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THE 



RAY SOCIETY. 



INSTITUTED MDCCCXLIV. 




LONDON. 

MDCCCLL 



A MONOGRAPH 



ON THE SUB-CLASS 



CIRRIPEDIA, 






WITH 



FIGURES OF ALL THE SPECIES. 



BY 



CHARLES DARWIN, F.R.S., E.G.S. 






THE LEPADID^E; 

OR, 

PEDUNCULATED CIRRIPEDES. 




LONDON: 
PRINTED FOR THE RAY SOCIETY. 

MDCCCLI. 



0. AND J. ADLARD, PRINTERS, BARTHOLOMEW CLOSE. 



PREFACE. 



My duty, in acknowledging the great obligations 
under which I lie to many naturalists, affords me most 
sincere pleasure. I had originally intended to have 
described only a single abnormal Cirripede, from the 
shores of South America, and was led, for the sake of 
comparison, to examine the internal parts of as many 
genera as I could procure. Under these circumstances, 
Mr. J. E. Gray, in the most disinterested manner, sug- 
gested to me making a Monograph on the entire class, 
although he himself had already collected materials for 
this same object. Furthermore, Mr. Gray most kindly 
gave me his strong support, when I applied to the 
Trustees of the British Museum for the use of the public 
collection ; and I here most respectfully beg to offer my 
grateful acknowledgments to the Trustees, for their most 
liberal and unfettered permission of examining, and when 
necessary, disarticulating the specimens in the magnificent 
collection of Cirripedes, commenced by Dr. Leach, and 
steadily added to, during many years, by Mr. Gray. 
Considering the difficulty in determining the species in 
this class, had it not been for this most liberal permission 
by the Trustees, the public collection would have been of 

b 



VI PREFACE. 



no use to me, or to any other naturalist, in systematically 
classifying the Cirripedes. 

Previously to Mr. Gray suggesting to me the present 
Monograph, Mr. Stutchbury, of Bristol, had offered to 
intrust to me his truly beautiful collection, the fruit of 
many years' labour. At that time I refused this most 
generous offer, intending to confine myself to anatomical 
observations ; but I have since accepted it, and still 
have the entire splendid collection for my free use. 
Mr. Stutchbury, with unwearied kindness, further sup- 
plied me with fresh specimens for dissection, and with 
much valuable information. At about the same period, 
Mr. Cuming strongly urged me to take up the subject, 
and his advice had more weight with me than that of 
almost any other person. He placed his whole mag- 
nificent collection at my disposal, and urged me to treat 
it as if it were my own : whenever I told him that I 
thought it necessary, he permitted me to open unique 
specimens of great value, and dissect the included animal. 
I shall always feel deeply honoured by the confidence 
reposed in me by Mr. Cuming and Mr. Stutchbury. 

I lie under obligations to so many naturalists, that I 
am, in truth, at a loss how to express my gratitude. 
Mr. Peach, over and over again, sent me fresh specimens 
of several species, and more especially of Scalpettum 
vulgar e, which were of invaluable assistance to me in 
making out the singular sexual relations in that species. 
Mr. Peach, furthermore, made for me observations on 
several living individuals. Mr. W. Thompson, the dis- 
tinguished Natural Historian of Ireland, has sent me the 



PREFACE. Ml 

finest collection of British species, and their varieties, 
which I have seen, together with many very valuable 
MS. observations, and the results of experiments. Prof. 
Owen procured for me the loan of some very interesting 
specimens in the College of Surgeons, and has always 
given me his invaluable advice and opinion, when con- 
sulted by me. Professor E. Forbes has been, as usual, 
most kind in obtaining for me specimens and information 
of all kinds. To the Rev. R. T. Lowe I am indebted for 
his particularly interesting collection of Cirripedes from 
the Island of Madeira — a collection offering a singular 
proof what treasures skill and industry can discover in 
the most confined locality. The well-known conchologist, 
Mr. J. G. Jeffreys, has sent for my examination a very 
fine collection of British specimens, together with a 
copious MS. list of synonyms, with the authorities 
quoted. To the kindness of Messrs. M c Andrew, Lovell 
Reeve, G. Busk, G. B. Sowerby, Sen., D. Sharpe, 
Bowerbank, Hancock, Adam White, Dr. Baird, Sir John 
Richardson, and several other gentlemen, I am greatly 
indebted for specimens and information : to Mr. Hancock 
I am further indebted for several long and interesting 
letters on the burrowing of Cirripedes. 

Nor are my obligations confined to British naturalists. 
Dr. Aug. Gould, of Boston, has most kindly transmitted to 
me some very interesting specimens ; as has Prof. Agassiz 
other specimens collected by himself in the Southern 
States. To Mr. J. D. Dana, I am much indebted for 
several long letters, containing original and valuable infor- 
mation on points connected with the anatomy of the 



Vlll PREFACE. 

Cirripedia. To Mr. Conrad I am likewise indebted for 
information and assistance. Both the celebrated Pro- 
fessors, Milne Edwards and Miiller, have lent me, from the 
great public collections under their charge, specimens which 
I should not otherwise have seen. To Professor W. Dunker, 
of Cassel, I am indebted for the examination of his whole 
collection. I have, in a former publication, expressed my 
thanks to Professor Steenstrup, but I must be permitted 
here to repeat them, for a truly valuable present of a 
specimen of the Anelasma squalicola of this work. I will 
conclude my thanks to all the above British and foreign 
naturalists, by stating my firm conviction, that if a person 
wants to ascertain how much true kindness exists amongst 
the disciples of Natural History, he should undertake, as I 
have done, a Monograph on some tribe of animals, and 
let his wish for assistance be generally known. 

Had it not been for the Ray Society, I know not how 
the present volume could have been published ; and 
therefore I beg to return my most sincere thanks to the 
Council of this distinguished Institution. To Mr. G. B. 
Sowerby, Junr., I am under obligations for the great 
care he has taken in making preparatory drawings, and 
in subsequently engraving them. I believe naturalists 
will find that the ten plates here given are faithful de- 
lineations of nature. 

In Monographs, it is the usual and excellent custom to 
give a history of the subject, but this has been so fully 
done by Burmeister, in his ' Beitrage zur Naturgeschichte 
der Rankenfusser,' and by M. G. Martin St. Ange, in 
his ' Mernoire sur 1' Organisation des Cirripedes/ that it 



PREFACE. IX 



would be superfluous here to repeat the same list of 
authors. I will only add, that since the date, 1834, of 
the above works, the only important papers with which 
I am acquainted, are, 1st. Dr. Coldstream ' On the 
Structure of the Shell in Sessile Cirripedes,' in the 
' Enclycopsedia of Anatomy and Physiology;' 2d. Dr. 
Loven ' On the Alepas squalicola,' (' Ofversigt of Kongl. 
Vetens.,' &c. Stockholm, 1844, p. 192,) giving a short 
but excellent account of this abnormal Cirripede; 3d. 
Professor Leidy's very interesting discovery, (' Proceed- 
ings of the Academy of Natural Sciences/ Philadelphia, 
vol. iv, No. I, Jan. 1848,) of eyes in a mature Balanus; 
4th. Mr. A. Hancock's Memoir, (' Annals of Natural 
History, 2d series, Nov. 1849,) on his Alcippe lampas, 
the type of a new order of Cirripedes ; 5th. Mr. Goodsir's 
Paper, ('Edinburgh New Philosoph. Journal,' July 1843,) 
on the Larvae in the First Stage of Development in 
Balanus; 6th. Mr. C. Spence Bate's valuable Paper on 
the same subject, lately published, (Oct. 1851,) in the 
' Annals of Natural History;' and lastly, M. Bernhardt 
has described, in the ' Copenhagen Journal of Natural 
History, Jan. 1851,' the Litliotrya Nicobarica, and has 
discussed its powers of burrowing into rocks. 

I have given the specific or diagnostic characters, de- 
duced from the external parts alone, in both Latin and 
English. As I found, during the progress of this work, 
that a similarly abbreviated character of the softer internal 
parts, was very useful in discriminating the species, I 
have inserted it after the ordinary specific character. 

In those cases in which a genus includes only a single 



X PREFACE. 

species, I have followed the practice of some botanists, 
and given only the generic character, believing it to be 
impossible, before a second species is discovered, to know 
which characters will prove of specific, in contradistinction 
to generic, value. 

In accordance with the Rules of the British Associa- 
tion, I have faithfully endeavoured to give to each species 
the first name attached to it, subsequently to the intro- 
duction of the binomial system, in 1758, in the tenth 
edition* of the ' Systema Naturae.' In accordance with 
the Rules, I have rejected all names before this date, 
and all MS. names. In one single instance, for reasons 
fully assigned in the proper place, I have broken through 
the great law of priority. I have given much fewer 
synonyms than is usual in conchological works ; this 
partly arises from my conviction that giving references 
to works, in which there is not any original matter, or 
in which the Plates are not of a high order of excellence, 
is absolutely injurious to the progress of natural history, 
and partly, from the impossibility of feeling certain to 
which species the short descriptions given in most works 
are applicable ; — thus, to take the commonest species, the 
Lepas anatifera, I have not found a single description 
(with the exception of the anatomical description by 
M. Martin St. Ange) by which this species can be 
certainly discriminated from the almost equally common 
Lepas Hillii. I have, however, been fortunate in having 

* In the Rules published by the British Association, the 12th edition, 
(17C)6,) is specified, but I am informed by Mr. Strickland that this is an 
error, and that the binomial method was followed in the 10th edition. 



PREFACE. XI 



been permitted to examine a considerable number of au- 
thentically named specimens, (to which I have attached the 
sign (!) used by botanists,) so that several of my synonyms 
are certainly correct. 

