens. oc. 6; 

2, 12, 13, u. v. phot. Zeiss, q. monochr. 6, q. oc. 7: 
1, an adult normal small macramphidise of form A; 
2, an adult normal large macramphidise of form A; 

- 3, 4, an adult normal large macramphidise of form A; 
3, focussed high; 4, focussed lower; 

5, an adult normal large macramphidise of form A; 
6, an adult normal large macramphidise of form D; 
7, an adult abnormal spiny large macramphidise of form D; 
8, a young normal large macramphidise of form D; 
9, a young normal large macramphidise of form A; 
10, 11, adult normal large macramphidiscs of form C; 
12, 13, adult normal large macramphidises of form A; 
14, 15, adult normal large macramphidises of form B; 
16, an adult normal large macramphidise of form D. 


PLATE 46. 


Fig. 1-16 Hyalonema (Hyalonema) agassizt n. Sp 


1-5, 9, 12, 13 form A; 6-8, 16 form D; 10, 11 form C; I4, 15 form B. 


PLATE 47. j 
' 


PLATE 47. 


Hyalonema (Hyalonema) agassizi LENDENFELD. 


Figures 1-13—form A, Station 4656. 


1, 2.— Side-view of an anchor of a large macramphidise; magnified 2000; u. v. phot. Zeiss, q. monochr. 
1.7, q. oc. 10: 


1, focussed lower; 2, focussed high. 
3.— Group of three small micramphidises; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
4.— Side-view of part of a small micramphidisec; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, 
q. oc. 10. 


5, 6.— Apical view of a large macramphidise; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12: 
5, focussed lower; 6, focussed higher. 

7.— Side-view of a small micramphidise; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 

8, 9.— Side-view of a small micramphidise; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
8, focussed higher; 9, focussed lower. 


10.— The central part of the shaft of a large macramphidise; magnified 2000; u. v. phot. Zeiss, q. 
monochr. 1.7, q. oc. 10. 


11-13.— Side-view of a larger macramphidisc; 
oc. 10: 


11, focussed high; 12, focussed low; 13, focussed intermediate, on the axis of the shaft. 


magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. 


‘HEXACTINELLIDA. 


PLATE 47. 


ON eel eer —_ & ee 


12 13 


Fig. 1-13 Hyalonema (Hyalonema) agassizi n. sp. 
Jorm A, 


Lichtdruck von Werner & Winter, Frankfurt a. M. 


wT, eS a 


PLATE 48. 


Hyalonema (Prionema) spinosum LENDENFELD. 
Figures 1-31. 


1-10.— Acanthophores; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
1-5, tetractines; 
6, a triactine; 
7-9, diactines; 
10, a monactine. 
11, 12.— Views of the two specimens; reduced 1: 0.9; phot. Zeiss, anastig. 480/412 mm.: 
11, side-view of the smaller specimen; 
12, the larger specimen seen from above. 
13.— Part of an axial section of the smaller specimen; magenta; magnified 10; phot. Zeiss, planar 50mm. 
14-16.— The central part of the shaft of a large macramphidise; magnified 2000; u. v. phot. Zeiss, q. 
monochr. 1.7, q. oc. 10: 
14, focussed high; 15, focussed low; 16, focussed intermediate. 
17—22.— Side-views of dermal pinules; magnified 300; phot. Zeiss, H. 1. apochr. 2, compens. oc. 6: 
17-19, 21, 22, pentactine pinules; 
20, a hexactine pinule. 
23.— Part of the gastral pinule-fur in an axial section; magnified 100; phot. Zeiss, apochr. 16, compens. 
OCwOL 
24, 25.— Gastral pinules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6: 
24, apical view of the lateral rays of one; 
25, side-view of another. 
26, 27.— Part of the distal ray of a gastral pmule; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, 
q. oc. 10: 
26, focussed lower; 27, focussed higher. 
28-31.— Small micramphidises; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
28, a larger one with slightly curved shaft; 
29, a smaller one with broad anchors; 
30, 31, a smaller one with narrow anchors; 
30, focussed higher; 31, focussed lower. 


PLATE 48. 


31 


—— al ‘5 a ek 
Nn Pe d 
Z Nn | hens —. q ~~. — 
=e a - mo y 
So ae amine ca = ts 
° g r if =uhe ee ~ 
t — - an 
- + S 
> oD i bol “ _ ~ a 
} 255-5 Nn 17 N - 

~ A > 
= ny CX =< 


Se ee ; : \ eS ewe ee i SS 


ae oe Pell \ «a, | = | i 
Y : SS \ a = , 


HEXACTINELLIDA. 


Fig. I-31 HHyalonema (Prionema) spinosum n. sp. 


Lendenfeld photographed . 


Lichtdruck von Werner & Winter, Frankfurt a. M. 


4 
ene yi i“ 7 —at ft) = 


PLATE 49. 


. 
a 
PLATE 49. 
Hyalonema (Prionema) spinosum LENDENFELD. 
Figures 1-23. . 


1-11.— Amphidises; magnified 500: . 
1-4, small micramphidises; phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
5, small macramphidises; phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
6, small macramphidise; u. v. phot. Zeiss, q. monochr. 6, q. oc. 7; 
7, 8, normal large macramphidisc; phot. Zeiss, H. I. apochr. 2, oc. 4; 
7, focussed high; 8, focussed low; 
9, normal large macramphidisc; u. v. phot. Zeiss, q. monochr. 6, q. oc. 7; 
10, abnormal large macramphidise; phot. Zeiss, apochr. 4, compens. oc. 6; 
11, normal large macramphidisc; phot. Zeiss, apochr. 4, compens. oc. 6. 
12-14.— Side-views of hypodermal pentactines; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6. 
15-18.— Microhexactines and parts of such; magnified 500: 
15, 18, u. v. phot. Zeiss, q. monochr. 6, q. oc. 7; 
16, 17, phot. Zeiss, H. I. apochr. 2, compens. oe. 6. 
19.— A hexactine megasclere; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6. 
20-22.— Part of a microhexactine; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
20, focussed high; 21, focussed intermediate; 22, focussed low. 
23.— Part of a ray of a microhexactine; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10, 


~~ Se r 


¥ . ¢. 


Ngo 


Fig. 1—23 Hyalonema (Prionema) spinosum n, Sp. 


Phototype by Charles Bellmann, Prague. 


PLATE 49. 


PLATE 50. 


PLATE 50. 


Hyalonema (Prionema) spinosum LENDENFELD. 
f/f 


Figures 1-5. 


1-5.— Anchor-teeth of large macramphidise; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
1, slightly oblique view of an anchor-tooth focussed high; 2, the same focussed lower; 
3, the uppermost two teeth of an anchor, nearly en face; 
4, an anchor-tooth en profile, focussed lower; 5, the same, focussed higher. 


Hyalonema (Phialonema) pateriferum Wison. 
Figures 6-15 — form E. 


6-8.— Ordinary pentactine pmules; magnified 300; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
9, 10.— Parts of microhexactines; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 

9, the central part of a microhexactine; 

10, the central part and one ray of a microhexactine. 
11-14.— Micramphidises; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 

11, a small micramphidise with short anchors; 

12, 13, a small micramphidise with longer anchors; 

12, focussed lower; 13, focussed higher; 

14, a large micramphidisc. ; 
15.— The central part of the shaft of a large macramphidisc; magnified 2000; u. v. phot. Zeiss, q. 
monochr. 1.7, q. oc. 10. 


spinosum n, Sp. 


Fig. 1—5 Hyalonema (Prionema) 


form E. 


Vilson 


15 Hyalonema (Phialonema) pateriferum V 


Fig. 6— 


Phototype by Charles Bellmann, Prague. 


e 


' 
a Tee Ts) 7 aA vy f rae’ yi t a 
tie ye! 2, i ee oh Fe 
ay i 
an, ; s 
phe! 
a 
9 
Ul 
\ 
i] 
> 
\ 
PLATE 51. : 
. 
J 
‘ e 
/ 
: = 


PLATE 51. 


Hyalonema (Phialonema) pateriferum Witson. 


Figures 1-28. 


1.— View of the specimen; natural size; phot. Zeiss, anastig. 480/412 mm. 
2.— Groups of large macramphidises from a spicule-preparation; magnified 100; phot. Zeiss, apochr. 
16, compens. oc. 6. 
3-6.— Small micramphidises; magnified 500: 
3, 5, phot. Zeiss, H. I. apochr. 2, compens. oc. 4; 
4, 6, phot. Zeiss, apochr. 4, compens. oc. 12. 
7-12.— Large micramphidises;, magnified 500: 
7, 8, 10-12, phot. Zeiss, H. I. apochr. 2, compens. oc. 4; 
9, u. v. phot. Zeiss, q. monochr. 6, q. oc. 7. 
13, 14.— A large micramphidise; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 4: 
13, focussed higher; 14, focussed lower. 
15.— Side-view of a small macramphidisc, with regular anchors; magnified 500; u. v. phot. Zeiss, q. 
monochr. 6, q. oc. 7. : - 
16.— Side-view of a large macramphidise with spirally twisted anchors; magnified 500; phot. Zeiss, 
apochr. 4, compens. oc. 6. 
17, 18.— Side-views of large macramphidises; with regular anchors; magnified 500; phot. Zeiss, apochr. __ 
4, compens. oc. 6. 
19, 20.— Side-views of a large macramphidise with regular anchors; magnified 500; phot. Zeiss, apochr. 
4, compens. oc. 12: 
19, focussed lower; 20, focussed higher. 
21, 22.— Apical views of anchors of large macramphidises; magnified 500: 
21, u. v. phot. Zeiss, q. monochr. 6, q. oc. 7; 
22, phot. Zeiss, apochr. 4, compens. oc. 12. 
23-28.— Microhexactines; magnified 500: 
23, 24, 26, 28, ordinary microhexactines with strongly and regularly curved rays; phot. Zeiss, 
apochr. 4, compens. oc. 12; 
25, an exceptionally large microhexactine with irregularly curved rays; u. v. phot. Zeiss, q. monochr. 
Oh Ch OOs 1/5 
27, a microhexactine with rays only slightly curved; phot. Zeiss, H. I. apochr. 2, compens. oc. 4. 


PLATE 41. 


es od 


ay OM, 


Fig. 1—28 Hyalonema (Phialonema) pateriferum Wilson, form E, 


Phototype by Charles Bellmann, Prague. 


ee oa 


PLATE 582. 


its. i. is ¥ “ ; . ; 


PLATE 52. 


Hyalonema (Phialonema) pateriferum Wi.son. 


Figs. 1-14, 16, 21-29 — form D. 
Figs. 15, 17-19 —form F. 
Fig. 20 —form C. 


1, 2.— Microhexactines of form D; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12. 
3-10.— Macramphidises of form D; magnified 500: 

3-9, phot. Zeiss, apochr. 4, compens. oc. 12; U 

10, phot. Zeiss, apochr. 4, compens. oc. 6; 

3, 4, 9, 10, large macramphidises; 
5-8, small macramphidises. 
11-14.— Ordinary pentactine pinules of form D; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
15.— A pentactine pinule with long distal ray of form F; magnified 300; phot. Zeiss, apochr. 4, compens. 
oc. 6. 

16.— A diactine pinule of form D; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12. 
17-19.— Acanthophores of form F; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 

17, a diactine; 

18, a pentactine; 

19, a triactine. 
20.— View of the specimen of form C; natural size; phot. Zeiss, anastig. 480/412 mm. 
" 21.— View of the specimen of form D; reduced 1: 0.84; phot. Zeiss, anastig. 480/412 mm. 
22, 23.— Parts of radial sections through,superficial portions of the marginal region of form D; magnified 

30; phot. Zeiss, planar 20 mm.: 

22, part of an unstained section; 

23, part of a section stained with magenta. 
24-29.— Micramphidises of form D; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12: 

24-26, small micramphidises; 

27-29, large micramphidiscs. 


Fig. 1—29 Hyalonema ( 


Lendenfeld photographed. 


Phialonema) pateriferum Wilson. 


Phototype by Charles 


1416), 21—29 form Dy 


Bellmann, Prague. 


15, 17—19 form 


PLATE 52. 


20 fi rm . 


ry 
ian ie i ae i : 
fis , ) ¥ 
i ~ | 
; 
i 
: - 
7 


PLATE 53. 


PLATE 53. 


Hyalonema (Hyalonema) polycaulum LEeNDENFELD. 
Figures 1-17. 


1-3.— Parts of a macramphidise; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
1, part of a terminal anchor, with the shaft in focus; 
2, the central part of the shaft; 
3, part of a terminal anchor with the uppermost teeth in focus. 
4.— View of the specimen; natural size; phot. Zeiss, anastig. 480/412 mm. 
5, 6.— A large micramphidise; magnified 2000; u. v. phot. Zeiss, q. monochr, 1.7, q. oc. 10: 
5, focussed higher; 6, focussed lower. 
7.— A small micramphidise; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
8.— A hexactine megasclere; magnified 50; phot. Zeiss, achr. aa., compens. oc. 6. 
9-12.— Parts of microhexactines; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
9, 10, the centrum and one ray of a smaller microhexactine; 
9, focussed higher; 10, focussed lower; 
11, 12, the centrum and one ray of a larger microhexactine; 
11, focussed higher; 12, focussed lower. 
13.— Group of macramphidises; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
14-16.— Microhexactines; magnified 500; phot. Zeiss, apochr. 4, compens. oe. 12. 
17.— A strongly bent rhabd from one of the hard superficial knobs; magnified 300; phot. Zeiss, apochr. 
4, compens. oc. 6. 


