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BULLETIN
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4 MUSEUM OF COMPARATIVE ZOOLOGY
AT
HARVARD COLLEGE, IN CAMBRIDGE.
OL ORT.
CAMBRIDGE, MASS., U.S. A.
1885-1886.
UNIVERSITY PRESs :
Joun WILSON AND SON, CAMBRIDGE.
613328
AP Thee
CONTENTS.
No. 1.—Chlamydoselachus anguineus Garm.—A Living Species of Clado-
dont Shark. By S. Garman. (20 Plates.)
No. 2.— Report on the Results of Dredging by the United States Coast
Survey Steamer “ Blake.” XXVII. Report on the Specimens of Bottom
Deposits. By Joun Murray : é : : s
No. 3.— Observations on the Development of Agelena nevia. By WiLiram
A. Locy. (12 Plates.)
No. 4. — Studies from the Newport Marine Laboratory. XVII. Preliminary
Observations on the Development of Ophiopholis and Echinarachnius. By
J. WALTER Fewxes. (8 Plates.)
No. 5.— Report on the Results of Dredging by the United States Coast
Survey Steamer “ Blake.” XXVIII. Description of thirteen Species and
two Genera of Fishes from the “Blake” Collection. By G. Browne
GoopeE and Tarteton H. Bean . A
No. 6.— Report on the Results of Dredging by the United States Coast
Survey Steamer “Blake.” XXIX. Report on the Mollusca. Part I.
Brachiopoda and Pelecypoda. By W.H. Datu. (9 Plates.)
PAGE
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No. 1. — Chlamydoselachus anguineus GARM.— A living Species
of Cladodont Shark.
By S. GARMAN.
Description.
MEASUREMENTS. — Total length 59.5 inches. Snout to angle of mouth 4.5, to
back of skull 4.25, to occipital pores 3.9, to end of gill-covers 7, to base of pecto-
rals 8.5, to end of pectoral 14.25, to vent 35.5, to base of ventrals 32, to end of
ventrals 38.6, to base of anal 39.75, to end of anal 47.6, to base of dorsal 42.25, to
end of dorsal 47.75, to base of caudal 48.5 ; distance from bases of pectorals to bases
of ventrals 23; greatest width (across ventrals) 7, width across caudal 5, width
across dorsal and anal 6.5, width of head across eyes 3.5, width of the largest tooth
between the ends of the outer prongs 0.25, length of the longest cusp 0.17; and
greatest circumference 11.5 inches.
Rows of teeth, 13.9. 42.
Rays on first branchial arch (hyomandibular and ceratohyal) 22, on second 15,
third 14, fourth 12, fifth 9, sixth 6, and seventh none.
Has. — Japan.
THE length of the specimen described is not far from fifteen times its
diameter, or a little more than five times its greatest circumference.
An elongate body, a long subtriangular and flattened head, an ante-
rior mouth, a most extensive gape, jaws bristling with sharp subconi-
cal hooked teeth, and a sinister look about the eyes, give it a remote
resemblance to certain ophidia; and the narrow isthmus between the
gills crossed by the free mantle or flap of the first gill-cover is strongly
suggestive of certain fishes. The resemblances to snakes and fishes are
only remote; the shagreen, the fins, the teeth, the gill-openings, the
cartilaginous skeleton, etc., show the animal at once to be a Selachian,
one of the Sharks.
The single small dorsal, and the large ventrals, anal, and caudal, have
the appearance of being bunched together; they are placed so far back
as to leave a space of almost two feet of the length entirely unrelieved
by fins, which contributes considerably toward an eel-like appearance.
The skull is short, and, jaws and suspensorium (hyomandibular) being
very long and loosely articulated, the hinder portion of the head spreads
easily till its width equals its length, and the outline from above resem-
bles an equilateral triangle, or, better, an arrow-head with barbs.
VOL. x11 — No. 1. 1
2 BULLETIN OF THE
The gape is wide. The structure of the mouth and throat is such as
to permit the creature to swallow with ease others whose bodies have
diameters as great as its own, or even greater. Both mouth and throat
are lined with shagreen. On the inner edges of the gill arches the scales
are larger. At the angles of the jaws there are neither labial folds nor
labial cartilages. i
The eye is moderately large ; it is on the side of the head, over the
middle of the length of the mouth, and, from the sharp rather prominent
brow, has a savage look. The pupil is horizontally oblong. Around the
pupil the skin covering the eyeball is rough with small scales. There 1s
no trace of a nictitating membrane.
The slightness of the convexity of the top of the head makes the angle
formed with the sides, in front of the eyes and around the snout, some-
what sharp. The snout extends but little in advance of the mouth.
The nostrils are lateral; they are placed about half-way from the
eyes to the end of the snout. Each nostril is vertically elongate, and so
constructed that the upper half opens forward and the lower half back-
ward. Internally the nasal chamber is not divided. During forward
motion the water enters through the upper section of the nostril, passes
downward behind the partition and out again through the lower section.
Backward motion reverses the current. The partition divides the open-
ing, but not the chamber; it is formed by a sharp fold pushing back-
ward from the middle of the front wall to meet a similar fold from the
opposite side. In the Notidanide the structure is similar. Commonly
among Selachians the anterior fold takes the form of a flap partially coy-
ering the nostril.
The gill-openings are large; the first, when extended, will admit an
object of four inches or more, and the last will take one of two inches in
width. A vertical from the upper angle of the fifth touches the front
edge of the pectoral, and a third part of the sixth opening passes back
above the same fin. The arches are quite slender. ‘The blade-like folds
of the membrane are free for a considerable extent of their length at the
outer end. Plate V. gives the appearance in the fourth opening on the
right side. Sharp points on the edges of the gill-covers indicate the
ends of the branchial rays. The opercular flap, or first gill-cover, is
broad and free around the neck, except for a short space behind the
occiput. A thin inner fold descending from a point in front of and be-
neath the first branchial cartilage connects the flap with the isthmus.
As is to be expected in connection with large branchial apertures, the
spiracles are very small.
Sa
Ne
MUSEUM OF COMPARATIVE ZOOLOGY. 3
An open canal, the lateral line, extends on each side from the back of
the skull to the end of the tail. Other open canals, branches of the
same system, are seen beneath and on the side of the head (Plates I. and
IV.). On the skull the canals are covered and appear as lines of pores
_ (Plate III.). In addition to the main lines indicated by the artist, a
transverse branch extends to the post-orbital process, where it makes a
short backward turn, then descends on the side of the face to join a line
parallel with the mouth and extending forward from the angles of the
jaws. Behind the post-orbital process, between it and the spiracle, there
gze short lines and groups of small pores. The line above the mouth con-
tinues to the tip of the snout ; in front of the eye a branch passes above
the nostril, and, a short distance in front of the latter, appears on the
upper surface and turns backward as the main branch. Smaller pores
are numerous over various parts of the head.
From the bases of the pectorals to those of the ventrals is about
twenty-two inches. ‘This section of the body is slightly compressed ; its
depth in life was probably in the neighborhood of four, and its width
somewhat near three inches.
ao BULLETIN OF THE
acters by the adult of the recent form that belong to the embryonic of
the lowest of the other recent sharks.
Whether Chlamydoselachus gives a fair idea of the shapes of the De-
vonian Galei is a question we may not be able to answer satisfactorily
at present. The genus bears evidence of having been considerably modi-
fied in more recent times. But, being of lower rank through possession
of characters comparatively more or less embryonic, it affords us a safer
starting-point for an estimate of ancestry than do the others, which have
in attaining higher rank experienced considerably more modification.
Starting from the specimen, then, its less remote ancestors differed
from it somewhat as follows: their teeth were less slender and more stri-
ate, more like the scales at the angle of the mouth ; the teeth not being
so much hooked, their jaws and the suspensorium were shorter ; their
branchial laminz were more free at the outer ends, — may have pro-
truded ; their scales in general were more like those of the flank or belly ;
and in them the dorsal resembled the anal in size and shape, or at an
earlier period both may have been confluent with the caudal.
If we were to hazard a conjecture as to Cladodus, we should make the
body elongate; the mouth anterior; the jaws and suspensorium but
moderately long; the scales flattened and irregular in shape, but, judg-
ing from the teeth, to some extent possessing keels or spines ; the oper-
cular flap broad and free across the isthmus, as in certain larval Batrachia
before coalescence with the pectoral region ; the branchial apertures six
or more in number ; the eye without a nictitating membrane ; the noto-
chord persistent and unconstricted ; the vertebrae imperfect or the col-
umn unsegmented ; the bulbus elongate and many-valved ; the pelvis a
broad elongate plate ; the lateral line an open groove; the dorsal large ;
and, possibly, the tail diphycercal, the abdomen with tropeic folds.
As we see them by the aid of Chlamydoselachus, it appears that the
Cladodonti of the Middle Devonian, though low in rank, were true
Sharks, and that the primitive form connecting them with the Fishes is
to be sought farther back, in the earlier Devonian or in the Silurian.
CAMBRIDGE, July 4, 1885.
MUSEUM OF COMPARATIVE ZOOLOGY. 39
DESCRIPTION OF THE PLATES.
PLATE I.
Entire figure, #4; natural size; side of head, about 3 nat.; ventral fins from
beneath.
PLATE I.
Front view of head, with open mouth.
PLATE III.
Upper view of head.
PLATE IV.
Head as seen from beneath.
PLATE V.
The fourth gill-opening.
PLATE VI.
Teeth, six times nat. Figs. 1 and 5, upper view; Figs. 2 and 6, as seen from
behind; Fig. 3, from the side; Fig. 4, from beneath; and Figs. 7 and 8, from
the front.
Scales. Fig. 9, from middle of the flank; Fig, 10, from the side of the tail on
the lateral line ; Fig. 11, upper edge of tail; Fig. 12, at angle of mouth; Fig. 13,
from middle of belly. Fig. 9 seven times, and Figs. 10-13 five times nat.
PLATE VII.
A. Skull, hyomandibular, and pterygo-quadrate from above, natural size.
a, rostrum ; 4, fontanelle ; ¢, nostril; d, nasal sac; e, preorbital canal; 4 preor-
bital process ; g, postorbital process ; 4, supraorbital pores; %, epiotic or postpari-
etal pore; /, backward extension of articular facet for hyomandibular or pterotic
process ; m, vertebre; x, parietal fossa and aqueducts of the vestibule ; 0, rugose
space on frontal region; p, frontal slit; Am, hyomandibular; g-pg, quadrato-
pterygoid; g-p, quadratic process of pterygo-quadrate; v, rostral sinus; ¢, epiotic
process.
B. Skull in longitudinal section (reversed in drawing). g, aqueducts of the
vestibule ; so, supraoccipital crest ; fim, foramen magnum; zc, notochord; do,
basioccipital ; zc, internal carotid; py, pituitary excavation; w and r+, bridges.
Numbers 2-10, second to tenth pairs of nerves.
VOL. XII.— No. 1. 3
34 BULLETIN OF THE
PLATE VIII.
A. Side view of skull, quadrato-pterygoid, hyomandibular, and Meckel’s carti-
lage, mk, natural size ; lettering as in Plate VII.; dr-r, branchial rays; ¢-hy, cera-
tohyal; ¢p, trabecular process of pterygo-quadrate; y, ligament attaching trabecular
process to the skull; g-p, quadratic process of pterygo-quadrate ; «2, orbito-nasal
pores.
B. Side view of quadrato-pterygoid, hyomandibular, ete., at rest in position
against the skull. All natural size.
PLATE IX.
Branchial cartilages and meckelian, lower view, size of nature. mk, Meckel’s
cartilage; b-hy, basihyal; c-hy, ceratohyal; 47-r, branchial rays; 6-47, basibran-
chials ; 4-47, hypobranchials ; c-ér, ceratobranchials ; e-dr, epibranchials ; p-dr,
pharyngobranchials.
PLATE X.
Vertebre : 1, side view of section from middle of body ; 2, longitudinal, and 4,
transverse section of same; 3, longitudinal section from back of head (reversed),
all twice nat. size. 5, nerve aperture showing the calcareous lump at the side;
m, neurapophysis ; 7s, interspinous process ; zc, neural canal; ch, notochord.
PLATE XI.
1. Pelvis, upper view, 2; nat. pz, pubic; 7, iliac ridge; dp, basipterygium.
(Reversed.)
2. Pectoral cartilages. er, coraco-scapular; prp, propterygium ; msp, meso-
pterygium ; mfp, metapterygium.
PLATE XII.
Pelvis and ventral cartilages from beneath: c/, cloaca; ad-p, abdominal pores ;
wa, urethral aperture. Size 44 nat.
PLATE XIII.
Cartilages of dorsal and anal fins, $ nat.: aa, radials of dorsal; 4d, radials of
anal; cc, anterior radials of caudal.
PLATE XIV.
1. Tail with cartilages exposed, ;’; nat.
2. Tip of tail, ? nat.
MUSEUM OF COMPARATIVE ZOOLOGY. SD
PLATE XV.
Brain, upper view, $ nat., and transverse sections. 1, olfactory lobe;
3, oculo-motorius ; 4, trochlearis ; 5, trigeminus; 7 and 8, facialis and acusticus ;
10, vagus.
PLATE XVI.
Brain: A from beneath, B from the side, and C in longitudinal section. Num-
bers as in Plate XV.; 2, optic nerve; 6, abducens; 9, glosso-pharyngeus.
PLATE XVII.
Lower view of heart, $ nat. 1, auricle; 2, ventricle; 3, bulbus ; 4, sinus;
.5, dark tissue between cardiac and abdominal chambers.
PLATE XVIIL
B. Heart in longitudinal section, showing cavity in ventricle, 6, and valves in
bulbus, 7. 3 nat.
C. Parasite, Zetrarhynchus wardii, } nat. Figs. 8 and 10 from the sides,
and Fig. 9 from the front.
PLATE XIX.
1. Ovaries and oviducts, $ nat. 0, ovary; ov, oviduct; zg, nidamental gland.
2. Longitudinal section through cloaca and oviduct, nat. size; showing ov, ovi-
ducts; ct, intestine; wa, urethral aperture; c/, cloaca; ab-p, abdominal pore ;
p, cecal pouch. Reversed in transfer.
3. Section of intestine showing spiral valves.
PLATE XX.
A. Transverse section of abdomen showing the tropeic folds, 3 nat.
B. Same section, natural size.
C. Longitudinal section of nidamental gland, ? natural size.
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No. 2.— Reports on the Results of Dredging, wnder the Swpervision
of ALEXANDER AGASSIZ, in the Gulf of Mexico (1877-78), in the
Caribbean (1878-79), and along the Atlantic Coast of the United
States, during the Summer of 1880, by the U. S. Coast Survey
Steamer “ Blake,” LIEUTENANT-COMMANDER C. D. SIGSBEE, U.S.N.,
and COMMANDER J. R. Bartuert, U. 8. N., Commanding. °
(Published by permission of CARLILE P. PAtreRsSON and J. E. Hitcarp, Super-
intendents of the U. S. Coast and Geodetic Survey.)
XXVII.
Report on the Specimens of Bottom Deposits. By JoHN Murray.
BLAKE DEPOSITS.!
1. Specimens of deposits procured in the Gulf of Maine and along the
Coast of North America between the Gulf of Maine and Cape Hatteras
im 1880 (Stations 301-312, and 330-347) and in the Gulf of Maine in
1875.
These deposits consist of blue or gray colored muds and sands, the
latter being found only in depths less than 100 fathoms. They lie be-
tween the coast and the inner edge of the Gulf Stream. The greatest
depths are 1394 and 1186 fathoms, situated between 30 and 40 miles
outside the 100-fathom line. These deposits are chiefly made up of the
debris of the land of the North American continent, the mineral par-
ticles and clayey matter making up usually from 80 to 85 per cent of
the whole deposit.
1 Mr. Jonn Murray, to whom the specimens of bottom deposits collected by the
‘* Blake” were sent for examination, has looked over the whole and selected some
typical specimens. These have been described in detail, and he has added some gen-
eral notes on the specimens characteristic, 1. of the Coast between the Gulf of Maine
and Cape Hatteras ; 2. of the coast between Cape Hatteras and Lat. 31° 48’ N.: 3.
of the coasts around the greater and lesser Antilles ; and, finally, of the Gulf of
Mexico and Straits of Florida.
, ALEXANDER AGASSIZ.
MuseruM oF ComPARATIVE ZoOLocy,
CAMBRIDGE, July 10, 1885.
VOL. XII.— No. 2,
38 BULLETIN OF THE
The mineral particles consist of fragments of ancient rocks, quartz,
monoclinic and triclinic felspars, magnetite, hornblende, augite, mica,
tourmaline, and occasionally glauconitic grains.
In 1240 fathoms, and Lat. 38° 34! N. off this coast, the “ Challenger”
dredged many rounded and angular pebbles of milky and hyaline quartz,
fine-grained quartzites, felspathic quartzites, mica schists, serpentine
rocks, and compact limestones. These fragments were not larger than
6 or 7 centimetres in diameter. The “ Blake,” in 1241 fathoms and
Lat. 39° 43’ N., dredged similar, but much larger, fragments of the same
rocks, some of which were glaciated. In Lat. 41° 14’ N. and in a
depth of 1340 fathoms, the ‘‘ Challenger” again dredged similar rock
fragments, and one block of syenite weighing 5 cwt. These deposits
being all within the influence of the Labrador Current, these rocks may
be regarded as chiefly ice-borne.
The carbonate of lime in these deposits consists of coccoliths and
coccospheres, of pelagic and other Foraminifera, and of fragments of
Echinoderms, Polyzoa, Ostracodes, and Mollusks. The pelagic Forami-
nifera shells and coccospheres are more abundant in the deeper deposits
far from the land than in those from shallower water near the coast.
The siliceous remains of Diatoms, Radiolarians, and Sponges, together
with arenaceous Foraminifera, and glauconitic casts of calcareous Foram-
inifera make up sometimes 4 or 5 per cent of the deposit.
The following are descriptions of some of the typical deposits :?—
Station 305. — Lat. 41° 13’ 53” N. Long. 65° 57’ 25” W. Depth, 810 fath-
oms. Surf. temp. 563°. Bot. temp. 39°. Gray mud, brown when wet, earthy,
plastic, dries into hard lumps. Mixed with the mud were some few pinnule of
Crinoids, also a few rock fragments (sandstone, diorite, and diabase) measuring
from 10 to 30 millimetres in diameter.
Carbonate of Calcium, 5.08 per cent, consists of coocoliths and coccospheres,
fragments of Echinoderms, and the following foraminifera : —
1 The methods employed in the examination of these deposits are the same as those
adopted by Messrs. Murray and Renard for the Challenger deposits. The carbonate
of calcium was determined by estimating the carbonic acid, weak and cold hydro-
chloric acid being used for the purpose. The part insoluble in the acid is designated
‘‘residue,” which by washing, decantation, and microscopic inspection is separated
into three parts : (a) Minerals, the contraction m. di. indicating their mean diameter
in millimetres ; (6) Siliceous Organisms, including the glauconitic casts of forami-
nifera and other calcareous organisms ; (c) Fine Washings, including those particles
which, resting in suspension, pass with the first decantation. The numbers in
brackets indicate the percentage of the whole deposit.
(ee, De ee eh
MUSEUM OF COMPARATIVE ZOOLOGY. 39
Globigerina bulloides Haplophragmium canariensis
G. inflata Textularia sp. Be
G. dutertret Pelagic Bulimina marginata ieee
Pulvinulina menardit species. Uvigerina pygmea species,
P. micheliniana Truneatulina lobatula
P. canariensis Pulvinulina elegans
Residue, 94.92 per cent, dark brown, consists of Minerals [75.00], m. di.
0.5 mm., quartz, mica, felspar, hornblende. St/iceous organisms [5.00], Diatoms,
Radiolarians, and Sponge spicules. ine washings (14.92), argillaceous matter,
fine mineral particles, fragments of Diatoms and siliceous spicules.
Station 308. — Lat. 41° 34% 45” N. Long. 65° 35% 30% W. Depth, 1242
fathoms. Surf. temp. 65°. Bot. temp. 38°. A dark gray mud, plastic, pul-
verulent, granular, dries into hard lumps.
Carbonate of Calcium, 7.27 per cent, consists of Echinoderm fragments, many
coccoliths and coccospheres : the following Foraminifera were observed : —
Orbulina universa, rare. Uvigerina pygmea, few.
Globigerina bulloides, common. U. pygmed, var. angulosa, few.
G. inflata, common. Bulimina marginata, few.
@. conglobata, few. Lagena fimbriata, rare.
G. dubia, few. Discorbina sp., few.
Pulvinulina menardit, few. Rotalia repanda, few.
P. canariensis, few. Pleurostomella sp., rare.
Pullenia obliquiloculata, rare. Cristellaria cultrata, rare.
Residue, 92.73 per cent, dark brown, consists of Minerals [75.00], m. di.
0.3 mm., quartz, monoclinie and triclinic felspars, magnetite, mica, hornblende,
tourmaline, glauconite, and glassy fragments. Siliceous organisms [4.00], Sponge
spicules, Radiolarians, and Diatoms. Fixe washings [13.73], argillaceous matter,
and many angular, fine mineral particles.
Station 312.— Lat. 39° 50’ 45” N. Long. 70° 11’ W. Depth, 466 fathoms.
Surf. temp. 713°. Bot. temp. 40°. A gray mud.
_ Carbonate of Calcium, 3.46 per cent, consists of a few Echinoderm fragments,
coccoliths, and the following Foraminifera ; —
Reophax fusiformis, few. Cristellaria cultrata, rare.
R. scorpiurus, few. Uvigerina pygmea, rare.
Haplophragmium fontinense ? few. U. pygmea, var. angulosa, rare.
Ammodiscus incertus, few. Globigering inflata, common.
A. gordialis, rare. G. dutertrei, few.
Clavulina communis, few. Pulvinulina menardii, var. tumida, rare.
Cyclammina pusella, rare. Cassidulina crassa, rare.
Bulimina marginata, rare. Polystomella sp., rare.
40 BULLETIN OF THE
Residue, 96.54 per cent, gray, consists of Minerals (80.00), m. di. 0.4 mm.,
fragments of milky and hyaline quartz 1 to 2 mm. in diameter, felspar, horn-
blende, mica, glauconite, augite, fragments of ancient rocks, and fragments of
serpentine rocks much decomposed. Siliceous organisms [6.00], Sponge spicules,
a few Radiolarians and Diatoms. Size washings [10.54], green argillaceous mat-
ter with glauconitic particles, fine minerals, and fragments of Sponge spicules and
Diatoms.
Station 340. — Lat. 39° 25’ 30” N. Long. 70° 58’ 40” W. Depth, 1394
fathoms. Surf. temp..763°. Bot. temp. 38°. A gray mud, coherent, plastic,
dries into hard lumps.
Carbonate of Calcium, 16.81 per cent, consists of coccoliths and coccospheres,
otoliths of fish, fragments of Deztalium and Echinoderms, and the following
Foraminifera : —
Globigerina bulloides, few. Rotalia repanda, rare.
G. inflata, few. Truncatulina lobatula, few.
G. dubia, few. Uvigerina pygmea, few.
G. rubra, few. Bulimina marginata, rare.
Pulvinulina menardii (dwarfed), rare. Nonionina umbilicatula, rare.
P. micheliniana, rare. Biloculina ringens (dwarfed), rare.
P. elegans, rare.
Residue, 83.19 per cent, dark brown, consists of Mizerals [40.00], m. di.
0.3 mm., quartz, felspar, mica, hornblende, magnetite, olivine, glauconite, glassy
fragments. Siliceous organisms [5.00], Diatoms, Radiolarians, and Sponge spi-
cules. Fine washings [38.19], argillaceous matter, fine mineral particles, and
fragments of siliceous organisms,
2. Specimens of deposits procured off the Coast of the United States
between Cape Hatteras and Lat. 31° 48! N.
These deposits are green muds or sands.. They are with two. excep-
tions under 1,000 fathoms, and are mostly under the waters of the Gulf
Stream, or along: its inner margin. The mineral particles are much
the same as those in the deposits north of Cape Hatteras, but are all
very much smaller, and have evidently not been transported by ice.
The mineral particles, with the exception of the concretions formed at
the bottom, seldom exceed 0.4 mm. in diameter, and consist of quartz,
felspars, augite, hornblende, magnetite, and a few fragments of glassy
rocks. Glauconitic grains and casts are frequently very abundant, as
are also grains of manganese peroxide.
The carbonate of lime makes up usually over 50 per cent of the
whole deposit, and consists chiefly of the dead shells of pelagic Forami-
nifera, along with shells of pelagic Mollusks, fragments of Echinoderms,
MUSEUM OF COMPARATIVE ZOOLOGY. 41
Polyzoa and coccoliths. All the tropical species of pelagic Forami-
nifera are abundant in these deposits, while they are relatively rare in
the deposits along the coast to the north of Cape Hatteras.
The remains of siliceous organisms, such as Diatoms, Radiolarians,
- Sponge spicules, and glauconitic casts of Foraminifera and other organ-
isms, make up usually 10 or 12 per cent of the deposit.
The finer washings of these deposits are of a greenish color, which
seems to be chiefly due to the presence of some organic substance, the
nature of which has not yet been determined. A similar greenish mat-
ter was met with by the “Challenger” in deposits from the same depths
off the coasts of Africa, Australia, Japan, and China.
Phosphate of lime and manganese concretions are present in all the
deposits, and one remarkable concretion of these substances is described
in detail from Station 317, in a depth of 333 fathoms, immediately
under the waters of the Gulf Stream.
Many of these deposits might equally well be called Globigerina oozes.
Station 314. — Lat. 32° 24’ N. Long. 78° 44’ W. Depth, 142 fathoms.
Surf. temp. 81°. Bot. temp. 563°. A greenish gray sand, granular, very slightly
coherent.
Carbonate of Calcium, 47.64 per cent, consists of shells of Gasteropods, Lamel-
libranchs, Pteropods, and Ostracodes, fragments of Echinoderms, coccoliths, and
the following pelagic and other Foraminifera : —
Biloculina ringens, few.
Planispirina celata, few.
Globigerina bulloides, common. Miliolina agglutinans, rare.
G. dubia, common. M. seminulum, rare.
G. inflata, common. M, venusta, common.
G. rubra, common. . Verneuilina triquetra ? rave.
G. conglobata, few. Textularia conica, few.
G, sacculifera, few. Bulimina marginata, few.