The Lepadidae, or pedunculated Cirripedes, have been 
neglected under a systematic point of view, to a degree 
which I cannot quite understand : no doubt they are 
subject to considerable variation, and as long as the 
internal surfaces of the valves and all the organs of the 
animal's body, are passed over as unimportant, there 
will occasionally be some difficulty in the identification 
of the several forms, and still more in settling the 
limits of the variability of the species. But I suspect 
the pedunculated Cirripedes have, in fact, been neglected, 
owing to their close affinity, and the consequent neces- 
sity of their being included in the same Work with the 
Sessile Cirripedes; for these latter will ever present, 
I am fully convinced, insuperable difficulties in their 
identification by external characters alone. 

I will here only further remark, that in the Introduction 
I have given my reasons for assigning distinct names to 
the several Valves, and to some parts of the included 
animal's body ; and that in the Introductory Remarks, 
under the general description of the Lepadidae, I have 
given an abstract of my Anatomical Observations. 



CORRIGENDA AND ADDENDA. 

Page 

12, twenty lines from bottom, for " hinder pair of true thoracic limbs," 
read " pair of true thoracic limbs." 

42, 43. I should have added, that the number of the segments in the 
cirri increases with the age of the specimen ; but that the 
relative numbers in the different cirri keep, as far as I have 
seen, nearly constant ; hence the numbers are often given in 
the descriptions. 

99 et passim, for Psecilasma, read Pcecilasma. 

156. In a foot-note, I have alluded to a new genus of sessile Cirripedes, 
under the name of Siphonicella, I now find that this species 
has been called, by Professor Steenstrup, Xenobalanus glo- 
bicipitis. 



i 



* 4f 






MONOGRAPH 



ON 



THE CIRRIPEDIA. 



INTRODUCTION. 



I should have been enabled to have made this Volume 
more complete, had I deferred its publication until I had 
finished my examination of all the other known Cirri- 
pedes ; but my work would thus have been rendered 
inconveniently large. Until this examination is com- 
pleted, it will be more prudent not to discuss, in detail, 
the position of the Lepadiclse amongst the Cirripedia, or 
of these latter in the great class of Crustacea, to which 
they now, by almost universal consent, have been 
assigned. I may, however, remark that I believe the 
Cirripedia do not approach, by a single character, any 
animal beyond the confines of the Crustacea : where such 
an approach has been imagined, it has been founded on 
erroneous observations ; for instance, the closed tube 
within the stomach, described by M. Martin St. Ange 
(to whose excellent paper I am greatly indebted), as 
indicating an affinity to the Annelides, is, I am con- 
vinced, nothing but a strong epithelial lining, which I have 
often seen ejected with the excrement. Again, a most 
distinguished author has stated that the Cirripedia differ 
from the Crustacea: — 1st. In having "a calcareous shell 
and true mantle;' but there is no essential difference, as 

1 



2 INTRODUCTION. 

shown by Burmeister, in the shells in these two classes ; 
and Cirripedes certainly have no more claim to a mantle 
than have the bivalve entomostraca. 2d. " In the sexes 
joined in one individual " but this, as we shall see, is not 
constant, nor of very much weight, even if constant. 3d. 
" In the body not being ringed ;" but if the outer integu- 
ment of the thorax of any Cirripede be well cleaned, it will 
be seen, (as was long ago shown by Martin St. Ange), to 
be most distinctly articulated. 4th. " In having salivary 
glands ;" but these glands are, in truth, the ovaria. 5th. 
" In the liver being formed on the molluscous type ;" I do 
not think this is the case, but I do not quite understand 
the point in question. 6th. " In not having a head or 
organs of sense ;" this is singularly erroneous : Professor 
Leidy has shown the existence of eyes in the mature 
Cirripede ; the antennae, though preserved, certainly 
become functionless soon after the last metamorphosis ; 
but there exist other organs of sense, which I believe 
serve for smelling and hearing : and lastly, so far from 
there being no head, the whole of the Cirripede externally 
visible, consists exclusively of the three anterior segments 
of the head. 

The sub-class, Cirripedia, can be divided into three 
Orders ; the first of which, mainly characterised by having 
six pair of thoracic cirri, includes all common Cirripedes : 
these latter may be divided into three families, — the 
Lepadidse, or pedunculated Cirripedes, the subject of the 
present memoir; the Verruciclse containing the single 
genus Verruca or Clisia ; and, lastly, the Balanidae, which 
consist of two very distinct sub-families, the Balaninse and 
Chthamalinse. Of the other two Orders above alluded 
to, one will, I believe, contain the remarkable burrowing 
genus Alcippe, lately described by Mr. Hancock, and a 
second burrowing genus, or rather family, obtained by 
me on the coast of South America. The third Order 
is highly singular, and differs as much from all other 
Cirripedes as does a Lernsea from other crustaceans ; it 
has a suctorial mouth, but is destitute of an anus ; it has 



■•') 



* 



NOMENCLATURE OF THE VALVES. 



Figure I. 



CAPITULTJM. 



TERGUM. 




CARINA. 



ROSTRAL TNFRA- CARINAL 



LATUS. 



MEDIAN 
LATUS. 



LATUS. 



SUB-CARINA. 



Figure II. 



Figure III. 



SCUTUM of LEPAS. 



TERGUM of LEPAS. 



Occhident 



Occluclent JBjjvtf 
margin. 

F 



Tergo- 
lateral 



Scutal 




Basal angle 
or Point. 



Basal margin. 



NOMENCLATURE. 



not any limbs, and is as plainly articulated as the larva 
of a fly ; it is entirely naked, without valves, carapace, or 
capitulum, and is attached to the Cirripede, in the sack 
of which it is parasitic, by tivo distinct threads, terminating 
in the usual larval, prehensile antennae. I intend to call 
this Cirripede, Proteolepas. I mention it here for the sake 
of calling attention to any parasite at all answering to 
this description. 

Although the present volume is strictly systematic, I 
will, under the general description of the Lepadidee, give 
a very brief abstract of some of the most interesting 
points in their internal anatomy, and in the metamor- 
phoses of the whole class, which I hope hereafter to treat, 
with the necessary illustrations, in detail. I enter on the 
subject of the metamorphoses the more readily, as by this 
means alone can the homologies of the different parts be 
clearly understood. 



On the Names given to the different parts of Cirripedes. 

I have unwillingly found it indispensable to give 
names to several valves, and to some few of the softer 
parts of Cirripedes. The accompanying figure of an 
imaginary Scalpellum includes every valve ; the two most 
important valves of Lepas are also given, in which the 
direction of the lines of growth and general shape differ 
from those of Scalpellum as much as they do in any genus. 
The names which I have imposed will, I hope, be thus 
acquired without much difficulty- 

Whoever will refer to the published descriptions of 
recent and fossil Cirripedia, will find the utmost confusion 
in the existing nomenclature : thus, the valve named in the 
woodcut the Scutum, has been designated by various well- 
known naturalists as the " ventral," the " anterior," the 
t( inferior," the " ante-lateral," and the " latero-inferior" 
valve ; the first two of these titles have, moreover, been 
applied to the rostrum or rostral valve of sessile Cirripedes. 



4 INTRODUCTION. 

The Tergum has been called the " dorsal/ 5 the "pos- 
terior/' the " superior/ 5 the " central/ 5 the " terminal/ 5 
the " postero-lateral/ 5 and the " latero-superior" valve. 
The Carina has received the first two of these identical 
epithets, viz. the " dorsal" and the " posterior ;" and 
likewise has been called the "keel-valve." The con- 
fusion, however, becomes far worse, when any individual 
valve is desciibed, for the very same margin which is 
anterior or inferior in the eyes of one author, is the 
posterior or superior in those of another; it has often 
happened to me that I have been quite unable even to 
conjecture to which margin or part of a valve an author 
was referring. Moreover, the length of these double 
titles is inconvenient. Hence, as I have to describe all 
the recent and fossil species, I trust I may be thought 
justified in giving short names to each of the more im- 
portant valves, these being common to the pedunculated 
and sessile Cirripedes. 

The part supported by the peduncle, and which is 
generally, though not always, protected by valves, I have 
designated the Capitulum. 

The title of Peduncle, which is either naked or squa- 
miferous, requires no explanation ; the scales on it, and 
the lower valves of the capitulum, are arranged in whorls, 
which, in the Latin specific descriptions, I have called by 
the botanical term of verticillus. 

I have applied the term Scutum to the most important 
and persistent of the valves, and which can generally be 
recognised by the hollow giving attachment to the 
adductor scutorum muscle, from the resemblance which 
the two valves taken together bear to a shield, and from 
their office of protecting the front side of the body. 
From the protection afforded by the two Terga to the 
dorso-lateral surface of the animal, these valves have 
been thus called. The term Carina* is a mere trans- 

* In the Carina of Eossil Species of Scalpellum, I have found it necessary 
to distinguish different parts, viz., A, the tectum, of which half is seen ; 
B, the parietes ; and C, the intra-parietes. 



NOMENCLATURE. 5 

lation of the name already used by some authors, of Keel- 
Valve. 

The Rostrum has been so called from its relative 
position to the carina or keel. There is often a Sub- 
carina and a Sub-rostrum. 

The remaining valves, when present, have been called 
Later a ; there is always one large upper one inserted 
between the lower halves of the scuta and terga, and this 
I have named the Upper Latus or Latera; the other 
latera in Pollicipes are numerous, and require no special 
names ; in Scalpellum, where there are at most only three 
pair beneath the Upper Latera, it is convenient to speak 
of them (vide Woodcut, I,) as the Carinal, Infra-median, 
and Rostral Latera. 