PLATE 53, 


Fig. 1—17 Hyalonema (Hyalonema) polycaulum n. sp. 


Lendenfeld photographed, 


Phototype by Charles Bellmann, Prague. 


— 


A 


PLATE 54. 


Hyalonema (Hyalonema) polycaulum LrenDENFELD. 


Figures 1—45. 


1-15.— Stout-rayed tetractine and monactine to triactine tetractine-derivate acanthophores fromthe 
hard superficial knobs; magnified 100; phot. Zeiss, apochr. 16, compens. oe. 6: 
1-8, tetractines; 
9, 10, triactines; 
11, a rectangularly bent centrotyle diactine; 
12, a straight centrotyle diactine; 
13-15, tylostyle monactines. 
16-20.— Rhabd, apparently diactine-derivate acanthophores of the hard superficial knobs; magnified 
100; phot. Zeiss, apochr. 16, compens. oc. 6: 
16, 18, 19, cylindrical forms; 
17, 20, centrotyle forms. 
21-25.— Small micramphidises; magnified 500: 
21, apical view of a terminal anchor; phot. Zeiss, H. I. apochr. 2, compens. oc. 4; 
22, side-view of a micramphidise; phot. Zeiss, apochr. 4, compens. oc. 12; 
23, 24, side-view of micramphidises; phot. Zeiss, H. I. apochr. 2, compens. oc. 4; 
25, group of micramphidiscs from a centrifuge spicule-preparation; phot. Zeiss, apochr. 4, compens. 
oc. 12. 
26, 27.— Large micramphidises; magnified 500: 
26, phot. Zeiss, apochr. 4, compens. oc. 12; 
27, phot. Zeiss, H. I. apochr. 2, compens. oe. 4. 
28, 29.— Macramphidises; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 6. 
30-33.— Small, slender-rayed, long-spined acanthophores from the hard superficial knobs; magnified 
300; phot. Zeiss, apochr. 4, compens. oc. 6. 
34.— A dermal pinule from one of the hard superficial knobs; magnified 300; phot. Zeiss, apochr. 4; 
compens. oc. 6. 
35.— A dermal pinule; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
36, 37— Apparently pinule-derivate, spiny pentactine acanthophores from the hard superficial knobs; 
magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
38—40.— Dermal pinules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
41-45.— Gastral pinules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 


PLATE 54. 


{o 
a 


~ . 
SS end | 
— A a , 
' 

| SSS 


ane grates 


AL ee tT te = 


45 Hyalonema (Hyalonema) polycaulum n. Sp. 


Fig. 1— 


Phototype by Charles Bellmann, Prague. 


PLATE 55. 


Hyalonema (Phialonema) brevancora LENDENFELD. 


Figures 1-37. 


1.— View of the larger fragment; natural size; phot. Zeiss, anastig. 480/412 mm. 
2,3.— Pentactine megascleres; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
4.— An angularly bent diactine megasclere; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
5.— The centrum of the shaft of a macramphidisc; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, 
q. oc. 10. 
6.— One end of an abnormal rhabd; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
7-12.— Micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 
7-9, small micramphidises; 
10-12, large micramphidises. 
13.— A small micramphidisc; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
14, 15.— Macramphidises; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 6. 
16-18.— A terminal anchor of a macramphidisc; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. 
oc. 6: ’ 
16, focussed high; 17, focussed intermediate; 18, focussed low. 
19, 20.— Part of a distal ray (19) and a whole distal ray (20) of a pinule; magnified 2000; u. v. phot. 
Zeiss, q. monochr. 1.7, q. oc. 10. 
21-30.— Side-views of pinules; magnified 300; phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 
21-28, of pentactine pinules with long-spined distal ray; 
29, of a pentactine pinule with short-spined distal ray; 
30, of a hexactine pinule with long-spined distal ray. 
31.— A hexactine megasclere; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
32, 33.— Apical views of the lateral rays of pentactine pinules; magnified 300; phot. Zeiss, H. I. apochr. 
2, compens. oc. 6. 
34, 35.— A whole microhexactine (34) and part of one (35); magnified 500; phot. Zeiss, H. I. apochr. 2, 
compens. oc. 6. : 
36, 37.— Parts of microhexactines; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 


¢ 


Fig. 


1—37 Hyalonema (Phialonema) brevancora 1. sp. 


Phototype by Charles Bellmann, Prague. 


PLATE 59. 


PLATE 56. 


et Lane 


PLATE 56. 


Hyalonema (Prionema) azuerone LenpENrELD. a) 


: Figure ill 


’ 


1.— View of the lower side of the specimen, floating in water and spread out flat; 
Zeiss, anastig. 480/412 mm. 


HEXACTINELLIDA. PLATE 56. 


oy « 
me ae. 


y~ ae 
jae aa eae 
2 Y * 


Fig. 1 Hyalonema (Prionema) azuerone 1. Sp. 


Lendenfeld photographed. 


7 
is 
: < 
« 
oop 
. 
J 
} 
} 
. 
* ‘ “ 
{ 
: 
' 


PLATE 57. 


PLATE 57. 


Hyalonema (Prionema) azuerone LENDENFELD. 
Figures 1-23. 


1—5.— Macramphidises and parts of such; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12: 
* 1, a large macramphidise with broad anchors; focussed lower (the shaft in focus); 
2, the broad terminal anchor represented in fig. 3, focussed high (the uppermost teeth in focus) ; 
3, the broad terminal anchor represented in fig. 2, focussed low (the shaft in focus); 
4, one (the upper) terminal anchor of the macramphidise represented in fig. 5, focussed higher (the 
uppermost teeth in focus); 
5, a large macramphidise with narrow anchors, focussed lower (the shaft in focus). 
6-8.— Mesamphidises; magnified 500: 
6, 7, medium mesamphidises; phot. Zeiss, apochr. 4, compens. oc. 12; 
8, large mesamphidisc; phot. Zeiss, apochr. 8, compens. oc. 12. 
9-12.— Stout-shafted micramphidises; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12: 
9, a large one; 
10-12, small ones. 
13-17.— Slender-shafted micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
18.— The central part of a microhexactine; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q.oc. 10, 
19-22.— Microhexactines; magnified 500; phot. Zeiss, apochr. 4, compens. oe. 12. 
23.— The centrum and one ray of a microhexactine; magnified 2000; u. v. phot. Zeiss, q. monochr. 
AG Cle OO, 10) 


HEX AOTINELLIDA. 


Fig. 1—23 Hyalonema (Prionema) azuerone n. sp. 


Lendenfeld photographed, 


FP 


Phototype by Charles Bellmann, Pracue. 


PLATE 58. 


PLATE 58. 


Hyalonema (Prionema) azuerone LENDENFELD. 
Figures 1-22. 


1.— Part of a section through the choanosome, showing a canal-wall; magnified 100; phot. Zeiss, 
apochr. 16, compens. oc. 6: 
a, canal-wall; b, canalar pinules; ec, microhexactines; d, micramphidises. 
2.— Part of a section through the choanosome, showing a region particularly rich in small macram- 
phidises; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
3.— Section vertical to the surface through the superficial part of the sponge; magenta; magnified 30; 
phot. Zeiss, planar 20 mm.: 
a, outer surface with pinule-fur; b, group of flagellate chambers; c, wall of a canal. 
4.— Surface-view of a pore-sieve on the lower side of the sponge; magnified 20; phot. Zeiss, planar 
20 mm. 
5-9.— Parts of anchor-teeth of macramphidises; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, 
q. oc. 10: 
5, a portion of the middle-part of a tooth; 
6, 7, the end-part of a tooth; 
6, focussed lower; 7, focussed higher; 
8, the end-part of a tooth; 
9, portion of the basal part of a tooth. 
10.— Part of the superficial pinule-fur, from a section vertical to the surface; magnified 100; phot. 
Zeiss, apochr. 16, compens. oc. 6. 
11.— Surface-view of a portion of the superficial pinule-fur on the lower side of the sponge; magnified 20; 
phot. Zeiss, planar 20 mm. : 
12.— A slender-shafted micramphidisc; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
13.— A medium mesamphidise; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
14, 15.— Apical views of the crosses formed by the lateral rays of the superficial pinules; magnified 300; 
phot. Zeiss, apochr. 8, compens. oc. 12. 
16—22.— Side-views of pinules; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12: 
16, 19, canalar pinules; 
17, 18, 20-22, superficial pinules. 


58, 


Soo a 
ee Sr ae es mae ante as “A 
S : 
: ’ 
— 
: > 
= = 
: ee \ 
: SS aS 
= _~ —— > * +.-.- + 
| 
p> Se z 
. ~ ro] 


Sn ee = oe —4 


ot. PS Ae yr ‘ 
Sg LM If 
ae ; 


1 


= scope RS 
Sao ye rs. 


~ HEXACTINELLIDA. 


Fig. 1—22 Hyalonema (Prionema) azuerone n. Sp- 


Lendenfeld photographed. 


ee 


PLATE 59. 


PLATE 59. 


Hyalonema (Prionema) fimbriatum LenpENFELD. 


Figures Gs 


ay 


1-3.— Three macramphidiscs with the shaft in focus; magnified 500 ; phot. Zeiss, apochr. 8, compens 
oc. 6. 


4—6.— Three anchor-heads of macramphidiscs, with the uppermost teeth in focus; magnified 500: 
4, an anchor with teeth terminating with two lobes; phot. Zeiss, apochr. 4, compens. oc. 12; 
5, an anchor with normal teeth; phot. Zeiss, apochr. 8, compens. oc. 6; 


6, an anchor with the ends of some of the teeth bent towards one side; phot. Zeiss, apochr. 8, com- 
pens. oc. 6. 


(Figs. 5 and 6 represent the two anchors of the same amphidisc). ¥ 


or 


HEXACTINELLIDA. PLATE 59. 


— 


: 
Pace Ae te aim ee  eartemaget, 


; 


\ tas 


Fig. 1-6 Hyalonema (Prionema) jfimbriatum n. Sp. 


Lendenfeld photographed. 


PLATE 60. 


a 


PLATE 60. 


Hyalonema (Prionema) fimbriatum LENDENFELD. 


Figures 1-34. 


1, 2.— Anchors of largest fimbriate amphidises with the upper teeth in focus; magnified 500; phot. 
Zeiss, H. I. apochr. 2, compens. oc. 6 (fig. 1 is the upper of the two anchors of the amphidise 
represented in fig. 38, focussed higher). 

3-6.— Largest fimbriate amphidises with the shaft in focus; magnified 500; phot. Zeiss, apochr. 4, 
compens. oc. 6. 

7, 8.— A large fimbriate amphidise; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 

7, focussed higher, on the uppermost teeth; 8, focussed lower, on the shaft. 
9, 10.— A large fimbriate amphidise; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 
9, focussed higher, on the uppermost teeth; ‘10, focussed lower, on the shaft. 

11, 12.— Large fimbriate amphidises; magnified 5000; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 

13, 14.— Small fimbriate amphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 

15.— A smallest fimbriate amphidise; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 

16, 17.— A micramphidise; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 

16, focussed higher; 17, focussed lower. 

18-23.— Micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 

24.— Group of largest fimbriate amphidises of the subgastral zone in situ in a section; magnified 100; 
phot. Zeiss, apochr. 16, compens. oc. 6. 

25.— Group of microhexactines in a centrifuge preparation; magnified 100; phot. Zeiss, apochr. 16, 
compens. oc. 6. 

26-30.— Microhexactines; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 

31.— A lateral ray of a micropentactine; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 

32-34.— The lateral ray-crosses of micropentactjnes; magnified 500; phot. Zeiss, H. I. apochr. 2, 
compens. oc. 6. , 


PLATE 60. 


HEXACTINELLIDA. 


“Ott er eee 1. 


Fig. 1-34 Hyalonema (Prionema) fimbriatum n. sp. 


Lendenfeld photographed. 


oe 


PLATE 61. 


PLATE 61. 


Hyalonema (Prionema) fimbriatum LeNDENFELD. 


Figures 1-11. 


J-10.— Parts of anchor-teeth of largest fimbriate pide magnified 2000; u. v. phot. TE igs 
monochr. 1.7, q. oc. 10: re 
1-3, the larger, middle-part of a tooth; : 
1, focussed low; 2, focussed intermediate; 3, focussed high (intervals 2 y); 
4, 5, the basal part of a tooth; : 
4, focussed higher; 5, facdeeed lower; 
6, 7, the end-part of a tooth; 
6, focussed higher; 7, focussed lower; 
j 8, 9, the basal part of a tooth; 
8, focussed higher; 9, focussed lower; 
10, the end-part of a tooth. 
11.— Part of an anchor of a largest fimbriate amphidise, with the uppermost teeth in focus; magnified 


2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 


PLATE 61. 


HEXACTINELLIDA. 


“~*~ 


Se 


r- 


PR Nhe 


a> 


oC eae naan a 


a coy coriaine aa oe 


Ea ¥ 


Fig. 1-11 Hyalonema (Prionema) fimbriatum n. sp. 


Lendenfeld photographed, 


PLATE 62. 


PLATE 62. 


Hyalonema (Prionema) fimbriatum LrNDENFELD. 