G. (Orbulina) universa, few. \ Pelagic Nodosaria communis, rare. Bottom-
Spheroidina dehiscens, few. species. Cristellaria cultrata, common. living
Pulvinulina menardii, common. C. rotulata, rare. species.
P. menardii, var. tumida, com- C. obtusata, rare.
mon. C. calcar, rare.
P. micheliniana, few. C. sp. few.
Pullenia obliquiloculata, com- Uvigerina pygmea, few.
mon. Truncatulina lobatula, few.
Pulvinulina elegans, rare.
Rotalia sp.
Nonionina umbilicatula, rare.
42 BULLETIN OF THE
Residue, 52.36 per cent, a green.sand, consists of Minerals [40.00], m. di.
0.3 mm., many glauconitic grains, quartz, mica, felspars, hornbleude, magne-
tite, augite, phosphatic grains. Svliceous organisms [8.00], Sponge spicules, Dia-
toms, Radiolarians, and many fine glauconitic casts of Foraminifera. Fine
washings [436], traces of argillaceous matter, fine mineral particles, fragments
of Diatoms, and much green amorphous matter.
Station 317.— Lat. 31°57! N. Long. 78° 18! 35” W. Depth, 333
fathoms. From this place, where the ground was said to be hard, there
was procured a very remarkable concretion that appears to have been
formed in the position from which it was dredged.
This was irregular in form, the greatest diameter being about nine
inches, and of a mottled black, red, and brown color. The surface was
somewhat irregular, and presented many ovoid, smooth projections, the
largest of which were about one centimetre in diameter. The whole
mass was overgrown with sponges, corals, and annelids. Imbedded in
the concretion were two sharks’ teeth, resembling ZLamna, the largest
being 2} inches in length and one inch across the base. This tooth is
similar to many found by the “Challenger” in great numbers in the
greater depths of the Central Pacific, frequently forming the centres of
manganese nodules. In the specimens from the deep water of the
Pacific the interior of the tooth had been in every instance completely
removed, only the hard outer dentine remaining. In the tooth imbedded
in this concretion, on the contrary, the vaso-dentine of the interior of
the tooth is well preserved, in this respect resembling the sharks’ teeth
of the same kind found in various tertiary deposits, as for instance in
South Carolina and in the Island of Malta. The vessels of the tooth are
infiltrated with peroxide of iron and manganese and phosphate of lime.
The whole mass has a breccia-like appearance, the several fragments
being cemented by deposits of carbonate of lime and manganese per-
oxide. When thin sections are prepared and examined with the micro-
scope, the preparation has a variegated appearance ; all the grains being
closely cemented together. There are numerous sections of pelagic and
other calcareous Foraminifera, of Pteropods, and fragments of Echino-
derms. The interior of the Foraminifera is sometimes completely filled
with calcite, and the same crystals are found cementing many of the
fragments of which the rock is composed. Small fragments of quartz, of
felspars, and of zoiene are also seen in the sections. But the most char-
acteristic element is formed by small rounded grains of a brownish or
yellow-green color, having much the aspect of glauconite, which is also
present. Chemical reactions show that these grains are phosphatic.
MUSEUM OF COMPARATIVE ZOOLOGY. 43
They are similar to the grains found in phosphatic nodules dredged off
the Cape of Good Hope and elsewhere by the “Challenger,” and iden-
tical in their physical and chemical properties to the phosphatic grains
in cretaceous rocks.
The manganese is infiltrated through the whole mass of the concretion,
appearing in the microscopic sections in the form of dendrites or concre-
tions, sometimes opaque, sometimes black-brown, and slightly transparent.
The phosphatic grains are sometimes enclosed in the manganese.
The “Challenger” dredged on several occasions, especially off the
Cape of Good Hope, concretionary masses like that above described, but
very much smaller. Phosphatic nodules were always found in the
deposits in depths less than 1,500 fathoms, near continental shores, but
never in the deeper deposits far removed from land.
An analysis of a portion of the above concretion by M. Klement,
Brussels, gave as follows : —
Phosphoric acid (P,O,) . . . . . . 23.53
Carbonies atiwnQ@Os). esheets
Sal plriiestay (SOs), Mo st (22D
Fluorine pte Reeeeg (Pet) me. A ioe case
Chineine Jils ewes a ate ke es OG
inten eae (hea aee 2 NF bee Sa |nces BBB
NERANCSIN (MEO aera. eee a fe ee! LOT
Tnpbliple-ftesidua: sso.) u, km ye oe § OFD2
PUDSRSON MOMALION Apes 4 sine ape eat et kD
100.65
Oxygen corresponding to Fluorine — 0.96
“corresponding to Chlorine — 0.04
99.65
Atomic Ratios.
ee a See Ee ee oe eee eee ee
1 ARTE RE Oe 2 ama aay Ty ga 07 |
SLE Re eae nn a ee 57 $ 1866
RM ark teas Ys 5s, owe Ree! ea
AN Wacute rs aek i
eM ins forth. live 5 ve, Labia’, Dna:
Mg te 50 } 1914
The substance analyzed also contained traces of silica, of iron, of
alumina, and of manganese.
44 BULLETIN OF THE
Station 323. — Lat. 33° 19' N. Long. 76° 12’ 30” W. Depth, 457 fath-
oms. Surf. temp. 83°. Bot. temp. 40°. Green mud, slightly coherent, granular.
Carbonate of Calcium, 59.43 per cent, chiefly made up of pelagic and other
Foraminifera, as in the following list, shells of Pteropods, Gasteropods, and Os-
tracodes, Echinoderm fragments, and coccoliths,
G. (Orbulina) universa, common. *|
Globigerina bulloides, common.
G. conglobata, few.
G. bulloides var. triloba, common.
G. equilateralis, few.
G. sacculifera, few.
G. dubia, common.
G. rubra, common.
Candeina nitida, common.
Spheroidina dehiscens, few.
Pullenia obliquiloculata, common.
Pulvinulina menardii, abundant. |
P. menardii, var. tumida, common.
P. menardii, var. fimbriata, com-
mon.
Biloculina ringens, rare.
Miliolina seminulum, few.
Bulimina marginata, rare.
Polymorphina sp., rare.
Uvigerina pygmea, vare.
Spheroidina bulloides, common.
Pullenia spheroides, few.
Truncatulina lobatula, few.
T. sp., rare.
Nonionina umbilicatula, few.
Nodosaria communis, rare.
N. levigata, rare. J
Ba
‘soloads O1svpod
ssoloads SUTATT-W0q}0¢T
P. micheliniana, few. |
P. canariensis, few. J
Residue, 40.57 per cent, greenish brown, consists of Minerals, [20.00], m. di.
0.1 mm. quartz, hornblende, felspars, glauconite, and glassy fragments. Sili-
ceous organisms [5.00], Diatoms, Radiolarians, and Sponge spicules, and casts
of many of the organisms mentioned above. Fine washings {15.57], argillaceous
and green amorphous matter, fragments of Diatoms, siliceous spicules, and fine
mineral particles.
3. Specimens of deposits procured around the Shores of the Greater and
Lesser Antilles,
The specimens are chiefly from depths between 100 and 1,000 fathoms,
although a few are in depths less than 100 fathoms and a few are over
2,000 fathoms. They are all in more or less close proximity to the
coasts. The mineral particles are chiefly fragments of volcanic rocks or
crystals derived from these, such as monoclinic and triclinic felspars,
hornblende, augite, olivine, magnetic iron, and pumice ; along with a few
fragments from ancient rocks, as quartz, tourmaline, mica, and epidote.
Glauconitic grains were rare in these deposits, and phosphatic grains
were likewise rare. In the deposits farthest from land the size of the
MUSEUM OF COMPARATIVE ZOOLOGY. 45
mineral particles seldom exceeded 0.1 mm. in diameter, but near shore
they were very much larger, and fragments of rocks and pebbles were
frequently dredged. Altered fragments of plagioclase, basalts, and dia-
base were rather frequent.
The percentage of carbonate of lime in these deposits was usually
very high, being frequently 70 or 80 per cent, and in the case of a chalk
rock 90.24 per cent. Where the shores were composed of volcanic or
other rocks not calcareous, the débris of these made up the larger part
of the deposits, which might be called voleanic muds. But the majority
of the deposits should be termed Pteropod or Globigerina oozes, owing
to the large number of these organisms present in them. It should be
remembered, however, that both in the size of the mineral particles and
in the nature of a large number of the calcareous particles, these de-
posits differ considerably from similar deposits found far away from land
in the open ocean and called also Pteropod and Globigerina oozes.
The siliceous organisms never make up more than four or five per
cent of the whole deposit, and consist of Radiolaria, Sponge spicules, and
a few Diatoms.
Fragment of White Chalk. — From 994 fathoms, off Nuevitas, Cuba,
there was obtained a fragment of white chalk coated on the surface with
streaks of peroxide of manganese. This chalk contained 90.24 per cent
of carbonate of lime. The sections showed the rock to be composed of
erystalline grains of carbonate of lime, which however were not the
result of precipitation. A few sections of Globigerina and Textularia
were observed, but no other organisms could be recognized. After dis-
solving away a considerable quantity, small fragments of quartz and
hornblende, Sponge spicules and Radiolarians were observed in the resi-
due. It is impossible to be certain that this rock was formed in the
position from which it was dredged, though there are reasons for sup-
posing that it was. The ooze which came up from the same place was
of a reddish or brownish tinge, and contained an immense number of
Pteropods, Heteropods, and pelagic Foraminifera; the percentage of
lime was not so high as in the white chalk rock, and the residue was
much darker in color.
Concretions. — Off the Barbadoes in 221 fathoms (St. 280) a very
hard calcareous concretion was obtained, which showed perfectly how
the rock was formed by crystallization of carbonate of lime around the
shells of Foraminifera and other centres. A zone is seen around the
shells, composed of fibro-radiate calcite; the crystals of calcite, coming
from the various centres, abut against each other, and frequently leave
46 BULLETIN OF THE
an empty space between. When these spaces are filled by a further
deposition of lime, the whole becomes very compact and massive.
The centres of the Foraminifera are frequently filled with a gray or
yellowish substance which does not, however, give the reactions of
phosphate of lime.
The mineral particles were very few in number, among them frag-
ments of quartz and plagioclase being observed. This concretion was
about two inches in diameter and had a rough areolar surface on which
Serpulz and Polyzoa were growing.
A similar and somewhat larger concretion from 200 fathoms (St.
291) was also obtained off the Barbadoes, which was much more over-
grown with organisms, and on its upper surface had a large cavity in
which a hermit-crab had lived. (Polycheles Agassizii, see Bulletin VIII.
No. 1.)
Off the north coast of San Domingo, in 772 fathoms (No. VI.), there
were obtained several small manganese Nodules and a few fragments of
a Corallium coated with manganese, precisely similar to that dredged by
the “Challenger” in 1,525 fathoms near the Cape Verdes (see Narrative
of the Voyage, page 125). The interior of the nodules were of a light
brownish color and were composed in all cases chiefly of a mass of pelagic
Foraminifera. The largest of these nodules had a diameter of about
two inches. Microscopic sections of the nodules and concretions were
easily made and showed with great distinctness the structure of the
mass, composed chiefly of pelagic Foraminifera cemented together as
above stated.
Station 103.— Old Bahama Channel. Depth, 438 fathoms. Surf. temp. 79°.
Bot. temp. 493°. A Pteropod ooze or white coral mud, slightly coherent when
dry, chalky.
Carbonate of Calcium, 87.06 per cent, consists of Gasteropod, Lamellibranch,
Ostracode, Pteropod and Heteropod shells, caleareous Alge, Echinoderm frag-
ments, Polyzoa, Aleyonium spicules, coccoliths and rhabdoliths, and the following
Foraminifera : —
Globigerina dubia Cymbalopora bulloides
G. rubra | Miliolina seminulum
G. hirsuta WM. linneana
G. equilateralis M. bicornis
G. (Orbulina) universa } Pelagic M. agglutinans
Pulvinulina menardii spe Biloculina cornuta
Pulvinulina sp.
Cassidulina crassa
Textularia turris
P. micheliniana
P. menardii, var. tumida
Pullenia obliquiloculata |
ee = lr
MUSEUM OF COMPARATIVE ZOOLOGY. AT
Discorbina sp. Cristellaria cultrata
Truncatulina sp. Vertebralina striata
Polytrema rubra Articulina conico-articulata
Carpenteria sp- Bulimina marginata
Orbiculina adunca Nodosaria costulata
Orbitolites marginalis
Residue, 12.94 per cent, light brown, consists of Minerals [3.00], m. di.
0.1 mm., quartz, hornblende, magnetite, mica, olivine, and a few glassy frag-
ments. Siliceous organisms [3.00], Sponge spicules, Diatoms, and a few casts.
Fine washings (6.94), argillaceous matter, fine mineral particles, and fragments
of siliceous organisms.
Station 112.-- W. of Navassa Bank, 19 Dec., 1878. Depth, 1050 fathoms.
Surf. temp. 82°. Bot. temp. 393°. A light brown Globigerina ooze, slightly
coherent, pulverulent, granular ; dries into lumps, which break easily between the
fingers.
Carbonate of Calcium, 62.38 per cent, consists of Lamellibranch, Pteropod, and
Heteropod shells, coccoliths and rhabdoliths, and the following Foraminifera: —
Globigerina bulloides P. menardii, var. fimbriata
G. rubra P. micheliniana
G. equilateralis P. canariensis
G. dubia Pullenia obliquiloculata
G. hirsuta Biloculina depressa
G. sacculifera B. sphera
G. (Orbulina) universa Cassidulina sp.
Spheroidina dehiscens Webbina clavata
Candeina nitida Truncatulina lobatula
Pulcinulina menardit Uvigerina sp.
P. menardii, var. tumida
Residue, 37.62 per cent, red, consists of Minerals [15.00], m. di. 0.07 mm.,
(angular) felspars, quartz, hornblende, mica, magnetite, many glassy fragments.
Siliceous organisms {4.00 |, Sponge spicules, Radiolarians, and a few casts. Fine
washings {18.62}, argillaceous matter, fine mineral particles, and fragments of
siliceous organisms.
Station 117.— Lat. 17° 47’ 20” N. Long. 67° 3’ 20” W. Off Porto Rico.
Depth, 874 fathoms. Surf. temp. 823°. Bot. temp. 40°. A coral mud or Ptero-
pod ooze, slight coherent, granular. Also, a small quantity of larger material,
which appears to have been washed from the dredge, consisting of Gasteropod,
Lamellibranch, Ostracode, Pteropod, and Heteropod shells, Echinoderm frag-
ments, Coral, Polyzoa, and Serpula tubes.
Carbonate of Calcium, 70.66 per cent, consists of Pteropods, Heteropods, frag-
48
BULLETIN OF THE
ments of Echinoderms and Gasteropod and Lamellibranch shells, calcareous Alew,
coccoliths, and the following Foraminifera : —
Globigerina rubra
G. dubia
G. hirsuta
G. sacculifera
G. equilateralis
G. conglobata
G. (Orbulina) universa
Spheroidina dehiscens
Pullenia obliquiloculata
Pulvinulina menardii
Pelagic
species.
Spheroidina bulloides
Truncatulina lobatula
T. sp-
Rupertia sp.
Rotala sp.
Cristellaria cultrata
Lagena squamata
Textularia biculeata
Clavulina cylindrica
P. menardii, var. tumida Guudryina rugosa
P. menardii, var. fimbriata Biloculina depressa
P. micheliniana B. ringens
P. canariensis B. sphera
P. sp.
Residue, 29.34 per cent, dirty brown, consists of Mixera/s [10.00], m. di.
0.05 mm., (angular) quartz. hornblende, mica, felspar, olivine, scorie, small
fragments of rocks. Stliceous organisms [7.00], Sponge spicules and Radiola-
rians. Fine washings [12.34], argillaceous matter, fine mineral particles, and
fragments of siliceous organisms.
Station 138. — Off Santa Cruz, January 7, 1879. Depth, 2,375 fathoms. Surf.
temp. 763°. Bot. temp. 388}°. A light brown Globigerina ooze, slightly coherent,
pulverulent.
Carbonate of Calcium, 63.54 per cent, consists of Gasteropod and Lamelli-
branch shells (larval forms), Ostracode, Pteropod, and Heteropod shells, Aley-
onium spicules, Echinoderm fragments, coccoliths and rhabdoliths, and the
following Foraminifera : —
Pulvinulina menardii
Pulvinulina micheliniana
P. canariensis
Planorbulina sp.
Miliolina bicornis
M. circularis
Globigerina rubra
G. dubia
G. conglobata
G. sacculifera
G. bulloides, var. triioba
G. (Orbulina) universa
Residue, 36.46 per cent, red, consists of Minerals [20.00], m. di. 0.2 mm.,
several fragments of mica schist 3 to 5 mm. in diameter, felspars, quartz, mica,
hornblende, magnetite. Siliceous organisms [5.00], Sponge spicules. Sine
washings [11.46], amorphous clayey matter, fine mineral particles, and frag-
ments of siliceous spicules.
MUSEUM OF COMPARATIVE ZOOLOGY. 49
Station 182. — Off Dominica. Depth, 1,131 fathoms. Surf. temp. 81°. Bot.
temp. 393°. shee Nsn in sels Sal
99.70
Oxygen corresponding to Fluorine . .—0.51
99.19
There were also traces of Silica and Chlorine.
Atomic Ratios.
iG Matinee 1 ih ee AM atta 5
COs as aA vat Bite aed
1814.
Sh aa: deter er eatin | Genk ire At GO
Fl RR aaa emo 64
CaO) oe: cee Fa Mee ee B= Wh 1853
\isss
EONS a, ek egeire se. Le! aie! vege OD
At the same place and depth there was a concretion of a brown color
consisting of an aggregation of calcareous organisms cemented by a
brownish yellow matter, often showing concentric rings after the man-
ner of agate. This yellowish brown matter is isotropic, between crossed
nicols only the calcite and the shells of the Foraminifera brighten up ;
the calcite lies crystallized in the interior of the Foraminifera. In
treating the brown or yellow parts under the microscope with molyb-
date of ammonium and nitric acid, there is an abundant yellow precipi-
tate characteristic of phosphoric acid.
At other stations small phosphatic concretions were also obtained by
the “ Blake,” all more or less resembling those described above. There
are difficulties in understanding how phosphate of lime and carbonate of
lime are deposited at the bottom of the sea, yet there is no doubt that
such a deposition does take place under some special circumstances.
Their solution is, however, an almost universal phenomenon in the
ocean.
Specimen 60, Line P’. — Lat. 24° 50’ N. Long. 84° 50’ 45” W. 15 May,
1875. Depth, 2008 fathoms. A reddish brown Globigerina ooze dries into
slightly coherent lumps.
~
54 BULLETIN OF THE
Carbonate of Calcium, 47.87 per cent, consists of coccoliths, rhabdoliths, and
the following Foraminifera : —
Globigerina conglobata Candeina nitida
G. bulloides Pullenia obliquiloculata
G. bulloides, vay. triloba Pulvinulina menardit
G. sacculifera P. menardii, var. tumida
G. equilateralis P. canariensis
G. rubra P. elegans
G. dubia Truncatulina lobatula
G. (Orbulina) universa Nonionina umbilicatula
Residue, 52.13 per eent, reddish brown, consists of Minerals [20.00], m. di.
0.05 mm., quartz, mica, felspar, hornblende, magnetite, palagonite, glauconite.
Siliceous organisms [5.00|, Sponge spicules, glauconitie or other casts. Fine
washings { 27.13], amorphous clayey matter, with fine mineral particles aud frag-
ments of siliceous spicules.
Specimen 4, Line P.— Lat. 26° 40’ N. Long. 96° 01’ W. 29 January, 1877.
Depth, 489 fathoms. A brown mud, coherent, plastic. This deposit resembles
very much a fine river clay, mixed with a very few pelagic Foraminifera; it would
seem, judging from its position, to be derived from the fine detrital matter carried
down by the rivers.
Carbonate of Calcium, 2.76 per cent, consists of one or two coccoliths along
with the following Foraminifera : —
Biloculina ringens }
Globigerina bulloides Ammodiscus charoides
G. dubia Bolivina enariensis |
G. rubra Bulimina rostrata
G conglobata Pelagic B. oculata Bottom-
Pullenia obliquiloculata | species. Nodosaria raphanus living
Pulvinulina menardii Uvigerina asperula species.
P. menardii, var. tumida U. asperula, var. auberiana
P. micheliniana Spheroidina bulloides
Truncatulina lobatula
Pulvinulina elegans J
Residue, 97.24 per cent, of a light slaty-brown color, consists of Minerals
[25.00], m. di. 0.01 mm., quartz, magnetite, mica, felspars, augite, hornblende,
and several small red particles. Siliceous organisms [1.00], siliceous spicules and
fragments of Radiolarians. Fine washings [71.24], amorphous clayey matter.
Specimen 21, Line FE E.— Lat. 20° 59’ N. Long. 96° 39’ W. 25 May, 1877.
Depth, 511 fathoms. Volcanic mud, very coherent, clayey.
Carbonate of Calcium, 15.14 per cent, consists of Echinoderm fragments, fish
teeth, and Foraminifera as follows : —
MUSEUM OF COMPARATIVE ZOOLOGY. 55
Glebigerina rubra ) Planispirina celata ih
G. dubia Bolivina enariensis
G. inflata | Nonionina umbilicatula |
G. conglobata Lagena squanosa Bott
G. bulloides Pelagic Ammodiscus charoides ee
G. bulloides, var. triloba {| species. Uvigerina asperula pes
G. (Orbulina) universa Cassidulina crassa appar e
Pullenia obliquiloculata | Bulimina marginata
Pulvinulina menardi Truncatulina lobatula
P. micheliniana J Pulvinulina elegans
Residue, 84.86 per cent, chocolate color, consists of Minerals (50.00), m. di.
0.1 mm., quartz, pumice fragments, magnetite, hornblende, tourmaline, glauconite,
mica, many glassy fragments. Séliceous organisms [300], Radiolarians and
Sponge spicules. Fixe washings [31.86], argillaceous matter, fine mineral par-
ticles, and a few fragments of siliceous spicules.
Specimen 28, Line D D. — Lat. 22° 06’ N. Long. 92° 18’ W. 22 May, 1877.
Depth, 353 fathoms. A light greenish gray fine calcareous mud, coherent.
Carbonate of Calcium, 67.81 per cent, consists of Echinoderm fragments,
Pteropod, Ostracode, Gasteropod, and Lamellibranch shells, and the following
Foraminifera : —
Globigerina rubra Bulimina marginata
G. dubia B. aculeata
G. conglobata Bolivina nobilis
G. inflata B. aenariensis
Truncatulina lobatula
Uvigerina pygmea
Nodosaria hispida
Textularia conica
7’. sp.
G. bulloides, var. triloba
Pullenia obliquiloculata
Pulvinulina menardit
P.. canariensis
Miliolina seminulum
MM. sp.
Residue, 32.19 per cent, consists of Minerals [3.00], m. di. 0.05 mm., quartz,
felspar, hornblende, magnetite, glauconite, glassy fragments, and a few red
particles. Stliceous organisms {10.00}, Geodia and other Sponge spicules,
Diatoms and Radiolarians. Fixe washings [19.19], argillaceous matter, fine
mineral particles, and fragments of siliceous organisms.
Specimen 51, Line P’.—Wat. 25° 08’ 15” N. Long. 87° 12’ 50” W. 14 May,
1875. Depth, 2119 fathoms. A brown Globigerina ooze, slightly coherent.
Carbonate of Calcium, 41.86 per cent, consists of a few coccoliths and rhab-
doliths, Ostracode valves, Echinoderm fragments, and the ivllowing Forami-
nifera ; —
56 BULLETIN OF THE
Globigerina inflata
G. rubra
G. dubia
G. equilateralis
G. sacculifera
G. conglobata
G. bulloides, var. triloba
G. (Orbulina) universa
Candeina nitida
Pullenia obliquiloculata
Spheroidina dehiscens
Pulvinulina menardit
P. menardii, var. tumida
P. menardii, var. fimbriata
P. micheliniana
P. canariensis
Truncatulina lobatula
Pulvinulina elegans
Biloculina depressa
Haplophragmium globigeriniformis
Hyperammina vagans
Ammodiscus charoides
Nonionina umbilicatula
NV. pompitioides
Uvigerina asperula
Clavulina communis
Reophax (fragments).
Residue, 58.14 per cent, light brown, consists of Minerals [80.00], m. di.
0.1 mm. (mostly rounded), quartz, felspar, mica, hornblende, glauconite, magne-
tite, tourmaline. Stliceous organisms [3.00], Sponge spicules and Radiolarians.
Fine washings (25.14), argillaceous matter, fine mineral particles, and fragments
of siliceous organisms.
Specimen 15, Line F'. — Lat. 27° 55’ N. ‘Long. 89° 53’ W. 17 March, 1875.
Depth, 407 fathoms. A gray mud, clayey, coherent, plastic.
Carbonate of Calcium, 10.27 per cent, consists of otoliths of fish, Pteropod .
fragments, and the following Foraminifera : —
Globigerina rubra 7
G. dubia
G. bulloides
G. equilateralis
G. sacculifera , Pelagic
G. (Orbulina) universa (i speties:
Pulvinulina menardii
P. menardii, var. tumida
P. micheliniana
Pullenia obliquiloculata J
Biloculina ringens
Planispirina celata
Pullenia spheroides
Spheroidina bulloides
Pulvinulina pauperata
P. elegans
Haplophragmium globigeriniformis
Chilostomella ovowdea
Bolivina enariensis
Bulimina marginata
Sagrina columnella
Virgulina subsquamosa
Truncatulina lobatula
Uvigerina pygmaa
U. asperula
Lagena orbignyana
L. sp.
Residue, 89.73 per cent, light brown, consists of Ménerals [10.00], m. di.
0.05 mm., quartz, augite, magnetite, felspars, hornblende, and a few small red
particles. Siliceous organisms [3.00], casts of Foraminifera, Sponge spicules, and
Radiolarians. Fine washings [76.73], amorphous clayey matter, and fragments
of siliceous organisms.