As each valve often requires (especially amongst the 
fossil species) a distinct description, I have found it in- 
dispensable to give names to each margin. These have 
mostly been taken from the name of the adjoining valvej 
(see fig. I.) In Lepas, Pollicipes, &c, the margin of the 
scutum adjoining the tergum and upper latus, is not divided 
(fig. II) into two distinct lines, as it is in Scalpellum, 
and is therefore called the Tergo-lateral margin. In 
Scalpellum (fig. I) these two margins are separately 
named Tergal and Lateral. The angle formed by the 
meeting of the basal and lateral or tergo-lateral margins, 
I call the Baso-lateral angle ; that formed by the basal 
and occludent margins, I call, from its closeness to the 
Rostrum, the Rostral angle. In Pollicipes the carinal 
margin of the tergum can be divided into an upper and 
lower carinal margin ; of this there is only a trace (fig. I) 
in Scalpellum. 

That margin in the scuta and terga which opens and 
shuts for the exsertion and retraction of the cirri, I have 
called the Occludent margin. In the terga of Lepas 
(fig. Ill) and some other genera, the occludent margin 
is highly protuberant and arched, or even formed of two 
distinct sides. 

Occasionally, I have referred to what I have called the 



6 INTRODUCTION. 

primordial valves : these are not calcified ; they are formed 
at the first exuviation, when the larval integuments are 
shed : in mature Cirripedes they are always seated, when 
not worn away, on the umbones of the valves. 

The membrane connecting the valves, and forming the 
peduncle, and sometimes in a harder condition replacing 
the valves, I have often found it convenient to designate 
by its proper chemical name of Cldtine, instead of by 
horny, or other such equivalents. When this membrane 
at any articulation sends in rigid projections or crests, for 
the attachment of muscles or any other purpose, I call 
them, after Auclouin, apodemes. For the underlying true 
skin, I use the term corium. 

The animal's body is included within the capitulum, 
within what I call the sack (see PI. IV, figs. 2 and 8' a, and 
PI. IX, fig. 4). The body consists of the thorax supporting 
the cirri, and of an especial enlargement, or downward 
prolongation of the thorax, which includes the stomach, 
and which I have called the prosom a. (PI. IX, fig. 4n). 
The cirri are composed of two arms or rami, supported 
on a common segment or support, which I call the pedicel. 
The caudal appendages are two little projections, either 
uni- or multi-articulate (PI. IV, fig. 8' a), on each side of 
the anus, and just above the long proboscis-like penis. 
On the thorax and prosoma, or on the pedicels of the 
cirri, there are in several genera, long, thin, tapering 
filaments, which have generally been supposed to serve 
as branchiae ; these I call simply filaments, or filamentary 
appendages (PL IX, fig. 4<g — /). The mouth (fig. 4 b) is 
prominent, and consists of palpi soldered to the labrum ; 
mandibles, maxillm, and outer maxilla, these latter serve 
as an under lip ; to these several organs I sometimes 
apply the title used by Entomologists, of " trophi." 
Beneath the outer maxillae, there are either two simple 
orifices or tubular projections ; these, I believe, serve as 
organs of smell, and have hence called them the olfactory 
orifices. Within the sack, there are often two sheets of 
ova (PL IV, fig. 2 b), these I call (after Steenstrup, and 



NOMENCLATURE. 7 

other authors) the ovigerous Lamella ; they are united to 
two little folds of skin (PL IV, fig. 2/), which I call the 
ovigerous Frcena. 

From the peculiar curved position which the animal's 
body occupies within the capitulum, I have found it far 
more convenient (not to mention the confusion of nomen- 
clature already existing) to apply the term Rostral in- 
stead of ventral, and Carinal instead of dorsal, to almost 
all the external and internal parts of the animal. Cirri- 
pedes have generally been figured with their surfaces of 
attachment downwards, hence I speak of the lower or 
Basal margins and angles, and of those pointing in an 
opposite direction as the Upper ; strictly speaking, as we 
shall presently see, the exact centre of the usually broad 
and flat surface of attachment is the anterior end of the 
animal, and the upper tips of the Terga, the posterior 
end of that part of the animal which is externally visible ; 
but in some cases, for instance in Coronula, where the 
base is deeply concave, and where the width of the shell 
far exceeds the depth, it seemed almost ridiculous to call 
this, the anterior extremity ; as likewise does it in 
Balanus to call the united tips of the Terga, lying deeply 
within the shell, the most posterior point of the animal, 
as seen externally. 

I have followed the example of Botanists, and added 
the interjection [!] to synonyms, when I have seen an 
authentic specimen bearing the name in question. 

Every locality, under each species, is given from spe- 
cimens ticketed in a manner and under circumstances 
appearing to me worthy of full confidence, — the specific 
determination being in each case made by myself. 



Class— CRUSTACEA. Sub-Class— CIRRIPEDIA. 

Family— LEPADID.E. 

Cirripedia pedunculo flexili, muscidis instruclo : scutis* 
musculo adductore solummodd instructis : valvis cceteris, 
siqum adsunt, in annulurn immobilem hand conjunctis. 

Cirripedia having a peduncle, flexible, and provided 
with muscles. Scuta* furnished only with an adductor 
muscle : other valves, when present, not united into an 
immovable ring. 

Metamorphoses ; larva, first stage, of body, and muscular system, p. 

pp. 9 — 12; larva, second stage, 39; mouth, ib.; cirri, p. 42; cau- 

p. 13; larva, last stage, p. 14; dal appendages, p. 43 ; alimentary 

its carapace, ib. ; acoustic organs, canal, 44 ; circulatory system, 

p. 15 ; antennae, ib. ; eyes, p. 16; p. 46; nervous system, ib. ; 

mouth, p. 17 ; thorax and limbs, eyes, p. 49 ; olfactory organs, p. 

p. 18 ; abdomen, p. 19 ; viscera, 52 ; acoustic(?) organs, p. 53; male 

ib. ; immature cirripede, p. 20 ; sexual organs, p. 55; female organs, 

homologies of parts, p. 25. p. 56; ovigerous lamellae, p. 58; 

ovigerous fraena, ib.; exuviation, 

Description of mature Lepadidae, p. 61 ; rate of growth, ib. ; size, 

p. 28 ; capitulum, ib. ; peduncle, ib. ; affinities of family, p. 64 ; 

p. 31 ; attachment, p. 33; fila- range and habitats, p. 65 ; geologi- 

mentary appendages, p. 38 ; shape cal history, p. 66. 

Metamorjrfioses. — I will here briefly describe the Meta- 
morphoses, as far as known, common to all Cirripedia, 
but more especially in relation to the present family. 
I may premise, that since Vaughan Thompson's capital 
discovery of the larvae in the last stage of development in 
Balanus, much has been done on this subject : this same 
author subsequently published! in the ' Philosophical 
Transactions, 5 an account of the larvae of Lepas and 
Conchoderma (Cineras) in the first stage ; and seeing how 
totally distinct they were from the larva of the latter stage 
in Balanus, he erroneously attributed the difference to 

* The meaning of this and all other terms is given in the Introduction, 
at pp. 3-7. 

T Philosophical Transactions, 1835, p. 355, PL vi. 



METAMORPHOSES. 9 

the difference in the two families, instead of to the stage 
of development. Burmeister* first showed, and the dis- 
covery is an important one, that in Lepas the larvae pass 
through two totally different stages. This has sub- 
sequently been proved by implication to be the case in 
Balanus, by Goodsir,f who has given excellent draw- 
ings of the larva in the first stage ; and quite lately, 
Mr. C. Spence Bate, of Swansea, has made other detailed 
observations and drawings of the ' larvae of five species 
in this same early stage, and has most kindly permitted 
me to quote from his unpublished paper J. I am enabled 
to confirm and generalise these observations, in all the 
Cirripedes in the Order containing the Balanidae and 
Lepadiclae. 

The ova, and consequently the larvae of the Lepadidae, 
in the First Stage, whilst within the sack of the parent, 
vary in length from *007 to "009 in Lepas, to '023 of an 
inch in Scalpellum : my chief examination of these larvae 
has been confined to those of Scalpellum vulgar -e; but I 
saw them in all the other genera. The larva is somewhat 
depressed, but nearly globular ; the carapace anteriorly is 
truncated, with lateral horns ; the sternal surface is flat 
and broad, and formed of thinner membrane than the 
dorsal. The horns just alluded to are long in Lepas 
and short in Scalpellum ; their ends are either rounded 
and excessively transparent, or, as in Ibla, furnished with 
an abrupt, minute, sharp point : within these horns, I 
distinctly saw a long filiformed organ, bearing excessively 
fine hairs in lines, so exactly like the long plumose spines 
on the prehensile antennae of the larvae in the last stage ; 
that I have not the least doubt, that these horns are the 
cases in which antennae are in process of formation. Pos- 

* Beitrage zur Naturgeschichte der Rankenfusser, 1834. Mr. J. E. Gray, 
however, briefly described, in lS33,(Proceedings, Zoological Society, October,) 
the larva in the first stage of Balanus ; in this notice the anterior end of 
the larva is described as the posterior. 

f Edinburgh New Philosophical Journal, July 1843, Pis. iii and iv. 

% This will appear in the October number (1851) of the 'Annals of 
Natural History.' 



10 LEPADID^E. 

teriorly to them, on the sternal surface, near each other, 
there are two other minute, doubly curved, pointed 
horns, about *004 in length, directed posteriorly; and 
within these I again saw a most delicate articulated fili- 
formecl organ on a thicker pedicel : in an excellent draw- 
ing, by Mr. C. S. Bate, of the larva of a Chthamalus 
{Balanus punctatus of British authors), after having 
kept alive and moulted once, these organs are dis- 
tinctly shown as articulated antennae (without a case), 
directed forwards : hence, before the first moult in Scal- 
pellum, we have two pair of antennae in process of for- 
mation. Anteriorly to the bases of these smaller antennae 
is seated the heart-shaped eye, (as I believe it to be,) 
•001 in diameter, with apparently a single lens, sur- 
rounded, except at the apex, by dark-reddish pigment- 
cells. In some cases, as in some species of Lepas, the 
larvae, when first excluded from the egg, have not an eye, 
or a very imperfect one. 