Figures 1—45. 


1—4.— Side-views of dermal pinules; magnified 300; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
5-9.— The distal parts of basal anchors; magnified 100; phot. Zeiss, apochr. 16, compens. oe. 6. 
10, 11.— Parts of shafts of basal anchors; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
12.— Part of a micramphidise; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
13, 14.— Micramphidises; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
15.— A smallest fimbriate amphidisc; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
16-18.— Lateral ray-crosses of dermal pinules; magnified 300; phot. Zeiss, H. I. apochr. 2, comp. oc. 6. 
19.— A lateral ray-cross of a canalar pinule; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
20-26.— Slender-rayed, long-spined, tetractine to hexactine acanthophores; magnified 300; phot. 
Zeiss, apochr. 4, compens. oc. 6. 
27.— The central part of the shaft of the largest fimbriate amphidisc; magnified 2000; u. v. phot. Zeiss, 
q. monochr. 1.7, q. oc. 10. 
28.— The central part of a micropentactine; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
29, 30.— Two of the specimens; reduced 1: 0.92; phot. Zeiss, anastig. 480/412 mm.: 
29, an irregularly outlined one seen from below; 
30, a regularly outlined one seen from above. 
31.— The end-part of an anchor-tooth of a macramphidise; magnified 2000; u. v. phot. Zeiss, q. monochr. 
WG Cla es 110). 
32—41.— Side-views of canalar pinules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
42-45.— Parts of microhexactines; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
42, the centrum and one ray of one, focussed lower; 
43, the centrum of the same, focussed higher; 
44, the centrum and four rays of another; 
45, the centrum and two rays of a third. 


PLATE 62. 


HEXACTINELLIDA. 


~~ 
ery yw 


—_— 


Fig. 1-45 Hyalonema (Prionema) fimbriatum n. sp. 


Lendenfeld photographed. 


PLATE 63. 


: 
7 
4 
oa 


PLATE 63. 


Hyalonema (Prionema) fimbriatum LENDENFELD. 


Figures 1-28. 


1-5.— Hexactine megascleres; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6. 
6-9.— Hypodermal pentactines; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6: 
6, apical view; 
7-9, side-views. 
10-14.— Rhabd megascleres; magnified 50; phot. Zeiss, achr. aa, RempeRs: oc. 6: 
10, 11, amphiox rhabds; 
12-14, rhabds rounded and thickened at one end. 
15-28.— Acanthophores; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
15, a small tetractine; 
16-18, large tetractines with fairly equal rays; 
19, a large tetractine with unequal rays; 
20-24, straight or only slightly curved, more or less centrotyle: diactines; 
25, 26, slender, strongly curved, terminally thickened rhabds; 
27, 28, stout, curved, terminally thickened rhabds. 


Hyalonema (Hyalonema) placuna LENDENFELD. 


Figs. 29-34, 36-41, 51 — form B. 
Figs. 35, 42-50 —form A. 


29-34.— Mesamphidises of form B; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12. 
35.— A mesamphidise of form A; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
36—41.— Micramphidises of form B; magnified 500: 
36, 39, phot. Zeiss, apochr. 4, compens. oc. 12; 
37, 38, 40, 41, phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
42-45.— Micramphidises of form A; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
46, 47.— Centrotyle amphioxes of form A; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
48-50.— Hypodermal pentactines of form A; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
48, an apical view; 
49, 50, side-views. 
51.— Part of a tetractine mesamphidisc-derivate (tetradisc) of form B; magnified 500; phot. Zeiss, 
apochr. 8, compens. oc. 12. 


51 


Sp. 


29-34, 36-41, 51 form B; 35, 42-50 form A. 


Fig. 1-28 Hyalonema (Prionema) fimbriatum n. sp. Fig. 29-51 Hyalonema (Hyalonema) placuna n. 


lenfeld photographed. 


= 
at 


PLATE 64. 


PLATE 64. 


Hyalonema (Hyalonema) placuna LeNDENFELD. 


Figs. 1-3, 5, 6, 9, 10, 12, 17-19 — form B. 
Figs. 4, 7, 8, 11, 13-16 —form A. 


1.— Centrotyle diactine spicule of form B; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 6. 
2-7.— Microhexactines and pentactine microhexactine-derivates; magnified 500: 
2, 6, 7, phot. Zeiss, H. I. apochr. 2, compens. oc. 6; ’ 
3-5, phot. Zeiss, apochr. 8, compens. oc. 12; 
2, 3, 5, 6, of form B; 
4, 7, of form A. 
8.— Part of a paratangential section of the dermal membrane of form A, showing the lateral ray-crosses 
of the dermal pinules in situ; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12. 
9, 10.— Two lateral ray-crosses of dermal pinules; magnified 300: 
9, of form B; phot. Zeiss, apochr. 4, compens. oc. 6; 
10, of form B; phot. Zeiss, apochr. 8, compens. oc. 12. 
11.— View of the specimen of form A; natural size; phot. Zeiss, anastig. 480/412 mm. 
12.— View of the specimen of form B; natural size; phot. Zeiss, anastig. 480/412 mm. 
13.— Part of the oscular frill of form A; magnified 30; phot. Zeiss, planar 20 mm.: 
a, dermal pinules; b, longitudinal rhabds. 
14-19.— Side-views of dermal pinules; magnified 300: 
14-16, of form A; 
17-19, of form B; 
14-17, phot. Zeiss, apochr. 8, compens. oc. 12; 
18, 19, phot. Zeiss, apochr. 4, compens. oc. 6, 


PLATE 64. 


HEXACTINELLIDA. 


16 


15 


14 


Fig. 1-19 Hyalonema (Hyalonema) placuna n. sp. 
1-3, 5, 6,9, 10, 12,17-19 form B; 4,7, 8, 11, 13-16 form A. 


Lendenfeld photographed. 


ws 
i 


Dl a 


; 
JE98. 


PLATE 65. 


PLATE 65. 


Hyalonema (Hyalonema) placuna LENDENFELD. 


Figs. 1, 3-138, 16-18, 23 —form B. 
Figs. 2, 14, 15, 19-22 —form A. 


1.— A terminal anchor of a macramphidise of form B, with a supernumerary tooth arising some distance 
below the others; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12. 
2.— Part of a mesamphidise of form A; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
3-8.— Parts of a microhexactine of form B; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
3, the centrum and a ray of the spicule, focussed high (the tip of the ray in focus) ; 
4, part of the distal portion of the same ray, focussed lower (a region about 17 » from the tip in focus); 
5, part of the middle-portion of the same ray, focussed still lower (a region about 32 u from the tip in 
focus); : 
6, part of the middle-portion of the same ray, focussed still lower (a region about 42 » from the tip 
in focus); 
7, part of the proximal portion of the same ray, focussed still lower (a region about 53 » from the tip 
in focus); 
8, the basal part of the same ray and the centrum of the spicule, focussed lowest (the base of the 
ray in focus). 
9-12.— Small internal pinules of form B; magnified 300: 
9, phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
10-12, phot. Zeiss, apochr. 4, compens. oe. 12. 
13-15.— Micramphidises; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
13, a micramphidise of form B; 
14, a micramphidise of form A, focussed higher; 15, focussed lower. 
16—21.— Internal pinules; magnified 300: 
16-18, of form B; 
19-21, of form A; 
16, 20, 21, phot. Zeiss, apochr. 8, compens. oc. 12; 
17-19, phot. Zeiss, apochr. 4, compens. oc. 6. 
22, 23.— Radial sections through a superficial part of the sponge; magnified 30; phot. Zeiss, planar 
20 mm.: 
22, of form A; 
23, of form B; 
a, dermal pinule-fur; b, choanosome, 


HEXACTINELLIDA. 


Fig. I-23 Hyalonema (Hyalonema) placuna n. sp. 
; 4, 3-13, 16-18, 23 form B; 2, 14, 15, 19-23 form A. 
’ Lendenfeld Photographed. 


PLATE 66. 


PLATE 66. 


Hyalonema (Hyalonema) placuna LENDENFELD. 


Figs. 1, 2, 5— form A. 
Figs. 3, 4, —form B. 


1-5.— Macramphidises and parts of same; magnified 500; phot. Zeiss, apochr. 4, compens. oc. Gus 
1, a terminal anchor of a macramphidise of form A; focussed low (the shaft in focus) ; 
2, the same anchor; focussed high (the upper teeth in focus) ; 
3, a macramphidise of form B; focussed low (the shaft in focus) ; 
4, the same macramphidise; focussed high (the upper teeth in focus); 
5, a macramphidise of form A, ‘ i 


ey Auto é i 


; 4) Sade a 
ayy es TOR) On ues f 


ad 


PLATE 66. 


HEXACTINELLIDA. 


fig. 1-5 Hyalonema (Hyalonema) placuna n. sp. 
1, 2,5 form A; 3,4 form B 


Lendenfeld photographed. 


‘ 


7. 
fi we br 
») ae 
i 
f 
— 
r 
' 


PLATE 67. 


PLATE 67. 


Hyalonema (Hyalonema) tenuifusum LENDENFELD. 


Figs. 1-7, 9, 13-17 —specimen a. 
Figs. 8, 10-12, 18-26 — specimen b. 


1.— View of specimen a; reduced 1: 0.84; phot. Zeiss, anastig. 480/412 mm. 
2-5.— Large macramphidises and parts of same of specimen a; magnified 500; phot. Zeiss, apochr. 4, 
compens. oc, 6: 
2, a whole macramphidise focussed low (on the shaft) ; 
3, one of the terminal anchors of the same spicule, focussed high (on the tips of the uppermost teeth) ; 
4, a terminal anchor of another macramphidisc, focussed high (on the tips of the uppermost teeth); 
5, the same terminal anchor, focussed low (on the shaft). 
6, 7.— Acanthophores of specimen a; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
6, a tetractine; 
7, a diactine. ; 
8.— Tetractine microhexactine-derivates of specimen b; magnified 500; phot. Zeiss, H. I. apochr. 2, 
compens. oc. 6. 
9.— Microhexactine of specimen a; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12. 
10, 11.— Parts of a tetractine microhexactine-derivate of specimen b; magnified 2000; u. v. phot. Zeiss, 
q. monochr. 1.7, q. oc. 10: 
10, part of the distal portion of a ray; 
11, the central part of the spicule. 
12.— The central part with the tyle of a minute centrotyle amphiox of specimen b; magnified 2000, 
u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
13-26.— Amphidises; magnified 500: 
13-17, of specimen a; 
18-26, of specimen b; 
13, 14, 16-21, 25, phot. Zeiss, H. I. apochr. 2, compens. oc. 4; 
15, 22-24, 26, phot. Zeiss, apochr. 4, compens. oc. 12; 
13, 14, 22-25, small macramphidises; 
15, 26, large macramphidises; 
16-21, micramphidiscs. 


PLATE 67. 


XAOTINELLIDA. 


7 


<_— ae 2 


tee 


26 specimen b, 


12, 13 


7, 9, 13—17 specimen a; 8, 10 


Fig. 1—26 Hyalonema (Hyalonema) tenuifusum n. sp. 1 


Lendenfeld photographed, 


an 


PLATE 68. 


PLATE 68. 


Hyalonema (Hyalonema) tenuifusum LENDENFELD. 


Figs. 1, 3-10, 20, 22, 23, 25 — specimen b. 
Figs. 2, 11-19, 21, 24 — specimen a. 


1.— The end-part of an anchor-tooth of a large macramphidise of specimen b; magnified 2000; u. v. 
phot. Zeiss, q. monochr. 1.7, q. oc. 10. y 

2-4.— Gastral (and canalar ?) pinules; magnified 300: 

2, of specimen a; phot. Zeiss, apochr. 16, compens. oc. 12; 

3, 4, of specimen b; phot. Zeiss, apochr. 8, compens. oc. 12. 
5, 6.— Micramphidises of specimen b; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
7-9.— Microhexactine-derivates of specimen b; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
10, 11.— Fairly regular microhexactines; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 

10, of specimen b; 

11, of specimen a. 
12-15.— Microhexactine-derivates of specimen a; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 


16, 17.— Minute centrotyle amphioxes of specimen a; magnified 200; phot. Zeiss, apochr. 8, compens. 


oc. 6. 7 
18-21.— Side-views of large dermal pinules; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 6: 
18, 20, 21, pentactine pinules; 
19, a hexactine pinule; 
18, 19, 21, of specimen a; 
20, of specimen b. 


22, 23.— Parts of the shafts of two small macramphidises of specimen b; u. v. phot. Zeiss, q. monochr. 


175 Gls Ores WO), 


24.— Side-view of a small pentactine dermal pinule of specimen a; magnified 300; phot. Zeiss, apochr. 


8, compens. oc. 12. 


25.— Apical view of the lateral rays of a dermal pinule of specimen b; magnified 300; phot. Zeiss, apochr. 


4, compens. oc. 6. 


Hyalonema (Hyalonema) sp. 


Figs. 26-33. Station 4656. 


26.— View of the specimen; reduced 100: 91; phot. Zeiss, anastig. 480/412 mm. 
27, 28.— Rhabd acanthophores; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
29, 30.— Two microhexactines: 
29, magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6; 
30, magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12. 
31-33.— Tetractine acanthophores; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 


PLATE 68. 