MUSEUM OF COMPARATIVE ZOOLOGY. | 57
Specimen 40, Line P’.— Lat. 25° 31’ 45” N. Long. 90° 28’ W. 13 May,
1875. Depth, 1,922 fathoms. A dark brown Globigerina ooze, coherent, plastic.
Carbonate of Calcium, 36.54 per cent, consists of Echini spines, Ostracode
valves, coccoliths, and the following Foraminifera : —
Biloculina depressa Pullenia obliquiloculata
Miliolina sp. Bottom-living Spheroidina dehiscens
Truncatulina lobatula species. Candeina nitida
Nonionina pompilioides Pulvinulina menardii
Globigerina rubra P. menardii, var. tumida
G. dubia P. menardii, var. fimbriata
G. conglobata P. micheliniana
G. sacculifera P. canartensis
G. bulloides, var. triloba
Residue, 63.46 per cent, reddish, consists of Mizerals [30.00], m. di. 0.07 mm.,
quartz, mica, felspar, augite, plagioclase, glauconite, and red palagonite-like par-
ticles. Siliceous organisms [5.00|, Radiolarians, Sponge spicules, and brown
flexible casts of Foraminifera. Fine washings [28.46], amorphous clayey matter,
with fine minerals and fragments of siliceous spicules.
Specimen 30, Line C C.— Lat. 23° 23! N. Long. 94° 39’ W. May 17, 1877.
Depth, 2,057 fathoms. A reddish Globigerina ooze, coherent, clayey, with lus-
trous streak.
Carbonate of Calcium, 32.12 per cent, consists of a very few coccoliths. and
rhabdoliths, and the following Foraminifera : —
Globigerina dubia Pulvinulina menardii
G. rubra P. menardii, var. tumida
G. sacculifera P. micheliniana
G. conglobata P. canariensis
G. helicina Truncatulina lobatula 7
G. bulloides, var. triloba Nonionina umbilicatula
G. several irregularly growing forms. NV. pompilioides aa
g yg g for pompiliot sy
G. (Orbulina) universa Pulvcinulina elegans ee
Pullenia obliquiloculata Bolivina textilarioides \ “P&E:
Spheroidina dehiscens Miliolina cultrata
Residue, 67.88 per cent, red, consists of Minerals [15.00], m. di. 0.05 mm.,
quartz, felspars, magnetite, augite, hornblende, a few red particles, glassy frag-
ments, and fragments of scorie. Séliceous organisms [3.00], Sponge spicules,
and fragments of Radiolarians. ine washings [49.88], argillaceous matter, fine
mineral particles, and a few fragments of siliceous spicules.
Specimen 21, Line C C.— at. 23° 18’N. Long. 92° 03’ W. Depth 2,080
fathoms. A light brown Globigerina ooze, reddish when wet, coherent, clayey.
Carbonate of Calcium, 35.52 per cent, chiefly made up of pelagic Foraminifera,
58 BULLETIN OF THE
along with Ostracode shells, fragments of Hchinoderms, coccoliths, and rhabdo-
liths. The following is a list of the Foraminifera : —
Globigerina bulloides, few, small. Pulvinulina menardii, abundant.
G. bulloides, var. triloba, common. P. menardii, var. tumida, abundant.
G. dubia, common, large. P. menardii, vav. fimbriata, few.
G. equilateralis, few. P. micheliniana, abundant.
G. rubra, abundant. P. canariensis, few.
G. conglobata, common. Truncatulina lobatula, few.
G. sacculifera, common. Nonionina pompilioides, ew Bitca
G. (Orbulina) universa, abundant. Rotalia soldanit, rare. gee
Candeina nitida, few. Bolivina sp., rare. 8
Pullenia obliquiloculata, abundant. Biloculina ringens, rare. | coe
Spheroidina dehiscens, few. Miliolina sp., rare.
Residue, 64.48 per cent, reddish, consists of Minerals [3.00], m. di. 0.05 mm.,
felspars, quartz, magnetite, augite, hornblende, glassy fragments. Séliceous or-
ganisms [3.00], Sponge spicules, Diatoms, Radiolarians, casts of Foraminifera.
Fine washings | 58.48], amorphous clayey matter, fine mineral particles, and frag-
ments of siliceous organisms.
Station 4. —Off Morro Light. Depth, 936 fathoms. Surf. temp. 773°. Bot.
temp. 393°. A Pteropod ooze, of a grayish white color, chiefly composed of
Pteropods, with many pelagic Foraminifera, slightly coherent.
Carbonate of Calcium, 68.84 per cent, consists of otoliths of fish, Gasteropod,
Lamellibranch, Ostracode, Pteropod, and Heteropod shells, Echinoderm frag-
ments, coccoliths and rhabdoliths, and Foraminifera as foliows : —
Globigerina bulloides 7} Biloculina sphera
G. rubra | B. depressa
G. dulia Miliolina sp.
Planispirina celata
Hyperammina ramosa
G. equilateralis
G. sacculifera
Q ae pacer =
. conglobata eae cite! . vagans et ies
G. (Orbulina) universa - HT. subnodosa gia aa
Candeina nitida Ammodiscus incertus P :
Spheroidina dehiscens Gaudryina pupoides
Pullenia obliquiloculata G. rugosa
Pulvinulina menardii J Cassidulina crassa
Truncatulina lobatula
Spharoidina bulloides J
Residue, 31.16 per cent, grayish brown, consists of Minerals [10.00], m. di.
0.07 mm., quartz, hornblende, felspars, plagioclase, orthoclase, mica. Siliceous
organisms [15.00], Radiolarians, Diatoms, and Sponge spicules. Fixe washings
[6.16], argillaceous matter, fine minerals, fragments of siliceous organisms, and
greenish organic matter.
Norte. — Fragments of an areolar tufaceous rock were obtained in the dredging.
MUSEUM OF COMPARATIVE ZOOLOGY. 59
Station 27.— Lat. 24° 30’ N. Long. 83° 49’ W. Depth, 392 fathoms. Surf.
temp. 73°. Bot. temp. 443°. A grayish green coral mud, pulverulent and
granular.
Carbonate of Calcium, $2.06 per cent, consists of otoliths of fish, Gasteropod,
Lamellibranch, Ostracode, Pteropod, and Heteropod shells, Echinoderm frag-
meuts, coccoliths and rhabdoliths, and Foraminifera as follows : —
Globigerina rubra Textularia sp.
G. dubia Bulimina aculeata
G. conglobata Nodosaria hispida
G. bulloides Uvigerina asperula
G. (Orbulina) universa Cristellaria variabilis
Pullenia obliquiloculata Discorbina obtusa
Pulvinulina menardi D. allomorphinoides
P. micheliniana Truncatulina lobatula
Spheroidina bulloides T. ungeriana
Miliolina venusta T. rosea
M. seminulum Rotalia soldanit
Cassidulina crassa Polystomella crispa
Bolivina dilatata P. striatopunctata
Bigenerina sp. Nonionina umbilicatula.
All the Foraminifera iu this deposit appear very small (dwarfed).
Residue, 17.94 per cent, dark green, consists of Minerals [5.00], m. di. 0.1 mm.,
quartz, felspars, hornblende, magnetite, plagioclase, mica, many glassy fragments.
Siliceous organisms [10 00], Sponge spicules, Radiolarians, Diatoms, and a few
casts of Foraminifera. Fine washings (2.94), argillaceous and green flocculent
matter, fine mineral particles, and fragments of siliceous organisms.
Station 33. — Lat. 24° 1’ N. Long. 88°58’ W. Depth 1,568 fathoms. Surf.
temp. 724°. Bot. temp. 405°. A light brown Globigerina ooze, with a rosy
tinge. dark brown when wet, coherent, pulverulent, granular.
Carbonate of Calcium, 72.21 per cent, consists of otoliths of fish, Pteropod
and Ostracode shells, Echinoderm fragments, coccoliths and rhabdoliths, and the
following Foraminifera : —
Globigerina rubra Miliolina seminulum
G. dubia Biloculina depressa
G. conglobata B. tubulosa
G. sacculifera Cassidulina crassa Bottom-
G. (Orbulina) universa Pelagic Lagena hispida living
Pullenia obliquiloculata species. Uvigerina asperula species.
Spheroidina dehiscens Pulvinulina elegans
Pulvinulina menardii Truncatulina lobatula
P. menardri, var. fimbriata TL. ungeriana
P micheliniana
60 BULLETIN OF THE
Residue, 27.79 per cent, reddish brown, consists of Mizerals [6.00], m. di.
0.15 mm., quartz, hornblende, magnetite, felspar, glassy fragments. Siliceous
organisms [10.00], Sponge spicules, Radiolarians, Diatoms. Fine washings
[11.79], argillaceous and flocculent matter, fine mineral particles, and fragments
of siliceous organisms.
Station 41. — Lat. 23°42’ N. Long. 83°13’ W. Depth, 860 fathoms. Surf.
temp. 73°. Bot. temp. 393°. A white chalky Pteropod ooze, granular; with
several hard chalky concretions, which are perforated by worms, and in parts
showing deposits of manganese.
Carbonate of Calcium, 83.67 per cent, consists of otoliths of fish, Pteropod and
Heteropod shells, coccoliths, rhabdoliths, and Foraminifera as follows : —
Globigerina rubra ) Biloculina depressa
G. inflata Miliolina seminulum
G. sacculifera M. circularis
G. conglobata Planispirina celata
G. dubia Rhabdammina discreta
G. bulloides, var. triloba t Hyperamina ramosa Raion:
G. (Orbulina) universa Pelagic Bulimina marginata c living
Spheroidina dehiscens a a Uvigerina oculata Ps
Candeina nitida Spheroidina bulloides
Pulvinulina menardit Truncatulina rosea
P. menardii var. tumida T. lobatula
P. menardii var. fimbriata Pulvinulina pauperata )
P. micheliniana
Residue, 16.33 per cent, light brown, consists of Minerals [4.00], m. di. 0.08
mm., quartz, magnetite, felspar, hornblende, and a few glassy fragments. Si/i-
ceous organisms (7.00), many Radiolarians, Sponge spicules, and Diatoms. Fixe
washings [5.33], light brown flocculent and argillaceous matter, with fine min-
eral particles and fragments of siliceous organisms.
Station 48. — Lat. 28° 47’ 30” N.. Long. 88° 41! 30” W. Depth, 533
fathoms. Surf. temp. 66°. Bot. temp. 413°. Mud (river), of a light brown
color, dark with a greenish tinge when wet, showing Gasteropod shells imbed-
ded, very coherent, clayey streak, dries into very hard lumps.
Carbonate of Calcium, 6.43 per cent, consists of a few Gasteropod shells, cocco-
liths, and the following Foraminifera : —
Globigerina inflata Pullenia obliquiloculata
G. conglobata Pulvinulina menardit
G. bulloides P. menardii, var. tumida
G. dubia P. micheliniana
G. rubra Miliolina seminulum
G. (Orbulina) universa, fragments. Bulimina marginata
MUSEUM OF COMPARATIVE ZOOLOGY. 61
Lagena gracillima Pulvinulina elegans
Cristellaria gibba Spheroidina bulloides
Uvigerina pygmaa
Residue, 93.57 per cent, brown, consists of Minerals [25.00], m. di. 0.05 mm.,
quartz, feldspars, hornblende, fragments of coal. Stéliceous organisms [3.00],
fragments of Radiolarians. Fine washings [65.57], argillaceous matter and fine
mineral particles, with a few fine siliceous fragments.
In the examination and description of these deposits I was assisted by the
abbé Renard, who determined many of the mineral particles. I have also to
acknowledge the services rendered by my assistants, Mr. James Chumley and
Mr. Frederick Pearcey. 7
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No. 3. — Observations on the Development of Agelena nevia. —
By Wm. A. Locy.*
SEVERAL memoirs have been published on the development of the
Araneina, but the results attained are still unsatisfactory on account of
the disagreement of authorities, and the limited extent to which the
method of sectioning has been employed in studying the subject. Up to
the present time only a single memoir, illustrated by figures of actual
sections, has appeared.
Valuable as were the works of the earlier writers, Herold (’24), Rathke
(42), and Von Wittich (45 and 49), they now are principally of his-
torical importance, since their labors were performed either before the
announcement of the cell theory, or before it had gained general recog-
nition, and before embryology had attained its pre-eminence among mor-
phological studies.
Claparéde (62) made extended observations on the external features
of development, but did not discuss the preblastodermic period nor the
period of the revolution of the embryo.
Salensky (’71) published in Russian a memoir, the figures illustrating
which show critical observations on the external features of development.
He was the first to figure the “rudimentary terga ” of the period of revo-
lution, and also the development of the procephalic lobes.
In a short paper on the development of Pholeus, Emerton (’72) con-
fines his observations to the external features of development. He figures
the polygonal areas of the blastema, and erroneously concludes that they
are blastodermic cells without distinct nuclei. The relation of the primi-
tive cumulus to the ventral plate is well figured.
Balbiani (’73) has produced one of the most satisfactory memoirs yet
written ; he figures and describes in detail the external features of the
early stages of development up to the period of the formation of the
appendages.
Ludwig’s (’76) observations were confined to the formation of the blas-
toderm, and are at variance with Balbiani’s, mainly in denying the exist-
* Contributions from the Embryological Laboratory of the Museum of Com-
parative Zodlogy at Harvard College, under the direction of E. L. Mark. No. VIII.
VOL. XII.— NO. 3.
64 BULLETIN OF THE
ence of the peripheral layer of protoplasm that is divided into polygonal
areas prior to the appearance of the blastoderm.
Barrois (’78) added to what was already known an extended descrip-
tion, with figures, of his so-called limuloid stage, and gave notes, without
figures, on the development of the germinal layers.
Balfour (’80) was the first to produce figures of actual sections to illus-
trate the history of the germinal layers. Unfortunately, he had no
material for the preblastodermic period.
Sabatier (81) contributes notes on the formation of the blastoderm,
and also on the yolk nucleus of spiders’ eggs.
Schimkewitsch (84) offers the latest contribution to the subject in a
preliminary notice in the Zoologischer Anzeiger for August 18, 1884,
which embraces notes on the entire development.
I.—The Egg.
The eggs of Agelena novia are very abundant in the autumn. Those
for the present study were obtained near Cambridge, Mass., from Sep-
tember 15 to October 15. They exist in cocoons of white silk attached
to the underside of fence boards or loosened bark, and in other sheltered
places. This species, as well as others, continues to deposit eggs in
captivity, thus furnishing a ready means of obtaining freshly laid
material.
Treatment. — For observations on fresh material the long-used method
of immersing the eggs in oil is indispensable. The oil should be per-
fectly clear and scentless. In hardened eggs the external features can be
studied to great advantage by mounting in alcohol after they have been
shelled and stained ; the structures previously obscured by the chorion
thus become properly exposed. Before using this method I was unable
to trace the “rudimentary terga.” Another valuable method for surface
study consists in clearing the already stained egg in clove oil. I have
found this especially applicable in determining, by means of optical
sections, the thickness of the blastoderm on entire eggs.
In the important work of preparing eggs for cutting, experiments were
made with several reagents. The most satisfactory method of treatment
proved to be the very simple one already long in use. The eggs were
heated in water to about 80° C, and cooled slowly, after which they were
passed successively from weak to stronger grades of alcohol.
Good results were also obtained with Perenyi’s fluid, which renders the
yolk less brittle, but at the same time changes somewhat its characteris-
MUSEUM OF COMPARATIVE ZOOLOGY. 65
tic appearance, and therefore can be used only in connection with other
methods.
Corrosive sublimate, either cold or hot, renders the eggs too brittle.
On account of the thickness of the chorion neither chromic acid nor
acid alcohol can be entirely extracted, and osmic acid will not penetrate.
Borax carmine (Grenacher’s alcoholic) has proved to be, on the whole,
the best staining fluid. It is difficult to make any stain penetrate the
material of the later embryonic stages and those subsequent to hatch-
ing, on account of the development of the cuticula. This difficulty was
at length overcome by prolonged immersion in the staining fluid. In
some cases seventy-two hours were required to obtain an adequate stain.
Owing to the weak grade of alcohol used in making the stain, the eggs,
to prevent maceration, were left in the stain only twenty-four hours at a
time. They were then re-hardened, and after an interval immersed again
in the staining fluid.
The brittleness of the yolk of spiders’ eggs constantly produces crum-
bling of the sections. I have found that the yolk of eggs treated with
Perenyi’s fluid may be cut satisfactorily ; in other cases I have used suc-
cessfully Mason’s collodion method.*
Composition of the Egg.—The composition of the freshly deposited
egg has already been described with accuracy in most particulars by
Balbiani and others. In certain points, however, there has been neither
agreement in descriptions nor great accuracy.
To make clear the subsequent account I shall describe briefly the con-
stituent parts of the egg. It is enveloped by two membranes in contact
with each other. The outer, or so-called chorion, is tough and homo-
geneous, with its external surface covered by granules, which vary in
size and abundance in eggs of different species. In Agelena nevia they
are arranged in a single layer, and do not offer any serious impediment
to observations ; in some species (e. g. Lpetra diadema), however, they
are several layers deep as well as very large, and must be removed to
allow accurate observations. On removing these granules the chorion
presents a finely punctate appearance, which is perhaps due, as Balbiani
has suggested, to the impressions left by the granules. This membrane,
unlike the chorion of insects, is added to the egg while it is passing
through the oviduct, and like the egg-shell of Apus would fall into the
eategory of “secondary egg membranes,” as defined by Ludwig (’74).
* See E. L. Mark, “ Notes on Section Cutting,” in the American Naturalist,
June, 1885, p. 628.
VOL. X1I.—NO, 3.
66 BULLETIN OF THE
Within the “chorion” is the structureless vitelline membrane which
closely invests the substance of the egg. It is thinner than the chorion,
from which it is easily separable after maceration, This membrane in-
vests mature eggs before they leave the ovarian follicle, and is doubtless
a product of the vitellus itself.
In making sections portions of these membranes were often cut. The
vitelline membrane stains faintly in Borax carmine; the chorion retains
its layer of outer granules, which are not dissolved in alcohol. There is,
however, no trace of the areal arrangement of these granules, such as has
been figured by Ludwig (’76) for Philodromus limbatus.
The egg is composed of finely granular protoplasm, in which is accu-
mulated a large amount of nutritive material in the form of albuminoid
yolk corpuscles, and minute fat globules. The albuminoid material is so
distributed as to give the protoplasm a characteristic arrangement. The
latter consists of a central mass enveloping the nucleus, a peripheral
layer, and a coarse network connecting the two,
The peripheral layer (couche germinative of Balbiani) is the most strik-
ing feature in the arrangement of the protoplasm. It is in immediate
contact with the inner surface of the vitelline membrane, and is so
crowded with fat globules that Balbiani concluded erroneously that it is
composed exclusively of such globules.
The central mass of protoplasm forms around the nucleus an irregu-
larly limited, spheroidal envelope, containing neither yolk corpuscles nor
the fatty globules which are so characteristic of the peripheral layer. Its
outer portion is continuous with branching protoplasmic strands, which
form a coarse network around the yolk corpuscles,
According to the observations of Balbiani the ‘‘ yolk nucleus ” persists
during a part, at least, of the embryonic development, and should there-
fore be mentioned as one of the constituents of the egg. There is also to
be included the perivitelline fluid, which makes its appearance during
the contraction of the vitellus. I have no positive information concern-
ing the source of this fluid, but having found no evidence of its existence
in a definite morphological condition before the contraction takes place,
I rest upon the assumption that up to this time it is uniformly distrib-
uted through the formative portion of the vitellus.
MUSEUM OF COMPARATIVE ZOOLOGY. 67
IIl.— The Embryo.
For convenience in describing the development of the embryo, the
following periods may be recognized : —
(1.) The preblastodermic period, in which are embraced the changes in the
mature egg up to and including the formation of the blastoderm.
(2.) The period from the completion of the blastoderm to the formation of the
rudimentary appendages, embracing, (a) the invagination, (6) the stage
of the primitive cumulus, (c) the formation of the ventral plate, and (d)
the division into protozonites.
(3.) The period from the appearance of the appendages to the reversion of the
embryo.
(4.) The period of reversion.
(5.) The period from the reversion to the hatching of the embryo.
1. Preblastodermic period. —The superficial and internal changes, al-
though going on simultaneously, may be more easily described if consid-
ered separately. The surface changes can be watched on the living egg,
and have been already thoroughly studied; but it is impossible to under-
stand fully these changes without that knowledge of the internal pheno-
mena which is to be obtained only by the aid of sections. The lack of
this method of study has led several previous observers into errors of
interpretation.
My earliest observations on the eggs of Agelena neevia were made a
few (probably not more than three or four) hours after their deposit. At
this time the polarity of the egg is very apparent ; one hemisphere is
characterized by small yolk corpuscles packed closely together, though
not joined in masses, and the other by agglomerations of larger yolk
corpuscles. The irregular masses thus formed are separated by spaces in
which are found smaller isolated corpuscles like those which distinguish
the opposite hemisphere.
Balbiani (’73) was the first to give an adequate account of the surface
changes which occur during this period, in which the peripheral layer of
protoplasm is principally concerned. We shall see by following the his-
tory of this protoplasmic layer, that it is the equivalent of the blastema
observed in the eggs of many insects (Diptera, Phryganids, etc.), and
Crustacea (crab, etc.), and I shall so designate it hereafter.
Ludwig (76) and Barrois (’78) have both called in question the accu-
racy of Balbiani’s observations as to the peculiarities of the blastema.
My own observations are more in agreement with those of Balbiani,
which they serve in a measure to confirm.
68 BULLETIN OF THE
In freshly laid eggs this layer is in contact with the vitelline mem-
brane, but early becomes separated from it by the contraction of the
vitellus. The perivitelline fluid which makes its appearance during this
process is coagulable by heat and is also stainable. At first the contrac-
tion of the egg is uniform on all sides, but soon it takes place more
rapidly on one side, thus giving rise to a flattened surface (compare
Fig. 5), upon which the ventral plate is afterwards established. Through
the pressure of this contraction the blastema is moulded upon the periph-
eral yolk corpuscles into regions that correspond in position and size
with the underlying corpuscles. Owing to mutual pressure these regions
become regular hexagonal areas, (Pl. V. figs. 24, 25,) and resemble the
subsequently formed cells of the blastoderm. The absence of nuclei is
the fundamental feature that at once distinguishes them from the blasto-
dermic cells, though they have frequently been mistaken for such on the
supposition that the nuclei were obscured.
The division of the blastema into areas as described above is a very
early phenomenon. At the time of my first observations a number of
faintly marked areas had already made their appearance at the more
active (animal) pole. At this time they could not be detected upon the
opposite hemisphere; but after a short interval they also made their
appearance there in isolated patches ; finally they covered the entire sur-
face of the egg. At the outset the boundary lines of the areas are very
faint, but they become more distinct as the contraction of the vitellus
continues. In some places the yolk corpuscles become separated from
the blastema by a more rapid contraction of the interior protoplasm, and
then the polygonal areas in such regions remain only partially outlined
and incomplete, as described and figured by Balbiani (73, Fig. 2).
After the areas are definitely formed the yolk corpuscles sometimes
shift their original positions, and thus cease to coincide with the areas,
since the latter do not at the same time undergo corresponding changes.
The next alteration in the surface makes its appearance only after the
lapse of a considerable interval (twelve to forty-eight hours) ; this led
Balbiani to assert, erroneously, that the egg is undergoing a period of
rest. Sections show on the contrary, that the interim is one of great
internal activity, during which repeated divisions of the nuclear sub-
stance lead to the formation of numerous cells which migrate towards the
periphery. The appearance of some of these at the surface marks
the beginning of new surface changes. The cells thus emerging from
the yolk constitute the primary blastoderm ; they first appear in the
interspaces between the yolk corpuscles, but often migrate afterwards to
MUSEUM OF COMPARATIVE ZOOLOGY. 69
positions directly over the yolk corpuscles. Each cell embraces a large,
clear, oval nucleus, which is surrounded by an irregularly radiating mass
of protoplasm.
The influence of these nuclei upon the protoplasm of the blastema
soon makes itself evident; a period of rearrangement supervenes in
which the boundaries of the polygonal areas described above are gradu-
ally effaced, and the protoplasm of the blastema, as well as that which
accompanies the migrating nuclet, is grouped into new masses with the
nuclei as centres. The cells formed in this manner are at first large,
irregular, and very unequal in size (Fig. 26), but by repeated divisions
they become smaller, polygonal, and of more nearly uniform dimensions
(Fig. 27). They ultimately form a continuous layer —the blastoderm
—in the production of which the whole of the protoplasm of the blas-
tema has been employed.
I now turn to a consideration of the internal changes which accom-
pany the external features already described.
The structural and other peculiarities of the blastema in the eggs of
spiders have been subjects of considerable discussion, and therefore
deserve especial attention.
Balbiani (’73) was the first to carefully study this layer,* and to
describe its division into areas.
Ludwig (76) denied its existence, and located the polygonal areas
described by Balbiani on the outside of the chorion, they being due, in
his opinion, to a peculiar arrangement of the granules covering the outer
surface of that membrane.
Barrois (78) admitted the existence of the blastema as a partial layer,
but denied its division into areas; the latter, according to his view, are
due to intersecting lines of granules located between the chorion and the
vitelline membrane.
Sabatier (81) agrees substantially with Balbiani.
Thus the four observers who have discussed this topic have given
three irreconcilable explanations of the polygonal areas that Balbiani
referred to the peripheral layer of protoplasm.
Sections of eggs during this period afford decisive evidence on the
points under consideration. In the eggs of Agelena nevia, at least,
there can be doubt neither as to the existence of this layer, nor as to its
division into areas. Figure 28 is from a section of an egg containing
the first segmentation-nucleus (n/.), in which the blastema (0//.) is seen
* It had been mentioned by earlier writers, Rathke (’37), Claparéde (’62), and
Emerton (’72), but they confounded it with the blastoderm.
70 BULLETIN OF THE
to be of considerable thickness, and to envelop closely the peripheral
layer of yolk corpuscles. An enlarged view of the same, given in
Figure 30, Pl. VI., shows the finely granular structure and the vesiculated
condition of the hardened blastema. It also shows how the blastema fits
over the yolk corpuscles, and dips down between them. It is to these
depressed regions that the boundary lines of the polygonal areas are due.
Figures 31-33 are enlarged views of separate yolk corpuscles with the
accompanying blastema.
The protoplasm of the blastema has a very characteristic appearance, :
In addition to the common character of being very finely granular, the
protoplasm is throughout finely vesicular or spongy. The latter charac-
teristic is especially marked in eggs heated in water to coagulate the pro-
toplasm, and arises, I think, in the following manner. The fat globules
described as filling the protoplasm of the blastema in the fresh egg are
dissolved in the alcohol used for hardening purposes, and consequently
leave in the protoplasm spheroidal spaces of nearly uniform size, which
constitute the interstices. A discussion of the cause of the division of
the blastema into areas will be found under general considerations at the
end of the paper.