There are three pairs of limbs, seated close together 
in a longitudinal line, but some way apart in a trans- 
verse direction : the first pair always consists of a single 
spinose ramus, it is not articulated in Scalpellum, but is 
inuiti- articulate in some genera ; it is directed forwards. 
The other two pair have each two rami, supported on 
a common haunch or pedicel : in both pair, the longer 
ramus is multi- articulate, and the shorter ramus is without 
articulations, or with only traces of them : the longer 
spines borne on these limbs (at least, in Scalpellum and 
Chthamalus,) are finely plumose. The abdomen terminates, 
a little beyond the posterior end of the carapace, in a 
slightly upturned horny point ; a short distance anteriorly 
to this point, a strong, spinose, forked projection depends 
from the abdominal surface. 

Messrs. V. Thompson, Goodsir, and Bate, have kept 
alive for several days the larvae of Lepas, Conchoderma, 
Balanus, Verruca, and Chthamalus, and have described 
the changes which supervene between the first and third 
exuviations. The most conspicuous new character is the 



METAMORPHOSES. 11 

great elongation of the posterior point of the carapace 
into an almost filiform, spinose point in Lepas, Concho- 
derma, Chthamalus, and Balanus, but not according to 
Goodsir, in one of the. species of the latter genus. The 
posterior point, also, of the abdomen becomes developed 
in Balanus (Goodsir) into two very long, spear-like pro- 
cesses, serrated on their outer sides ; in Lepas and Con- 
choderma, according to Thompson, into a single, tapering 
spinose projection ; and in Chthamalus, as figured by Mr. 
Bate, the posterior bifid point, as well as the depending 
ventral fork, increase much in size. Another important 
change, which has been particularly attended to by Mr. 
Bate, is the appearance of spinose projections and spines 
(some of which are thick, curved, and strongly plumose, 
or, almost pectinated along their inner sides) on the 
pedicels and lower segments of the shorter rami of the 
two posterior pairs of limbs. 

The mouth in its earliest condition alone remains to 
be described ; in 8. vulgare, it is seated on a very slight 
prominence, in a most remarkable situation, namely, in a 
central point between the bases of the three pairs of legs. 
I traced by dissection the oesophagus for some little way, 
until lost in the cellular and oily matter filling the whole 
animal, and it was directed anteriorly, which is the 
direction that might have been expected, from the course 
followed by the oesophagus in the larva in the last stage, 
and in mature Cirripedes. Mr. A. Hancock has called 
my attention to a probosciformed projection on the under 
side of the larva of Lepas fascicidaris, when just escaped 
from the egg. Mr. Bate has described this same pro- 
boscis in Balanus and Chthamalus, and states the im- 
portant fact, that it is capable of being moved by the 
animal ; and, lastly, I have seen it in an Australian Chtha- 
malus, and in Ibla, of remarkable size. This proboscis, 
which is always directed posteriorly, (like the mouth in 
the mature animal,) certainly answers to the mouth as 
made out by dissection in Scalpellum ; and I believe I 
saw, as has Mr. Bate, a terminal orifice : it certainly does 



12 LEPADIDiE. 

not possess any tropin. In Ibla (in which the larva is 
large enough for dissection), the base of the proboscis 
arises posteriorly to the first pair of legs, and the orifice 
at the other end reaches beyond or posteriorly to the 
point, where the mouth in Scalpellum opens, namely be- 
tween the middle pair of legs. The mouth being either 
so largely probosciformed or seated only on a slight 
eminence, in two genera so closely allied as Ibla and 
Scalpellum, and (judging from Mr. Thompson's figures, 
and from what I have seen myself,) in the species of the 
same genus Lepas, is a singular difference : in the cases in 
which, at first, the proboscis is absent, it would probably 
soon be developed. I cannot but suppose that the in- 
wardly directed spines on the bases of the two posterior 
legs, which are so rapidly developed, serve some important 
end, namely, as organs of prehension for the larvae, like the 
mandibles and maxillae of mature Cirripedes, for seizing 
their prey, and conveying it to their moveable mouths, 
conveniently seated for this purpose. 

The first pair of legs answers, as I believe from reasons 
hereafter to be assigned, to the outer pair of maxillipods 
in the higher Crustacea ; and the other four legs to the 
first two pair of thoracic limbs in these same Crustacea ; 
this being the case, the highly remarkable position of the 
mouth in the larva, either between the bases of the two 
posterior pair of legs, or at least posteriorly to the first 
pair, together with the probable functions of the spiny 
points springing from the basal segments of the two 
hinder pair of true thoracic limbs, forcibly bring to mind 
the anomalous structure of the mouth being situated in 
the middle of the under side of the thorax, in Limulus, 
— that most ancient of crustaceans, and therefore one 
likely to exhibit a structure now embryonic in other orders. 
I will only further remark, that I suspect that the trun- 
cation of the anterior end of the carapace, has been 
effected by the segments having been driven inwards, 
and consequently, that the larger antennae within the 
lateral horns, though standing more in front than the 



METAMORPHOSES. 13 

little approximate pair, are normally the posterior of the 
two pair. According to Milne Edwards, the posterior 
pair are normally seated outside the anterior pair, and this 
is the case with those within the lateral horns. 

Larva in the Second Stage. — Notwithstanding the 
considerable changes, already briefly given, which the 
larva undergoes during the first two or three exuviations 
after leaving the egg, all these forms may be conve- 
niently classed under the first stage. The larva in the 
Second stage is known only from a single specimen 
described, figured, and found by Burmeister,* adhering to 
sea-weed in the midst of other larvae of Lepas in the 
last stage. In its general shape and compressed form, 
it seems to come nearer to the last than to the first stage. 
It has only three pair of legs, situated much more pos- 
teriorly on the body than in the first stage, and all directed 
posteriorly ; they are much shorter than heretofore, and 
resemble rather closely those of the last stage, with the 
important exception that the first pair has only one ramus. 
It is this circumstance which leaves no doubt on my mind, 
that we here have the three pair of limbs, of the first 
stage, metamorphosed. The body is prolonged some way 
behind these limbs, and ends in a blunt, rounded point, in 
which, probably, are developed the three posterior pair 
of legs and the abdomen of the larva in the last stage. 
The mouth is now seated some way anteriorly to the 
limbs, is large and probosciformed, and is, I presume, still 
destitute of tropin. There are now two closely approximate 
eyes, but as yet both are simple. The smaller pair of 
antennae has disappeared. The whole animal was attached 
to the sea-weed by a (I presume, pair of,) " fleischigen 
Fortsatz," which Burmeister considers as the prehensile 
antennae, to be presently described, in an early state of 
development. I have little doubt that this is correct, for 
in an abnormal Cirripede of another order, in which 
the larva appears in the^rs^ stage with prehensile an- 
tennae, the eggs have two great projecting horns including 

* Beitrage zur Naturgeschichte der Rankenfiisser, s. 16, Tab. i, figs. 3, 4. 



14 LEPADID.E. 

these organs, and attached by their tips, through some 
unknown means, to the sack of the parent, apparently in 
the same maimer as Burmeister's larva was attached to 
the sea-weed. I will only further remark on the larva 
of this Second stage, that its chief development since the 
first stage, has been towards its anterior end. The next 
great development, to be immediately described, is towards 
the posterior end of the animal. 

Larva, Last Stage. — My chief examination has been 
directed, at this stage of development, to the larvae of 
Lepas australis, which are of unusual size, namely, from 
•065 to even almost '1 of an inch in length; I examined, 
however, the larvse of several other species of Lepas, of 
Ibla and of Balanus, with less care, bat sufficiently to 
show that in all essential points of organisation they were 
identical ; this, indeed, might have been inferred from 
the similarity of the larval prehensile antennas, preserved 
in the bases of all mature Cirripedes, and which I have 
carefully inspected in almost every genus. The larvse in 
this final stage, in most of the genera, have increased many 
times in size since their exclusion from the egg; for 
instance, in Lepas australis, from *007 to '065, or even to 
*1 of an inch. They are now much compressed, nearly 
of the shape of a cypris or mussel-shell, with the anterior 
end the thickest, the sternal surface nearly or quite 
straight, and the dorsal arched. Almost the whole of 
what is externally visible consists of the carapace ; for 
the thorax and limbs are hidden and enclosed by its 
backward prolongation ; and even at the anterior end of 
the animal, the narrow sternal surface can be drawn up, 
so as to be likewise enclosed. As in several Stomapod 
crustaceans, the part of the head bearing the antennse 
and organs of sense, in front of the mouth, equals, or 
even exceeds in length, and more than exceeds in bulk, 
the posterior part of the body, consisting of the enclosed 
thorax and abdomen. I will now briefly describe, in the 
following order, the carapace, the organs of sense, mouth, 
thorax and limbs, abdomen, and internal viscera. 



METAMORPHOSES. 15 

The form of the Carapace has been sufficiently de- 
scribed ; it consists of thick chitine membrane, marked with 
lines, and sometimes with stars and other patterns ; it is 
obscurely divided into two halves by a line or suture along 
part of the dorsal margin ; these halves or two valves are 
drawn together by an adductor muscle, in the same rela- 
tive position as in the mature Cirripede. The part over- 
hanging and enclosing the thorax is lined by an excessively 
delicate membrane, obviously homologous with the lining 
of the sack in the mature animal, and is nothing but a 
duplicature of the carapace, rendered very thin from being 
on the under or protected side : a layer of true skin or 
coriuin, probably double, separates these two folds. 