Fig. 1—25 Hyalonema (Hyalonema) tenuifusum n. sp. 1, 8—10, 20, 22, 23, 25 specimen b; 2, 11—19, 21, 24, specimen a, 


Fig. 26—83 Hyalonema (Hyalonema) spec. from station 4656. 
n eld Photographed, 


PLATE 69. 


PLATE 69. 


Hyalonema (Hyalonema) sp. 


Figs. 1-5. Station 4656. 


1, 2.— Pinules; magnified 300; phot. Zeiss, apochr. 8, compens. oe. 6. 
3-5.— Amphidises; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12. 


Hyalonema (Hyalonema) tylostylum LENDENFELD. 


Figures 6-25. 


6.— A hexactine megasclere; magnified 50; phot. Zeiss, planar 20 mm., compens. oc. 6. 
7.— A hypodermal pentactine; magnified 50; phot. Zeiss, planar 20 mm., compens. oe. 6. 
8, 9.— Normal tylostyles; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
10.— The tyle-bearing part of an abnormal tylostyle; magnified 100; phot. Zeiss, apochr. 16, compens. 
oc. 6. 
11-13.— Amphiox megascleres; magnified 50; phot. Zeiss, planar 20 mm., compens. oc. 6. 
14-25.— Amphidiscs and parts of such; magnified 500: 
14, a large macramphidise; phot. Zeiss, apochr. 8, compens. oc. 12; 
15-18, micramphidises; phot. Zeiss, H. 1. apochr. 2, compens. oc. 6; 
19, centrum and one anchor of a large macramphidise; phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
20, a small macramphidise; phot. Zeiss, apochr. 4, compens. oc. 12; 
21, a small macramphidise; phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
22, 23, small macramphidises; phot. Zeiss, apochr. 4, compens. oc. 6; 
24, 25, the central tyle of the shaft of two large macramphidises; phot. Zeiss, apochr. 8, compens. 
oc. 12. 


PLATE 69, 


=| 
=| 
= 
S| 
= 
= 


Fig. 1—5 Hyalonema (Hyalonema) spec. from station 4656. 


Fig. 6—25 Hyalonema (Ayalonema) tylostylum n. sp. 


PLATE 70. 


a 


PLATE 70. 


Hyalonema (Hyalonema) tylostylum LENDENFELD. 


Figures 1-10. 


1, 2.— Dermal pinules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
3.— Part of a radial section through the superficial part of the sponge and the pinule-fur; magnified 100; 
phot. Zeiss, apochr. 16, compens. oc. 6: 
a, a large macramphidise; b, dermal pinules. 
4.— A microhexactine; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
5.— Group of spicules in a centrifuge spicule-preparation; magnified 200; phot. Zeiss, apochr. 8, com- 
pens. oc. 6: 
a, microhexactines; b, a micropentactine; ¢, a micramphidisc. 
6.— View of the smaller specimen; reduced 100: 91; phot. Zeiss, anastig. 480/412 mm. 
7.— A microhexactine; magnified 200; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
8.— Surface view of the dermal pinule-fur; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
9, 10.— Gastral pinules; magnified 300: 
9, phot. Zeiss, apochr. 8, compens. oc. 12; 
10, phot. Zeiss, apochr. 4, compens. oc. 6. 


Hyalonema (Prionema) pinulifusum LENDENFELD. 


Figures 11-24. 


11-24.— Pinules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6: 
11-14, small, probably canalaria; 
15-19, large; 
20-24, medium. 


0. 


PLATE 


HEXACTINELLIDA. 


astylum n, Sp. 


11—24 Hyalonema (Prionema) pinulifusum 


Fig. 1—10 Hyalonema (Hyalonema) ty 


Fig. 


i. 


Lendenfeld photographed, 


PLATE 71. 


. A ON ade 8 a inl Fe 
i é 


PLATE 71. 


Hyalonema (Prionema) pinulifusum LENDENFELD. 


Figures 1-11. 


1-3.— A microhexactine; magnified 500; phot. Zeiss. H. I. apochr. 2, compens. oc. 6: 
1, focussed high (on the tips of the three upwardly directed rays); 2, focussed intermediate 
centre of the spicule); 3, focussed low (on the tips of the three downwardly directed ra: 
4.— Part of a microhexactine; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
5-8.— Macramphidises and parts of such; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 
5, a whole one; 
6, 7, the centrum and one anchor of two others; 
8, a tooth seen nearly en face. 
9.— Group of microhexactines from a spicule-preparation ; magnified 200; phot. Teles ‘ape ock 
compens. oc. 6. 
10.—A micropentactine; magnified 200; ppbek: Zeiss, erodes 8, compens. oc. 6. 


- HEXAOTINELLIDA. PLATE 71. 


Fig. 1—11 Hyalonema (Prionema) pinulifusum n, sp. 


Lendenfeld photographed. 
‘=. 


aA 


PLATE 72. 


PLATE 72. 


Hyalonema (Prionema) pinulifusum LENDENFELD. 
4 


Figures 1-15. 


1, 2.— A large mesamphidise with serrated teeth; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 6: 
1, focussed high (on the upper anchor-teeth); 2, focussed lower (on the axis of the shaft). 
3-8.— Mesamphidises with smooth teeth, and parts of such; magnified 500; phot. Zeiss, apochr. 4, ~ 
compens. oc. 12: 
3, a large one; 
4, 5, the centrum and one anchor of two large ones; 
6-8, small ones. 
9-15.— Micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 
9-14, small ones with long anchors; 
15, a large one with short anchors. 


Hyalonema (Prionema) agujanum tenuis LENDENFELD. 


Figs. 16, 22, 26 —form B. 
Figs. 17-21, 23-25, 27 —form A. 


16-18.— Microhexactines; magnified 200; phot. Zeiss, apochr. 8, compens. oe. 6: . 
16, of form B; . 
17, 18, of form A. { 
19.— A hypodermal pentactine of form A; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6. 
20.— Part of an axial, longitudinal section of form A showing the gastral pinule-fur; magnified 100; 
phot. Zeiss, apochr. 16, compens. oe. 6. 
21-25.— Pinules; magnified 300: 
21, 23-25, of form A; phot. Zeiss, apochr. 4, compens. oc. 6; 
22, of form B; phot. Zeiss, apochr. 8, compens. oc. 12. 
26, 27.— Hexactine megascleres; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6: 
26, of form B; 
27, of form A, 


HEXACTINELLIDA. 


Fig. 1—15 Hyalonema 


Le 16977 Hyalonema (Prionema) agujanum 


Ographed. 


‘endenfeld phot 


a 


PLATE 73. 


ad 


a 


. PLATE 73. 


Hyalonema (Prionema) agujanum tenuis LENDENFELD. 


Figs. 1-6 —form A. 
Fig. 7 —form B. 


1.— Front-view of the tip of a tooth of a macramphidise of form A; magnified 500; phot. Zeiss, H. I. 
apochr. 2, compens. oe. 6. 
2, 3.— Front-view of the tip of a tooth of a macramphidise of form A; magnified 2000; u. v. phot. Zeiss, 
q. monochr. 1.7, q. oc. 10: 
2, focussed lower; 3, focussed higher. 
4.— Half of a macramphidise of form A; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12. 
5-7.— Macramphidises; magnified 500: 
5, 6, of form A; 
7, of form B; 
5, phot. Zeiss, apochr. 8, compens. oc. 8; 
6, 7, phot. Zeiss, apochr. 4, compens. oc. 6. 


PLATE 73. 


Fig. 1—7 Hyalonema (Prionema) agujanum n. sp. var. tenuis. 1—6 form A; 7 form B. 


PLATE 74. 


PLATE 74. 


Hyalonema (Prionema) agujanum tenuis LenpENFELD. 


Figs. 1-5, 8 —form A. 
Figs. 6, 7,9 —form B. 


1, 2.— Two anchor-teeth of large serrated mesamphidises of form A; magnified 500: 
1, phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
2, phot. Zeiss, apochr. 4, compens. oc. 12. 
3, 4.— A large serrated mesamphidise of form A; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 6; 
3, focussed lower (the centre of the shaft in focus); 4, focussed higher (the uppermost teeth in focus). 
5.— A large serrated mesamphidise of form A; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 6. 
6, 7.— A large serrated mesamphidise of form B; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12: 
6, focussed lower (the centre of the shaft in focus); 7, focussed higher (the uppermost teeth in focus). 
8, 9.— The terminal anchors of two large serrated mesamphidiscs with the uppermost teeth in focus; 
magnified 500: 
8, of form A; phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
9, of form B; phot. Zeiss, apochr. 8, compens. oc. 12. 


7 


TH 


PLA 


aan 


sry ce AAA 


6, 7, 9 form ZB. 


, 8 form A, 


1—5 


eCnuls, 


Fig. 1—9 Hyalonema (Prionema) agujanum n. sp. var. t 


3 
a 
bs 
2 
2 
a 


Pracue. 


es 


Phototype by Charles Bellmann 


a 
4 

4 

. 
> 
a 

- 7 

if 


PLATE 75. 


S| ak ot 


PLATE 75. 


Hyalonema (Prionema) agujanum tenuis LeNDENFELD. 


Figs. 1-13, 15, 17, 19-27, 29-37 —form A. 
Figs. 14, 16, 18, 28 —form B. 


1, 2.— A small serrated mesamphidise of form A; magnified 500; phot. Zeiss, apochr. 4 
1, focussed higher (the uppermost teeth in focus); 2, focussed lower (the centre of the 
3-21.— Macramphidises; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6: 
3-13, 15, 17, 19-21, of form A; i 
14, 16, 18, of form B. EA 
22, 23.— A small serrated mesamphidise of form A; magnified 500; phot. Zeiss, H. I. apoc 
pens. oc. 6: 
22, focussed higher (the uppermost teeth in focus); 23, focussed lower (the centre of 
focus). 
24-27.— Micramphidises of form A; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. 
28-30.— Three specimens; natural size; phot. Zeiss, anastig. 480/412 mm.: 
28, form B; A 
29, 30, aoe A. 
31-34.— Two micramphidises of form A; magnified 2000; u. v. phot. Zeiss, q. monochr. 
31-33, a smaller one: 
31, focussed high; 32, focussed intermediate; 33, focussed low; 
34, a larger one. 
35-37.— An abnormal macramphidise of form A; magnified 500; phot. Zeiss, apochr. 4, compe 
35, focussed low; 36, focussed intermediate; 37, focussed high. 


HEXACTINELLIDA. 


Fig. 1—37 Hyalonema (Prionema) agufanum n. sp. var. tenuis. 1—18, 15, 17, 


endenfeld photographed, 


Phototype by Charles Bellmann, Prague 


19 


PLATE 75, 


PLATE 76. 


Me : — ay 2 ~~ 


PLATE 76. 


Hyalonema (Prionema) agujanum tenuis LeNnpENrELD. 


Figs. 1-7, 11, 12, 15-36 —form A. 
Figs. 8-10, 18, 14 —form B. 


1.— The centrum and one ray of a microhexactine of form A; magnified 2000; u. v. phot. Zeiss, q. 
monochr. 1.7, q. oc. 10. 
2, 3.— Micramphidises of form A; magnified 500: 
2, phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
3, phot. Zeiss, apochr. 4, compens. oc. 12. 
4-6.— Portions of transverse sections of a Palythoa polyp attached to the stalk of a ape of form A; 
magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
7.— Axial, longitudinal section through the upper part of the stalk with Palythoa attached, and the 
lower| part of the body of form A; magnified 6; phot. Zeiss, planar 50 mm. 
8-14.— Acanthophores from the sponge; magnified 200; phot. Zeiss, apochr. 8, compens. oe. 6: 
8, a small regular tetractine of form B; 
9, a large regular pentactine of form B; 
10, a large irregular tetractine of form B; 
11, 12, small regular tetractines of form A; 
13, a large regular tetractine of form B; 
14, a large diactine of form B. 
15-32.— Acanthophores and other sponge-spicules formed in a Palythoa polyp on the stalk of a speci- 
men of form A; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 
15, 16, short diactines, much more spiny at the ends than in the middle; 
17-20, short and stout rod-shaped spicules; uniformly spined throughout; 
21, 22, small stout triactines; uniformly spined throughout; 
23-30, small stout tetractines, uniformly spied throughout; 
31, a small only terminally spined tylostyle; 
32, a minute pentactine. 
33.— The tip of an anchor-tooth of a large serrated mesamphidise of form A; magnified 2000; u. v. 
phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
34.— Transverse section through the upper part of a Palythoa polyp attached to the stalk of a specimen 
of form A; magnified 30; phot. Zeiss, planar 20 mm. 
35, 36.— The end-part of an anchor-tooth of a large mesamphidise of form A; magnified 2000; u. v. 
phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
35, focussed higher; 36, focussed lower. 


36 


<a) 
< 
= 
» 
S 
<i 
~ 
of 
a 
S 
™ 
19 wa 
sp) 
Ory 
es 
\ 
= 
S 
5 
SS 
Je) 
oF 
1D 
~ 
oF 
~ 
Ww 3 
s En 
= 
Ww Bs 
= 
n 5 
= 
2 3 
3 wn 
IN S 
ES a 
~ a 
- = 
2 tS) 
iS) > 
sy 2 
- a 
= 2 
2 
s 2 
R cq 
9 
eS 
3 
S> 


Fig. 1—36 Hyalonema (Prionema) agu, 


| photographed, 


vr } 
; Mi ical a . 
iy i “ i) roe 
an Paid neo ee on 
“be Autry ga etn AG Tike oe , 
Pe as ' 
tes) 4 : a » et By 
; : > ; ‘ 
: \ } ‘, = 
{ ' ; 
: 
; » 
; eg 
PLATE 77. 
\ 


PLATE 77. 