I have been unable, for the want of material, to trace the final changes
in the germinative vesicle. In the earliest condition of the deposited
egg that I have been able to procure there is a single central nucleus
(Figs. 28, 29 nl.), which is doubtless the descendant of the germina-
tive vesicle. This is the first segmentation-nucleus ; it is large, oval,
very finely granular, and surrounded by a spheroidal mass of protoplasm.
The latter is in immediate continuity with the network of protoplasm,
which extends throughout the egg. The yolk corpuscles in the vicinity
of the protoplasm, which envelopes the nucleus, are much broken and
become successively smaller in approaching the nucleus, and at length
appear to merge into the finely granular protoplasm.
In the succeeding stage the central nucleus divides into two of equal
size, which occupy a sub-central position (Fig. 34, n/, ni’). These nuclei
have essentially the same character as the one already described. Fig. 36,
from a two-cell stage of another egg, shows one of the nuclei with a cen-
tral vacuole (v/.). The yolk is rudely divided at the same time, and
having been previously arranged in radiating branched columns (Deuto-
plasmasdulen of Ludwig), now forms two groups of such columns (Fig. 34).
It is probable that each of the two nuclei is divided into two others,
and that each resulting therefrom is similarly divided, but I have not
seen the four-cell stage. The next stage sectioned is one with eight
MUSEUM OF COMPARATIVE ZOOLOGY. ra
nuclei, all of which are nearer the centre than the surface of the egg. In
an egg still further advanced, containing at least thirty nuclei, none of
the cells have as yet emerged at the surface.
These internal cells are, however, continually migrating towards the
periphery, and, as might be expected from other evidences of the bipolar
condition of the egg, make their appearance first in that region which I
have already designated as the animal pole. The further history of these
cells after they have emerged at the surface has already been described
under the head of surface changes.
The preblastodermie period, then, so far as I have been able to study
it, begins with the incomplete separation of the protoplasm into two
masses: one forming a thin layer at the surface —the ‘ blastema ” —
and the other concentrated around a nuclear structure inferred to bea
derivative of the germinative vesicle. The division of this nucleus is
accompanied by a corresponding division of the central mass of proto-
plasm ; a repetition of this process of division results in the formation of
a number of cells which, migrating to the surface, appropriate the contig-
uous portions of the blastema until the latter ceases to exist as a separate
layer ; there is no evidence that the nuclei of any of these cells arise in
any other way than by the repeated divisions of this single, central, first
segmentation-nucleus ; finally, the peripheral cells continue to subdivide
as well as to receive accessions from more tardily migrating elements until
a continuous single layer of cells —the blastoderm — envelops the egg.
2. The second period includes the changes from the formation of the
blastoderm to the appearance of rudimentary appendages.
In the eggs of Agelena nevia the blastoderm was established on the
third day of development, the temperature being about 23°C during the
day, and 19° to 20°C at night. Within certain limits * the tempera-
ture has a marked influence on the rapidity of the development, and one
can hasten or retard the growth by elevating or lowering the temperature.
For a day or two the blastodermic cells undergo rapid division, and are,
as a consequence, much reduced in size. There is a condition of the
blastoderm intermediate between those shown in Figs. 26 and 27, in
which the cells are regularly polygonal, but much larger than in Fig. 27.
My observations on the next surface change are not entirely satisfac-
tory, as I have seen it in only one instance. It appeared late on the
third day of development, and consisted of a depression at one pole simi-
lar to the depression in the surface of a peach at its stem end. This is
* The eggs are killed by a temperature higher than 30° C.
ies BULLETIN OF THE
probably the same phenomenon that Salensky (’71) described as a pro-
cess of invagination, but to what extent it is comparable to a true in-
vagination I am not at present able to say. Although a direct connection
between this depression and the primitive cumulus has not yet been
traced, it is certain that in point of time the depression is the forerunner
of the cumulus, and the circumstantial evidence of their similar positions
on the egg indicates a connection between the two.
The external feature just spoken of as the primitive cumulus origi-
nates as a thickening of the blastoderm, at one end of the flattened sur-
face of the egg, and usually terminates in the production of a low conical
elevation. In surface aspect the cumulus is ovoid, with its more pointed
end directed towards the centre of the flattened surface, and it often
shows a tendency to elongate in that direction. This patch of cells being
rather opaque, appears whitish by reflected light, and dark by transmit-
ted light. In some specimens it is considerably elevated above the sur-
face of the egg, but in other cases it is only slightly or not at all raised.
Upon hardened eggs the surface of the cumulus is often depressed by a
median longitudinal furrow from which two or three smaller irregular
furrows radiate towards its margin (Pl. I. fig. 4).
A second thickening, which I shall call the caudal thickening (¢ dn.
ca.), soon makes its appearance on the flattened surface of the egg, at a
distance of about 80° from the cumulus (Fig. 2.) It increases rapidly
in size, spreading out most in the direction of the cumulus, and ulti-
mately becomes shield-shaped. In the region between these two struc-
tures the ventral plate is gradually formed by a blastodermic thickening,
which is not at first continuous with the two terminal thickenings. In-
dications of the existence of a ventral-plate thickening, which appears
lighter by reflected light, are to be seen in the surface view shown in
Wie, 2Pl: i.
Immediately following the stage just described, the whole ventral
surface of the egg becomes divided by a series of transverse ridges and
furrows into protozonites (PI. II. fig. 6). I have not the material to
determine all the steps in the process, for the time involved in passing
from the stage of the primitive cumulus to the protozonite stage is a com-
paratively short one. The earliest condition in the latter stage which I
have examined shows three zonites and the cephalic plate. At this time
the latter is only faintly outlined. It isa broad thickening, rounded
towards the dorsal region of the egg, and fading into the protozonites on
the ventral surface. The caudal plate does not become visible until two
or three more zonites are established. It is similar in outline to the
MUSEUM OF COMPARATIVE ZOOLOGY. 73
cephalic plate. The addition of new zonites to those already existing
goes on rapidly ; the two anterior ones (those of the cheliceree and the
pedipalpi) are cut off from the posterior end of the cephalic plate. They
are late in making their appearance, and, as Balfour puts it, ‘‘lag behind”
the others in their development. The other zonites are developed from
the caudal plate.
Soon after the protozonites are first established they form ridges which
reach nearly around the egg, and thus appear to radiate from the dorsal
region. (Compare Emerton, ’72, Figs. 8, 9.) They soon undergo con-
centration which so shortens the thickened ridges, that together they
form a band about 45° wide on the ventral surface of the egg — the
embryonic band. Fig. 6, Pl. II., gives a side view of an egg in which
this concentration is well advanced but not yet completed. At the same
time the embryonic band increases in length, thus extending in an antero-
posterior direction further and further around the egg. When at length
seven or eight protozonites are fully established, the band embraces
approximately two-thirds of its circumference. At about this time also
the rudimentary appendages begin to appear; these mark the commence-
ment of the third period of growth.
The internal condition of the egg during the second period can be
satisfactorily studied only by means of sections. I have made sections
passing through the primitive cumulus in two directions, sagittal and
transverse. In sagittal sections two features are conspicuous: (1) The
ventral surface of the egg is clearly differentiated from the dorsal surface
by the condition of the cells along its entire length (Pl. VII. fig. 41).
(2) The cells in the region of the cumulus are arranged in several irregu-
lar layers. A thickening of the blastoderm has also arisen at the caudal
eminence, and there is a tendency to thicken along the ventral region
embraced between these two structures.
Figure 41 is from a sagittal section of the egg represented ‘in PI. I,
Fig. 3; the cells of the ventral side are large and rounded or oval,
while those of the dorsal side are much flattened. The cells of the
primitive cumulus (cum. pr.) are conspicuous for their size; they are
loosely arranged in layers. In some cases (Pl. VI. fig. 39) they are four
layers deep.
Sections of eggs a little more advanced show a large number of cells
along the ventral-plate region, and also at the caudal thickening.
Balfour’s figure (1. ¢., Fig. 11) of this stage cannot be compared criti-
cally with my own, as he was uncertain about the direction in which the
egg was cut; but from its close resemblance to my sections, I think it
74 BULLETIN OF THE
safe to infer that he was wrong in supposing the larger accumulation of
cells shown in his figure to represent the caudal thickening rather than
the primitive cumulus. Fig. 39 is a transverse section through the
primitive cumulus in the region of its greater width.
In radial sections of the egg during this stage the cells of the unmodi-
fied blastoderm appear lens-shaped, the deep surface being more convex
than the outer, and contain each a single large nucleus, that is usually
central in position (Fig. 40). They are frequently preserved in the pro-
cess of division, their nuclei exhibiting the customary dumb-bell shaped
figure (Figs. 42, 44).
The “interzonal filaments” are quite persistent, remaining distinguish-
able even after the formation of the dividing cell wall (Fig. 44).
The nuclei in nearly all the sections which were stained in borax car-
mine are in a condition very favorable for study. The filaments of
chromatine are deeply stained, the nucleoplasm only faintly. The ar-
rangement of the chromatic substance in the nuclei varies from a condi-
tion in which it is concentrated into a bail at the centre of the nucleus
(Fig. 43), to one in which it forms a hollow shell near the surface of the
latter.
Sections during the protozonite stage show that the blastoderm of the
embryonic region consists of two distinct cell layers — the ectoderm and
the mesoderm (Figs. 49, 45). The cells of the outer layer (ectoderm)
are columnar (Fig. 45), and their nuclei, which are smaller than in pre-
vious stages, are very close together and much nearer the superficial
than the deep ends of the cells. The cells of the inner layer (meso-
derm) are not columnar but rounded cuboidal, and in general are much
less regularly arranged than the ectodermic cells; their nuclei, which
occupy the centres of the cells, do not at this stage present any other
characteristic differences from the nuclei of the ectoderm. At a later
period the nuclear elements of the mesoderm become spindle-shaped, and
thereby can be readily distinguished from those of the ectoderm. As
in the preceding stage, the cells of the non-embryonic or dorsal region
of the blastoderm are much flattened, even more than previously, and
only a single layer deep.
The cellular elements of the mesoderm are not everywhere definitely
arranged, and the deep margin of the layer especially is irregular in out-
line ; it partly envelops the yolk corpuscles, which are reduced to small
fragments on the surfaces adjacent to the protoplasm, but it does not at
this time form an uninterrupted layer.
The yolk corpuscles of this and succeeding stages are not absolutely
MUSEUM OF COMPARATIVE ZOOLOGY. 75
alike in constitution ; some of them are stained deeply and appear homo-
geneous, while others are stained lighter and appear granular. During
the whole of this period there continue to remain in the yolk mass a
large number of cells, which are distributed through its substance at
tolerably regular intervals. There is often a comparatively small amount
of protoplasm enveloping the large angular nuclei of these yolk-cells, and
about them the yolk corpuscles are more or less definitely grouped.
3. At the beginning of the third period the embryo still has a trans-
versely banded appearance as in the protozonite stage ; the concentration
from the sides is completed, and about six zonites are distinguishable
between the head- and tail-lobes. The zonites now begin to grow thin-
ner in the ventral median line, and at the same time their ends become
gradually more prominent and rounded. The small knob-like promi-
nences at the ends of the zonites are the rudiments of the appendages, and
in about two days after their first appearance (at the temperature stated)
the six cephalo-thoracic appendages are fully established as represented
in Pl. Il. fig. 7. The two anterior pairs of appendages are much
smaller than the four succeeding pairs, the latter being about equal in
size. The appendages thus established correspond to the chelicere, the
pedipalpi, and the four pairs of ambulatory appendages of the adult.
Simultaneous with the growth of the appendages new zonites, derived
from the tail-lobe, make their first appearance; the four anterior of
these are very prominent, and a little later they bear four pairs of pro-
visional appendages (Pl. IV. fig. 20, pr. app.). In this first part of the
third period the head plate is faintly bilobed; the tail-lobe is broad and
rounded.
A ventral view (Pl. IV. fig. 19) of the same ege (Pl II. fig."'7)
shows a faint median furrow, which marks the thinning out of the ecto-
derm in the median plane after the separation of the lateral halves of the
underlying mesoderm. There are slight elevations just inside the bases
of the limbs, best seen in optical section along the upper margin of the
figure; they are the beginnings of the nervous ganglia.
At first the appendages grow out perpendicular to the axis of the
body (Pl. II. fig. 7), but as they increase in length they curve towards
the median line, as shown in Fig. 8. They are now indistinctly four-
jointed. The central lumen, which can be observed readily in optical
sections of the leg, is shown by actual sections to be a prolongation of
the cavity of the corresponding mesodermic somite.
At the present stage —the last part of the third period —the head
plate has become distinctly bilobed, a prominent upper lip composed of
76 BULLETIN OF THE
two lateral elements has been developed, and the stomodzum has be-
come faintly marked (Pl. III. fig. 16, Pl. IV. fig. 23). The four pairs
of provisional appendages are now fully established, and the embryo has
increased in length till the head- and tail-lobes are nearly in contact ;
the dorsal region is, as a consequence, much reduced. Behind the
somites which bear the provisional appendages the tail-lobe has given
rise to at least six indistinct additional somites ; the terminal end of the
tail is much narrowed and is becoming more pointed. The swellings
produced by the rudimentary ganglia, at the bases of the appendages, are
further developed, and the median ventral furrow has increased both in
depth and in width.
Balfour has given good figures and descriptions of the germinal layers
during the formation of the appendages. The mesoderm is of especial
interest at this time. Early in the protozonite stage it forms a con-
tinuous band, about as wide as the embryo, composed of a single layer of
cells extending the whole length of the embryonic band. About the
time the appendages begin to appear the mesoderm splits along the
median ventral line, thus forming two parallel bands, which remain
united, however, in the head and tail regions. The division of the
mesoderm into lateral halves is followed by an increase in the thickness
of the resulting bands, each of which becomes split into a somatic and a
splanchnic layer. It is also at this stage that the mesoderm is divided by
transverse constructions into somites, each of which contains a central
lumen. I am unable to determine from my specimens whether its divis-
ion into successive blocks precedes or follows the appearance of the
lumen. In the growth of the appendages the somatic layer of the meso-
derm accompanies the outgrowing ectoderm, and forms a continuous
lining to its cavity.
During this period the ectoderm has also increased in thickness, but
along the median ventral line it remains thinner; from this it results
that there are two bands of thickened ectoderm corresponding to the two
deep bands of mesoderm. The ventral median depression previously
mentioned is at first due to the relative thinness of the ectoderm in this
region ; it is afterwards made more conspicuous by the further separa-
tion of the mesodermic bands. From the ectodermic bands are formed
the nervous ganglia. They are developed first in the thoracic region in
the form of swellings at the bases of the appendages, but by the time the
stage represented in Fig. 8 has been reached, they have also been formed
in the abdominal region.
As already correctly maintained by Balfour, the segment of the cheli-
-
MUSEUM OF COMPARATIVE ZOOLOGY. 77
ceree has a separate pair of ganglia which ultimately disappear, serving
only to aid in the formation of the cireumcsophageal commissure. At
an early stage, then, the nervous elements consist of two rows of ganglia,
a pair of ganglia for each somite, which are widely separated except in the
head lobe and the tail lobe, where they are continuous in the median
line.
Another important growth on the part of the ectoderm leads to the
formation of the stomodeum, which arises as a simple tubular infolding
between the ganglionic thickenings of the cheliceral somites, and imme-
diately below the ventral margin of the cephalic plate. It becomes ex-
panded at its deep end into a sort of pocket, but it has only a small
external opening. The walls of the stomodzum are composed of cells,
two or three rows deep, which are elongated and somewhat wedge-shaped
rather than distinctly columnar.
4, The period of reversion is marked by the origin of many important
organs: proctodeum, heart, lungs, trachez, spinning glands, muscles,
etc. The embryo undergoes great changes in external form, gradually
passing from the condition represented in Pl. II. fig. 8, where the ven-
tral surface of the embryo is uniformly convex, and occupies an are of
about 300°, to a form (Pl. II. fig. 11) in which the ventral surface is
folded upon itself.
As a prelude to reversion the tail-lobe of the embryo becomes promi-
nent, being raised from the surface of the egg. The early steps in the
process of reversion will be best understood from the examination of a
series of dorsal views. Fig. 13 (Pl. III.) presents the dorsal aspect at
the beginning of reversion, and Fig. 8 (Pl. II.) a side view at nearly the
same stage. The tail-lobe has lost its broad rounded character, and is
being changed into a more distinctively caudate structure. It still re-
mains nearly in contact with the cephalic lobe. The dorsal elements
(‘‘terga” of Barrois) have begun their upward growth, and appear in
the figure as four pairs of prominent lateral elevations. A corresponding
growth of the abdominal segments is also in progress ; the dorsal elements
growing upward finally meet in the median line of the back.
Each of the lobes of the procephalic plate has a semilunar form, and is
composed of a central area, apparently separated from a marginal rim by
means of a deep fold (Pl. IV. fig. 23). The prominent upper lip (/r.)
is apparently an outgrowth of the ventral border of the cephalic plate,
and overhangs the entrance to the stomodeeum (s d.).
The cheliceree (1 app.) and the pedipalpi (2 app.) both appear as post-
oral structures. The prominent ganglia (gz.) belonging to the cheli-
78 BULLETIN OF THE
ceral segment lie just in front of the bases of the cheliceree, and are like-
wise post-oral structures, as claimed by Balfour.
The next stage in the process is represented in Pl. III. fig. 14, in
which the tail-lobe is much narrower and more clearly circumscribed ; a
considerable interval now separates it from the procephalic plate. Five
pairs of dorsal (tergal) elements belonging to the abdominal segments
are now visible; the four anterior pairs belong to the segments bearing
provisional appendages, and a fifth, smaller pair, has been interpolated
between these and the tail-lobe. The tail-lobe is apparently split in the
median line into two bands that, in passing forwards, diverge rapidly.
These are the two bands of ectoderm which, as before mentioned, join
each other in the head and the tail-lobes. Between these divergent
bands of ectoderm is to be seen a part of the yolk mass covered by only
a thin layer of ectoderm. The legs have increased in length until they
nearly meet in the median plane (Pl. IV. fig. 22).
In the next stage (Pl. III. fig. 15) the dorsal region is much elon-
gated owing to the retrogression of the tail-lobe, and the rudimentary
terga extend much further dorsad. Up to this time the only dorsal ele-
ments developed were the five pairs belonging to the abdominal somites,
but during this stage the dorsal elements of the limb-bearing somites
begin a more rapid growth. The dorsal elements of the somite bearing
the fourth pair of legs grow much more rapidly than the others.
In a dorsal view of a somewhat later stage (Pl. III. fig. 16) the tip of
the tail is just visible at the posterior margin of the embryo, the dorsal
region having increased proportionately in extent. The procephalic lobes
are closing together in the median plane. The dorsal elements of the
somites now nearly meet in the median line of the back. In the figure
some of the provisional appendages (pr. app.) are visible along the sides
of the body.
In a slightly older embryo (Pl. III. fig. 17) the tail-lobe is no longer
visible from above ; the cephalic lobes have become fused, and the dorsal
elements of the somites have met in the median line. Along this line a
narrow slightly elevated ridge indicates externally the position of the
heart.
The much reduced caudal lobe is to be seen from below (Pl. IV.
fig. 21) and, diverging from it in two lines, the provisional appendages.
Owing to the wide separation of the neural bands the legs of each pair
are far apart. Between them a part of the yolk (not the whole, as stated
by Barrois) protrudes, forming a sort of ventral yolk sack. The rapid
appropriation of this store of yolk causes the disappearance of the sack ;
MUSEUM OF COMPARATIVE ZOOLOGY. 79
the embryo becomes more folded upon itself ventrally, as shown in
Pl. II. fig. 10, and the legs, increasing in length, gradually approach and
finally overlap each other in the median line. The embryo has now
acquired a strong ventral flexure — the reversion is completed.
During this period the bases of the chelicere in growing have moved
forwards and met in the median plane, so that they appear as pre-oral
appendages. There has also appeared between their bases a prominent
outgrowth to form the rostrum.
Balfour (’80, p. 180) endeavors to account for the process of rever-
sion as the result of a rapid ‘‘ elongation of the dorsal region, that is, the
region on the dorsal surface between the anal and the procephalic lobes.”
I understand by this that it is to the growth of the ectodermic cells of
the dorsal region that he would ascribe the elongation of the dorsal surface.
I shall endeavor to show presently that this explanation is not sufficient
to account for the changes which actually take place during reversion.
The growth of the derivatives from the ectoderm during the period
under consideration is very great. At the beginning of the period the
stomodeum forms a pocket-shaped invagination with a small external
opening. Its calibre diminishes, except at its anterior end ; it continues
to grow inwardly, and at length forms an arched tubular organ, with its
free end directed backward, and projecting some distance into the yolk.
Near the close of the period its deep end becomes somewhat enlarged to
form the rudiment of the sucking stomach. To the latter are attached a
vertical muscle (mz. wrt. Pl. IX. fig. 62) extending to the dorsal wall of
the embryo, and two lateral muscles (mw. /at.).
The proctodzeum is a later formation, which makes its appearance as an
infolding at the tip of the tail-lobe some time after the beginning of this
period. ‘The relation of the tail-lobe to the rest of the body is best ap-
preciated from sections, since it is not always evident from surface views
that there is a deep fold which serves to separate it from the underlying
portion of the dorsal surface. The prominence which it attains and the
changes which it undergoes are readily traceable in a series of figures
from successive stages during reversion (Pl. VIII. figs. 50-54). The
strong resemblance of the condition shown in Fig. 50 to that which
Bobretzky (74, Fig. 15) has figured for Oniscus at an apparently similar
stage of development, misled me into the supposition that I should find
the proctodeum of Agelena developing in the manner described by him
for Oniscus. But such is not the case. In Agelena the tip of the lobe
is the tip of the tail—the morphological end of the body, and the
' depression which separates this lobe from the neighboring portion of the
80 BULLETIN OF THE
embryo is not the proctodzum, but simply a fold in the dorsal wall of
the embryo. The pocket resulting from this fold is flattened in a plane
perpendicular to the sagittal plane, and is not a tubular infolding like
the real proctodeum., This pocket is lined with ectodermic cells, which
subsequently form a part of the epidermis at the posterior end of the
dorsum. By the traction exerted along the median ventral line of the
body during reversion the tail is drawn downwards and greatly short-
ened, thus obliterating the pocket. When in the progress of its rever-
sion the embryo has reached about the stage represented in Figs. 10,
16, the proctodzeum is formed as an invagination just ventral to its tip.
At this early period it has the appearance shown in the sagittal section,
Pl. VIII. fig. 54. The tail-lobe is now a short thick prominence, and
the dorsal fold has nearly disappeared.
At an early period the proctodseum is enlarged by the outgrowth of
its dorsal wall into the form of a capacious pocket, which is retained by
the embryo throughout its development. This diverticulum (67. ste.
Pl. VIIL. figs. 55, 56) is the so-called stercoral pocket of the adult. The
walls of the rectum and the stercoral pocket are composed of columnar
epithelium, and are closely invested by mesodermic elements.
The nervous system is characterized during this period by the wide
separation of the nerve bands and a gradual concentration of their sub-
stance headwards. The distance between the bands is greatly increased
by the passage of the yolk from the dorsal to the ventral side through
the aperture left by their separation. At the period of their great-
est separation they occupy curved lines along the lateral walls of the
yolk sack, separated from each other by its diameter. During reversion
also the actual length of the nerve cords is somewhat decreased. At the
beginning of this period they reach nearly around the egg from the head-
to the tail-lobe (Pl. XII. fig. 77), but during reversion they pass through
the stages of shortening represented in Pls. XI. XII. figs. 72, 71, 70, 78.
Their connection with the tail-lobe is severed, and the nerve cords grad-
ually move forwards ; with the absorption of the yolk mass this lateral
separation is diminished until they are in contact along the ventral line.
After the process of reversion is well advanced certain cells in the
bases of the chelicerze become conspicuous from their enlarged condition
and spongy appearance, which serve to distinguish them sharply from
surrounding cells. They are the rudiments of the poison glands, and
although I have not been able to trace an external outlet until a later
period, it is probable that these cells are derived from an infolding of the
ectoderm at the point where later an outlet is discernible.
MUSEUM OF COMPARATIVE ZOOLOGY. rom
The spinning glands are not yet definitely established, but in the anal
region on the ventral side of the proctodzum there is a large accumula-
tion of ectodermic cells (Pl. XI. fig. 70) from which they are subse-
quently developed.
Late in this period the infoldings for the lungs arise. There appear a
pair of large oval masses of cells, the nuclei of which are arranged in par-
allel lines (Pl. XI. fig. 73). From these cells the respiratory lamelle of
the lungs are finally formed.
The mesoderm likewise has been growing rapidly during reversion.
In the previous period it was confined to the ventral portion of the em-
bryo, but during the present period it grows upward on either side until
it reaches the dorsal median line, thus forming a continuous layer be-
neath the ectoderm, as well as an investment for all organs, which arise
as outgrowths of either ectoderm or entoderm.
The dorsal growth of the rudimentary terga, already spoken of as
external features, is followed by this underlying layer of mesoderm.
Early in the formation of the dorsal elements this mesodermic layer is
divided into corresponding somites. Balfour (80, p. 181) concluded
that the cells out of which are formed the dorsal somites of the meso-
derm ‘‘are not derived from prolongations of the somatic and splanchnic
layers of the already formed [ventral] somites, but are new formations
derived from the yolk.” My sections, however, indicate that there is a
direct continuity between the two (Pl. IX. figs. 59, 61), and that the
dorsal mesoderm is an outgrowth from the previously established ventral
mesodermic somites.
It is during this period also that the heart is formed. While I have
been unable to arrive at an entirely satisfactory understanding of the
details of its formation, I am convinced that it is not, as Balfour states,
developed from a solid cord of cells, but from the dorsal limb of the up-
growing mesoderm, and that its dorsal wall is closed first, while the
ventral wall—the floor —remains for a time widely open below, thus
communicating freely with the yolk. My sections also show that ata
later period the aorta is formed, by means of a constriction, from the
mesenteron. This agrees with the recent observations of Schimkewitsch,
(84°).