Acoustic Organs. — On the borders of the carapace, at 
the anterior end, on the sternal surface, there are two 
minute orifices, in Z. australis *002 in diameter, some- 
times having a distinct border round them ; the mem- 
brane of the carapace on the inside is prolonged upwards 
and inwards in two short funnel-shaped tubes, lodged 
in closed sacks of the corium : within these sacks on each 
side a delicate bag is suspended, and hangs in the mouth 
of the above funnel ; at the upper end a large nerve could 
be distinctly seen to enter the bag : I cannot doubt that 
this is a sense-organ; from its position and from the animal 
not feeding (as we shall presently see), I conclude that 
it is an acoustic organ. 

Antennce. — These are large and conspicuous ; they are 
attached very obliquely on the sternal surface, a little way 
from the anterior end of the carapace, beyond which, 
when exserted, they extend ;* they can (at least in Ibla) 

* Mr. J. D. Dana, who has examined these organs in the larvae of Lepas, 
informs me in a letter, that in his opinion they " correspond with the inferior 
antennae, the superior being wanting, as in most Daphnidee." He continues 
— " I know of no case in which the inferior are obsolete when the superior 
are developed ; but the reverse is often true." In position these antennae 
certainly correspond to the inferior and central pair of the larva in the first 
stage, which belong, as it would appear, to the first segment of the body ; but 
judging from the drawing by Burmeister of the larva in the second stage, 
I am, in some respects, more inclined to consider that they correspond to the 
larger pair seen within the lateral horns of the carapace in the first stage. 



16 LEPADID.E. 

be retracted within the carapace. They consist of three 
segments : the first or basal one is much larger than the 
others, and apparently always has a single spine on the 
outer distal margin. The second segment consists either 
of a large, thin, circular, sucking disc, or is hoof-like 
(Tab. V, figs. 5, 10, 11, 12) ; in all cases it is furnished 
with one or more spines, (seven very long ones in Lepas,) on 
the exterior-hinder margin. The third and ultimate seg- 
ment is small ; it is articulated on the upper surface of the 
disc, and is directed rectangularly outwards ; it is some- 
times notched, and even shows traces of being bifid ; it 
bears about seven spines at the end; some of these spines 
are hooked, others simple, and in Lepas and Conchoderma, 
two or three are very long, highly flexible, and plumose, 
a double row of excessively fine hairs being articulated on 
them. I can hardly doubt that these latter spines, (within 
which the purple corium could be seen to enter a little 
way,) floating laterally outwards, serve as feelers. The 
antenna?, at first, are well furnished with muscles. They 
serve, in Lepas, according to Mr. King, and in Balanus, 
according to Mr. Bate, and as I saw myself in another 
unnamed order, for the purpose of walking, one limb being 
stretched out before the other ; but their main function 
is to attach the larva for its final metamorphosis into a 
Cirripede. The disc can adhere even to so smooth a 
surface as a glass tumbler.* The attachment is at first 
manifestly voluntary, but soon becomes involuntary and 
permanent, being effected by special and most remarkable 
means, which will be most conveniently described in a 
later part of this Introduction. I will here only state 
that I traced with ease the two cement- ducts running 
from two large glandular bodies, to within the antenna? 
up to the discs. 

Eyes. — Close behind the basal articulations of the 
antenna?, the sternal surface consists of two approximate, 
elongated, narrow, flat pieces, or segments. These 

* Rev. R. L. King. Annual Report of R. Institution of Cornwall, 
1848, p. 55. 



METAMORPHOSES. 17 

Burmeister considers as the basal segments of the an- 
tennae : as they are not cylindrical, I do not see the 
grounds for this conclusion : their posterior ends are 
rounded, and the membrane forming them is reflected 
inwards, in the form of two, forked, horny apodemes, 
together resembling two letters, UU, close together; these 
project up, inside the animal, for at least one third of its 
thickness from the sternal to the dorsal surface. The 
two great, almost spherical eyes in L. australis, each -^tli 
of an inch in diameter, are attached to the outer arms, 
thus, •UU # , in the position of the two full stops. Hence 
the eyes are included within the carapace. Each eye con- 
sists of eight or ten lenses, varying in diameter in the 
same individual from ^ to ^th of an inch, enclosed in 
a common membranous bag or cornea, and thus attached 
to the outer apodemes. The lenses are surrounded half 
way up by a layer of dark pigment-cells. The nerve does 
not enter the bluntly-pointed basal end of the common 
eye, but on one side of the apodeme. The structure here 
described is exactly that found, according to Milne 
Edwards, in certain Crustacea. In specimens just 
attac7ied, in which no absorption has taken place, 
two long muscles with transverse striae may be found 
attached to the knobbed tips of the two middle arms 
of the two °UU°, and running up to the antero-dorsal 
surface of the carapace, where they are attached ; other 
muscles (without transverse striae) are attached round 
the bases, on both sides of both forks. The action of 
these muscles would inevitably move the eyes, but I 
suspect that their function may be to draw up the narrow, 
deeply folded, sternal surface, and thus cause the retrac- 
tion of the great prehensile antennae within the carapace. 
Mouth, — This is seated in exactly the same position 
as in the mature Cirripede, on a slight prominence, 
fronting the thoracic limbs, and so far within the cara- 
pace, that it was obviously quite unfitted for the seizure 
of prey; and it was equally obvious, that the limbs were 
natatory, and incapable of carrying food to the mouth. 

2 



18 lepadid^e. 

This enigma was at once explained by an examination of 
the mouth, which was found to be in a rudimentary con- 
dition and absolutely closed, so that there would be 
no use in prey being seized. Underneath this slightly 
prominent and closed mouth, I found all the masticatory 
organs of a Cirripede, in an immature condition. The 
state of the mouth will be at once understood, if we 
suppose very fluid matter to be poured over the pro- 
tuberant mouth of a Cirripede, so as to run a little way 
down, in the shape of internal crests, between the dif- 
ferent parts, and in the shape of a short, shrivelled, 
certainly closed tube, a little way ('008 of an inch in 
L. australis) down the oesophagus. Hence, the larva in 
in this, its last stage, cannot eat; it may be called a 
locomotive Pupa;* its whole organisation is apparently 
adapted for the one great end of finding a proper site for 
its attachment and final metamorphosis. 

Thorax and Limbs, — The thorax is much compressed, 
and consists of six segments, corresponding with the six 
pair of natatory legs ; the anterior segments are much 
plainer (even the first being distinctly separated by a fold 
from the mouth), than the posterior segments, which is 
exactly the reverse of what takes place in the mature 
Cirripede ; in the latter, the first segment is confounded 
with the part bearing the mouth. The epimeral elements 
of the thorax are distinguishable ; the sternal surface is 
very narrow, and is covered with complicated folds and 
ridges. The six pair of legs are all close, one behind the 
other, and all are alike in having a haunch or pedicel of 
two segments, directed forwards, bearing two arms or 
rami, each composed of two segments, the outer ramus 

* M. Dujardin has lately ('Comptes Rcndus, 5 Feb. 5, 1850, as cited in 
'Annals of Nat. History,' vol. v, p. 318,) discovered that the "Hypopi are 
Acari with eight feet, without either mouth or intestine, and which, being 
deprived of all means of alimentation, fix themselves at will, so as to undergo 
a final metamorphosis, and they become Gamasi or Uropodi." Here, then, 
we have an almost exactly analogous case. M. Dujardin asks — " Ought, 
therefore, the Hypopi to be called larvae, when, under that denomination, 
have hitherto been comprised animals capable of nourishing themselves ?" 



METAMORPHOSES. 19 

being a little longer than the inner one. On the lower 
segments in both rami of all the limbs, there is a single 
spine. In all the limbs, the obliquely truncated summit 
of the terminal segment of the inner ramus bears three 
very long, beautifully plumose spines : in the first pair, 
the summit of the outer ramus bears four, and in the 
five succeeding pair, six similar spines. This difference, 
small as it is, is interesting, as recalling the much greater 
difference between the first and succeeding pairs, in the 
first and second stage of development. The terminal seg- 
ments of all the rami, bearing the long plumose spines, 
are directed backwards. The limbs and thorax are well 
furnished with striated muscles. The animal, according 
to Mr. King, swims with great rapidity, back downwards. 
The limbs can be withdrawn within the carapace. 

Abdomen and Caudal Appendages. — The abdomen is 
small, and its structure might easily be overlooked with- 
out careful dissection of the different parts : it consists of 
three segments ; the first can be seen to be distinct from 
the last thoracic segment, bearing the sixth pair of limbs, 
only from the fold of the epimeral element, and from its 
difference in shape; the second segment is very short, 
but quite distinct ; the third is four or five times as long 
as the second, and bears at the end two little appendages, 
each consisting of two segments, the lower one with a 
single spine, and the upper one with three, very long, 
plumose spines, like those on the rami of the thoracic 
limbs. The abdomen contains only the rectum and two 
delicate muscles running into the two appendages, be- 
tween the bases of which the anus is seated. 

Internal Viscera. — Within the body, in front of the 
mouth, it was easy to find the stomach (with two pear- 
shaped cseca at the upper end), running first anteriorly, 
and then curving back and reaching the anus by a long 
rectum, difficult to be followed : it appeared, however, 
to me, that this stomach had more relation to the young 
Cirripede, of which every part could now generally be 
traced, than to the larva, with its closed and rudimentary 



20 LEPADID^:. 

mouth : the fact, however, of its being prolonged to the 
anus, which is in a different position in the larva and 
mature state, shows that the stomach serves, at least, as 
an excretory channel. Besides the stomach, the several 
muscles already alluded to, and much pulpy and oily 
matter, the only other internal organs consist of two long, 
rather thick, gut-formed masses, into the anterior ends 
of which the cement-ducts running from the prehensile 
antennas could be traced. These masses are formed 
of irregular orange balls, about '001 of an inch in 
diameter, made up of rather large cells, so to have a 
grape-like appearance, held together by a transparent 
pale yellowish substance, but apparently not enclosed in 
a membrane : these masses lie rather obliquely, and ap- 
proach each other at their anterior ends ; they extend 
from above the compound eyes, to the cseca of the stomach 
to which they cohere, but in young specimens, they ex- 
tend some way beyond the caeca, between the folds of the 
carapace. The two cement-ducts, at the points where 
they enter these bodies, expand and are lost ,• at this point, 
also, the little orange-coloured masses of cells have the 
appearance of being broken down into a finer substance. 
Within the cement- ducts I saw a distinct chord of rather 
opaque cellular matter. We shall presently see, that these 
gut-formed masses are the incipient ovaria. 