_“ = 
Hyalonema (Prionema) agujanum lata LenpENFELD. 


‘ Figures 1-10. 


1.— The greater part of the shaft and one terminal anchor of a macramphidise; magnified 

Zeiss, apochr. 8, compens. oc. 12. 

2, 3— Half (one terminal anchor) of an ordinary, large serrated mesamphidise; magnifi 

Zeiss, apochr. 4, compens. oc. 6: a 

2, focussed higher (on the uppermost teeth); 3, focussed lower (on the shaft). 

4, 5.— An ordinary, small serrated mesamphidise; magnified 500; phot. Zeiss, H. I. apochr 
oc. 6: 

4, focussed higher (on the uppermost teeth); 5, focussed lower (on the centre of the sh 

6, 7.— A large, broad-anchored mesamphidise; magnified 500; phot. Zeiss, apochr. 8, compe 

6, focussed higher (on the uppermost teeth); 7, focussed lower (on the centre of the s 

8.— Micramphidise; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12. — 

9, 10.— Apical view of a terminal anchor of a macramphidise; magnified 500; phot. Zeiss, 

compens. oc. 12: : 

9, focussed low (on the tips of the teeth); 10, focussed high (on the web connecting the ti 


n q an Ae 
—— a ee 


HEXACTINELLIDA. 


PLATE 77. 


Fig. I-10 Hyalonema (Prionema) agujanum n. sp. var. lata. 


Lendenfeld Photographed 


+, 
4 PS EEX Eye pA ae ple 


wh 


PLATE 78. 


PLATE 78. 


Hyalonema (Prionema) agujanum lata LENDENFELD. 


Figures 1-15. 


1, 2.— Parts of stalk-spicules; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
3.— A diactine pinule; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12. 

4.— View of the specimen; natural size; phot. Zeiss, anastig. 480/412 mm. 

5-7.— Microhexactines; magnified 200; phot. Zeiss, apochr. 4, compens. oc. 6. 

8.— A microhexactine; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
9-11.— Pentactine pinules; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12. 
12-15.— Macramphidises; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6. 


Hyalonema (Hyalonema) grandancora LENDENFELD. 


Figures 16-45. 


16-19.— Macramphidises; magnified 50; phot. Zeiss, achr. aa, compens. oc. 6. 
20.— Transverse section through the upper part of a Palythoa polyp attached to the stalk of the sponge; 
magnified 30; phot. Zeiss, planar 20 mm. 
21-40.— Uniformly and densely spined acanthophores from the Palythoa polyps; attached to the stalk; 
magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
(Hach vertical pair of views represents the same spicule; the upper views of the pairs, figs. 21, 23, 
25, 27, 29, 31, 33, 35, 37, 39, are focussed high, the views beneath these, figs. 22, 24, 26, 28, 30, 32, 
34, 36, 38, 40, are focussed low; thus 21 and 22 represent the same spicule, 23 and 24, and so on). 
41-45.— Pinules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6: 
42, 43, gastral pinules; 
41, 44, 45, dermal pinules. 


PLATE 78. 


HEXACTINELLIDA, 


3 


le, 


t------------ 


Ca 


} 
4 


t—-——— — —_ ____ 


SSS Sa 


31 


9 


2 


agujanum n. sp. var. lata. 


(LLyalonema) grandancora n. Sp. 


15 Hyalonema (Prionema) 


16-45 Hyalonema 


Fig. 1- 


Fig. 


Lendenfeld photographed 


e 


: , ee if : an i ew li i ae ips 7 ‘ ae ys i 
} 
PLATE 79. 


PLATE 79. 


Hyalonema (Hyalonema) grandancora LENDENFELD. 
Figures 1-26. 


1, 2— Macramphidises; magnified 500: 
1, phot. Zeiss, apochr. 8, compens. oc. 12; 
2, phot. Zeiss, apochr. 8, compens. oc. 8. 
3-11.— Small micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
12.— View of the sponge; reduced 1: 0.85; phot. Zeiss, anastig. 480/412 mm. 
13-19.— Hexactine megascleres; magnified 30; phot. Zeiss, planar 20 mm. 
20.— Apical view of the lateral ray-cross of a dermal pinule; magnified 300; phot. Zeiss, apochr. 4, 
compens. oc. 6. 
21-23.— Microhexactines; magnified 500: 
21, phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
22, 23, phot. Zeiss, apochr. 4, compens. oc. 12. 
24, 25.— Large micramphidises; magnified 500: 
24, phot. Zeiss, apochr. 4, compens. oc. 12; 
25, phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
26.— Part of a terminal anchor of a macramphidisc; magnified 500; phot. Zeiss, apochr. 8, compens. 
oc. 12. 


HEXACTINELLIDA. PLATE 79. 


a A Fig. I-26 Hyalonema (Hyalonema) grandancora n. sp. 


_ Lendenfeld photographed 


» 


f aa ; 
b ‘ ne ’ it cae 
f + eet ’ Ne wee 
ee a e ai ar j ; Te | 
; Mie Pi fi ! 
ne " a , ee | 
ts i , A i 


Al 
AD ia 


PLATE 80. 


3 


t f is 
eh, Oe 


' PLATE 80. 


Hyalonema (Hyalonema) sp. 


Figures 1-16. Station 3684 (A. A. 17). 


1, 2.— Parts of two macramphidises; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 6. 

3.— A micramphidise; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12. 

4.— A microhexactine; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12. 

5-9.— Macramphidises; magnified 50; phot. Zeiss, apochr. 16, compens. oc. 2. 

10.— The end-part of an anchor-tooth of a macramphidisc; magnified 500; phot. Zeiss, apochr. 8, 
compens. oc. 12. 

11, 12.— An anchor of a stalk-spicule; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 

11, focussed lower (the shaft in focus); 12, focussed higher (the end-parts of the uppermost anchor- 

teeth in focus). 

13.— An acanthophore; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 

14.— A pentactine pinule with short distal ray; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12. 

15.— Part of a group of diactine pinules in situ m a section; magnified 300; phot. Zeiss, apochr. 8, 
compens. oc. 12. 

16.— A pentactine pinule with long distal ray; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12, 


z 
= 


HEXACTINELLIDA. = PLATE 80. 


—_ _ 
Se 


——————O y 


ee a 


\ fig. I-16 Hyalonema (Hyalonema) spec. from station 3684 [AA 17]. 
- a te 


. 
ry Lendenfeld photographed 


ty { a § cd Naty, ; i ni : | : 
\ Fe . a ‘ : oy & 
} Nee y tall 4 pe ; rOsmey © j rm Sane 4 i 
: ; i 
mu { 
ant 
Pas le 
‘ 
/ 
PLATE 81. 
‘ 
- / 
{ 
, 
‘ 
‘ 
< ‘ 
. 
i 
wi OP aay 


PLATE 81. 


Hyalonema (Leptonema) campanula LeNDENFELD. 
Figures 1-26. 


1, 2.— Parts of a diactine pinule; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12: 
1, the middle- and end-parts of the distal ray; 
2, the central part of the spicule. (The lower end of fig. 1 fits on to the upper end of fig. 2). 
3-6.— Microhexactines; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12: 
3, a larger one, focussed lower; 4, focussed higher; 5, a smaller one, focussed lower; 6, focussed 
higher. 
7-10.— Macramphidises, and a part of one, magnified 500: 
7, 8, phot. Zeiss, apochr. 8, compens. oc. 12; 
9, 10, phot. Zeiss, H. 1. apochr. 2, compens. oe. 6; 
7, a macramphidise with straight shaft; 
8, a macramphidise with strongly bent shaft; 
9, a macramphidise with slightly bent shaft, focussed low (on the shaft); 
10, the lower of the two anchors of the spicule represented in fig. 9 focussed higher (on the tips 
of the upper teeth). 
11.— Part of a stalk-spicule; magnified 30; phot. Zeiss, planar 20 mm. 
12, 13.— Two pentactine pinules with long and slender distal ray; magnified 100; phot. Zeiss, apochr. 
16, compens. oc. 6. 
14.— Part of a group of diactine pmules; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
15.— View of the specimen; natural size; phot. Zeiss, anastig. 480/412 mm. 
16-18.— Three pentactine pinules with long and slender rays; magnified 300; phot. Zeiss, apochr. 8, 
compens. oc. 6. 
19, 20.— Apical views of the lateral rays of two pentactine megascleres; magnified 50; phot. Zeiss, 
apochr. 16, compens. oe. 2. 


21, 22.— Micramphidiscs; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12. 
23, 24— Mesamphidises; phot. Zeiss, apochr. 8, compens. oc. 12. 
25, 26.— Pentactine pinules with short and stout distal ray from the basal part of the sponge; magnified 


300; phot. Zeiss, apochr. 8, compens. oc. 12: 
25, a single one; 
26, a group in situ in a section, 


PLATE 81. 


HEXACTINELLIDA. 


campanula n. Sp 


1-26 Hyalonema (Leptonema) 


vi 7g. 


Lendenfeld photographed 


PLATE) 82. 


is 


PLATE 82. 


Hyalonema (Oonema) bianchoratum pinulina LeNDENFELD. 


Figs. 1-23  — specimen b. 
Figs. 24-34 — specimen a. 


1.—Side-view of specimen b; reduced 1: 0.72; phot. Zeiss, anastig. 480/412 mm. (The stalk is broken 
at its point of origin. It lay loose in the bottle with the sponge-body. It fitted well to a broken 
stump of a stalk in the latter, and in all probability belonged to the sponge-body. I fixed itto 
the stump and photographed body and stalk together). 
2-5.— Parts of microhexactines of specimen b; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. 
oc. 6. 
6-9.— Two microhexactines of specimen b; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6: a 
6, microhexactine focussed lower (on the three lower rays); 7, focussed higher (on the three upper {- 
rays); 8, another microhexactine focussed lower (on the three lower rays); 9, focussed higher ry, 7 
(on the three upper rays). 
10-12.— Parts of the centrum and one ray of a microhexactine of specimen b; magnified 2000; u. v. 
phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
10, focussed high (the centrum and basal part of the ray); 
11, focussed lower (the whole ray and the centrum); 
12, focussed still lower (the distal part of the ray). 
13-19.— More or less centrotyle amphioxes from the gastral region of specimen b; magnified 50; phot. 
Zeiss, apochr. 16, compens. oc. 4. 
20.— Group of microhexactines from a spicule-preparation of specimen b; magnified 200; phot. Zeiss, 
apochr. 8, compens. oc. 6. 
21-34.— Pinules; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12: 
21-30, 32-34, side-views; 
31, apical view of the lateral rays; 
21-23, of specimen b; 
24-34, of specimen a; 
21, 23-28, 34, basal dermal pinules; 
22, 31-33, ordinary dermal pinules; 
29, 30, gastral pinules. 


PLATE 82. 


HEXACTINELLIDA. 


a ~ 


| 18 19 


| 


1 


| 16 


\ 


(Oonema) bianchoratum, Wilson var. pinulina n. var. 


Fig. 1-34 Hyalonema 


1-23 specimen b; 24-34 specimen a. 


Lendenfeld photographed 


“i i i 
+ 4 ci Ln 
vie oO ‘ o ye ae he fb 2 7 
i a) 7 J a « 
fie aa 
ad Tee Wey 3 
r aa * A, 1 
~~ U 
s i 
Mv 
¥ 
, 
. 
y 
' 
. 
. 


; hs =, PLATE 83. 


PLATE 83. 


Hyalonema (Oonema) bianchoratum pinulina LeNnpENFELD. 


Figs. 1-23, 60, 62-64, 68 — specimen b. 
Figs. 24-59, 61, 65-67 —specimen a. 


1-35.— Acanthophores; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
1-23, from the basal part of the body of specimen b; 
24-35, from the basal part of the body of specimen a. 
36-44.— Acanthophores from the Palythoa attached to the stalk of specimen a; magnified 100; phot. 
Zeiss, apochr. 16, compens. oc. 6. 
45.— Part of a section vertical to the gastral surface of specimen a; magnified 100; phot. Zeiss, apochr. 
16, compens. oc. 6: 
a, surface (zone of the paratangential rays of the pinules); b, pinules; ec, a small macramphidisc. 
46-59.— Acanthophores from the Palythoa attached to the stalk of specimen a; magnified 200; phot. 
Zeiss, apochr. 8, compens. oc. 6: 
46, 51, 55, 56, 59, tetractines (stauractines) ; 
47, 48, 52, 57, 58, rhabds; 
49, a rhabd, focussed lower; 50, focussed higher; 
53, a very short and stout rhabd, focussed lower; 54, focussed higher. 
60.— Part of the dermal surface of specimen b; magnified 5; phot. Zeiss, planar 50 mm.: 
a, symbiotic polyps. 
61.— Part of the gastral sieve-membrane of specimen a; magnified 30; phot. Zeiss, planar 20 mm. 
62.— Part of the dermal sieve-membrane of specimen b; magnified 30; phot. Zeiss, planar 20 mm. 
63, 64.— Choanosomal hexactine megascleres of specimen b; magnified 20; phot. Zeiss, planar 20 mm. 
65-68.— Superficial pentactine megascleres; magnified 50; phot. Zeiss, apochr. 16, compens. oc. 4: 
65-67, subdermal pentactines of specimen a; 
68, a subgastral pentactine of specimen b. 