A layer of characteristic cells, to which Balfour alludes in speaking of
the formation of the dorsal mesoblast, precedes the formation of the
heart in the dorsal region. These are what have been called “ primary
entoderm ” cells, and are sharply distinguished from the surrounding cells
by their large size, their large, oval nuclei, and their yellowish tint. These
VOL. XII. — NO. 3. 6
82 BULLETIN OF THE
cells are derivatives from the yolk-cells, and first appear just before the
reversion of the embryo begins. ‘They are abundant along the sides of
the body, and about the cesaphagus as well as in the dorsal region.
The yolk during this period is somewhat changed from its early char-
acteristics. The corpuscles are undergoing disintegration, and are much
vacuolated, which gives them in certain regions a spongy appearance.
The nuclei of the yolk-cells, while they have increased in number, are
smaller and angular (often triangular) in outline.
5. The period from reversion to hatching. — Few surface changes of
importance are necessary to convert the embryo of the period just de-
scribed into the adult. The following are the most obvious: The embryo
becomes more closely flexed upon itself (Pl. II. fig. 11), and the constric-
tion which separates the abdomen and the cephalo-thorax is formed. At
least two pairs of provisional appendages are modified into as many
large spinning mammille.* In addition to these two large pairs there
is a pair of smaller median mammille, the origin of which I have not
traced. The remnant of the tail persists for some time as a post-anal
knob; upon the ventral surface appear the infoldings, from which are
formed the trachez, and also those of the generative organs; upon the
head the eyes make their appearance. Two or three days before hatch-
ing the embryo begins to unroll, and undergoes a moult ; at the time of
hatching it is completely straightened.
I shall now proceed, after this general account of the more important
embryonic stages, to the consideration of the development of separate
organs and sets of organs.
Ill. — Organogeny.
In the present paper only the following organs will receive attention :
(1) the alimentary tract, including stomodeum, pharynx, stomach, mid-
intestine, stercoral pocket and rectum; (2) the eyes; and (3) the lungs.
* Balfour (’80, p. 183) has stated: ‘The four rudimentary appendages have
disappeared, unless, which seems to me in the highest degree improbable, they
remain as the spinning mammille.” Notwithstanding his doubt, I think I have
traced the development of two pairs directly into the mammille. The mammille,
therefore, are appendages of abdominal somites, homodynamic with the cephalo-
thoracic appendages, and there are consequently six somites condensed into the
space between the posterior pair of mammille and the anus. Upon the ventral face
the evidences of this are early obliterated, but upon the dorsal surface the poste-
rior somites are recognizable by the arrangement of the longitudinal muscles, at
least as late as the stage represented in Fig. 70, Pl. XI.
MUSEUM OF COMPARATIVE ZOOLOGY. 83
The portion of the alimentary canal first to appear — the stomodzum
—arises as an invagination of ectoderm just before the beginning of
the third period of development, and therefore after the establishment
of a mesodermic layer in the region in which the invagination occurs.
As already stated, it grows rapidly during the third period, and in the
fourth period it acquires certain muscular attachments, developed out
of mesodermic cells. After the reversion of the embryo is completed,
a tube of about the same calibre as the stomodzum arises behind the
stomach, and, extending through the cephalothorax, opens widely, by
a bell-shaped expansion, into the yolk of the abdomen (Pl. XII. fig.
78). This post-gastric portion of the canal was evidently overlooked by
Balfour, as he (1. ¢., p. 187) states that he was unable to find “any trace
of an anterior part of the mesenteron adjoining the stomodzeum.” An-
teriorly it apparently does not open into the sucking stomach during
embryonic stages, but is so plugged with cells that its relations are
obscured.
At the time of hatching the intestinal tract is still incomplete, the
epithelial wall of the mesenteron being largely or altogether wanting.
There may be distinguished in the anterior portion of the tract the fol-
lowing parts: pharynx, oesophagus, sucking stomach, and post-gastric
tube.
The pharynx passes from the mouth obliquely upwards and backwards,
and, turning at nearly a right angle, is continued into the csophagus.
The latter is of uniform calibre and extends backwards with a slightly
downward curve, terminating in the enlarged sucking stomach. 380.
PLATE VI.
Enlarged view of a portion of Fig. 28, showing the blastema (d/’.) and
underlying yolk corpuscles (yk.).
2. Isolated peripheral yolk corpuscles, to which portions of the blastema
are attached.
Isolated yolk corpuscie with a vacuole, which in turn contains a rounded
yolk globule.
Section through the nuclei of an egg in the two-cell stage, showing the
two groups of yolk columns (Deutoplasmasaulen). XX 110.
One of the deep internal cells, surrounded by yolk.
A nucleus containing a central vacuole; from an egg in the two-cell
stage.
A migrating cell that has just reached the periphery, abutting on the
blastema (0/’.).
Detached portion of the blastema viewed from within, showing depres-
sions into which the yolk corpuscles fit.
89. Section of an egg passing transversely through the primitive cumulus in
40.
41.
42.
the region of its greatest width. X 110.
PLATE VIL
Radial section of two blastodermic cells.
Section passing sagittally through the primitive cumulus. X 110.
A blastodermic cell in the process of division, with ‘‘ interzonal filaments.”
~~
et
ce
“
44.
45.
48.
49,
MUSEUM OF COMPARATIVE ZOOLOGY. 101
. 43, 46, 47. Blastodermic cells ; to show some of the conditions presented by
the chromatine and nucleoplasm of their nuclei.
A cell in the process of division, further advanced than the one repre-
sented in Fig. 42.
A portion of Fig. 49 highly magnified to show the columnar nature of the
ectodermic cells and the complete differentiation of the mesoderm.
Ectodermic cells with two nuclei from a late stage, during the infolding,
to form the ovary.
Sagittal section through an embryo in the protozonite stage, X 110.
Note. — In cutting and mounting, the section was artificially ruptured in
two places, but none of the blastoderm has fallen away.
PLATE VIII
Sagittal section through an embryo during reversion, showing stomo-
deum, tail-lobe, etc. XX 110.
51, 52. Views of sagittal sections of the posterior region during reversion, to
55.
5€.
g. 57.
58.
60.
61.
62.
show the condition of the tail-fold.
Section of the tail region and a part of the dorsal region, to show the
mesodermic somites of the rudimentary terga. The section is cut
obliquely to the median plane. X 110.
Sagittal section of the morphological tip (7) of the body near the close
of reversion, to show the early condition of the proctodeum. x 110.
Sagittal section of the hind part of the body, to show the stercoral pocket
(br. ste.) and the pre-stercoral tube (pr-stc.).
Sagittal section of the hind part of the body, to show the trumpet-shaped
condition of the pre-stercoral tube and the somatization of the body as
indicated by the segmental grouping of the muscles (mu. 1— mu. 5).
PLATE IX.
A nearly horizontal section of the proctodeum and the stercoral pocket
(br. stc.), about three days before hatching, showing the columnar
epithelium and the narrow lumen of the proctodeum. X 310.
Sagittal sections of anus and stercoral pocket, about eight days after
hatching. X 110.
About one half of a transverse section in the region of the “ rudimentary
terga,” to show the mesodermic somites of these dorsal elements and
their connection with the ventral portion of the mesoderm. > 100.
Transverse section of an embryo near the beginning of reversion, pass-
ing through the stomodzum and the 2nd pairs of legs. 100. Com-
pare the separated nerve bands (gn.) with those of Fig. 62.
A section from the same embryo as Fig. 59, showing entodermic cells
(en.) in the region of the tergal elements.
Transverse section after completed reversion, through that part of the
stomodzum which becomes the sucking stomach. Itshows the mus-
cles attached to sucking stomach (mu. vrt., mu. lat.), and the approxi-
mation of the nervous bands (gn.). > 110.
BULLETIN OF THE
PLATE X.
Sections illustrating the development of the eyes.
The four pairs of eyes are called according to their positions: anterior lateral,
anterior median, posterior lateral, posterior median.
Fig. 63.
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aaUG:
ile
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A sagittal section showing an early condition of an anterior median eye,
—a thickened mass of “hypodermis” cells with the beginning of an
invagination. X 490.
Sagittal section of an anterior median eye after the invagination is fully
established, three or four days before hatching. X 430.
A frontal section through the anterior median pair of eyes, showing the
narrow lumen of the invagination and its limited lateral extension.
X about 300.
An older stage (one to two days before hatching) showing an elongation
on the part of the “ hypodermis ” cells which constitute the “ vitreous
body,” and also the closure of the invagination. X 430.
A sagittal section passing through an anterior and a posterior eye of the
same side, two days after hatching. X 430. !
Sagittal section through an anterior median eye one day before hatching.
X 480.
Sagittal section through an anterior median eye, eight days after hatch-
ing; the retinal portion has not yet reached its full devolopment.
X about 350.
PLATE XI.
Fig. 70-72, 77, 78, show the gradual headward concentration of the nerve bands.
m0.
(Me
mea
Fig. 77 represents the earliest stage, in which the nerve bands reach
nearly around the egg; Fig. 72 shows the nervous elements con-
tracted so as to occupy only the folded ventral region ; in Fig. 71, the
abdominal cord is shortened considerably more; Fig. 70 represents
the ventral ganglia concentrated within the thorax; Fig. 78 shows
the condition of the brain and ventral ganglia at the time of hatching.
Sagittal section approximately in the median plane, from an embryo
about two days before hatching.
Sagittal section through the brain and nervous ganglia at about the com-
pletion of reversion. X 110.
Sagittal section through the nervous system at the stage of the formation
of the proctodeum. X 100.
‘“« 73-76 show four successive stages in the formation of the lungs, all magnified
about 300 diameters.
“ 73. View of the right-hand surface of a sagittal section of the lungs in an
early condition (about the middle of the period of reversion), showing
the nuclei arranged in parallel rows.
THU
78.
MUSEUM OF COMPARATIVE ZOOLOGY. 103
PLATE XII.
Sagittal section (left-hand surface) from an embryo somewhat older than
the preceding.
Sagittal section of the lungs at about the time of hatching.
Sagittal section of the lungs five or six days after hatching; the upper
and lower walls of each lamella are connected by the union of the
nuclei (z/.).
Sagittal section showing the nervous system at the beginning of reversion.
Sagittal section of the cephalothorax at the time of hatching, to show the
post-stomodeal portion of the alimentary canal, and also the concen-
trated condition of the ventral ganglionic mass.
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No. 5.— Reports on the Results of Dredging, under the Supervision
of ALEXANDER AGASSIZ, in the Gulf of Mexico (1877-78) and in
the Caribbean Sea (1879-80), by the U. S. Coast Survey Steamer
“ Blake,” LrEuT.-COMMANDER C. D. S1GsBEE, U.S. N., and Com-
MANDER J. R. Barrett, U.S. N., commanding.
(Published by Permission of Cartite P. Patterson and J. E. Hitearp, Super-
intendents of the U. S. Coast and Geodetic Survey.)
XXVIII.
Description of Thirteen Species and Two Genera of Fishes from the
Blake Collection. By G. Brown GoopE and Tarueton H. Buay.
Tux following descriptions relate to species first brought to light by
Mr. Agassiz during his earlier “ Blake ” explorations in the Gulf of Mexico
and the Caribbean Sea, in 1877, 1878, and 1879. Several other species
have been diagnosed, and their characters will soon be published.
Aphoristia marginata, n. sp.
The species is described from a specimen collected by the steamer “ Blake”
at Station CLXXI, with 1 specimen from Albatross Station 2376 as a collateral
type.
The extreme length of the type is 102 millimeters.
The body is slender lanceolate in form, its greatest height contained 43 times
in the extreme length. The scales are moderate, strongly and sharply denticu-
late, the surface ornamented with many lines and striations, which are so
arranged as to form a semblance of median furrows ; 88 to 90 scales in a longi-
tudinal series, 34 in a transverse series.
Jaws and snout covered with scales.
The length of the head is contained 53 times in total length. The length of
the snout in that of the head 4} times, and equal to the diameter of the upper
eye.
The eyes are moderate, close together, the upper very slightly in advance.
The nostril, in a long, slender tube, nearly midway between lower eye and tip
of snout. ;
Mouth moderate, oblique, curved, its posterior angle beneath the anterior
margin of the pupil of the upper eye; its length of gape in that of head 4}
times, and 5 times in greatest height of body. Dentition feeble.
VOL. XII.— NO. 5.
154 BULLETIN OF THE
The dorsal fin begins at a point over the posterior margin of the upper pupil.
It is composed of 96 to 100 rays, those about the middle of the body the longest,
and contained about 2} times in the height of the body.
The anal origin is separated from the snout by a distance equal to four
times the length of the snout. It has 86-87 rays, and its height is slightly
less than that of the dorsal.
The median caudal rays are short, included 82 times in total length.
The distance of the ventral from the snout is contained 54 times in the total
length ; its distance from the anal, 14 times the diameter of the eye ; its rays,
four in number, the longest contained 22 times in head.
Color in life, reddish gray much speckled with brown. Belly bluish gray.
Bases and membrane covering fin-rays dark brown. Dorsal and anal fins very
dark on their last tenth. Caudal pale, in marked contrast with the dark area
of dorsal and anal. Tips of dorsal and anal rays, and some of the membrane
covering caudal rays, vermilion.
Color in alcohol, uniform grayish brown, lighter below, with a dark brown
line marking margin between the body and the base of the vertical fins, with a
lighter line or stripe, as wide as eye, inside.
Radial formula : D. 96-100; A. 86-87; V.4; P.none. Scales, 88 to 90-34.
SPECIMENS.
Sta. Lat. Long. Fms. No, Spec.
CLXXXI. 28° 49’ 88° 40/ 321 1
2376 20°) 3! 88° 16’ 324 1
XXVII. Off St. Vincent. 94 13
1154 1
Aphoristia pigra, n. sp.
This species is described from a specimen obtained by the steamer “ Blake”
from dredging off St. Kitts, at a depth of 250 fathoms, with the Fish Commis-
sion specimens from Stations 2318 (4) and 2405 (2) as collateral types.
It is distinguished by its abbreviated form, and its large, rough, strongly
pectinate scales. The extreme length of the type is 98 millimeters.
The body is shorter than in the congeneric Atlantic species ; its greatest
height is contained 3} times in its total length, or three times in total without
snout.
The scales are large, very rough, with strong horizontal strize and stoutly
denticulated margins, and rather loosely fixed to the skin; about 65 in a
horizontal series, 34 in a transverse series. The jaws and snout are covered
with small scales. The length of the head is contained 44 times in the total
length. The length of the snout is contained 4} times in that of the head.
The eyes are moderate in size, very close together, with no scales between ;
the upper is very slightly in advance, and is distant from the dorsal outline a
MUSEUM OF COMPARATIVE ZOOLOGY. 155
space equal to its own short diameter. The greatest diameter of the eye is
contained six times in the length of the head. The mouth is oblique, curved,
its posterior angle directly beneath the middle of the lower eye. Length of
gape in that of head four times. The teeth are feeble, closely placed, a little
stronger on the colored side.
The nostril tubular, a little nearer to the lower eye than to the tip of the
snout.
The dorsal fin begins at a point over the middle of the upper eye, and con-
tains about 90 rays to the middle of the base of the caudal. The rays about
the middle of the fin are the longest, their height being a little more than
i that of the body. The distance of the anal fin from the snout is contained
32 times in total length. The longest anal rays are about the middle of the
body ; their length is equal to that of the longest in the dorsal. The anal is
connate with the caudal, and consists of 69-75 rays.
The length of the median caudal rays is contained nearly seven times in the
total length. The distance of the ventral from the snout is contained 43 times
in the total length. It is separated from the anal by a distance equal to the
long diameter of the eye. The number of ventral rays is four ; the longest ray
is 34 times as long as head.
Color grayish or brownish, with a sub-metallic lustre upon the scales when
examined separately. The denticulations of the scales are dark and promi-
nent, giving a clouded general aspect. Some of the smaller specimens (from
Station 2318) have a few large irregular brownish blotches above and a dark
subcircular blotch near the root of the tail, its diameter twice that of the eye.
Colorless below.
Radial formula: D. 90; A. 69-75; V.4; P. none. L. lat. 65.
Specimens: “ Blake” Station xxm1.; 250 fms., off St. Kitts, W.I. ‘ Alba-
tross”” Stations 2318, 2425, 2405, 2374. Off Key West, Fla., and between
Delta of Mississippi and Cedar Keys, Fla.
Monolene atrimana, n. sp.
The length of the specimen described to base of caudal is 114 millimeters
(xvi. “ Blake,” off Barbadoes, 288 fathoms).
The height of the body (37 mm.) is one third of the total length without
the snout, and equals four times the long diameter of the eye ; it also equals
12 times the distance of the ventral origin from the snout. The height at the
origin of the ventrals (29 mm.) equals about three times the length of the lower
eye (9mm.). The least height at the base of the tail (8 mm.) equals 4 of
the length of the mandible (10 mm.). The body is thin, its greatest width
(45 mm.) equalling half the length of the eye.
Scales ovate, or oblong, smaller than in M. sessilicauda, and without evident
pectinations. The head is everywhere scaly, except on the lips and the ante-
rior half of the snout. The scaling of the fins is essentially the same as in
156 BULLETIN OF THE
MM. sessilicauda. There are 30 rows of scales above and 32 below the lateral
line on the colored side.
The lateral line of the colored side is strongly arched in its anterior part over
the base and anterior third of the pectoral fin. The arc of the curved portion
of the lateral line (10 mm.) equals 23 times the height of the curve (4 mm.).
The curve is entirely similar to that of VW. sessilicauda. The lateral line of the
blind side is nearly straight, very slightly ascending anteriorly. There are 105
scales in the lateral line to caudal base, 18 of these in the curved portion.
The length of the head (24 mm.) equals 2 of the standard length and 23
times the diameter of the eye. The distance from the snout to the front of
the upper eye (6 mm.) is much greater than the distance to the lower eye
(3mm.). The inter-orbital area is a mere narrow ridge, whose width (1 mm.)
equals only 4 of the length of the eye. The length of the maxilla (8 mm.)
equals + the length of the head, and on account of its oblique position its hind
margin does not extend much beyond the vertical through the front margin
of the lower eye.
The length of the mandible (10 mm.) equals 4; of the head’s length. The
teeth are uniserial, and well developed on both sides. The nostrils are in very
short tubes, in the same line with the interorbital ridge, the posterior one being
slightly less distant from the lower eye than the anterior is from the tip of the
snout. A concavity above the snout.
The dorsal fin begins upon the snout on the blind side in the perpendicular
through the front of the lower eye. It contains 124 simple rays, the longest
rays being in the posterior fourth of the fin, and half as long as the head. The
anal fin begins between the tips of the ventrals and under the origin of the
pectoral. The vent is not on the ventral outline, but on the blind side and
close to the beginning of the anal fin. The anal is composed of 100 simple
rays, the longest (14 mm.) being behind the middle of the fin and slightly
longer than the longest of the dorsal (13 mm.). The caudal is sessile, rounded,
the middle rays (20 mm.) about 4 of standard length of body. The pectoral
is present only on the colored side, is inserted close to the edge of the oper-
culum, its length (27 mm.) exceeding that of the head, and contained 4} times
in the standard length. The ventral of the colored side is nearly on the ridge
of the abdomen, while that on the blind side is mostly lateral and slightly
larger than its fellow. The length of the left ventral (7 mm.) is contained
about 33 times in length of head.
The color on the left side is light brownish gray ; the fins are mostly dusky,
except the right ventral, which is pale; the pectoral and the eyelids are
black.
D. 124; A. 100; V.6; P. 12. Scales, 30-105-32 (18 in curved portion of
lateral line).
A single specimen (XvI.) was taken by the “ Blake” off Barbadoes, in 288
fathoms, and another one (XviI.) in the same locality, at a depth of 218
fathoms.
MUSEUM OF COMPARATIVE ZOOLOGY. 157
Citharichthys dinoceros, n. sp.
The type is a specimen 92 mm. long to base of caudal, obtained by the
steamer “Blake” at Station xxt., off Guadaloupe, 175 fathoms.
The greatest height of the body (40 mm.) is contained 2.3 times in the total
length, and equals about four times the least height of the tail.
Scales thin, deciduous, cycloid, large, 48 in the lateral line, which is slightly
curved over the pectoral; 14 above and 16 below the lateral line.
The length of the head (27 mm.) is contained 34 times in the total length,
and equals about 34 times the diameter of the eye (8 mm.). The interorbital
space is very narrow, its width less than 4 diameter of eye ; ridge rather
prominent, narrow, sharp.
The upper eye distant from profile by a space (2 mm.) about 7 of the orbital
diameter.
The length of the maxillary (12 mm.) is less than half the length of the head ;
that of the mandible (16 mm.) morethan half, and twice the diameter of the eye.
The teeth uniserial in both jaws, those in the front much the largest. A
strong spine upon the snout overhanging the upper lip (much lower than in
C. unicornis). Above this there is a second, shorter spine.
The dorsal fin begins upon the snout in advance of eye upon blind side. It
is composed of 91 rays, the longest somewhat behind the middle of the fin
(its height 13 mm.), about equal to half the length of the head.
The anal fin originates about under the origin of the pectoral ; its distance
from the snout (30 mm.) equals 4 of the total length. It is composed of 73
rays, and is as high as the dorsal.
Caudal subsessile, pointed, its length (17 mm.) contained about 5} times in
total length, and equalling twice the diameter of the orbit.
The pectorals originate immediately behind the branchial opening, far below
the lateral line. The third and fourth rays of the fin upon the eyed side elon-
gated. Its length (88 mm.) is contained 23 times in total length. ‘This fin has
10 rays ; that of the blind side contains 6 rays; its length (12 mm.) is less
than 4 that of its mate, and is less than half the length of the head.
The ventral on the eyed side originates upon the ventral ridge at a distance
from the snout (27 mm.) equal to the length of the head; it contains 5 rays,
the length of the first (64 mm.) contained four times in length of the head.
The ventral of the blind side has 6 rays ; its length is contained 22 times in
length of the head.
Radial formula: D. 91; A. 73; P.10/6; V. 5. L. lat. 48, 14/16.
Color, grayish brown above, white below.
xxi Off Martinique. xix. Off Barbadoes.
xxvi. Off St. Lucie. RXEX, s “e
xxvilIl. Off Barbadoes.
158 BULLETIN OF THE
BATHYGADUS Gthr.
A genus of Macruride with large terminal mouth, prominent nape, no teeth,
lanceolate gill-rakers, free notched branchiostegal membrane, high vertical fins,
first dorsal composed largely of branched rays, anal fin set far back. Head
large, fleshy, without prominent ridges, spiny armatures, or external depres-
sions. Nape elevated, hump-like.
Snout broad, obtuse, not produced. Mouth terminal, very large. Suborbital
ridge very low, not joined to the angle of the preoperculum. The maxillary
may be received entirely within a groove under the prefrontal and suborbital
bones, its tip narrowed and blade-like. Intermaxillaries protractile downwards,
separated anteriorly, rib-shaped, compressed vertically, very broad and without
true teeth, and provided posteriorly with a short flange which is received under-
neath the maxilla. Mandible received within the intermaxillary bones, without
true teeth, but with minute asperities, similar to those in the intermaxillaries.
A barbel. Vomer and palatines toothless.
No pseudobranchie. Gill-rakers numerous, moderate, lanceolate, with mi-
nute denticulations along the inner edges. Branchiostegal membrane free from
the isthmus, deeply cleft; branchiostegals 7, very stiff. Gill-opening very wide.
Operculum with a blunt spine-like prominence at its angle. Ventrals below
the pectorals, many rayed, the anterior rays produced.
Dorsal consisting for the most part of branched rays.
Scales cycloid, plain : lateral line strongly arched over the pectoral.
Bathygadus arcuatus, n. sp.
The type is a specimen, 325 mm., obtained by the steamer “ Blake ” at Sta-
tion LXXXxIXx., off Martinique, at a depth of 334 fathoms. A much larger
specimen, 580 mm., was taken by the Fish Commission at Station 2394. This
specimen is referred to as a collateral type.
The body is shaped much as in Chalinura simula, but the nape is still more
convex. Its greatest height (57 mm.) is 53 in its total length. The back is
gibbous, the dorsal outline rising rapidly from the interorbital region to the
origin of the first dorsal, whence it descends gradually to the end of the tail.
The scales are moderate, cycloid, subovate, without armature ; those of the
abdominal region and those above the pectorals the largest. The lateral line
is strongly arched over the pectorals, the length of the arched portion con-
tained about 3} times in the straight portion ; the greatest height of the arch
is about ¢ of the length of its chord. 'The number of scales in the lateral line
is about 140, eight rows of scales between the origin of the dorsal and the arch
of the lateral line, 13 or 14 rows of scales between the vent and the lateral
line counting backwards, 22 counting forwards. Scales cover all parts of the
head except the jaws and chin.
The length of the head is contained 5 times in total. Interorbital area flat,
MUSEUM OF COMPARATIVE ZOOLOGY. 159
its width (11 mm.) equal to 4 length of head. Postorbital portion of head about
24 times diameter of eye. The operculum terminates in a flat obtuse spine, its
length, including the flap, about equal to diameter of eye. Preoperculum
entire, with a prominent ridge in advance of its posterior edge. The orbit is
rounded, the least diameter of the eye equal to the length of the snout, and
contained 43 times in length of head (slightly less in the larger specimen).
Snout very broad, obtuse, the intermaxillaries extending beyond it, its width
at the nostrils equal to about twice the length of the eye. Posterior extremi-
ties of the intermaxillary processes elevated, producing a decided hump upon
the top of the snout. The ridge formed by the prefrontal and suborbital bones
terminates very slightly behind the posterior margin of the orbit, and is not
connected with the angle of the preoperculum.
Nostrils immediately in front of the lower part of the eye, not tubular, the
anterior one very small, pore-like, only about } as large as the posterior one.
Distance of anterior nostril from tip of snout about 3 length of eye. Length
of barbel (51 mm.) 62 in length of body, and equal to length of head without
snout (in the larger specimen the barbel is as long as the mandible), more than
3 times as long as the eye.
There are no true teeth, the intermaxillaries and mandible being broad
plates, covered with minute asperities. A naked space at the symphysis of
the intermaxillaries.
Distance of first dorsal from snout (77 mm.) nearly 33 times length of its
base ; the fin contains 2 spinous and 10 or 11 branched rays ; the first spine
is minute, the second (in the types) somewhat mutilated, its length nearly 3
in length of head.* It is not stouter than the branched rays, and is entirely
smooth.