The Young Cirripede within the Larva. — Several times 
I succeeded in dissecting off the integuments of the 
lately-attached larva, and in displaying the young Lepas 
australis entire. The following description applies to the 
Cirripede in this state ; but for convenience sake, I shall 
occasionally refer to its condition when a little more 
advanced. I may premise, and the fact in itself is curious, 
that the bivalve-like shell of the larva, together with the 
compound eyes, is first moulted, and some time afterwards, 
the inner lining of the sack, together with the integu- 
ments of the thorax and of the natatory legs : hence, I 
often found specimens, which externally seemed to have 
perfected their metamorphoses, but which, within their 



METAMORPHOSES. 21 

sacks, retained all the characters of the natatory larva. 
According to Mr. King, the larva of Lepas throws off its 
external shell five days after becoming attached. Whilst 
the young Lepas is closely packed within the larva, the 
capituliun, as known by the five valves, about equals in 
length the peduncle. The peduncle occupies the anterior 
half of the larva ; when fully stretched, it becomes nar- 
rower and slightly longer than the capituliun ; the sepa- 
ration between the capituliun and peduncle is almost 
arbitrary in the mature animal, and corresponds with no 
particular line in the larva. Even at this early period, 
the muscles of the peduncle are quite distinct. No 
vestige is preserved in the outer integument, of the sternal 
and dorsal sutures of the larval carapace ; but in the 
corium of the peduncle, three coloured marks which 
occur near the eyes, and two little curled marks which 
occur near the acoustic orifices of the larva, are all pre- 
served for some time after maturity. The compound 
eyes, as we have seen, are attached to apodemes, spring- 
ing from the sternal surface of the larval carapace, and 
are consequently cast off with it ■ whilst the young Cirri- 
pede is packed within the larva, the outer integument of 
its peduncle necessarily forms a deep transverse fold pass- 
ing over the eyes and apodemes, and this, as we shall 
presently see, plays an important part in the future 
position of the animal. The antennas are not moulted 
with the carapace, but left cemented to the surface of at- 
tachment; their muscles are converted into sinewy fibres, 
the corium after a short period is absorbed, and they are 
then preserved in a functionless condition. No trace of 
the two acoustic sacks can be perceived in the corium 
of the young Cirripede, excepting the coloured marks 
above alluded to. 

In the young capitulum, the five valves stand some 
way apart from each other; they are elegant objects 
under the microscope ; they are not calcified, but con- 
sist exclusively of chitine; they are rather thick, com- 
posed of an outer membrane lined by hexagonal prisms, 



22 LEPADIMJ. 

quite unlike any other membrane in the animal. These 
valves, which I have called primordial valves, resemble 
pretty closely in shape the valves of the mature animal ; 
the fork of the carina, however, is indicated only by a 
slight constriction above the lower end. After the 
exuviation of the larval integuments, and when calcifi- 
cation commences, the first layer of shell is deposited 
under, and then round these primordial valves. The latter, 
in well preserved old specimens, may often be detected 
on the umbones of the scuta, terga, and carina, but not 
on the umbones of any other valves. 

The mouth seems one of the earliest parts developed : 
in the youngest larva dissected, I could make out at least 
points corresponding with each organ ; and, at the period 
when the young Cirripede could be dissected out of its 
larval envelopes, their general details were quite plain. 
The labrum, however, had not become bullate. The 
mouth, as we have seen, is formed under the rudi- 
mentary mouth of the larva, and at the same relative 
spot occupied by the probosciformed mouth of the larva 
in the second stage. Thus far, in the young Cirripede 
and larva, there has been no great change in the relative 
positions of the parts : the rudimentary eyes, however, of 
the former are developed posteriorly to (or above, as ap- 
plied to a Cirripede,) the cast-off compound eyes of the 
larva ; but the position of the mouth, of the antennas, and 
of the several coloured marks in the corium, prove to 
demonstration, the correspondence in both of part to part. 
The case is rather different with what follows. 

The Cirri are developed at first of considerable length, 
so that the young animal may soon provide itself with 
food ; in Lejpas australis they are of great length, the 
sixth pair consisting of seventeen or eighteen obscure 
segments. The extreme tips of the twenty-four rami 
of the six pair of cirri, are formed within the twenty- 
four, corresponding, little, bi-segmental rami of the six 
pair of natatory legs ; but as the cirri are many times 
longer than these legs, they occupy in a bundle the 



METAMORPHOSES. 23 

whole thorax of the larva; no part whatever of the 
thorax of the Cirripede is formed within the thorax 
of the larva, but (together with the pedicels of the an- 
terior cirri) within the cephalic cavity. As a consequence 
of this, the longitudinal axis of the thorax of the young 
Cirripede lies almost transversely to the longitudinal axis 
of the larva ; and the Cirripede, from this transverse 
position of its thorax, comes to be, as it were, internally, 
almost cut in twain, and the sack thus produced. As 
soon as the young Cirripede is free and can move itself, 
the cirri are curled up, and the thorax is advanced to- 
wards the orifice of the capitulum, its longitudinal axis 
resuming the position of approximate parallelism to the 
longitudinal axis of the whole body, which it had in the 
larval condition. The reader will, perhaps, understand 
what I mean, if he will look at the mature Cirripede, 
figured in PL IX, fig. 4. In this, he will see that the 
body or thorax is united to the peduncle only by a small 
part below the mouth ; on the other hand, if he imagines 
the whole bottom of the body (as high up as the letter It) 
united and blended into the peduncle, he will see the 
state in which these parts exist in the larva. Now, let him 
greatly shorten the cirri, so as to resemble the natatory 
legs of the larva, and then imagine a young Cirripede, 
with cirri of full length, formed within the old one, he 
will see that the new thorax supporting the cirri will 
have to be developed in an almost transverse position, — 
the animal consequently being internally almost separated 
into twain. 

Of the internal organs, whilst the Cirripede is still 
within the larva, I have already mentioned the stomach 
with its pair of caeca : from the retracted position of the 
thorax and rudimentary abdomen, and consequently of 
the anus, compared with these parts in the larva, the 
alimentary canal is not above half its former length. 
There is, as yet, no trace of the filaments supposed by 
some to act as branchiae, at the base of the first pair 
of cirri. Nor could I perceive a trace of the testes or 



24 lepadiDjE. 

vesiculse seminales : the penis is represented by a minute, 
apparently imperforate projection. I have already briefly 
described the pair of large, gut-formed bodies in the 
larva, into the anterior ends of which the cement-ducts 
ran, and evidently derived their slightly opaque, cellular 
contents. At a very early age, before the young Cirripede 
can be distinctly made out, the posterior ends of these 
gut-formed bodies are absorbed, so as not to pass beyond 
the caeca of the stomach. When the young Cirripede is 
plainly developed within the larva, these bodies in a rela- 
tively reduced condition are still distinct near the cseca, 
and at the opposite or anterior end (i. e. lower, in the 
position in which Cirripedes are usually figured), they have 
branched out into a sheet of delicate inosculating tubes ; 
these could be traced by every stage, until, in the young 
perfected Cirripede, they filled the peduncle as ordinary 
ovarian tubes. In the larva, the two gut-formed bodies 
or incipient ovaria keep of equal thickness from one to 
the other end, but in the mature Cirripede, the ovarian 
tubes in the peduncle and the small, glandular, grape- 
like masses, near the stomach-cseca, are connected only 
by a delicate tube ; this I failed in tracing in specimens 
in the very immature condition of those now under 
description. 

The larva fixes itself with its sternal surface parallel 
and close to the surface of attachment, and the antennas 
become cemented to it : if the Cirripede, after its 
metamorphosis had remained in this position, the cirri 
could not have been exserted, or only against the sur- 
face of attachment ; but there is a special provision, that 
the young Cirripede shall immediately assume its proper 
position at right angles to the position which it held 
whilst within the larva, namely with its posterior end 
upwards. This is effected in a singular manner by the 
exuviation of the great compound eyes, which we have 
seen are fastened to the outer arms of the double # UU # - 
like, sternal apodemes : these together with the eyes 
stretch transversely across, and internally far up into, 



METAMORPHOSES. 25 

the body of the larva ; and, as the whole has to be rejected 
or moulted, the membrane of the peduncle of the young 
Cirripede has necessarily to be formed with a wide and 
deep inward fold, extending transversely across it ; this 
when stretched open, after the exuviation of the larval 
carapace and apodemes, necessarily causes the sternal 
side of the peduncle to be longer than the dorsal, and, 
as a consequence, gives to the young Cirripede its normal 
position, at right angles to that of the larva when first 
attached. 

I may here state, that I have examined the larva 3 in 
this the final or perfect stage in four species of Lepas, in 
Conchodermavirgata, Ibla quadrivalvis, and, though rather 
less minutely, in Balanus balanoides, and I find all 
essential points of organisation similar. With the excep- 
tion of diversities in the proportional sizes of the different 
parts, and in the patterns on the carapace, the differences, 
even in the arrangement of the spines on the limbs and 
antennae, are less than I should have anticipated. 