HEXACOTINELLIDA. 


ic 
id 
ff 


var. 


pinulina n. 


1ar. 


fig. 1-68*Hyalonema (Oonema) bianchoratum Wilson, 


/ Specimen a. 


3, 60, 62-64, 68 specimen b; 24-59, 61, 65-6 


1-2. 


Lendenfeld photographed 


ie " Ta ot 
Nay yale ae a) Pee — see : 
my x ; Pa Ona, ° 5 eens - ey J p 
at ‘ ’ hy 
; sid 
1 ' - 
iD , - 4 
/ 
\ 
‘ 
‘ 
PLATE 84. 
C 
\ 
; 2 
\ 
/ 
i i; : 
vd wy } a ee = 


E PLATE 84. 


em 


Hyalonema (Oonema) bianchoratum pinulina Lenpenrexp. 


Figs. 1-10, 15, 26, 27, 30-32 " specimen a. 
Figs. 11-14, 16-25, 28, 29 —specimen b. 


: 1.— Part of a transverse section of one of the Palythoa polyps attached to the stalk o 
magnified 30; phot. Zeiss, planar 20 mm. : 
2.— Part of a section of the choanosome of specimen a; magenta; magnified 30; ph 
20 mm.: a, flagellate chambers. 
3-13.— Small macramphidiscs from the gastral zone, magnified 100; si Zeiss, apochr. 
oc. 6: . 
3-10, of specimen a; 
11-13, of specimen b. 
14.— Transverse section of one of the polyps imbedded in the body of specimen b; magni 
Zeiss, planar 20 mm. : 
15.— A small micramphidise of specimen a; magnified 2000; u. v. phot. Zeiss, q. monochr. 1 
16-25.— Small micramphidises of specimen b; magnified 500: 
16, 21, phot. Zeiss, apochr. 4, compens. oc. 12; : 
17-20, 22-25, phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
26, 27.— A terminal anchor of a small macramphidise of specimen a seen from within; m 
phot. Zeiss, apochr. 8, compens. oc. 12: 
26, focussed lower (on the base of the teeth); 
27, focussed higher (on the tips of the teeth). 
28-32.— Side-views of small macramphidises; magnified 500; phot. Zeiss, apochr. 8, compens 
28, a macramphidise of specimen b, focussed lower (the shaft in focus); 
29, the same macramphidise focussed higher (the tip of the upper teeth in focus) ; 
30, a macramphidise of specimen a, focussed lower (the shaft in focus) ; 
31, the same macramphidise, focussed higher (the tip of the upper teeth in focus) ; 
32, another macramphidise of specimen a. 


HEXACTINELLIDA, 


PLATE 84, 


Fig. I-32 Hyalonema (Oonema ) bianchoratum Wilson, var. pinulina n. var. 


4-10, 15, 26, 27, 30-32 specimen a; 11-14, 16-25, 28, 


4 Lendenfeld photographed 


29 specimen b. 


7 a 
> : i 
‘ » 
> ; 
a - 
= Oo 
> 
i 
- 
. 
— ‘ 
‘ 
s 
. 
2 
’ 
‘ 
. 
! 
i x 
a . 
- 
4 \ 
; 
a 
: 
7 
. 
. 
=f 
‘ 
> 
" 
. a 
mW ~ 
. 
: 
. i 


fi 
‘ 
De gor 
i 
, 


PLATE 85. 


a 


"0 *. ee ee 


PLATE 85. : 


Hyalonema (Oonema) bianchoratum pinulina LENDENFELD. 


Figs. 1, 4-7 — specimen b. 
Figs. 2, 3, 8 — specimen a. 


1.— A large macramphidise from the choanosome of specimen b; magnified 500; phot. Zeiss, apochr. 
8, compens. oc. 8. F 
2-7.— Large macramphidises from the choanosome; magnified 100; phot. Zeiss, apochr. 16, compens. 
oc. 6: 
2, 3, of specimen a; 
4~7, of specimen b. ’ 
~8.— An abnormal small macramphidise from the choanosome of specimen a; magnified 500; phot. 
Zeiss, apochr. 8, compens. oc. 12. — ~ 


Hyalonema (Oonema) sequoia LeNDENFELD. 
Figures 9-21. 


9-19.— Acanthophores; magnified 200: r 
9-14, 16-19, short-rayed di- to pentactines; phot. Zeiss, apochr. 8, compens. oc. 6; 
15, a long-rayed diactine; phot. Zeiss, apochr. 8, compens. oc. 4. 

20, 21.— Hexactine megascleres; magnified 20; phot. Zeiss, planar 20 mm. 


a) sequoia n. sp. 


tum Wrlson, var. pinulina n. var. 
specimen a. 


, 


L, 4-7 specimen b; 2,3, 8 
Lig. 9-21 Hyalonema (Oonem 


Lig. I-S Hyalonema (Oonema) bianchora 


ee eee eee 


-endenfeld photographed 


HEXACTINELLIDA. 


PLATE 86. 


he 


PLATE 86. 


Hyalonema (Oonema) sequoia LENDENFELD. 


Figures 1-36. 


1-6.— Large macramphidises; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
7.— Portion of the gastral sieve; magnified 20; phot. Zeiss, planar 20 mm. 
8.— View of the specimen; reduced 1: 0.83; phot. Zeiss, anastig. 480/412 mm. 
9.— A ray of a microhexactine; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
10.— A monactine microhexactine-derivate; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
11, 12.— Part of a microhexactine; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
11, a whole ray, focussed higher; 
12, the distal part of the same ray, focussed lower. 
13-26.— Large superficial pinules; magnified 50; phot. Zeiss, apochr. 16, compens. oc. 4: 
13, a hexactine one; 
14-26, pentactine ones. 
27-34.— Small macramphidises; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
35, 36.— Microhexactines; magnified 500: 
35, a small one; phot. Zeiss, apochr. 8, compens. oc. 12; 
36, a large one; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 


PLATE 86. 


HEXACTINELLIDA. 


OT Nee eg re nenar Ah 


-_-—- catty | 


a) sequoia n. Sp. 


6 Hyalonema (Oonem 


> 
, 


Fig. I- 


Lendenfeld photographed 


ie Tn ers 
' PLATE 87. 


PLATE 87. 


Hyalonema (Oonema) sequoia LENDENFELD. 
Figures 1-7. 


1-7.— Parts of large superficial pinules, and a whole one; magnified 300: 
1, a portion of the middle-part of one, where the spines are straight and upwardly directed; phot. 
Zeiss, apochr. 8, compens. oc. 12; 
2, a portion of the middle-part of one, where the spines are strongly oblique, all twisted in the same 
direction; phot. Zeiss, apochr. 8, compens. oc. 12; 
3, a whole one; phot. Zeiss, apochr. 8, compens. oc. 6: 
3a, the distal part; 
3b, the proximal part (there is no overlapping and nothing missing; the upper end of fig. 3b 
fits exactly on the lower end of fig. 3a). 
4, 5, the distal end of one, with the spines very irregular at one point of the upper surface; phot. 
Zeiss, apochr. 8, compens. oc. 12: 
4, focussed higher; 5, focussed lower. 
6, 7, the distal end of one, with the spine very irregular at one point of the side (profile); phot. 
Zeiss, apochr. 8, compens. oc. 12: 
6, focussed higher; 7, focussed lower. 


PLATE 87. 


= —_ * > y 
, ? _— . 
/ . >. 
* = ~~ - - ~ el . 
—_ a ‘> ’ 
« P ~ 
a 
— eer aad os : ay 
™ mel . | - . —_— _ 1 ” 
ft 


- 


— 


wel el 


= 


at. 
a 


Se TR An - 
ee ™ ’ “™y io - 


PLATE 88. 


a) elas 


PLATE 88. 


Hyalonema (Oonema) sequoia LENDENFELD. 
Figures 1-13. 


1-4.— Microhexactines; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
5, 6.— Small microhexactine-derivate pinule-like hexactine canalars; magnified 300; phot. Zeiss, apochr. 
8, compens. oc. 12. 
7-10.— Small superficial pinules; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12: 
7-9, pentactine ones; 
10, a hexactine one. 
11-13.— Superficial pentactine pinules; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 6: 
lla, 12a, 13a, the distal parts of three; 
11b, 12b, 13b, the proximal parts of the same (three; there is no overlapping and nothing missing. 
the upper ends of figs. 11b, 12b, and 13b fit exactly on the lower ends of figs. 11a, 12a, and 13a 
respectively) ; 
11, a medium-sized one; 
12, 13, large ones. 


PLATE 88. 


HEXACTINELLIDA. 


~ 


~~ > c 


\ 
\ 


; 


| ——_, 


Fig. 1-13 Hyalonema (Oonema) sequoia n. sp. 


_ Lendenfeld photographed 


ible 
vu 4 
fr tae 


PLATE 89, 


free? een 
Wi s 4 
i ia Lee id 
ny 
’ (ee 
i 
‘ 4 


Hyalonema (Oonema) sequoia LENDENFELD. 


Figures 1-36. 


a 
PLATE 89. ; { 
1 


1—5.— Large superficial amphioxes (tignules); magnified 20; phot. Zeiss, planar 20 mm. 


6-14.— Large micramphidises; magnified 500: ; 
6, 7, 9-14, phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
8, phot. Zeiss, apochr. 8, compens. oc. 12. 


15.— Group of spicules from a Solem Deanna oe of the superficial part of the body; magnified 20; 
phot. Zeiss, planar 20 mm.: 

a, slender amphioxes; b, stout amphioxes; ec, large superficial pinules; d, small macramphi- 
dises; e, large amphidises, probably of Hyalonema agassizi and foreign to the sponge, which 
are remarkably frequent. 

16-19.— An abnormal amphidise with reduced anchors; magnified 500; phot. Zeiss, H. I. apochr. 2, 
compens. oc. 6: 
16, one end, focussed high; 
17, the whole spicule, focussed lower; 18, focussed still lower; 
19, the other end, focussed lowest. 
20-30.— Small micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
31, 32.— End-parts of anchor-teeth of large macramphidises; magnified 500: 
31, phot. Zeiss, apochr. 8, compens. oc. 12; 
32, phot. Zeiss, apochr. 8, compens. oc. 6. 
33.— A somewhat abnormal small macramphidisc; magnified 500; phot. Zeiss, apochr. 8, compens. 
oc. 12. 
34.— A small micramphidise; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
35, 36.— An abnormal small macramphidise; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12; 
35, focussed higher; 36, focussed lower, 


o 


HEXACOTINELLIDA. PLATE 89, 
f i) h : \ 
Hy : | 4 \ 
| , Bh 
rm lg ya 
ra) Na We 
\ 
\ | “he 


ve 
\> ome 
- 


Fig. 1-36 Hyalonema (Oonema) sequoia n. sp. 


eld photographed 


PLATE 90. 


meee | eee ene Ce 


PLATE 90. 


Hyalonema (Oonema) sequoia LmNDENFELD 


e2 


_ Figures 1-10. 


1-10.— Small macramphidises; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 190 
1, 3, 5, 7, 9, focussed high (the upper teeth in focus) ; 
2, 4, 6, 8, 10, the same spicules focussed low (the shaft i in focus); 
1, 2, a small one; 
3, 4, a medium-sized slender one; 
5, 6, a medium-sized broad one with partly irregular anchor-teeth; 
7, 8, a large one; 
9, 10, a medium-sized broad one with regular anchor-teeth. 


-HEXACTINELLIDA. 


PLATE 90. 


fig. I-10 Fyalonema (Oonema) Sequora n. Sp. 


‘ . Lendenfeld photographed 


r ia ‘ i * 
j 7 
ound ee 
| hei P a " 
‘44 
ke » Rey 
hs , "7 
\! 
5 
sy 
1 
\ 
~ 
} 
‘ 
. 
. 
PLATE 91. 
i : 
a ae, . 
¥ ~ 
¥ 
° 
rae 
5 
‘ a 
5 , 
r at 


oe aw Pe © -. 


PLATE 91. 


Hyalonema (Oonema) sequoia LENDENFELD. 
Figures 1-6. 


1-6.— Parts of large macramphidises; magnified 500: 
1-4, phot. Zeiss, apochr. 8, compens. oc. 12; 
5, 6, phot. Zeiss, apochr. 8, compens. oc. 6; 
1-3, parts of terminal anchors, showing irregular teeth; 
é 4, a regular terminal anchor; 


5, 6, the shaft and half of the terminal anchors of two regular ones. 


PLATE 91, 


Fig. 1-6 Hyalonema (Oonema) sequoia n. sp. 


Lendenfeld photographed 


ru 


/~ 


PLATE 92. 


ya yee ew ee CPSC Te Ree oo, eee ee 


ney hat, hh 


PLATE 92. 


Hyalonema (Oonema) crassipinulum LENDENFELD. 
Figures 1-23. 