The second dorsal is separated from the first by a very short interspace,
equal to about 4 of the length of the eye. Its rays are long, subequal, the
first slightly the longest, its length equal to that of the base of the first dorsal.
The anal is much lower than the dorsal, the longest rays being in front, its
third ray about half as long as the first ray of the second dorsal ; this fin is
inserted under the seventh ray of the second dorsal. About three of the termi-
nal rays might be considered caudal rays.
Pectoral inserted slightly in advance of the ventral, which is in about the
same vertical with the origin of the first dorsal. The second ray of the pecto-
ral is slightly produced. The length of the fin equal to that of the head
without the snout.
Ventral insertion distant from the tip of the snout a distance equal to that
of first dorsal from snout. The first and second rays are filamentous, the latter
slightly the longer, and extending to the fifteenth (or eighteenth in larger
specimen) ray of the anal fin.
* Judging from the larger specimen, this spine in a usual state would be consid-
erably longer.
160 BULLETIN OF THE
Radial formula: D, 11. 9-10 (135); A. (120); P. 25; V. 8.
Color, brown ; vertical fins, bluish or black ; peritoneum, black ; inside of
gill-covers and roof of mouth, bluish.
2394.
2374. 2 juv.
Lxxxvul. Off Martinique. 476 fathoms. 1 “
LXXXIX. * rh 334“
Bathygadus favosus, n. sp.
The type is a specimen, 350 millimeters in length, obtained by the “ Blake”
at Station Lxxx., off Martinique, at a depth of 472 fathoms, with the Fish
Commission specimens catalogued below as collateral types.
The body is heavy, stout ; its greatest height, at origin of first dorsal (57 mm.),
is contained a little more than six times in the total length. The profile of
the body descends gradually and in a slight curve from the first dorsal to the
snout.
The scales are small, deciduous, cycloid, without armature, about 135 in the
lateral line, about 10 above and 16 below the lateral line, the latter series
counted from the vent.
The length of the head (65 mm.) is contained about 5} times in total length.
The interorbital area is slightly convex ; its greatest width (22 mm.) equals
about 4 of the length of the head. The postorbital part of the head is 22 times
as long as the eye, which is nearly round, its diameter equal to 4 the length of
the head. The snout is broad, oblique, its width at the nostrils (23 mm.) a
little more than the width of interorbital area; its length (17 mm.) slightly
more than } that of the head. The nostrils are close to and in front of the
middle of the eye, the posterior one somewhat the larger. No barbel.
The teeth in both jaws in villiform bands ; a naked space at the symphysis
of the intermaxillaries. The intermaxillary bands are more than twice as wide
as those on the mandible. Vomer and palatine toothless. The longest gill-
raker on the anterior arch is slightly more than half as long as the eye. The
number of gill-rakers on this arch is 25, 20 being below the angle.
Pseudobranchie present, very rudimentary in some individuals, in others
wanting or present only upon one side.
The first dorsal is distant from snout (68 mm.), which is slightly more than
length of the head; the length of its base (24 mm.) is about equal to width of
the snout at the nostrils. The fin consists of 2 spines, the first of which is mi-
nute, and 9 branched rays. The length of the longest spine, which is armed,
is contained twice in that of the head (specimens examined imperfect). The
second dorsal begins immediately behind the first, the membrane being con-
tinuous. The anterior rays are longest (apparently about } the length of the
head).
MUSEUM OF COMPARATIVE ZOOLOGY. 161
The anal is lower than the second dorsal; its distance from the snout (112 mm.)
is about equal to 4 of the total length.
The pectoral is inserted under the anterior rays of the first dorsal, and very
slightly in advance of the origin of the ventral. Its length is more than half
that of the head.*
The distance of the ventral from the snout (69 mm.) is contained 5 times in
the total. This fin is inserted nearly under the base of the pectoral ; the first
ray is somewhat produced ; f its tip reaches to the fourth ray of the anal fin.
Radial formula: D. 11. 9, 125; A. 110; V.9; P. 14; B. 7.
Color, bluish brown, darkest upon head and abdomen, especially in Museum
specimens.
Lxxx. Off Martinique. 472 fathoms. “ Blake.”
34,911. N. Lat. 15° 24’ 40”, W. Long. 68° 31’ 40”. “ Albatross.”
34,909. 2:
34,910. N. Lat. 15° 24’ 40”, W. Long. 63° 31’ 40”. i
34,920. “ « «“
34,918. «“ «“ “
(2392).
YLXXx1I. 1 juv.
(2394). 1 “
Neobythites robustus, n. sp.
The type is from “Blake” Station xcrv., off Moro Castle, Cuba. 250-400
fathoms. Length, 88 mm.
With specimen (No. 29,057) from ‘‘ Fish-Hawk ” Station 1043, Lat. 38° 39’,
Long. 73° 11’, 130 fathoms, as a collateral type.
Body rather short and deep, its greatest height (19 mm.) nearly 42 in total
length and about equal to length of head. The interorbital area is convex ;
its width (6 mm.) is greater than the diameter of the circular eye (5 mm.)
and 14 times the length of snout (4mm.). The length of the head (19 mm.)
is about 4 times the diameter of the eye. The mouth is moderate, the max-
illa extending to the vertical through the posterior margin of the eye, the
mandible a little beyond, its length (10 mm.) equal to that of postorbital part
of head. Teeth in villiform bands in the jaws, and on the palatines. Vo-
merine teeth bunched in a circular patch. Gill-rakers moderate, the longest
a little more than twice in diameter of eye, four above angle of first arch,
eleven below. Pseudobranchie rudimentary. Gill-opening wide, the mem-
brane deeply cleft, behind free from the isthmus. A pair of short flat spines
* In one of the “ Albatross” specimens the pectoral extends to the vertical
from the eighth ray of the second dorsal.
Tt Its length in one of the “ Albatross” specimens is equal to that of the head
without snout.
VOL. XII. — NO. 5. 11
162 BULLETIN OF THE
upon the anterior portion of the operculum, extending backward nearly to
its posterior edge.
The nostrils are smali, the anterior as close to the snout as the posterior
ones are to the eyes. No apparent cirri. The scales are minute ; the lateral
line is obsolete on the last fourth of the length of the body.
The dorsal origin is behind that of the ventral and pectoral; its distance
from the snout (24 mm.) is contained 32 times in length of the body. The
height of the fin is moderate; the longest ray is contained about 3 times in
the length of the head.
The anal origin is under the eighteenth ray of the dorsal; the height of the
fin about equals that of the dorsal. The vertical fins are not connate with the
caudal, which consists of 12 or 13 very slender rays, its length nearly equal
to half that of head.
The pectoral with a broad base, close to gill-opening, its length nearly 2 that
of the head,
The ventral a single bifid ray, inserted slightly in advance of the vertical
through the base of the pectorals, and not far from the humeral symphysis.
It reaches nearly half-way to the vent, the distance of which from the origin
of the ventral is equal to the length of the head.
Color yellowish brown.
Neobythites marginatus, n. sp.
The type is from “ Blake” Station Lxx1x., off Barbadoes, 209 fathoms.
Body compressed, somewhat elongate ; its height (18 mm.) contained 5§ times
in total length, and less than the length of the head. Interorbital area convex,
its width (54 mm.) greater than the diameter of the circular eye, which is 44 mm.
The length of the head (22 mm.) is contained 4% times in that of the body.
Mouth large, the maxilla extending considerably behind vertical through pos-
terior margin of orbit ; its length equals half that of the head. The length
of the mandible (13 mm.) is slightly more than 2 of height of body.
The teeth as in N. gillit.
Gill-rakers slightly longer than half the diameter of the eye, 7 and 3 rudi-
ments below the angle of the anterior arch. Pseudohranchie absent. Gill-
openings as in N. robustus. A long flat spine upon the upper edge of the
operculum, extending back nearly to its margin. Two short flat spines upon
the angle of the preoperculum. Nostrils as in N. gillit.
The scales small, very closely imbricated, in about 123 rows, 7 above and 29
below the lateral line.
The lateral line obsolete in its posterior half.
The dorsal is composed of 101 rays; its distance from the snout is contained
4 times in total length.
The anal originates uader the fourteenth dorsal ray at a distance from the
snout contained more than 22 times in total length.
MUSEUM OF COMPARATIVE ZOOLOGY. 163
The caudal consists of about 8 or 9 rays very closely placed ; its length is
contained about 10} times in the total length.
The pectoral is placed as in N. robustus ; its length about equal to 2} times
that of the head, extending to vertical through the vent.
The ventral, a bifid ray inserted in advance of base of pectoral, not reaching
to the vent; its length (14 mm.) considerably less than the height of body.
The distance from its origin to the vent (19 mm.) slightly more than the
height of the body.
Color light yellowish brown, an obscure narrow band of darker brown com-
mencing on the snout, interrupted by the eye, and extending backward 3% of
the distance to the tail, another beginning on the snout, extending ove> the eye
and back as far as the first described, interrupted posteriorly. Dorsal fin milky
white at base in its anterior third, above this a blackish band extending the
whole length of the fin. A narrow white margin above.
Aphyonus mollis, n. sp.
The type is a specimen obtained at “ Blake” Station ccxx1., Lat. 24° 36’ N.,
Long. 84° 5’ W., at a depth of 955 fathoms. 85 + «mm.
This species is closely allied to Aphyonus gelatinosus, Gthr., obtained by
H. M.S. “ Challenger.”
The body is much compressed, its greatest height (14 mm.), 6 in its total
length. Head thicker than body, its height (15 mm.) slightly greater. Length
of head (20 mm.) about 4} in total; width (11 mm.) over half its length.
Snout, 3} in length of head. Eye not externally visible. Diameter of orbit, as
seen through the skin, about } length of head. Maxilla extends to vertical
through posterior margin of orbit, the mandible somewhat farther back, its
length (13 mm.) nearly equal to height of body. A few weak teeth on vomer
and palatines, mandible, and very rudimentary ones in maxillary ; not visible
to the eye, but appreciable to the touch. Gill-lamine on the fourth and rudi-
mentary gill-rakers, 8 rudiments and 4 developed below the angle. Dorsal
origin almost over posterior edge of operculum, its distance from the snout } of
total length ; fin-rays, more than 110 well developed, the longest 3 in head.
Anal origin slightly nearer base of caudal than to tip of snout, its rays shorter
than those in the dorsal. Pectoral with a fleshy base ; its origin somewhat
behind that of the dorsal, its length equal to width of head. Ventral origin in
advance of that of pectoral, close to humeral symphysis; the fin is a single
simple ray, whose length (11 mm.) equals that of the pectoral: its tip does
not reach the vent, by a space equal to height of head.
Skin not loose. Texture of body rather firm, not transparent, whitish.
164 BULLETIN OF THE
BARATHRONUS, n. gen.
Head stout, body and tail compressed, covered closely by skin, scaleless.
Vent far behind pectoral, included in a cleft. Mouth wide, oblique, the lower
jaw projecting. Intermaxillary teeth rudimentary ; several fang-like teeth
on the head of the vomer, none on palatines. A few rather large recurved,
separated teeth in the mandible. WNostrils close together and small. Eye
visible through the skin, partly upon the top of the head, with or without
dark pigment in the iris. Barbel none. Gill-rakers very numerous and slender,
and rather long. Gill-laminz well developed on all the arches. No pseudo-
branchiz. Head full of muciferous channels. Gill-membranes not united, but
covered by a fold of skin. Ventrals reduced to single simple rays, placed in
advance of the pectorals and close to the humeral symphysis. Dorsal and anal
placed far back.
Caudal scarcely differentiated, composed of rather numerous very slender
rays upon a somewhat narrow base.
Barathronus bicolor, n. sp.
The type is an individual, 120 mm. long, from “ Blake” Station Lxx1., off
Guadaloupe, at a depth of 769 fathoms.
Body much compressed, its greatest height (19 mm.) contained 63 times in
the total length. Head much thicker than body, its greatest width equal to 2
of its length (23 mm.), which is contained 5} times in the total length. Eye
concealed by the skin ; diameter of orbit about equal to width of interorbital
area, and contained 42 times in length of the head. Maxilla extends slightly
beyond the perpendicular through posterior margin of orbit; it is almost
entirely concealed under the preorbital, and is much expanded at the tip,
where its width is rather greater than that of the eye. Intermaxilla very
thin, broad, and slightly protractile.
Vomer very close to intermaxillary symphysis, its head somewhat raised and
bearing three fang-like teeth (two of which are on one side and one on the
other, in the type separated by a moderately wide interspace). The mandible
has five enlarged, separate, recurved teeth upon each side, which increase in
size posteriorly ; its upper edge, posteriorly, is produced above the level of the
tooth-bearing surface, and is received under the expanded maxilla. The long-
est gill-raker is about as long as the eye. The dorsal origin is distant from the
snout (54 mm.), which is contained slightly less than twice in the total length.
Its rays are well developed, numerous, long and slender, about 70 in number ;
the longest contained about 3 times in the length of head.
The anal originates in vertical from fourteenth dorsal ray, equidistant be-
tween eye and base of caudal. It contains 57 rays, about as long as those in
the dorsal.
The pectoral with a fleshy base, its length (18 mm.) a little less than height
of body.
MUSEUM OF COMPARATIVE ZOOLOGY. 165
The ventral well in advance of pectoral, close to humeral symphysis, the
rays being placed very close together at their origin, the length of the fin
(13 mm.) contained about 9 times in the total length, about 3 times in distance
from its origin to the vent.
The caudal has about 10 rays; its length is contained about 8 times in the
total length.
Color, yellowish white, with a broad vertical band of black from the origin
of ventral nearly to the vent, another similar and narrower band above it upon
each side.
Bregmaceros atlanticus, n. sp.
Specimens were obtained by the “ Blake” at the following stations : —
xorx. Off Granada. 90 fathoms. 3 spec.
CV. ? 2 1 «&
oxi. Off Neris. 305 fathoms. |
CLXxxv. Lat. 25° 33’ N. Long. 84° 21’ W. 101 fathoms. L$
The species agrees very closely with the only other known species of the
genus, B. macclellandii, Thompson (= Calloptilum mirum, Richards.), from the
Western Pacific, from which, however, it differs in the lesser number of rays
in the first anal, and in the greater height of the vertical fins (judging from
figures.
The type (cv.) is 46 mm. long to base of caudal. Form compressed, mod-
erately elongate. Body height (6 mm.) 72 in its length. Interorbital area
convex, its width (2} mm.) greater than diameter of eye (2 mm.), which is four
in length of head (8 mm.). Length of head 53 in total. Jaws even in front.
Maxilla reaches to vertical through middle of eye ; the mandible to vertical
through its posterior margin.
Teeth on intermaxillary minute, apparently in a single series, mandibulary
teeth biserial, the inner teeth enlarged.
Scales large, about 10 in a transverse series, about 65 in a longitudinal
series.
Cephalic appendage reaches nearly to base of first dorsal, its length (10 mm.)
44 in total.
Distance of dorsal from snout (17 mm.) 23 in total ; that of anal the same.
The dorsal and anal fins received in a groove formed by the scales along
their bases.
Anterior portion of second dorsal and second anal less elevated than in
B. macclellandii. The differentiations between the developed and undeveloped
rays of the anal are so slight that the limits of the so-called anterior and pos-
terior sections of the fin cannot be determined.
Length of the longest anal ray (22 mm.) about 2 in body length.
D. 1415-16. A. 15-16 +2 (7 or 8) + 21-22.
166 BULLETIN OF THE
Peristedium longispatha, n. sp.
Ly. Off Santa Cruz. 314 fathoms.
Body high anteriorly, its greatest height (89 mm.) contained 4} times in
total length. The length of the head, without prolongations, is contained 24
times in the total length ; with prolongations, 2 times. The crown of the
head is flat, separated from the nuchal plate by a deep furrow, which is convex
forward. The interorbital space is deeply concave, the supraorbital margins
being swollen ; its width (16 mm.) equal to the long diameter of the orbit.
No protuberance on the forehead, which is much depressed, its outline descend-
ing abruptly and rapidly in front of the eyes. A ridge, but no spine, beneath
the eye. The length of the snout (49 mm.), including the preorbital extension,
is more than half the length of the head; the preorbital extension equals
about half the length of the snout. The processes are flat, rounded anteriorly,
and covered with minute granulations ; they diverge considerably, the distance
of the tips apart (36 mm.) being nearly twice that at their bases (19 mm.).
A ridge arises at the base of the preorbital process and extends to the angle
of the preoperculum, and its width at the angle (8 mm.) is contained twice
in the diameter of the orbit. A narrow inconspicuous and interrupted ridge
below. A ridge on the operculum, ending in a sharp spine at the angle ; its
length is equal to the diameter of the eye.
The jaws are feeble, toothless ; the lower jaw with 2 long, much fringed
barbels, and 14 shorter ones. The length of the long barbels (82 mm.) twice
the diameter of the eye.
The maxilla does not quite reach the vertical through the anterior margin of
the eye. The diameter of the eye (16 mm.) is contained four times in the
length of the head without its prolongations. The greatest width of the head
over the preopercular ridge (61 mm.) is contained three times in the total
length.
The dorsal origin is directly in a line with the upper angle of the gill-open-
ing. The longest spine (18 mm.) slightly longer than the width of interorbital
space. The fin has 8 + 19 rays.
The anal origin is under that of the second dorsal. The fin has 19 rays.
Caudal small, slightly emarginate, the length of its middle rays (23 mm.)
equals 14 times the diameter of the eye.
Ventrals slightly in advance of the pectorals and extending farther back,
reaching slightly beyond vent, and to vertical through seventh row of scales.
Pectoral short, extending to vertical from fifth scale of the lateral line, the
longest detached ray to the sixth. Twenty-nine rows of scales.
Color in life, bright roseate; a black blotch near the tip of the pectoral.
Dorsal with narrow dark margin; tip of caudal black.
The elongation of the preorbital extension is noticeable in the smallest
examples.
MUSEUM OF COMPARATIVE ZOOLOGY. 167
Lyi. Off Santa Cruz. (Type.) “ Blake.”
Lx. Off Barbadoes. 209 fathoms. ‘
Ext “ 66 66 “cc
2397. * Albatross.”
2376. ss
2407. ee
2358. sf
Peristedium platycephalum, n. sp.
The length of the type to tip of snout, without prolongations, is 145 mm.
Type Lx. Off Barbadoes. 123 fathoms.
LIX. re x 288) 9"
2299 yg.?
Body much depressed, its greatest height (23 mm.) 6} in body length, 6? in
total.
Length of head without prolongations (47 mm.), twice the height of body, 34
in its length, with prolongations 24 in body length. Interorbital space deeply
concave, the supraorbital margin being swollen, its width (14 mm.) equal to the
long diameter of the eye. No protuberance on the forehead, which is much
depressed, its outline descending abruptly and rapidly in front of the eyes. A
ridge below the eye, not armed; a small vertical spine behind each nostril.
Stout spines upon operculum and several upon the vertex. The length of the
snout with its extensions (29 mm.) is half the length of the head, its processes
(10 mm.) about 3 in its own length. The processes are flat, triangular, di-
verging slightly, the distance apart of their tips 2-24 that at their bases. A
ridge extends backwards from the base of each process along the lower edge of
the preoperculum, ending behind in a sharp flat spine, the greatest width of the
expanded portion, on the preoperculum, only } as wide as the eye. Beneath
this is another less conspicuous ridge with minutely serrated edge, which is
double in front and single behind, the two portions separated by a slight notch.
Jaws normal, the two tentacles much fringed, their length (16 mm.) not
much exceeding the diameter of the eye ; between them, and placed about equi-
distant from each other, are two bunches of short tentacles, about four in each.
Chin with numerous short tentacles, some of them as long as the eye, arranged
for the most part in bunches of four.
Maxilla does not reach to the anterior margin of orbit.
Diameter of eye (13 mm.) nearly four in greatest length of head, and exactly
half total length of snout. Greatest width of head, over the preopercular
ridges (43 mm.), nearly equal to its own length without the processes. Dorsal
origin over the upper angle of gill-opening. The fin has 8+ 17 rays. The
length of the longest spine (18 mm.) is equal to that of postorbital portion
of head.
168 BULLETIN OF THE
Anal origin about under origin of second dorsal, a trifle farther back, and in
the vertical through the space between the seventh and eighth lateral scutes.
The fin has 17 rays. It is about as high as the dorsal.
Caudal small, slightly emarginate, with tips slightly produced, the length
of the middle rays (18 mm.) equal to that of the dorsal.
Ventral origin in advance of the axil of the pectorals; the fin extends slightly
beyond the vent, but not quite to the origin of the anal ; its length (35 mm.)
about twice the length of the dorsal.
Pectoral rather long, extending to the ninth scute of the lateral line, and
past the vertical through the origin of the anal. Twenty-nine rows of scutes.
Color red. Body and fins mottled and blotched with darker.
BENTHOSAURUS, n. gen., Synodontid.
Body long, somewhat compressed, tapering into a slender elongate caudal
peduncle. Scales cycloid, of moderate size. Head slightly depressed ; cleft
of mouth wide, horizontal, the lower jaw projecting at its extremity and
anteriorly at the sides. The maxilla is long, not stout, dilated posteriorly ;
the intermaxillary very long, styliform, tapering, immovable. The inter-
maxillary and mandible with bands of small teeth, of uniform size, inter-
rupted at the symphysis. A short oblong band of similar teeth on each
side of the vomer, separated by a rather wide interspace. Palate and tongue
smooth. Eye very small, inconspicuous. Gill-opening extremely wide, the
branchiostegal membrane free from the isthmus. Gill-rakers long and slender,
numerous, about twice as many below the angle as above. Pseudobranchiz
absent. Branchiostegals eleven. All the fins well developed; no adipose
dorsal. Dorsal fin median, anal post-median. Caudal forked, with lower
lobe produced. Ventral seven-rayed, inserted opposite the interspace between
pectoral and dorsal, the outer ray produced.
Benthosaurus is closely allied to Bathysaurus and Bathypterois, resembling
the latter in nearly every particular save in the structure of the pectoral fins.
Benthosaurus grallator, n. sp.
Body elongate, somewhat compressed, depressed slightly forward, tapering
pehind into a long slender tail; its greatest height contained 7} times in its
standard length, and equalling half the length of the head, its greatest width
3 the length of the head; its height at the origin of the anal, of its greatest
height. Least height of tail half the height of the body at the ventrals.
Length of caudal peduncle 64 times its least height.
Scales very thin, cycloid, leathery, deciduous ; oval in form, except at the
base of the dorsal and anal fins, where they become more elongate ; the hori-
zontal diameter of a scale in the lateral line equals twice the diameter of the
eye. The lateral line is straight, above the median line anteriorly, becoming
MUSEUM OF COMPARATIVE ZOOLOGY. 169
median on the caudal peduncle, the tube-bearing scales being prominent, and
about 55 in number. Between the dorsal fin and the lateral line are about
nine rows of scales ; between the latter and the anal fin, eight or nine rows.
Head twice as long as the greatest height of the body, its length contained
a little less than four times in the standard body length, considerably depressed,
scaleless except on the vertex and the preoperculum. Operculum, perhaps
accidentally, denuded.
The snout is much produced, almost equal to the width of the interorbital
space, which is convex. The maxilla extends far behind the posterior margin
of the eye, its length equalling that of the postorbital part of the head. The
mandible projects beyond the upper jaw to a distance slightly more than the
diameter of the orbit, and receives the snout within its extremity when the
jaws are closed. The teeth have been fully described in the generic diagnosis.
The mandible has a series of seven large pores on its lower surface. There are
several similar pores under the eye. The nostrils are situated about midway
between the eye and the extremity of the snout, small, slit-like, the posterior
about twice as large as the anterior one in each pair.
The dorsal fin contains eleven rays, and is inserted midway between the tip
of the snout and the base of the middle caudal rays. The fin is highest in
front, the length of the rays diminishing rapidly posteriorly. sake is ap-
parently no adipose dorsal.
The anal fin contains twelve rays and is similar in shape to the dorsal, the
anterior rays being the longest, and about equal in length to the mandible ; its
distance from the snout is about three times the length of its longest ray.
The caudal is forked, its middle rays 2 as long as those in the upper caudal
lobe ; the lower lobe is much prolonged, ‘tlle lower ray being more than 4 times
as long as the middle rays. Its extremity is broken off in our specimen, but
apparently it must have been nearly twice as long as the stump which now
remains.
The pectoral fin is normal, composed of 9 rays, and is inserted close to the
opercular flap ; its length is slightly greater than that of the head (though
mutilated), extending beyond the origin of the dorsal.
The ventral is composed of 7 rays, and its base is entirely in advance of the
perpendicular from the origin of the dorsal ; the inner rays reach to the vent,
while its outer ray is enormously prolonged, extending far beyond the extrem-
ity of the upper caudal lobe ; the length of the prolonged ray is fully 4 times
that of the head. The two ventrals are close together.
Radial formula: D.11; A. 12; P.9; V.7; B.11. Scales, 9-55-8 or 9.
Color brown, the roof of the mouth and inside of the branchiostegal flap
black, as well as the operculum and branchiostegal membrane.
A single specimen, 392 mm. (15} inches) long to the tips of the prolonged
ventral rays, was taken at a depth of 1850 fathoms, at Station CLXXIV., in
Lat 24° 33’ N., Long. 84° 23’ W.
A second example of the same fish, and of nearly the same size, was taken
170 BULLETIN OF THE MUSEUM OF COMPARATIVE ZOOLOGY.
by the steamer “ Albatross,” September 6, 1884, in Lat. 39° 3/15” N. and
Long. 70° 50’ 45” W., at a depth of 1537 fathoms. This is well preserved, and
throws additional light on the external characters of the species ; the fins,
especially, are more nearly perfect. Measurements are given alongside of those
taken from the “ Blake” specimen.
Benthosaurus grallator.
Current number of specimen. . . ..... . . cCLxxiv. Blake. 35,651.
Length to base of middle caudalrays. . . .... =. 275mm. 267 mm.