I have in this abstract treated the metamorphoses at 
greater length than I should otherwise have done, on 
account of the great importance of arriving at a correct 
homological interpretation of the different parts of the 
mature animal. In Crustacea, according to the ordinary 
view, there are twenty-one segments ; of these I can re- 
cognise in the Cirripede, on evidence as good as can 
generally be obtained, all with the exception of the four 
terminal abdominal segments ; these do not occur in any 
species known to me, in any stage of its development. 
If that part of the larva in front of the mouth, bearing the 
eyes, the prehensile antennae, and in an earlier stage two 
pair of antennae, be formed, as is admitted in all other 
Crustacea, of three segments, then beyond a doubt, from 
the absolute correspondence of every part, and even every 
coloured mark, the peduncle of the Lepadidae is likewise 
thus formed. The peduncle being filled by the branch- 
ing ovarian tubes is no objection to this view, for I am 



26 LEPAD1D.E. 

informed on the high authority of Mr. J. D. Dana,* 
that this is the case with the cephalo-thorax in some true 
Crustaceans, for instance, in Sapphirina. To proceed, 
the mouth, formed of mandibles, maxillae, and outer 
maxillae, correspond with the fourth, fifth, and sixth 
segments of the archetype Crustacean. Posteriorly 
to the mouth, we come, in the larva, to a rather wide 
interspace without any apparent articulation or organ, 
and then to the thorax, formed of six segments, bearing 
the six pair of limbs, of which the first pair differs slightly 
from the others. The thorax is succeeded by three small 
segments, differently shaped, with the posterior one alone 
bearing appendages ; these segments, I cannot doubt, 
from their appearance alone, and from their apparent 
function of steering the body, are abdominal segments. 
If this latter view be correct, the thoracic segments are 
the six posterior ones of the normal seven segments, and 
there must be two segments missing between the outer 
maxillae and first thoracic pair of legs, which latter on this 
view springs from the ninth segment. Now, in a very sin- 
gular Cirripede, already alluded to under the name of 
Proteolepas, the two missing segments are present, the 
mouth being actually succeeded by eight segments, and 
these by the three usual abdominal segments, — every 
segment in the body being as distinct as in an Annelid : 
hence in Proteolepas, adding the three segments for the 
mouth and three for the carapace, we have altogether 

* This distinguished naturalist has given his opinion in the ' American 
Journal of Science/ March, 1846, that " the pedicel of Anatifa corresponds 
to a pair of antennae in the young ;" although the peduncle or pedicel is 
undoubtedly thus terminated, even in mature individuals, I think it has been 
shown that it is the whole of the anterior part of the larva in front of the 
mouth, which is directly converted into the peduncle. Professor E. Forbes, 
in his Lectures, and Professor Steenstrup, in his ' Untersuchungen iiber das 
vorkommen des Hcrmaphroditismus in der Natur/ ch. v, have considered 
the peduncle as a pair of fused legs. Loven has taken, judging from a single 
sentence, the same view of the homologies of the external parts as I have 
done ; in his description of Alepas squalicola, (Ofversigt of Kongl. Yetens., 
&c, Stockholm, 1844, pp. 192-4), he uses the following words : " Capitis 
reliquse partes, ut in Lepadibus semper, in pedamulum mutates et invo- 
ucrum" &c, ; his involucrum is the same as the capitulum of this work. 



METAMORPHOSES. 27 

seventeen segments, which, as I stated, is the full number 
ever observed in any Cirripede, the four missing ones 
being abdominal, and, I presume, the four terminal seg- 
ments. That the cavity in which the thorax is lodged, 
in the larva and therefore in the mature Cirripede, is 
simply formed by the backward production of the cara- 
pace, does not require any discussion. The valves have 
no homological signification. 

As we have just seen that the first pair of natatory legs 
is borne on the ninth segment of the body, so it must be 
with the first pair of cirri, which consequently correspond 
to the outer maxillipods (the two inner pair of maxillipods 
or pied-machoires being here aborted) of the higher Crus- 
tacea, and hence their difference from the five posterior 
pair, which correspond with the five, ordinary pair of am- 
bulatory legs in these same Crustacea. The part of the 
body, which I have called the prosoma, that is the protu- 
berant, non-articulated, lower part of the thorax (PI. IX, 
^g. 4 n), is a special development, either of the ninth 
segment, bearing the first pair of cirri, or of the segments 
corresponding with the organs of the mouth. The three 
abdominal segments of the larva are represented in the 
mature Cirripede, in the Order containing the Lepadidaa, 
only by a minute, triangular gusset, let in between the 
V-shaped tergal arches of the last thoracic segment : in 
this gusset, small as it is, is seated the anus, and on each 
side the caudal appendages, often rudimentary and some- 
times absent. In another order, I may remark, (includ- 
ing, probably, the Alcippe of Mr. Hancock,) the cirri, 
of which there are only three pair, are abdominal. 

I feel much confidence, that the homologies here given 
are correct. The cause of their having been generally 
overlooked arises, I believe, from the peculiar manner, 
already described, in which the animal, during its last 
metamorphosis, is internally almost intersected : even for 
some little time after discovering that the larval antennae 
were always embedded in the centre of the surface of 
attachment, I did not perceive, that this was the anterior 



28 



lepadim:. 



end of the whole animal. The accompanying woodcut 
gives at a glance, a view of the homologies of the exter- 
nal parts : the upper figure (from Milne Edwards) is a 




Ml I i 

t ■ 




[w. — Mouth.] 

Stomapocl Crustacean, Leucifer of Vaughan Thompson, 
and the abdomen, which we know becomes in Cirripedes, 
after the metamorphosis, rudimentary, and therefore does 
not fairly enter into the comparison, is given only in 
faint lines : the lower figure is a mature Lepas, with 
the antennae and eyes, which are actually present in the 
larva, retained and supposed to have gone on growing. 
All that we externally see of a Cirripede, whether pedun- 
culated or sessile, is the three anterior segments of the 
head of a Crustacean, with its anterior end permanently 
cemented to a surface of attachment, and with its posterior 
end projecting vertically from it. 



CAPITULUM. 

I will now proceed to a general description of the 
different parts and organs in the Lepadidse. The Capi- 
tulum is usually much flattened, but sometimes broadly 
oval in section. It is generally formed of five or more 
valves, connected together by very narrow or broad strips 
of membrane ; sometimes the valves are rudimental or 
absent, when the whole consists of membrane. When 
the valves are numerous, and they occasionally ex- 



CAP1TULUM. 29 

ceed a hundred in number, they are arranged in whorls, 
with each valve generally so placed as to cover the 
interval between the two valves above. Of all the valves, 
the scuta are the most persistent; then come the terga, 
and then the carina ; the rostrum and latera occur only in 
Scalpellum and Pollicipes, and in a rudimentary condition 
in Lithotrya, and, perhaps, in the fossil genus Loricula. 
The valves are formed sometimes of chitine (as in Tbla and 
Alepas), but usually of shell, which varies from trans- 
parency to entire opacity. The shell is generally white, 
occasionally reddish or purple; exteriorly, the valves are 
covered by more or less persistent, generally yellow, strong 
membrane. The scuta and terga are always consider- 
ably larger than the other valves : in the different genera 
the valves differ so much in shape that little can be pre- 
dicated of them in common ; even the direction of their 
lines of growth differs, — thus, in Lepas and some allied 
genera, the chief growth of the scuta and of the carina is 
upwards, whereas in Pollicipes and Lithotrya, it is en- 
tirely downwards ; in Oxynaspis, and some species of Scal- 
pellum, it is both upwards and downwards. Even in the 
same species, there is often very considerable variation in 
the exact shape of the valves, more especially of the 
terga. The adductor muscle is always attached to a 
point not far from the middle of the scuta, and it gene- 
rally has a pit for its attachment. In several genera, 
namely, Psecilasma, Dichelaspis, Conchoderma, and 
Alepas, the scuta show a tendency to be bilobed or 
trilobed. The valves are placed either at some distance 
from each other, or close together; but their growing 
margins very rarely overlap each other, though this is 
sometimes the case with their upper, free, tile-like apices ; 
in a few species the scuta and terga are articulated to- 
gether, or united by a fold. The membrane connecting 
the valves, where they do not touch each other, is like 
that forming the peduncle, and is sometimes brilliantly 
coloured crimson-red ; generally, it appears blueish-gray, 
from the corium being seen through. Small pointed 



30 LEPADID^l. 

spines, connected with the underlying corium by tubuli, 
are not unfrequently articulated on this membrane : the 
tubuli, however, are often present where there are no 
spines. To allow of the growth of the capitulum, the 
membrane between the valves splits at each period of 
exuviation, when a new strip of membrane is formed 
beneath, connected on each side with a fresh layer of shell, 
— the old and outer slips of membrane disintegrating 
and disappearing: when there are many valves, the line of 
splitting is singularly complicated. This membrane 
consists of chitine,* and is composed of numerous fine 
laminae. After the valves have been placed in acid, a 
residue, very different in bulk in different genera, is left, 
also composed of successive laminae of chitine. It appears 
to me that each single lamina of calcified chitine, com- 
posing the shell, must once have been continuous with a 
non-calcified lamina in the membrane connecting the 
several valves : at the line where this change in calcifi- 
cation supervenes, the chitine generally "assumes some 

* Chitine is confined to the Articulata. It was Dr. C. Schmidt (Contri- 
butions, &c, being a Physiologico-Chemical investigation: in Taylor's 
' Scientific Memoirs/ vol. v), who discovered that the membrane connect- 
ing the valves and forming the peduncle, and the tissues of the internal 
animal, were composed of this substance. But Dr. Schmidt says that the 
valves in Lepas are composed of 3*09 of albuminates, and 96*81 of incom- 
bustible residue ; I cannot but think that the existence of the albuminates is 
an error caused by Dr. Schmidt's belief that the Cirripedia were intermediate 
between Crustacea and Mollusca, in the shells of which latter, the animal 
basis consists of albuminates. For after placing the valves of Lepas and 
Pollicipes in cold acid, I found that the membrane left could not be dissolved 
in boiling caustic potash, but could, though slowly, (and without change of 
colour,) in boiling muriatic acid ; and these are the main diagnostic charac- 
ters of Chitine, compared with albuminous substances. I may add, that 
Schmidt was also induced to consider the shells of Cirripedia as having the 
same nature with those of Mollusca, from finding that in the above 96*81 of 
incombustible matter, 99*3 consisted of carbonate and only 0*7 of phosphate of 
lime ; but Dr. Schmidt's own analyses prove how extremely variable the pro- 
portions of these salts are in the Crustacea, as the following instance shows : — 

Lobster. Squilla. 