1-7.— Superficial pinules; magnified 50; phot. Zeiss, apochr. 16, compens. oc. 2: “ 7 ; is 
1-5, gastral pinules; 
6, 7, dermal pinules. 
8.— Portion of the lower layer (without the pinules) of the gastral membrane; magnified u 
Zeiss, apochr. 16, compens. oc. 6. oi es 
9-11.— Microhexactines; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
12-15.— Parts of microhexactines (13-15) and a whole one (12); magnified 500; phot. nag 
apochr. 2, compens. oc. 6. Ln 
16, 17.— Canalar pinules; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12: ac 
16, a pentactine one; ‘7 - 
17, a hexactine one. ; q : 
18-21.— Side-views of superficial pinules; magnified 300; pioHl Zeiss, apochr. 8, compens. oc. 6: ¢ 
18, a dermal pinule; 2s 
19-21, gastral pinules. 
6 22, 23.— The basal part of a gastral superficial pinule with the distal ray broken off rather short 
from above; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12: 
22, focussed higher, an optical transverse section of the distal ray; 
23, focussed lower, the lateral rays. : * t 


= 
5 
=| 
z 
= 
= 
= 


fig. 1-23 Hyalonema ( Oonema) crassipinulum n. sp. 


Lendenfeld photographed 


‘ 


PLATE 93. 


a 


<: Pew art ewe Ny eee. Oe eae eee 


PLATE 98. 


Hyalonema (Oonema) crassipinulum LENDENFELD. 


Figures 1-10. 


3, a middle-sized one, focussed high a the Rea teeth): 

4, the same spicule focussed low (on the shaft); 

5, a small one, focussed high (on the uppermost teeth) ; 

6, the same spicule focussed low (on the shaft); 

7, a large one, focussed high (on the uppermost teeth); ~ 

8, the same spicule focussed low (on the shaft). 
9.— View of the specimen; natural size; phot. Zeiss, anastig. 480/412 mm. 
10.— A large macramphidisc; magnified 100; phot. Zeiss, apochr. 16, compens. oc.6. | 


HEXACTINELLIDA. PLATE 93. 
Neri 


Pe) : 
Fig. 1-10 Hyalonema (Oonema) crassipinulum n. Sp. 


Lendenfeld photographed 


ao A oa ae 


‘a 


Mi 


. L) a ' 
, k 
5 | oye) ie 
1 < 
a ‘ 
PLATE 94. 
- i i 
- 
é 
2 
F 
\ 
' 
; 
iy! ‘ 


- 24-33.— Acanthophores from the sponge-body; magnified 200; phot. Zeiss, apoc 


PLATE 94. 


Hyalonema (Oonema) crassipinulum LENDED 
Figures 1-33. 


1—4.— Small macramphidises;. magnified 100; phot. Zeiss, apochr. 16, compens. ¢ 
1-3, broad ones; 
4, a narrow one. 
5-11.— Micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2 compens. oc. 
12, 13.— A micramphidisc; magnified 500; phot. Zeiss, H. I. apochr. 2, compe: 
12, focussed higher (on the uppermost teeth); 

13, focussed lower (on the shaft). 
14-23.— Acanthophores from the Palythoa attached to the stalk; magnified 2005 1 phot 
8, compens. oc. 6. 


Hyalonema (Oonema) densum LENDENFELD. 
Figures 34-42. 


34-36.— Acanthophores; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
37-39.— Two whole microhexactines and part of one; magnified 200; phot. Zeiss, ap 
oc. 6. 
40.— Part of a microhexactine; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
41, 42.— Radial sections through the choanosome; magenta: ; 
41, magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6; 
42, magnified 30; phot. Zeiss, planar 20 mm. 


PLATE 94. 


2. Mp VN x 4 ay 


AR IR, 54)'- } 


bet eg 


oe 
Y tae 


Fig. 1-33 Hyalonema (Oonema) crassipinulum n. sp.; Fig. 34-42 Hyalonema (Oonema) densum n. sp. 


HEXACTINELLIDA. 
Lendenfeld photographed 


Tet ae 


» 
af 
® 7 
be : ; 
; ~ ; 
7" 4 
A nu, - 
4 a 
5 . ) 
- 
« 
F 
i 
iv 
7 


a. 
i] va of) cn 
(npg “_ 
Gis , al 
r 

=u fa 
~~ 
-_ 7 » —- 
i 4 , a 

} : “~ 
a) 

S, 

‘ 

\ 


PLATE 95. 


Hyalonema (Oonema) densum LENDENFELD. 
Figures 1-20. 


1.— Radial section through the dermal membrane and the underlying part of the choanosome; magni- 
fied 30; phot. Zeiss, planar 20 mm. 
2.— Radial section through the gastral membrane and the underlying part of the choanosome; magni- 
fied 30; phot. Zeiss, planar 20 mm. 
3.— View of part of the gastral surface; magnified 8; phot. Zeiss, planar 50 mm. 
4.— View of the specimen; reduced 1: 0.89; phot. Zeiss, anastig. 480/412 mm. 
5-10.— Micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 
5-8, large micramphidiscs; 
9, 10, small micramphidiscs. 
11, 12.— Apical views of the lateral rays of gastral pinules; magnified 300; phot. Zeiss, apochr. 8, 
compens. oc. 12. : 
13-16.— Side-views of superficial pinules; magnified 300: 
13, 14, gastral pinules; phot. Zeiss, apochr. 16, compens. oc. 12; 
15, a dermal pinule; phot. Zeiss, apochr.’8, compens. oc. 12; 
16, a gastral pinule; phot. Zeiss, apochr. 8, compens. oc. 12. 
17-20.— Superficial pinules; magnified 50; phot. Zeiss, apochr. 16, compens. oe. 2: 
17, 18, gastral pinules; 
19, 20, dermal pinules. 


HEXACTINELLIDA. PLATE 95. 


Liha 


A, 
— 


ind 


= 


eee + 

=~ 

= 

for) 
ar 
= 
To 


20 


Lendenfeld photographed 


Bye 7-20 Hvyalonema (Oonema) densum 1. Sp. 


* ; oa 
te a \ 
—_— 


PLATE 96. 


Hyalonema (Oonema) densum LENDENFELD. 
Figures 1-14. 


1-7.—Small macramphidises; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. Mi 
8, 9, 14.— Large macramphidises; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
10, 11.— A larger small macramphidise; magnified 500; phot. Zeiss, apochr. 8, compens 
10, focussed high (on the uppermost teeth); 11, focussed low (on the shaft). : 
12, 13.— Two smaller small macramphidiscs; magnified 500; phot. Zeiss, apochr. 8, compens. 


PLATE 96. 


HEXACTINELLIDA. 


Fig. 1-14 Hyalonema ( Oonema) densum 1. Sp. 


} 


TLendenfeld nhotocranhed 


PLATE 97. 


PLATE 97. 


Hyalonema (Oonema) henshawi LENDENFELD. 
Figures 1-36. 


1-5.— Superficial pinules; magnified 50; phot. Zeiss, apochr. 16, compens. oc. 2: 
1, 3-5, gastral pinules; 
2, a dermal pinule. 
6.— A canalar pinule; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12. 
7-14.— Macramphidises; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
7-12, side-views; 
18, 14, apical views. 
15.— View of the specimen; natural size; phot. Zeiss, anastig. 480/412 mm. 
16—28.— Micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 
16-20, large micramphidises; 
21-28, small micramphidises. , 
29-31.— Superficial pinules; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12: 
29, 30, gastral pinules; 
31, a dermal pinule. 
32.— Part of a gastral pore-sieve; magnified 20; phot. Zeiss, planar 20 mm. 
33, 34.— Parts of microhexactines; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
35, 36.— Microhexactines; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6, 


HEXACTINELLIDA. PLATE 97. 
b A A (Wh fh (PAY 

} (! A\) / \ (i ‘. } 
Wy iy \e V/A \ 

bi 4 ; \Ay/ iy) \! / 
| | ae 7 8 9 

ie ik | ty 

as aS : 


fi} 


an 
Wy) | Mth 
a4 f 25 


fi) 
J 


2 
| 


36 


Fig. 1-36 Hyalonema (Oonema) henshawi n. sp. 


4 Lendenfeld photographed 


out ee ee ee a a 
‘ id A . 


~~ 9 


EO 


may? 


rwee pee 


= I a ' ia oh, 
i] J { r ; 1 
vay y 
a 
j 
4 
J _ v 
& 
a ; 
-) 
PLATE 98. LA 
ig 
Hyalonema (Oonema) henshawi LENDENFELD. Pn Bit 
: Ars 
Figures 1-7. 7 a : 
7 7 
ie 
1-6.— Side-views of macramphidises; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12: ‘- : 
1, a middle-sized one, focussed high (on the uppermost teeth); 2, focussed lower (on the shaft); 
3, a small one, focussed high (on the uppermost teeth); 4, focussed lower (on the shaft); “2 a 


5, a large one, focussed high (on the uppermost teeth); 6, focussed lower (on the shaft). 
7.— Apical view of a middle-sized macramphidise; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12. 


4 


4 by a hi 0, es). Af uy 


HEXACTINELLIDA. 


PLATE 98, 


> 


as 


- 
% 


Fig. 1-7 Hyalonema (Oonema) henshawi n. Sp. 
| 


_ Lendenfeld photographed 


= 


LE Preto eae 


: 


\ 


PLATE 99. 


Hyalonema (Skianema) aequatoriale LeNDENFELD. 
Figures 1-37. 


1, 2.— Apical view of a large macramphidisc; magnified 500; phot. me apochr. 8, compens. oc. 12: 
1, focussed higher; 2, focussed lower. 
3-10.— Microhexactines; magnified 200; phot. Zeiss, apochr. 8, esitpens, oc. 6. 
11-16.— Large micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 
11-13, focussed high (on the uppermost teeth); 14-16, focussed lower (on the shaft) (11 = 14; 
117) = illsy3 als}, = 1I(3))). 
17.— View of the specimen; reduced to 1: 0.9; phot. Zeiss, anastig. 480/412 mm. 
18.— A middle-sized, somewhat irregular macramphidisec; magnified 500; phot. Zeiss, apochr. 8, com-— 
pens. oc. 12. 
19, 20.— A small irregular macramphidisc; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12: 
19, focussed higher; 20, focussed lower. 
21-24.— Small micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
25-28.— Gastral superficial pmules; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12. 
29-31.— Dermal superficial pinules; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12. 
32-35.— Parts of microhexactines; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
36.— Apical view of the lateral ray-cross of a gastral superficial pinule; magnified 300; phot. Zeiss, 
apochr. 8, compens. oc. 12. 
37.— Part of a terminal anchor (two teeth) of a large macramphidisc; magnified 500; phot. Zeiss, apochr. 
8, compens, oc. 12. 


 _ 


HEXACTINELLIDA. PLATE 99 


Fig. 1-37 Hyalonema (Skianema) aeguatoriale n. sp. 


% Lendenfeld photographed 


PLATE 100. 


Hyalonema (Skianema) aequatoriale LENDENFELD. 


Figures 1-12. 


1, 2.— A slender small macramphidisc; magnified 500 ; phot. Zeiss, apochr. 8, compens. oc. 12: 
1, focussed high (on the uppermost teeth); 2, focussed lower (on the shaft). 

3, 4.— A broad small macramphidisc; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12: 
3, focussed high (on the uppermost teeth); 4, focussed low (on the shaft). 

5.— A large macramphidisc; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12. 

6, 7.— A large macramphidisc; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12: 
6, focussed high (on the uppermost teeth); 7, focussed lower (on the shaft). 

8-11.— Large macramphidises; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 

12.— A small macramphidise; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 


i. 5 i 
HEXACTINELLIDA. 
iB PLATE 100, 


Fig. 1—12 Hyalonema (Skianema) aequatoriale n, sp. 


Lendenfeld photographed. 


Phototype by Charles Bellmann, Prague. 


PLATE 101. 


PLATE 101. 


Hyalonema (Skianema) aequatoriale LeNDENFELD. 


Figures 1-3. 


1.— Radial section through the marginal part of the sponge; magnified 20; phot. Zeiss, planar 20 mm.: 
a, gastral face; b, dermal face. 

2.— Radial section through the gastral membrane and the adjacent parts of the choanosome; magnified 
100; phot. Zeiss, apochr. 16, compens. oc. 6: 

a, gastral pinule-fur; b, gastral membrane; c, small macramphidises protruding over the 

gastral membrane; d, large macramphidiscs in the subgastral region. 

3.— Paratangential section through the gastral membrane, containing the zone occupied by the lateral 
rays of the pinules. 


Hyalonema (Skianema) umbraculum LENDENFELD. 


Figures 4-17. 


4—7.— Microhexactines; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
8, 9.— An abnormal large macramphidisc; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12: 
8, focussed high (on the uppermost teeth); 9, focussed lower (on the shaft). 

10.— Half (one anchor) of an abnormal large macramphidise; magnified 500; phot. Zeiss, apochr. 8, 
compens. oc. 12. 

11-13.— Parts of microhexactines (11, 13) and a whole one (12); magnified 500; phot. Zeiss, H. I. 
apochr. 2, compens. oc. 6. 

14.— A diactine microhexactine-derivate; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 

15-17.— Acanthophores; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 


HEXAOCTINELLIDA, PLATE 1 


Fig, 1—3 Hyalonema (Shianema) aequatoriale n. sp. 


Fig. 4—17 Hyalonema (Skianema) umbraculum n. sp. 
Lendenfeld photographed, 


Phototype by Charles Bellmann, Prague, 
> 


PLATE 102. 


PLATE 102. 