Body.—Greatestiheight. . « <, ¢ « Bos & te S16 oe ai)
Greatest wiGths ios. ase seals oe miey an yan tek 2A. 20)
Heizht ataventrala ss curse ass aceon et lauee nota | ar en) se 3a;
Least height of tail . loa dao MORE Mio, eat ce see iLGy Ij
Ihengthoficaudal’peduncle’ = es 2) se Ob) BH
Head —Greatestlengthy “so cn area's.) eer ee eae eee Tas (0)
Gréatest-width® 2472) "sai (SB 2B 266
Width, of interorbitaljareai-.0. 6) sce Hille “ee G) 20m ce 18
Mengthiof snoutiis fees aid <0 lente ae kee Rae LD ees Ihe}. 6
enegth of upper jawey So. ft) io) (ie) toy Wildes mel 48 “ 48 “
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Distance from snout toorbit ........ 7A —
Diameter OfOrbDit.e-— cece «Mme e ee Ge DAs 2.5
Worsal’— Distancefromisnout, ~. = sere pen es) Owen os 125.
Length of base. . .. Tike eeRomet Poteet: ai 46 «
Length of longest ray (first) . Hal Abie Gh = eee See 49+ “ — «
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PLATE V.
Pecten (Propeamusium) cancellatus E. A. Smith. Page 213.
Same; bit of the sculpture enlarged ; 26.0.
Pecten (Propeamusium) Sayanus Dall; 15.5. Page 214.
Pecten caurinus Gould, young valve ; 6.0. Page 216.
Pecten (Propeamusium) Holmesti Dall; 12.0. Page 214.
Hinnites Adamsi Dall; upper valve; 28.0. Page 223.
Pecten (Propeamusium) alaskensis Dall; 22.8. Page 2165.
Pecten (Pseudamusium) reticulus Dall; 7.0. Page 221.
Pecten (Propeamusium) Sayanus Dall; 15.5. Page 214.
Pecten (Pseudamusium) reticulus Dall; 7.0. Page 221.
Pecten (Propeamusium) Holmesii Dall ; 12.0. Page 214.
(
Pecten (Propeamusium) Pourtalesianus Dall; 13.5. Page 211.
BLAKE MOLLUSCA. PLATE V.
ZPTZE
rata ar
!
McConnell del. Photo, Lith. by L. S. Punderson, New Haven, Conn.
=> Lut
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PLATE VI.
Magasella radiata Dall ; 6/1 [N. W. America].
Thecidium Barretti Davidson ex Woodward; 5.1. Page 205.
Modioln polita Verrill & Smith; 42.5. Page 234.
Terebratula Bartlettii Dall; 40.0. Page 200.
Pecten (Janira) hemicyclica Ravenel; 4.0; inside upper valve of
young shell. Page 207.
Terebratula incerta Davidson; 11.5; interior. Page 201.
Same, horizontal view of loop.
Modiolaria lateralis Say ; 7.5. Page 286.
Arca ectocomata Dall; 46.0. Page 248.
Tellina sybaritica Dall; 7.0. Page 277.
Crassatella floridana Dall; 11.0; young shell. Page 256.
MUSEUM OF COMPARATIVE ZOOLOGY. 185
glossa, as represented chiefly by the Plewrotomide, outnumber any other
single group of mollusks in the abyssal fauna.
.The groups of less specialized character, such as the tooth-shells
(Dentalium), are rather abundant in species, more so than those of a
medium character which intervene between them and the highly spe-
cialized Pleurotomide, but our knowledge of the deep-sea Mollusca is
yet too imperfect to afford any important generalizations on this score.
So far as yet determined, the groups systematically lowest in the scale,
such as the Chitonide, or mail-shells, are rare in deep water, yet the
representatives of this family found there belong to the more archaic
sections of their class. » Some very interesting forms of the molluscoid
Brachiopoda are found in the abyssal region, among them some of the
largest known species; but as a general rule the number of species is
small, and bears no comparison to that afforded by the archibenthal
area. In the early days of deep-sea exploration it was more or less
confidently anticipated that the deeps would afford specimens of ani-
mals characteristic of remote geological ages, which might have been
preserved there, little changed, while their shallow-water relatives
had perished from the earth. This expectation has been disappointed.
While there are numerous representatives of forms first made known
from Tertiary strata and hitherto unknown from shallow water, there
are not enough of these to characterize the abyssal mollusk fauna as
archaic in type, — not more, perhaps, than still exist in comparatively
shallow water ; none so remarkable as the 7’rigonia of austral seas, the
Pleurotomaria of the Antilles, or the Nautilus of the Spice Islands.
There is no relation of abyssal species with fossil species of mollusks
which compares with that between the land and fresh-water faune of
to-day and those of the Carboniferous and Jurassic strata, whose Unios,
Physas, and Pupas are hardly more than specifically distinct from still
existing members of the same genera, I am impelled to insist more
forcibly on these facts from realizing that, in the reports on the mollusks
collected by the “ Blake,” as in the lists of those found by the Fish Com-
mission and by foreign dredging expeditions, many species find a place,
and attract general attention from intrinsic interest, which are not to
be counted as true abyssal species. Such are the Plewrotomaria, just
mentioned, of which two species were found by the “ Blake” in 69-200
fathoms, and which belong to a group going back almost unchanged to
the earliest fossiliferous rocks, such as the Cambrian formation. One
great value of the Blake collection consists in the fact that it contains
representatives of animals from all depths in the same general area,
186 BULLETIN OF THE
beginning near the shores and extending to the abysses, while most
deep-sea dredging parties have ceased work as soon as they came into
comparatively shallow water, for fear of confounding what were sup-
posed to be two sharply differentiated faune. We learn from the work
of the “ Blake” that the differentiation is much less marked than would
be anticipated, and that, in addition to the species found widely dis-
tributed over the floor of ocean, there is an important contingent of
species which are probably derived from the adjacent litorale, as well
as a tolerable number which are found in water of all depths, from a few
fathoms on the Florida coast to two thousand fathoms in the adjacent
deeps, without affecting their external characters. Further exploration
in other seas will probably prove that there are local faune in the ar-
chibenthal areas, as there are on the shores, a conclusion which would
accord well with what we learn from paleontology.
One point has been brought out by the study of the Blake collections
which was foreshadowed by Pourtaleés in his study of the deep-sea corals
dredged by him in the vicinity of the Florida reefs. It is being con-
firmed by present study of the mollusk fauna of our southern coast in
connection with the tertiary and quaternary fossils of the Atlantic and
Gulf slopes. It is that a large proportion of the tertiary shells which
have been called Pliocene, or even Miocene, in this country and in
Sicily, still exist in a living condition near our shores. The tertiaries of
Calabria and of localities in the South of Italy having been pretty fully
studied, Pourtalés was able to identify many of his corals with those
found by Italian paleontologists. Had our own tertiaries been half as
well known, or had he had a good collection of the shells of the southern
and West Indian tertiaries, he would have been able to recognize their
relations with his dredgings as being equally close. At least this is the
case with the molluscan fauna, if not with other invertebrate groups.
His dredgings, it should be clearly understood, were in the archibenthal,
and not the abyssal region, which last his operations never reached,
There is not enough known, so far, of the strictly abyssal mollusk
fauna, to afford a safe basis for generalization in connection with these
tertiaries. I may observe, however, that from middle Louisiana, on
the edge of the Eocene beds, I have recently received certain fossils
which present every appearance of being a deep-water (archibenthal ?)
deposit, including ZLimopsis and several other characteristic forms. ‘The
data which have been received relating to the circumstances under
which the fossils are found are as yet insufficient for a satisfactory
discussion of the subject.
MUSEUM OF COMPARATIVE ZOOLOGY. 187
SYSTEMATIC LIST OF THE SPECIES.
A. MOLLUSCOIDEA.
CLtass BRACHIOPODA.
Order ARTHROPOMATA.
Famity TEREBRATULIDZ.
TEREBRATULA (Auct.).
Terebratula cubensis Pourtalés.
Terebratula Moseleyi Davidson.
Terebratula Bartletti Dall.
Terebratula incerta Davidson.
THREBRATULINA D’Orbigny.
Terebratulina Cailleti Crosse.
Famity EUDESIIDZ.
EUDESIA King.
Eudesia floridana Pourtalés.
Famiry MEGATHYRID.
MEGATHYRIS D’Orbigny.
Megathyris (Cistella) Barrettiana, var. rubrotincta Dall.
Megathyris (Cistella) Barrettiana, var.? Schrammi C. & F.
Megathyris (Cistella) lutea Dall.
Famiry PLATIDIIDZ.
PLATIDIA Costa.
Platidia anomioides Scacchi, var. radiata, Dall.
Famity THECIDUDZ.
THECIDIUM Sowerby.
Thecidium mediterraneum Sowerby?
Thecidium Barretti Woodward.
188 BULLETIN OF THE
Order LYOPOMATA.
Famity CRANIIDZ.
CRANIA Retzius.
Crania Pourtalesii Dall.
B. MOLLUSCA VERA.
Ciass PELECYPODA.
Famiry PECTINIDZ.
PECTEN Miller.
Subgenus JANIRA Schumacher.
Janira hemicyclica Ravenel.
Subgenus AMUSIUM Schumacher.
Amusium Dalli Smith.
Section Propeamustum De Gregorio.
Amusium Pourtalesianum Dall.
Amusium Pourtalesianum, var. striatulum Dall.
Amusium Pourtalesianum, var. marmoratum Dall.
Amusium cancellatum Smith.
Amusium Hoskynsi Forbes.*
Amusium Holmesii Dall.
Amusium Sayanum Dall.
Amusium alaskensis Dall.*
Subgenus PECTEN s.8
Pecten magellanicus Gmelin.
Pecten caurinus Gould.
Pecten nucleus Born. °
Pecten dislocatus Say.
Pecten phrygium Dall.
Pecten exasperatus Sowerby.
Pecten ornatus Lamarck.
Pecten antillarum Récluz.
Pecten effluens Dall.
MUSEUM OF COMPARATIVE ZOOLOGY.
Section Pseupamusium H. and A. Adams.
Pecten imbrifer Lovén.*
Pecten reticulus Dall.
Pecten thalassinus Dall.
Pecten Sigsbeei Dall.
HINNITES Defrance.
Hinnites Adamsi Dall.
Famity LIMIDZ.
LIMA Brugiére.
Lima squamosa Lamarck.
Lima tenera Sowerby.
Lima inflata Lamarck.
Lima hians Gmelin.
Lima albicoma Dall.
LIMATULA S. Wood.
Limatula setifera Dall.
LIMAZA Bronn.
Limza Bronniana Dall.
Limeza Bronniana, var. lata Dall.
Famity SPONDYLIDZ.
SPONDYLUS Linné.
Spondylus Gussoni Costa.
PLICATULA Lamarck.
Plicatula spondyloidea Meuschen.
Famiry DIMYIDZ.
DIMYA Rouault.
Dimya argentea Dall.
189
190
BULLETIN OF THE
Famiy AVICULIDZ.
AVICULA Lamarck.
Avicula atlantica Lamarck.
Famity MYTILIDA.
MYTILUS Linné.
. Mytilus exustus Linné.
MODIOLA Lamarck.
Modiola polita Verrill and Smith.
Modiola opifex Say.
CRENELLA Brown.
Crenella decussata Montague.
MODIOLARIA Beck.
Modiolaria lateralis Say.
Famity ARCID.
LIMOPSIS Sassy.
Limopsis minuta Philippi.
Limopsis tenella Jeffreys.
Limopsis antillensis Dall.
Limopsis cristata Jeffreys.
Limopsis aurita Brocchi.
PECTUNCULUS Lamarck.
Pectunculus undatus Linné.
Pectunculus undatus, var. scriptus Born.
Pectunculus pectinatus Gmelin.
Pectunculus pectinatus, var. carinatus Dall.
ARCA Linné.
Arca pectunculoides Scacchi.
Arca pectunculoides, var. orbiculata Dall.
MUSEUM OF COMPARATIVE ZOOLOGY.
Arca polycyma Dall.
Arca glomerula Dall.
Arca auriculata Lamarck.
Arca lienosa Say.
Arca reticulata Chemnitz.
Arca Adamsi Shuttleworth.
Arca Noe Linné, var. occidentalis Philippi.
Arca umbonata Lamarck.
Arca ectocomata Dall.
Arca barbata Linné.
MACRODON Lycett.
Macrodon asperula Dall.
Macrodon sagrinata Dall.
Famiry NUCULIDZ.
NUCULA Lamarck.
Nucula egeénsis Forbes.
Nucula cymella Dall.
Nucula crenulata A. Adams.
Nucula crenulata, var. obliterata Dall.
Nucula Verrillii Dall.*
Famity LEDID/A.
LEDA Schumacher.
Subgenus YOLDIA Morch.
Yoldia solenoides Dall.
Yoldia liorhina Dall.
Subgenus LEDA s. s.
Leda Carpenteri Dall.
Leda messanensis Seguenza.
Leda solidula Smith.
Leda vitrea D’Orbigny, var. cerata Dall.
Leda concentrica Say.*
Leda acuta Conrad.
Leda solidifacta Dall.
Leda Verrilliana Dall.*
191i
192 BULLETIN OF THE
Leda Bushiana Verrill.*
Leda subequilatera Jeffreys.
Leda hebes Smith.
Section Saturnia Seguenza.
Leda pusio Philippi.
Leda quadrangularis Dall.
Section NEILONELLA Dall.
Leda corpulenta Dall.
MALLETIA Desmoulins.
Section Tinparta Bellardi.
Malletia cytherea Dall.
Malletia Smithii Dall.*
Malletia dilatata Philippi.
Famity CARDITIDZ.
CARDITA Brugitre.
Cardita domingensis D’Orbigny.
Famity CRASSATELLIDE.
CRASSATELLA Lamarck.
Crassatella floridana Dall.
Subgenus ERIPHYLA Gabb (em.).
Eriphyla parva C. B. Adams.
Famiry ASTARTIDZ.
ASTARTE J. Sowerby.
Astarte Smithii Dall.
Astarte Smithii, var. globula Dall.
Astarte nana Dall.
CIRCE Schumacher.
Circe (Gouldia) cerina C. B. Adams.
MUSEUM OF COMPARATIVE ZOOLOGY. 193
Famity UNGULINID&.
DIPLODONTA Bronn.
Diplodonta turgida Verrill and Smith.
Diplodonta venezuelensis Dunker.
Famity LUCINIDZ.
LUCINA Brugiere.
Lucina antillarum Reeve.
Lucina sombrerensis Dall.
Lucina leucocyma Dall.
Lucina funiculata Reeve.
Lucina lenticula Reeve.
Lucina scabra Lamarck.
Lucina sagrinata Dall.
Lucina quadrisulcata D’Orbigny.
LORIPES Poli.
Loripes compressa Dall.
Loripes lens Verrill and Smith.
CRYPTODON Turton.
Cryptodon orbiculatus Seguenza.
Cryptodon pyriformis Dall.
Cryptodon flexuosus Montague.
Famiry CHAMIDZ.
CHAMA Brugitre.
Chama lactuca Dall.
Chama sarda Reeve.
Famity CARDIIDA.
CARDIUM Linné.
Cardium ceramidum Dall.
Cardium medium Linné.
Cardium peramabilis Dall.
Cardium muricatum Linné.
Cardium levigatum Linné.
Cardium serratum Linné.
VOL. XII. — NO. 6. 13
194
BULLETIN OF THE
Famiry ISOCARDIIDZA.
ISOCARDIA Lamarck.
Subgenus MEIOCARDIA H. and A. Adams,
Meiocardia Agassizii Dall.*
CALLOCARDIA A. Adams.
Subgenus VESICOMYA Dall.
Vesicomya subquadrata Jeffreys.*
Vesicomya atlantica Smith.
Vesicomya pilula Dall.
Vesicomya venusta Dall.
Famity VENERIDZ.
CYTHEREA Lamarck.
Subgenus DIONE Megerle.
Dione hebreea Lamarck.
Dione albida Gmelin.
Section VENERIGLOSSA Dall.
Dione (Veneriglossa) vesica Dall.
VENUS (Linné) Deshayes.
Venus pilula Reeve.
Subgenus CHIONE Megerle.
Chione pygmeza Lamarck.
Chione cancellata Lamarck.
Famity PETRICOLIDA.
PETRICOLA Lamarck.
Petricola divaricata Chemnitz.
Famiry TELLINID.®.
TELLINA Linné.
Tellina Antoni Philippi.
Tellina squamifera Deshayes.
MUSEUM OF COMPARATIVE ZOOLOGY.
Tellina sybaritica Dall.
Tellina tenera Say.
Tellina? plectrum Hanley.
Tellina Gouldii Hanley.
Famity SEMELIDE.
ABRA (Leach) Risso.
Abra longicallis Scacchi.
Abra lioica Dall.
ERVILIA Turton.
Ervilia nitens Montague.
CUMINGIA Sowerby.
Cumingia tellinoides Conrad.
SEMELE Schumacher.
Semele obliqua Wood.
Semele cancellata D’Orbigny.
Famity POROMYIDE.
POROMYA Forbes.
Poromya granulata Nyst and Westendorp.
Section CreroconcHa Dall.
Poromya (Cetoconcha) albida Dall.
Poromya (Cetoconcha) elongata Dall.
Poromya (Cetoconcha) bulla Dall.
Poromya (Cetoconcha) margarita Dall.
Famity VERTICORDIIDZ2.
VERTICORDIA Wood.
Verticordia acuticostata Philippi.
Verticordia Woodii Smith.
Verticordia perversa Dall.
Verticordia Seguenze Dall.
Subgenus TRIGONULINA D’Orbigny.
Trigonulina ornata D’Orbigny.
196 BULLETIN OF THE
Section Eucrroa Dall.
Verticordia (Euciroa) elegantissima Dall.
Subgenus PECCHIOLIA Meneghini.
Pecchiolia argentea Mariti.*
Subgenus HALIRIS Dall.
Haliris Fischeriana Dall.
MYTILIMERIA Conrad.
Mytilimeria Nuttallii Conrad.*
LYONSIELLA Sars.
Lyonsiella insculpta Jeffreys.*
Famity CUSPIDARIIDZ.
CUSPIDARIA Nardo.
Subgenus CUSPIDARIA s.s.
Cuspidaria rostrata Spengler.
Cuspidaria rostrata (? var.) microzhina Dall.
Cuspidaria Jeffreysi Dall.
Cuspidaria obesa Loven.
Cuspidaria? arcuata Dall
Subgenus CARDIOMYA A. Adams.
Cardiomya californica Dall.*
Cardiomya perrostrata Dall.
Cardiomya costellata Deshayes.
Cardiomya costellata, var. curta Jeffreys.
Cardiomya costellata, var. corpulenta Dall.
Cardiomya striata Jeffreys.
Subgenus LEIOMYA A. Adams.
Leiomya adunca Gould.*
Section Vutcanomya Dat.
(?Leiomya) Vulcanomya Smithii Dall.*
Section Precropon Carpenter.
Leiomya (Plectodon) scaber Carpenter.*
Leiomya (Plectodon) granulata Dall.
Leiomya (Plectodon) granulata, var. velvetina Dall.
“MUSEUM OF COMPARATIVE ZOOLOGY.
Section Rurnocrama Dall and Smith.
Leiomya (Rhinoclama) halimera Dall.*
Subgenus TROPIDOMYA Dall and Smith.
Tropidomya abbreviata Forbes.*
Subgenus HALONYMPHA Dall and Smith.
Halonympha claviculata Dall.
(Genus?) MYONEHRA Dall and Smith.
Myonera paucistriata Dall.
Myonera undata Verrill.
Myonera lamellifera Dall.
Myonera limatula Dall.
Myonera laticella Dall.*
Famity ANATINID.
PERIPLOMA Schumacher.
Periploma fragilis Totten.*
Periploma papyracea Say.
THRACIA Leach.
Thracia Stimpsoni Dall.*
Thracia corbuloidea Blainville.*
Thracia distorta Montague.*
Thracia phaseolina Lamarck.
ASTHENOTHAIRUS Carpenter.
Asthenotherus Hemphillii Dall.
Subgenus BUSHIA Dall.
Bushia elegans Dall.
Famity. PANDORIDZ.
PANDORA Hvass.
Subgenus CLIDIOPHORA Carpenter.
Clidiophora carolinensis Bush.
Clidiophora trilineata Say.*
Clidiophora Gouldiana Dall.*
Subgenus PANDORA s. s.
Pandora (Kennerlia) Bushiana Dall.*
197
198 BULLETIN OF THE
Famity CORBULIDZE.
CORBULA Brugiere.
Corbula cubaniana D’Orbigny.
Corbula Barrattiana C. B. Adams.
Corbula Swiftiana C. B. Adams.
Corbula Dietziana C. B. Adams.
Corbula disparilis D’Orbigny.
Corbula (Tzniodon?) cymella Dall.
Corbula Krebsiana C. B. Adams.*
Corbula Chittyana C. B. Adams.*
Corbula Kjaeriana C. B. Adams.*
BASTEROTIA Mayer.
Basterotia quadrata Hinds, var. granatina Dall.
Famity SAXICAVIDZA.
SAXICAVA F. de Bellevue.
Saxicava azaria Dall.
Famity PHOLADIDE.
XYLOPHAGA Turton.
? Xylophaga abyssorum Dall.
This Report contains twelve new subgenera or sections, and eighty-one new
species. The species marked by an asterisk are introduced for purposes of
illustration, etc., and were not collected by the “ Blake.” The total amounts to
thirteen species and varieties of Brachiopods and two hundred and fourteen
species and varieties of Pelecypods obtained by the “ Blake,”’ beside the thirty
or more species casually mentioned but not collected.
MUSEUM OF COMPARATIVE ZOOLOGY. 199
MOLLUSCOIDEA.
CLass BRACHIOPODA.
Order ARTHROPOMATA.
Famity TEREBRATULID.
Genus THREBRATULA atcrTorum.
Terebratula cubensis Pourra tks.
Terebratula cubensis, Pourtales, Bulletin M. C. Z., I. p. 109, 1867; Dall, ibid., IIL
p. 8, pl. i. figs. 2, 8-16, 1871; ibid., IX. p. 103, 1881.
Habitat. Station 45, 101 fms.; Station 16, 292 fms.; Sigsbee, off Ha-
vana, 175 and 400 fms.; Lat. 26° 31’, Lon. 85° 3’, 119 fms. ; Barbados, 100
fms.; Stations 231 and 232, St. Vincent, 95 and 88 fms.; Stations 193 and
202, Martinique, 169 and 210 fms. ; station 155, Montserrat, 88 fms., bottom
temperature 69°.0 F. ; Station 167, Guadalupe, 175 fms. ; Stations 249, 253,
and 254, near Grenada, in 262, 92, and 164 fms. ; and Stations 273, 276, 282,
293, 296, and 300, about Barbados, in 103, 94, 154, 82, 125, and 82 fms., re-
spectively. In general, at a depth of 80-400 fms., sandy or stony bottom, with
the temperature ranging from 50° to 70° and averaging about 58°.5 F.
This species has been fully described, figured, and discussed by me in the
papers referred to, especially volume third of this Bulletin, and nothing more
can be added to the data there accumulated except the additional localities
here recorded.
Its distinctness from T. vitrea may be considered as fully established.
Terebratula Moseleyi Davinson.
Terebratula Moseleyi Dav. Chall. Rep. Brach., p. 30, pl. xi. figs. 12-14, 1880.
A specimen sent to Mr. Davidson was identified by him as this species. It
was obtained at Station 193, off Martinique, in 169 fms., sand, shell, and dark
mud, the bottom temperature being 51°.0 F. The Challenger specimens were
dredged west of Kerguelen Island in the Southern Ocean, at Station 148, lati-
tude 46° 471 south, and longitude 51° 37’ east of Greenwich, on a rocky bottom
in 210 fms.
200 BULLETIN OF THE
.Terebratula Bartletti Dat.
Terebratula Bartletti Dall, Am. Nat., Nov. 1882, p. 885.
Plate VI. Figs. 4 a-c.
Shell whitish or often with a delicate madder-brown tinge, moderately thin,
ovoid, inflated, polished, with occasional traces of delicate evanescent ex-
tremely fine radiating lines, especially on the sides near the hinge line ; apex
of the neural valve rather attenuated, curving over and closely appressed to
the apex of the hemal valve ; foramen complete, small, its lower margin pro-
duced into a sharp point lying over the apex of the hemal valve and conceal-
ing it; area short, very wide, triangular, bounded by a sharp carina on each
side, concave, with a median slightly impressed line, posterior margin a little
arched in a posterior direction; it is entirely concealed in the living shell,
being as before mentioned closely appressed to the outer surface of the other
valve; cardinal border rather pointedly arched, teeth small but stout; margin
of the valve smooth, flexuous ; it falls away a little from a point immediately
in front of the teeth, then continuing forward is emarginated and its front
border strongly squarely produced upward and forming two well-marked
corners between which the front margin is nearly straight ; outer surface of
the valve roundly convex. Hzemal valve with the margin correspondingly
flexuous, generally rounded but with a more or less obtuse ridge extending
toward the beak from the inner angles of the anterior flexuosity: beak rather
pointed, incurved cardinal process small, semicircular, fimbriated in all cases,
showing six to eight anteriorly pointing irregular denticulations ; cardinal
plate divided, its lateral platforms wide, deeply concave ; tooth sockets small,
narrow, close to the margin of the beak; loop large, very square, curved up-
ward, proportionally wider and shorter than in 7. cubensis, with a less convex-
ity in the median line, and without the lateral notches and median prominence
of T. cubensis. Interior of valves smooth except for the muscular impressions
and certain ridges due to their changes in the development of the individual ;
in the hemal valve there is an obtuse ridge (seen through the shell it resem-
bles a septum as in Waldheimia) between the abductor scars, in the neural
valve there is a well-marked groove in the same place : in T. cubensis the ante-
rior margin of the adductor scars is underneath and behind the anterior margin
of the loop ; in this species (as in T. vitrea) they are considerably in advance
of it, a circumstance resulting from the greater bulk of the soft parts in the
latter species, compared with the size of the shell. The measurements in an
adult individual are as follows. Lon. of neural valve 40.0, of hemal do. 38.0,
lat. 31.5, lat. of anterior flexuosity 22.0; beak to anterior edge of loop 8.0, to
points of crura 5.5, width of anterior margin of loop 6.5; diameter 26.75 mm.
The greatest width of the shell is behind its middle in T. vitrea, as already
pointed out by me (Bull. Mus. Comp. Zodl., III. No. 1, p. 3, 1871); in the
present species it is anterior to the middle of the shell.