Hyalonema (Skianema) umbraculum LENDENFELD. 
Figures 1-8. 


1, 2.— Apical view of a large macramphidise; magnified 500; phot. Zeiss, apochr. 8, compe 
1, focussed higher; 2, focussed lower. 

3-6.— Small macramphidises; magnified 500; phot. Zeiss, apockt: 8, compens. oe. 12: 
3, 5, focussed high (on the uppermost teeth); 4, 6, focussed lower (on the shaft) (3 = 

7, 8— A large macramphidisc; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12: 
7, focussed high (on the uppermost teeth); 8, focussed lower (on the shaft). : 


- 


; 
HEXAOTINELLIDA. 
PLATE 102. 


Fig. 1—8 Hyalonema (Skianema) umbraculum n. Sp. 


Lendenfeld photographed. 


Phototype by Charles Bellmann, Prague. 


2 
al * =e 
<i 
—*® =e 
oe 
7 
‘ 
F 7 
& 
~*~ 
’ 
a. 


PLATE 103. 


Hyalonema (Skianema) umbraculum LENDENFELD. 


Figures 1-36. 


1-8.— Large macramphidises; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
1, 3, 5, 7, focussed high (on the uppermost teeth); 2, 4, 6, 8, focussed lower (on the shaft) (1 = 2; 
on On —1Ol e/a) s 
9-13.— Superficial pmules; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12. 
14-23.— Large macramphidiscs; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
14-21, side-views; 
22, an oblique view; 
23, an apical view. 
24-26.— Small macramphidises; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
27-29.— Small micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
30-34.— Large micramphidises; magnified 500: 
30-32, 34, phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
33, phot. Zeiss, apochr. 4, compens. oc. 12. 
35, 36.— A large micramphidise; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6: 
35, focussed high (on the uppermost teeth); 36, focussed lower (on the shaft). 


Hyalonema (Thallonema) geminatum LENDENFELD. 


Figures 37-62. 


37, 38.— One anchor and part of the shaft of a large micramphidise; magnified 2000; u. v. phot. Zeiss, 
q. monochr. 1.7, q. oc. 10: 
37, focussed lower (on the shaft); 38, focussed high (on the uppermost teeth). 
39-44.— Microhexactines; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 
45-48. — Parts of microhexactines (47, 48) and two whole ones (45, 46); magnified 500; phot. Zeiss, 
H. |. apochr. 2, compens. oc. 6. 
49-52.— Small micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
53-57.— Large micramphidises; magnified 500: 
53, phot. Zeiss, apochr. 8, compens. oc. 12; 
54-57, phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 
58-62.— Superficial pinules; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12. 


PLATE 103. 


Fig. 1—36 Hyalonema (Skianema) umbraculum n, Sp. 
Fig. 87—62 Hyalonema (Thallonema) geminatum n. Sp. 


\denfeld photographed. 
Le 
Phototype by Charles Bellmann, Prague. 


i! 
‘ 
: 
iy 
- 
“ 
. 
a 
. F 7 
i 
' 
. 
* ' 
® 
. 
~~ 

L 

7 
Feel fe 
y me it - 


PLATE 104. 


Hyalonema (Thallonema) geminatum LENDENFELD. 
Figures 1-14. 


1-4.— Parts of anchors of large geminate macramphidises; magnified 500; phot. Zeiss, apochr. 8, 
compens. oc. 12. 
5.— A large macramphidise with the teeth of one anchor geminate; magnified 500; phot. Zeiss, apochr. 
8, compens. oc. 12. 
6, 7.— A simple large macramphidisc; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
6, focussed high (on the uppermost teeth); 7, focussed lower (on the shaft). 
8.— A geminate large macramphidisc; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 
9, 10.— Small macramphidises; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
9, apical view; 
10, side view. 
11, 12.— A large geminate macramphidisc; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 
11, focussed high (on the uppermost teeth); 12, focussed lower (on the shaft). 
13, 14.— A small macramphidise; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12: 
13, focussed high (on the uppermost teeth); 14, focussed lower (on the shaft). 


—-HEXAODINEDLIDA. 


PLATE 104, 


Fig. 1—14 Hyalonema (Thallonema) 


geminalum n, Sp. 


endenfeld photographed, 


Phototype by Charles Bellmann, Prague, 


*- ; oa : S = bale : @ < . 
Sle +" ® , 7 ¥ 7 
PLATE 105. 
ne f it m 


PLATE 105. 


Hyalonema (Thallonema) geminatum LENDENFELD. 
Figures 1-14. 


1-14.— Large geminate macramphidises; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 


a ' 


PLATE 106. 


} 


PLATE 106. 


Euretid. Station 4641. 
Figures 1-3. 


1.— Part of the gastral face of the skeleton of the tube-wall; magnified 30; phot. Zeiss, planar 20 mm. 


2. Part of the dermal face of the skeleton of the tube-wall; magnified 30; phot. Zeiss, planar 20 mm. 


3.— View of the skeleton; natural size; phot. Zeiss, anastig. 480/412 mm. 


Hyalonema (Prionema) crassum LENDENFELD. 


Figures 4-37. 


- 4-12.— Microhexactines; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6: 


4-6, the same microhexactine; 
4, focussed high; 5, focussed on the centre of the spicule; 6, focussed low; 
7-10, different microhexactines; 
11, 12, a group of microhexactines in a spicule-preparation; 
11, focussed higher, 12, focussed lower. 
13-20.— Micramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 4. 
21-25.— Micramphidises; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
21-23, the same micramphidise; 
21, focussed high: 22, focussed 0.7 » lower; 23, focussed 1.4 » lower; 
24, 25, two different micramphidises. 
26-30.— Pinules; magnified 300; phot. Zeiss, apochr. 8, compens. oc. 12. 


31.— A microhexactine (of which only two opposite rays are in focus); magnified 500; phot. Zeiss, 


H. I. apochr. 2, compens. oe. 4. 
32-37.— Rays of microhexactines; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
32, the basal quarter of a ray, focussed low; 
33, the basal half of the same ray, focussed higher; 34, focussed still higher; 
35, the distal third of the same ray focussed highest; 
36, the tip of another ray; 
37, another ray. 


HEX ACTINELLIDA. on haere 
al } ). 


ae (ae 
eG ar a a amma 


Fig. 1—3 Euretid from Station 4641. 


Fig. 4—87 Hyalonema (Prionema) crassum n. Sp. 


Lendenfeld photographed, 


Phototype by Charles Bellmann, Prague 


a a sel 


PLATE 107. 


Poe te Ve 


; 
F 
. 
% 
. 
? 


Se po 
m vans 
- a 
v = : thy 
a 
or 
Pak 
ve 


PLATE 107. 


Hyalonema (Prionema) crassum LENDENFELD. 


Figures 1-20. 


1, 2.— A large serrated macramphidise; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12: 
1, focussed high, on the uppermost teeth; 2, focussed lower, on the centre of the shaft. 
3, 4.— A terminal anchor of a large serrated ranernrtnatadiae: magnified 500, phot. Zeiss, H. I. a a 
compens. oc. 4: 
3, focussed high; 4, focussed a little lower. S 
5.— A medium-sized serrated macramphidisc; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12. — 
6-15.— Paratangential superficial amphioxes; magnified 50; phot. Zeiss, apochr. 16, compens. oc. 2: 
6-10, slender ones from the dermal membrane; 
11-15, stouter ones from the gastral membrane. 
16.— View of the largest specimen; natural size; phot. Zeiss, anastig. 480/412 mm. a 
17-20.— Parts of an anchor-tooth of a large serrated macramphidise; magnified 2000; u. v. phot. 
Zeiss, q. monochr. 1.7, q. oc. 10: £ 
17, the tip of the tooth, focussed high; 
18, the distal part of the same tooth, focussed lower; 19, focussed still lower; 
20, the middle-part of the same tooth, focussed lowest. 


ose ¥ 
> 


fs 


> 


a 
i 
- " 
4 
« 
a 


PLATE 107. 


HEXACTINELLIDA. 


~~. 


See ih RFE 


=* 


Fig. 1—20 Hyalonema (Prionema) crassum n. Sp. 


Lendenfeld photographed. 


Phototype by Charles Bellmann, Prague. 


rs 


7 . « © > ol. ae aaa ee eae. Fae 


PLATE 108. 


PLATE 108. 


Hyalonema (Prionema) crassum LENDENFELD. 
Figures 1-17. 


1-9.— Superficial pentactines; magnified 30; phot. Zeiss, planar 20 mm.: 
1, 3-5, 8, 9, hypodermal pentactines; 
2, 6, 7, hypogastral pentactines. 
10-13.— Hexactine megascleres; magnified 30; ee Zeiss, planar 20 mm. 
14, 15.— Two smooth macramphidises; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12. 
16, 17.— Parts of smooth macramphidises; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 
16, an anchor, focussed high, on the tips of the uppermost teeth; 
17, a little more than half of a macramphidisc, focussed on the centre of the shaft. 


ye 


a Pr, > & ee &, _ 


HEXAOTINELLIDA. 


PLATE 108, 


Lendenfeld photographed. 


Fig. 1—17 Hyalonema (Prionema) crassum n. Sp. 


Phototype by Charles Bellmann, Prague. 


j 
2 : 
4 * 
PLATE 109. 
The projection measuring apparatus, = 


Front-view. The mirror is behind the frosted glass-plate and therefore invisible. 
The spicules seen projected on the frosted glass-plate are macramphi 
Hyalonema (Hyalonema) agassizi Lendenfeld. 


PLATE 109. 


HEX ACTINELLIDA. 


ad 


~ WALA EN 


wettnial 
pebeee 


Sais 


a) 


wy 


JUNG 198 


err 
Wee eee le 


BINDING 


er roars 


tid ord fipllemphaiontebd 
Tey AF tee Sm pete 
i 


etter 
- w 


hide is SE 


Peet 
So neee 


— 


is 
> ms oO ory 
pert: 
’ iw 


ete Ah er tak 
SParagesdotet pl Foy aids 


yr 
bev ahye> of 
Petes 
crsrerss 


o> > 
* 


3 
tei beste 
esas iia : 
sia ira reopen senate 
meter 


beiw kein be 
eerie 
sete om) ma behe by, 
pa ae 4 oye hehe 
“one a 


45 

eel oe py sioner 

Goreme linemen 

apn We 4 | r + 
ec te ste! oceme 
so pahapeyernres 
marke 


ascot 
9 OE be hed the he 
: 


fateh te 


ser bd 4 fyrteeded 


ees dat tr 
Wet 
cad ee MAwe 


iva 


pieheuel wr eeheae ue 
Teigikt belahetaten 
1 be Hee peti: 
vs Nem 
ase erieress te i 


oetetele 
Laashel ate 
apranedms 


eueaase nat 

pat gre cea 

au Heaaes a 
Veie by 


re 
7 Ae Al 
ea 


ea taniieins 
Renee ‘ 


Chats 


i 
ie 
* Phere ii S 
Beloit Grier ata ahs 
bed 
zs 


an seat 
oP [ >: ee be 
ae earieis ‘ott! 
DAT pet ie ie At 
bed on So @ 
pale Hokia it frdm ne 
y 


ie 


mena 


bpstoty ich 
ad 
eu 
etait 


ee} 
eben es 
Set wet reymens sy 


2 ¥ 
Sites tateanee 
REA Seeteltaniee 
oo ay chery Be Ly 
tera ufaeenertag 
er jm ee he 


LA rg eee a 
iekeiikiee HAS tee 


rneaeat ii 
aright lor 


ang he ae. 
winlalaiebets ne 
tetias 

Widuesaeth 


ee tae 


sakes 


of 
eae sadist 
ce ria eed nake 
pees 

ie 


te 
aap 


iene hee ve 


b ha arkip be’ 


Loeela 


Hashes ts 


» 
Jone 
tad 


jet 
saat beaks 


Shee thal 


ene Ve tells bi 
Le hee eB 


orn 


ne pisibee eb 


Pep balls be bi be be Det 
nn rei bel oie bs le Teleiom > 


} Doel 
“ 


aelsherr rahe dene s 


pies 


rep heiploed sheet, ie 


“Tite ih prin ne 
Die brah 


iy 


Pel we here lee 
Tip ee he Pa babes bp oe ya ams 


oe att ree Vik 
cette hed Sgt 
Vepericeetaeohent 


tes “yen 
niche eee 


34 
bees hs teat 


Wel beet? 


bite itecl iste 


es 


a 


t 
te 


Sip beptee> 
Shed iatiate 
pr bah ye 
te 


ei 


Sade ior An) begs Ob 
; Weipteae 


hoe 
bee) Mot beh 


Perr) 
mbtoa'e’ tae ese 
1,38 15% etary nist Pog f mln 


pe brie 
1 PRRs Leb oe hey veh. 
hie sh ckhet 

a 


- 
ries 
Deus ie 
tibie. 


fe Pim bok betieveee 
eetse ae 


eremclee 
ir Bien 
eat 
peta ies 
feerog 
i 


ve 
asthe 


Tega Os ow: 


aS neeistcae 
arte tats 

of Sas 
me 


aateg 


: at ahral i 


ie 


nperts mbene. 
OWE ree 


eters 
time west 
* . 
re pe be 
yb linvenet 
Denatid 
es 


Sh) 


44 
jes eee b 


<aidege 


tir 


Paste tt 


de 


errr