MUSEUM OF COMPARATIVE ZOOLOGY. 201
Habitat. Stations 290, Barbados, 73 fms. ; 232, St. Vincent, 88 fms.; 155,
Montserrat, 88 fms. ; 253, Grenada, 92 fms. ; 273, Barbados, coral and shells,
103 fms. ; 45, in Lat. 25° 33’ N., and Lon. 84° 21’ W. Gr., 101 fms.; 177,
Dominica, sand and shells, 118 fms. ; 157, Montserrat, sand and stones, 120
fms. ; 297, Barbados, stones, 123 fms. ; 258 and 254, Grenada, 159 and 164
fms. ; 193, Martinique, 169 fms. ; 291, Barbados, 200 fms. ; 139, Santa Cruz,
sand and gravel, 218 fms. ; 147, St. Kitts, 250 fms. Its location, therefore,
appears to be between seventy and two hundred and fifty fathoms, in water
varying from 51°.0 to 699.0 Fahrenheit in temperature.
The relations of this form appear to be with 7. vitrea, T. cubensis, T. sphe-
noidea, and T. scille. Its assemblage of characters does not appear to be shared
by any of those forms. The rather large number of specimens of all ages, col-
lected as above, show its range of variation very well. Those who would unite
all the above-mentioned species under one name, would doubtless include the
present form within that limit, and logically so. I do not see my way clear,
however, whatever may be thought to be the value of a “species,” to ignore
what appear to be constant differences in the organisms under consideration.
It is probable that there are too many specific names in the group of Terebra-
tula of which T. vitrea is an example, a number of additions having been re-
cently made to the list. The present form is certainly more differentiated
from either vitrew or cubensis than several which have been named and are
generally accepted. The form of the loop resembles closely that of T. siracu-
sana Seguenza (Bull. Malac. Ital., IV., tab. 4, fig. 13), its general form is more
like T. scille Seg. (1. c., tab. 3, fig. 8), at least like the variety mentioned.
Other discriminating characters may be found mentioned in the preceding
description, which, with the figures, will be a sufficient means for identification.
The anterior flexuosity is often, though not usually, as strong relatively in the
young as in the adult. The appressed neural apex is very constant.
Terebratula incerta Davipson.
Megerlia incerta Davidson, Challenger Brach., p. 49, pl. xi. figs. 17, 18, 1880.
Plate VI. Figs. 6, 6 a.
Habitat. Challenger Expedition, Mid-Atlantic, Lat. 1° 47’ N., Lon. 24° 26'
W., 1850 fathoms. Blake Expedition, Stations 235 and 236, in 1507 and 1591
fms., oozy bottom, off Bequia, bottom temperature 39°.0 F.; and Station 16,
292 fms., off Morro Light, Havana, Cuba, bottom temperature 55°.6 F., one
specimen only.
This species was obtained of adult size at the stations cited. It is readily
recognizable from Mr. Davidson’s excellent figures (by his kindness I com-
pared specimens) and the peculiar and characteristic radiating filaments which
surround the base of the peduncle. In all the specimens examined the loop is
incomplete, or rather the crura are not united, but the soft parts, the sete, and
202 BULLETIN OF THE
the shell canals are those of Terebratulina. It, and perhaps T. Murrayi Dav.,
may be considered Terebratulinas in which the crura do not unite.
Genus THREBRATULINA D’Orziexry.
Terebratulina Cailleti Crosssz.
Terebratulina Cailleti Crosse, Journ. de Conchyl., XIII. p. 27, pl. i. figs. 1-8, 1865;
Dall, Bull. M. C. Z., III. p. 10, 1871; IX. p. 103.
Habitat. Barbados, 100 fms. ; Sigsbee, off Havana, in 80, 119, 127, 240, and
450 fms.; Yucatan Strait, 640 fms.; Station 2, 805 fms. ; West Florida, 30
fms. ; Station 16, 292 fms.; Station 20, 220 fms. ; Station 44, 539 fms. ; Sta-
tion 45, 101 fms. ; off Morro Light, Station 16, 292 fms. ; Santa Lucia, Sta-
tions 216 and 218, 154 and 164 fms. ; St. Vincent, Stations 224, 231, and 232,
114, 95, and 88 fms. ; Dominica, Station 177, 18 fms.; Montserrat, Stations
154, 155, and 156, in 298, 88, and 88 fms.; Grenada, Stations 246, 247, 253,
and 254, in 154, 170, 92, and 164 fms. ; off the Grenadines, Station 238, in 127
fms. ; Barbados, Stations 272, 273, 276, 278, 281, 282, 290, 291, 292, 296, and
298, in 76, 103, 94, 69, 288, 154, 70, 200, 56, 84, and 120 fms. respectively.
As this series of localities proves, this little species is abundant and widely
distributed in the Antillean region, from which it extends southward to the
vicinity of Pernambuco and Rio de Janeiro. It occupies for this fauna the
place taken by 7. caputserpentis L. and its varieties in the north. It ranges
between 30 fms. and 805 fms. in depth, and exists in water the temperature of
which may be 45°.0 to 75°.0 F. Its favorite location, however, appears to be
at a depth of between 100 and 200 fms., and in water of the temperature of
60°.0. It has been fully discussed in the papers cited.
Famity EUDESIIDA.
Genus HUDESIA Kiva.
Eudesia floridana Pourratis.
Waldheimia floridana Pourtalés, Bull. M. C. Z., I. p. 127; Dall, Ibid., III. p. 12,
pl. i. fig. 3, pl. ii. figs. 1-3, 1871; IX. p. 108.
Habitat. Off Sand Key, 125 fms. ; Sigsbee, off Havana, 175 fms. ; Lat.
26° 31’, Lon. 85° 3’, 119 fms.; Station 45, 101 fms.; Station 5, 229 fms.;
Station 19, 310 fms. ; Station 291, 200 fms., Barbados.
The generic name WValdheimia being preoccupied for a genus of insects, as
heretofore pointed out, Hudesia, King, is the next in order of priority, and
should therefore be adopted, although in its original significance it was merely
a synonym of Waldheimia King.
MUSEUM OF COMPARATIVE ZOOLOGY. 203
Famitry MEGATHYRID.
Genus MEGATHYRIS D’Ozzienry.
Surcenus CISTELLA Gray.
Cistella Barrettiana Davivsoy, var. rubrotincta Dat.
Cistella Barrettiana Dall, Bull. M. C. Z., IX. pp. 103, 104.
Argiope Barrettiana Davidson, P. Z. S., Feb. 1866, p. 103, pl. xii. fig. 3.
Argiope antillarum Crosse & Fischer, Journ. de Conchyl., XIV., July, 1866, p. 270,
pl. viii. fig. 6.
Cistella (Schrammi var.?) rubrotincta Dall, Bull. M. C. Z., III. p. 19, pl. i. fig. 6, 1874.
Habitat. Sand Key, 80 fms.; Station 2, 805 fms.; Yucatan Strait, 640
fms. ; Station 45, 101 fms.; Station 20, 220 fms. ; Barbados, 100 fms.; Sigs-
bee, off Havana, 450 fms. ; Station 276, 94 fms.; Station 231, St. Vincent, 95
fms. ; Tortugas, 43 fms.; Station 297, 170 fms., off Grenada; Station 132, 115
fms., Santa Cruz; Station 155, 88 fms., near Montserrat, W. I.
This pretty little species has about the same range in depth and temperature
as T, Cailleti. The above synonymy represents the conclusions of Mr. David-
son and myself, after several years of correspondence and the study of quite
abundant material.
Cistella (Barrettiana var.?) Schrammi Crossr & Fiscner,
Cistella (Barrettiana (2) var.) Schrammi, Bull. M. C. Z., IX. p. 104.
Argiope Schrammi, Crosse & Fischer, 1. c., p. 269, pl. viii. fig. 6, 1866.
Habitat. Station 45, 101 fms.; Barbados, 100 fms.
There is much doubt as to the distinctness of this form from C. Barrettiana,
which seems very variable in sculpture and color.
Cistella lutea Datu.
Cistella lutea Dall, Bull. M. C. Z., IIT. p. 20, pl. i. fig. 5, pl. ii. figs. 4-8, 1871;
Ibid., IX. p. 103.
Habitat. Sigsbee, off Havana, 80 to 127 fms.; Barbados, 100 fms.; Station
21, 287 fms.; Tortugas, 30 fms.
Owing to the differences in the form of the shell and especially of the sep-
tum, Mr. Davidson was inclined to regard this as a valid species, and so stated
in his last communication on this subject. It may, however, be only an
extreme form of Barrettiana, though intermediate specimens are still wanting.
204 BULLETIN OF THE
Famity PLATIDIIDA.
Genus PLATIDIA Costa.
Platidia anomoides Scaccu1.
Platidia anomoides Dall, Bull. M. C. Z., UX. p. 104.
Terebratula anomioides Scacchi, Philippi, Moll. Sicil., IL. p. 69, pl. xviii. fig. 9, 1844.
Habitat. Near Morro Light, Cuba, Station 16, 292 fms.; Station 253, 92
fms.; Barbados, Station 280, 221 fms. ; Grenada, Station 260, 291 fms.; St.
Vincent, Station 232, 88 fms. Also San Diego, California, Orcutt; and off
the coast of North Carolina in 16 fms. by the U. S. Fish Commission, 1885.
Variety radiata Datt, Proc. U. S. Nat. Mus., 1885, p. 551.
Shell radiately ribbed with small irregular ribs, apex of the dorsal valve
not notched but even with a trace of flattened area ; hemal valve deeply
notched ; margin with rather prominent setz lying in the grooves correspond-
ing to the ridges ; labia as usual with short brachial membrane and fringe
behind them; a broad smooth area of membrane in front of them ; about
25-30 single brachial processes on each lobe turned down and curled under ;
the point of the septum projects in front of the broad membranous area; the
anterior labium and perhaps both of them, somewhat reinforced by chitine ;
size the same as the typical form.
Habitat. Station 139, off Santa Cruz, in 218 fms., bottom temperature
51°.0; sessile on smooth Terebratula. The Californian specimens are also
of this variety.
This specimen was sacrificed to get at the soft parts. This is the only form
in which the brachia are turned downward, and the only living form in which
the hemal valve is notched in the adult state, as far as known to me.
Famity THECIDIIDA.
Genus THECIDIUM Sowersy.
Thecidium mediterraneum Sowersy.
2 Thecidium mediterraneum Sowerby, Dall, Bull. M. C. Z., IX. p. 104.
Habitat. Station 241, 163 fms.
The specimens being loose dorsal valves, it is possible that they may belong
to the preceding species; but Mr. Davidson thought not. No complete speci-
mens were found in the Blake collection.
MUSEUM OF COMPARATIVE ZOOLOGY. 205
Thecidium Barretti Woopwagrp.
Thecidium Barretti, Woodward, Dall, Bull. M. C. Z., IX. p. 104. Davidson, Geol.
Mag,., I. pl. ii. figs. 1-3, 1864; P. Z. S., 1866, p. 104.
Plate VI. Fig. 2.
Habitat. Barbados, 100 fms. ; Station 232, St. Vincent, 88 fms. ; Station
115, Montserrat, 88 fms.
This rare species was identified by Mr. Davidson after comparison with his
type. It is here satisfactorily figured, so far as the interior is concerned, for
the first time, acccording to that eminent authority.
Order LYOPOMATA Owen.
Famity CRANIID Gray.
Genus CRANIA Rerzivs.
Crania Pourtalesii Dat.
Crania Pourtalesii Dall, Bull. M. C. Z., IX. p. 104; Ibid., III. p. 35, pl. i. fig. 7, 1871.
Habitat. St. Vincent, W. I., 88 fms., Station 232; Sand Key, Fla., 105
fms.; off the Sambos, 116 fms. (single valves).
This species is probably abundant in suitable places, but no satisfactory haul
of them has yet been made.
206 BULLETIN OF THE
MOLLUSCA VERA.
Ciass PELECYPODA GoLpFuss.
Famity PECTINIDA.
Genus PECTEN Mutter.
Pecten Miiller, Prodr. Zool. Dan., p. xxxi, 1776. Type Pecten (Ostrea) mazi-
mus L., 1. c., p. 248.
This ancient genus has been cut up into many sections, most of which shade
into one another by imperceptible gradations, or interchange characters, or
would belong to different sections at different stages of post-embryonic growth.
For purposes of convenience and usefulness most of these sections were better
discarded, as a name without any essential characters is merely an incumbrance
to workers and a stumbling-block for learners. For my own purposes I find
the following arrangement convenient : 1. Pecten, with the subgenera Janira ;
Amusium and section Propeamusium ; Pseudamusium and section Camptonectes ;
Pecten typical and the sections Palliwm and Lyropecten ; 2. Netthea ; 3. Hemi-
pecten; 4. Hinnites.
In form of shell and characters of hinge, Dimya is related to Pecten, and by
its habit to Hinnites ; in its shell structure, it is nearer the Aviculide@ and
Ostreide ; in its anatomical peculiarities it is archaic, foreshadowing the pearl-
shells, the oysters, and the scallops in different degrees. It is well entitled to
family rank, and for present purposes I prefer to arrange it between the Pecti-
mide and the Aviculide, though no linear arrangement will express all its
relations.
The form of the foot in typical Pecten is recorded as cylindrical, with or with-
out the posterior margin grooved. In P. cawrinus the groove is deep, the stem
calibre uniform, the distal end a little swollen, with a minute slit and radiated
aperture on the posterior median line, the whole extremely phallic in appear-
ance ; in P. antillarum the foot is grooved, subcylindrical and worm-like, with
no perceptible slit at the tip, and that of P. nucleus Born is much the same ;
P. irradians has a beginning of a sucker-slit and hardly expanded tip ; P. ma-
gellanicus has the tip much enlarged, solid, with a large sucker ; when we get
to Amusiwm pleuronectes we have a spade-shaped tip and well-developed sucker,
with moderate stem ; and, finally, in A. Dall the sucker is large, hood-shaped,
thin-walled and darkly pigmented, with a broad base abruptly enlarged from
a very slender stem. Similar modifications appear in the anal extremity,
which from elongate and free varies to the usual appressed type of most bi-
MUSEUM OF COMPARATIVE ZOOLOGY. 207
valves. Other characters seem equally interchangeable, such as the armature
of the lips, which may be internally striate or smooth, externally smooth, papil-
lose, or arborescent.
All these facts confirm me in my belief that the subdivisions of the group
may advantageously be limited to a comparatively small number,
Suscenus JANIRA ScHUMACHER.
Pecten (Janira) hemicyclica RaveEnet.
Janira hemicyclica Tuomey & Holmes, Miocene Fos. S. Car., p. 25, pl. viii. figs.
1-4, 1855.
Pecten hemicyclicus Ravenel, fide T. & H. 1. c.
Plate VI. Fig. 5.
Two lower valves of this species were dredged on the west coast of Florida
by the Bache in 19 fathoms. It is found not very rarely on the east and west
coasts of South Florida, and often identified as P. ziczac. The ribs on the flat
valve differ greatly in different specimens, being sometimes obsolete and some-
times very strong. The color of this valve is much as in P. ziczac. The color
of the convex valve and its sculpture are quite different from those of P. ziczac,
which grows to a considerably larger size at present. The fossil specimens
of hemicyclica, as figured, are larger than any recent ones I have yet heard of.
The very young of this species are externally indistinguishable from the fry of
P. magellanicus Gmelin and Amusium plewronectes. The transverse rugosities
or grooves of the hinge-line referred to in Pseudamusiwm thalassinum are well
marked in the fry of this species, and very evident traces of them are visible
in the adult. In the young they occupy a lanceolate area on each side of the
cartilage pit, and are shown in the figure, considerably magnified, on Plate VI.
These shells and some other young fry are not to be distinguished from young
Pecten similis Laskey, of most collectors. I find fully half the “ P. similis” of
the Jeffreys collection to be of this character. Many of them might have
grown to be that species, but many probably might not. Unusual localities,
such as Korea or Jamaica, quoted for P. similis (genuine) on the authority of
Dr. Jeffreys, should be suspected or held for more information.
Suscenus AMUSIUM (Botten) ScHuMACHER.
Historical Synonymy.
Amusium Rumphius, Amboinische Rariteitkamer, pp. 144, 188, pl. xlv. figs. A, B,
1705. Klein, Tent. Meth. Ostrac., p. 184, 1753. Martini, Verzeichn.
Samml. Nat., 1774.
Synonymy Proper.
Amusium Bolten, Mus. Boltenianum, ed. i. p. 165, 1798; Pecten pleuronectes auct. (no
description or type mentioned).
208 BULLETIN OF THE
Amusium Megerle von Muhlfeld, Entwurf. (ete.) Mag. d. Gesellschaft f. Naturh.
Freunde zu Berlin, V. i. p. 59, 1811.
Bolten, Mus. Bolt., ed. ii. p. 115, 1819 (name only).
Schumacher, Essai, p. 117, 1817; P. pleuronectes (full description).
Pectinium b, Link, Beschr. Rostock Samml., part 3, p. 156, 1807; P. japonicum.
Amussium Herrmannsen, Ind. Gen. Mal., I. p. 47, 1846;== Amusium Klein corr.
H. & A. Adams, Gen. Rec. Moll, II. p. 554, 1858. Jeffreys, Annals
and Mag. Nat. Hist., Nov. 1876, p. 424; P. Z. S. 1879, p. 561.
Pleuronectia Swainson, Malacol., p. 388, 1840, P. pleuronectes (description).
Chenu, Man. de Conchyl., II. p. 187, 1862; P. japonica. Jeffreys, in
Wyville-Thomson, Depths of the Sea, p. 464, 1873.
Amusium Woodward, Manual, ed. ii. p. 412, 1866. Stoliczka, Pal. Indica, III. Cret.
Pelecypoda, p. 426, 1871.
Shell smooth or very slightly sculptured externally ; valves gaping at the
sides, nearly equally convex, with radiating internal ribs ; ears subequal, small ;
notch obsolete or none ; hinge line straight; margin entire; shell free (byssif-
erous?). Type Pecten pleuronectes L.
The name Amusiwm is of uncertain meaning or origin, but appears to
have been in use colloquially at least two hundred years ago to denominate
the ‘compass shell” or “flounder scallop.” It was used by Rumpf in his
Treasury of Rarities from Amboyna, as pointed out by Dr. Jeffreys, and
probably here made its first entry into print. It was adopted by Klein, in his
curious and very unequal work on shells, for one of the groups in which he
placed the Pectens of Lamarck and later authors ; it was referred to by Martini,
and doubtless by other non-binomial writers, whom it would be profitless to
search out.
Its first entry into binomial scientific literature (if an auctioneer’s sale cata-
logue without figures or descriptions may be so called) was in the obscure
pamphlet usually known as the Museum Boltenianum, of which a new edition
was published in 1819. The first place where the name Amusiwm received a
description entitling it to recognition was in Schumacher’s Essai, in 1817,
though Link had characterized the group as a section of his genus Pectinvum
(= Pecten) ten years previously. Apparently in ignorance of Schumacher’s
work, Swainson described it as a new genus in 1840, under the name Pleuro-
nectia, which was adopted later by Chenu. Herrmannsen and others have
suggested that the name should be spelled Amussium, but the uniformity of
previous usage and the uncertainty in regard to its derivation seem to render
this inadvisable,
The characters which separate this group from the typical genus are chiefly
conchological. The byssus (if any exists, for so far I have not been able to
find any) passes between the gaping valves, and the notch, which usually exists
in the very young, is not found in the adult form, which would seem to have
discarded the byssus entirely, and supplied its place by using the terminal
sucker of the foot, which is large and expanded. The group frequents deep
MUSEUM OF COMPARATIVE ZOOLOGY. 209
and temperate waters for the most part, and the prismatic structure of the
shell is especially evident in the abyssal species, which in other characters
differ from the type, and form a transition toward Pseudamusiwm and the more
typical scallops.
A few species of Amusiwm are reported from the Cretaceous, but it appears
to be rather a modern member of the Pectiude.
A living specimen of the type species, previously only known from the
eastern Asiatic seas, was dredged in the Gulf of Mexico by the U. 8S. Fish Com.
steamer “ Albatross” in the winter of 1884-85, at Station 2388, in 35 fms. sand,
Lat. 29° 24’, Lon. 88° lf W. Gr., and dead fragments at Station 2404, in
60 fms., Lat. 28° 44’, Lon. 85° 16’ W. Gr., both on a line between the delta of
the Mississippi and Cedar Keys, Florida.
Amusium Dalli E. A. Suits.
Amussium Dalli Smith, Challenger Rep. Lamellibranchiata, p. 308, pl. xxii., figs.
7 a-c, 1886. (Off Bermudas, 435 fms.)
Amussium lucidum Jeffreys, var. striata, in part? (P. Z.S., 1879, p. 562.)
Plate IV. Figs. la, 1b.
Valves nearly equal, the right slightly more convex ; the adults gaping at
the sides ; the young closed or almost closed; diversely sculptured ; right
valve nearly smooth except for growth lines, the internal lire (7-9) marked
by obscure radiating ridges of the outer surface; prismatic structure in a
radiating sense, distinctly marked, visible to the naked eye; auricles sculp-
tured only with growth lines, their upper edge denticulate in the very young,
arched internally, almost exactly equal, very small; hinge line very short and
straight; left valve with somewhat irregular sharpish concentric waves, hardly
raised above the surface and more distant toward the periphery; prismatic
structure reticulate, the prisms almost separable at the extreme margin becom-
ing effaced toward the umbo with age; auricles flat, subequal, without byssal
notch or fasciole, smooth or with faint growth-lines ; interior glassy, lire 9-10,
usually 9, stouter longer and more opaquely white (in adults) in this valve
than in the other; auricular crura very prominent, strong, forming the feet
of a stout arch of which the cartilage pit represents the keystone ; color trans-
lucent white near the margins, fuliginous in the central part which covers the
viscera. Alt. 62.0, lon. 59.0, max. diam. 6.0 mm., but reaching a larger size
as indicated by fragments. The shell is extremely thin and fragile, or rather
brittle.
Obtained at Station 41 in 860 fms. in the Gulf of Mexico; Station 117, in
874 fms., Lat. 17° 47’, Lon. 67° 3’ W. Gr. in the Caribbean Sea; Station 147,
off St. Kitts, in 250 fms. (bottom temperature 52°.5 F.); Station 150, between
St. Kitts and Nevis, in 375 fms.; Station 151, in 356 fms., off Nevis; Station 153,
in 303 fms., off Montserrat (bottom temperature 48°.75); Stations 161, 162, 163,
and 173, off Guadalupe, in 583, 734, 769, and 734 fms.; Stations 227 and 228,
VOL. XII.— NO. 6, 14
210 BULLETIN OF THE
off St. Vincent, in 573 and 785 fms.; Station 236, off Bequia, in 1591 fms., soft
mud; Stations 245 and 268, off Grenada, in 1058 and 955 fms.; Station 275, off
Barbados, in 218 fms, sand, bottom temperature 52°.5 F.
The bottom was, in all cases, sand, ooze, or mud, and the temperatures, except
those above cited, varied from 39° to 47°.5 F., averaging about 41°.0 F.
Amusium meridionale Smith would appear from the figures and description
closely to resemble the young of this species. Mr. Smith kindly informs me
that the form differs, and the sculpture of the deeper valve is not identical ; in
A. Dalli the valve is much more glossy and the radiating lire are hardly ap-
parent. Mr. Smith thinks A. meridionale does not attain a large size.
This elegant species was obtained by the “Challenger” as well as the
‘* Blake.” It is evidently a true inhabitant of the deeps, although its range
is nearly 1400 fms. It is of extreme tenuity, and all the specimens obtained
were more or less broken about the margin. The adult valves are convex
nearly or quite to their edges, but the lower one while young has a concave
margination, as in the species of Propeamusiwm. Notes in regard to the
synonymy will be found under the head of Amusiwm Pourtalesianum.
The soft parts of this species present some features of interest. The ocular
papille or ocelli are present, but devoid of pigment. The mantle is slightly
tinged with purple. The gills are long, single on each side, and furnished
with long separate filaments much as in Dimya. There are no branchial
palpi, but the lips are produced to a very unusual length, forming an arch
over the space below the mouth, both upper and lower lips being equally pro-
longed and applied to each other in a sort of horseshoe-shaped manner. They
are internally concentrically rugose in the specimen, which may be due to
contraction caused by the alcohol. The ovary projects from the body between
the gills in the form of a legume ; from its anterior end springs the stalk of
the foot, which is slender, the groove being well marked; the distal end of the
foot is greatly enlarged, looking like the end of an Anatifa without a shell; it
is dark purple, the only part of the animal so strongly pigmented ; the enlarge-
ment or “cornet” is hollow, the aperture, with a stout margin, looking for-
ward and downward; internally it is domed and radiately striate, being in fact
an exaggerated and efficient sucker, by means of which the animal should be
able to hold on to any flat surface, or (by expanding and contracting it like
the foot of Yoldia) to move about on the semifluid mud of the bottom. The
anus does not project from the surface to an appreciable extent.
Section PROPEAMUSIUM De Gregorio (em.), 1883.
Shell small, thin, vitreous, smooth or sculptured, the lower valve usually
concentrically waved and with a byssal notch, but no pectinium or byssal ser-
rations ; when adult internally lirate; the upper valve smooth or sculptured,
but usually, if sculptured, with the radiating sculpture prominent; valves
closed, the lower one convex over the internal lirations, then angulated and
MUSEUM OF COMPARATIVE ZOOLOGY. 211
applied to the internal surface of the upper valve, thus forming in the adult
and perfect shell a concave area about the distal margin of the inferior valve.
Type Amusium fenestratum Forbes,
The species of this section are found in deep waters, widely distributed,
except in the arctic seas. It should be noted that in this group, as in many
other Pectens, there are often a pair of ridges or lire, sometimes very promi-
nently elevated, on the inside, nearly parallel with the margin of the body
of the valve and situated at or on the prominence inside which is adjacent
to the auricular sulcus outside. These are not peculiar to either section of
Amusium, and are not counted by me in enumerating the internal lire of
species of Propeamusium. I notice that Smith in the Challenger Report has
counted them as lire; so in the same species, when they are present, the num-
ber of lire by my enumeration would always be two less than his. I have
called them the auricular crura for distinction’s sake. They are found in
species of Pseudamusium as well as of Propeamusium proper, and are some-
times absent in species of either group.
Amusium (Propeamusium) Pourtalesianum Datt.
Amussium lucidum Dall, Bull. M. C. Z., IX. p. 117, 1881.
< Pleuronectia lucida Jeffr., Depths of the Sea, p. 464, fig. 78 b, 1873.
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