Phosphate of Lime . . 12*06 . . 47*52 
Carbonate of Lime . . 87*94 . . 52*48 

And, therefore, it is not very surprising that Cirripedia should have still 
less phosphate of lime in their shells, than has a lobster compared with a 
squilla. 



PEDUNCLE. 81 

colour, and becomes much harder and more persistent ; 
and as the whole valve is formed of component laminae 
thus edged (the once continuous laminae of non-calcified 
chitine connecting the valves, having disintegrated and 
disappeared) the surfaces of the valves are generally left 
covered by a persistent membrane, constituted of these 
edgings : this membrane has been called the epidermis. 
In some genera, as in Lepas, this so-called epidermis is 
seldom preserved, excepting on the last zone of growth : 
in Scalpellum and Pollicipes it usually covers the whole 
valves. It appears to me that the laminae of chitine, 
and of calcified chitine composing the valves, are both 
formed not by secretion, but by the metamorphosis of an 
outer layer of corium into these substances. 

Within the capitulum is the sack, which, together with 
the upper internal part of the peduncle, encloses the 
animal's body. The sack is lined by a most delicate mem- 
brane of chitine, under which there is a double layer of 
corium ; this double layer is united together by short, 
strong, transverse bundles of fibres, branched at both 
ends :* in some genera, the ovarian tubes extend between 
these two layers. We have seen, under the head of the 
Metamorphoses, that the delicate tunic lining the sack is 
simply a duplicature of the thick membrane and valves 
forming the capitulum, the whole being the posterior 
portion of the carapace of the larva slightly modified. 

Peduncle. — Its length varies greatly in different species, 
and even in the same species, according to the situation 
occupied by the individual; its lower end is some- 
times pointed, but generally only a little narrower than 
the upper end. In outline, the peduncle is usually 
flattened, but sometimes quite cylindrical. It is com- 
posed of very strong, generally thick, transparent mem- 
brane, rarely coloured reddish, and often penetrated by 
numerous tubuli. The underlying corium is sometimes 

* I am much indebted to Mr. Inman of Liverpool for having kindly sent 
me excellent specimens illustrating this structure. 



32 



LEPADIDiE. 



coloured in longitudinal bands. At each period of 
growth a new and larger integument is formed under the 
old one, which gradually disintegrates and disappears ; 
the extreme lower point is often deserted by the corium, 
and ceases to grow, whilst the whole upper part still 
continues increasing in diameter: in length the chief 
addition is made (as is clearly seen in those genera having 
calcified scales), round the upper margin, at the base of 
the capitulum. The surface of the membrane is either 
naked or superficially clothed with minute, pointed, 
articulated spines, or it is penetrated by calcified scales 
or styles, (in Ibla alone formed of chitine,) which pass 
through it to the corium, and are added to at their bases, 
like the valves, at each period of growth. In Lithotrya 
alone the scales of the peduncle are moulted together 
with the connecting membrane. These scales on the 
peduncle are generally placed symmetrically in whorls, 
with each scale corresponding with the junctions of two 
scales, both above and below. Except in Scalp ellum 
ornatum and the fossil Loricula pulchetta, they are very 
small compared with the valves of the capitulum. When 
the scales are symmetrical, new ones are first formed 
only round the summit of the peduncle, and only those 
in the few uppermost whorls continue to grow or to be 
added to at their bases ; afterwards membrane is depo- 
sited under them. The shelly matter of the scales 
resembles that of the valves, and the manner of growth 
is the same ; tubuli generally run to and through them 
from the corium. From the continued enlargement of 
the membrane of the peduncle, the scales come to stand, 
in the lower portion, some way apart. In Ibla, new 
horny styles are formed indifferently in all parts of the 
peduncle. In some species of Pollicipes, the calcareous 
styles are not symmetrical or symmetrically arranged ; 
and besides those first formed round the top of the pe- 
duncle, there are other and larger ones formed near its 
base. Lastly, in Lithotrya we have a row of calcareous 
discs or an irregular, basal cup, formed in the same 



ATTACHMENT. 33 

manner as the valves of the capitulnm : in this genns 
alone (as already stated,) the calcified scales are moulted, 
and here alone their edges are serrated. 

The peduncle is lined within by three layers of muscles, 
longitudinal, transverse, and oblique, all destitute of the 
transverse striae, characteristic of voluntary muscles ; they 
run from the bottom of the peduncle to the base of the 
capitulum, as in Lepas, or half way up it, as in Concho- 
derma; in Alepas alone they surround the whole 
capitulum up to its summit. In Lithotrya there are two 
little, fan-like, transverse muscles (involuntary), extending 
from the basal points of the terga to a central line on the 
under side of the carina. The gentle swaying to and 
fro movements, and the great power of longitudinal con- 
traction, — movements apparently common, as I infer 
from facts communicated to me by Mr. Peach, to all the 
Pedunculata, — are produced by these muscles. The 
interior of the peduncle is filled up with a great mass of 
branching ovarian tubes ; but in Ibla and Lithotrya, the 
upper part of the peduncle is occupied by the animal's 
body. 

Means of Attachment. — If the peduncle be very care- 
fully removed (Tab. IX, fig. 7 and Tab. I, fig. 6b), from 
the surface of attachment, quite close to the end, but not 
at the actual apex, the larval prehensile antennae can 
always be found: these have been sufficiently described 
for our present purpose under the head of the Metamor- 
phoses ; but I may add, that the diagnostic differences 
between them in the several genera are briefly given, for 
a special purpose, in a discussion on the sexes of Scal- 
pellum at the end of that genus. We have seen in the 
larva, that the cement-ducts, with their opaque cellular 
contents, can be traced from within the discs of the 
antennae to the anterior or lower ends of the two gut- 
formed bodies, which it can be demonstrated are the 
incipient ovaria. 

In mature Cirripedes these ducts can be followed, in a 
slightly sinuous course, along the muscles on each side 

3 



34 LEPADID.E. 

within the peduncle, till they expand into two small 
organs, which I have called cement-glands. These glands 
are found with great difficulty, except in Conchoderma 
aurita, where they are placed on each side under the inner 
layer of corium, at the bottom of the sack, so as to be just 
above the top of the peduncle ; they resemble in shape a 
retort, (PI. IX, fig. 3.) In Potticipes mitella and polymer us 
they lie half way down the peduncle, close together, 
and apparently enclosed within a common membrane; in 
these two species the broad end of the gland is bent 
towards the neck of the retort. In Scalpellum the position 
is the same, but the shape is more globular. In Ibla the 
structure is more simple, namely, a tube slightly enlarged, 
running downwards, bent a little upwards, and then 
resuming its former downward course, the lower portion 
forming the duct. The gland contains a strongly co- 
herent, pulpy, opaque, cellular mass, like that in the 
cement-ducts ; but in some instances, presently to be 
mentioned, this cellular mass becomes converted within 
either the ducts or gland, or within both, into transparent, 
yellow, tough cement. Generally in Conchoderma, Pol- 
licipes, and Scalpellum, two ovarian tubes, but in one 
specimen of Conchoderma aurita, three tubes, and in Ibla 
one tube could be seen running into or forming the 
gland ; of the nature of the tubes there could not be the 
least doubt, for at a little distance from the glands they 
gave out branches (PL IX, fig. 3), containing ova in every 
state of development. In some specimens as in that 
figured of Conchoderma aurita,the ovarian tube on one side 
of the gland is larger than on the other, and has rather 
the appearance of being deeply embedded in the gland 
than of forming it; but, in other specimens, the two 
ovarian tubes first formed a little pouch, into which their 
cellular contents could be clearly seen to enter ; and then 
this pouch expanded into the gland ; thus quite removing 
a doubt which I had sometimes felt, whether the ovarian 
tube was not simply attached to or embedded in the 
gland, without any further connection. By dissection 



ATTACHMENT. 35 

the multiple external coats of the gland and ovarian tubes 
could be seen to be continuous. The cellular contents of 
the tubes passed into the more opaque cellular contents of 
the gland, by a layer of transparent, pulpy, pale, yellowish 
substance. There appeared in several instances to be a 
relation, between the state of fulness and condition of the 
contents of the gland, and of the immediately adjoining 
portions of the ovarian tubes. In one specimen of 
Pollicipes mitella it was clear that the altered, tough, 
yellow, transparent, non-cellular contents of the two 
glands and ducts, had actually invaded for some little 
distance, the two ovarian tubes which ran into them, thus 
showing the continuity of the whole. From these facts I 
conclude, without hesitation, that the gland itself is a part 
of an ovarian tube specially modified ; and further, that 
the cellular matter, which in the ovarian tubes serves for 
the development of the ova, is, by the special action of the 
walls of the gland, changed into the opaquer cellular matter 
in the ducts, and this again subsequently into that tissue 
or substance, which cements the Cirripede to its surface 
of attachment. 

As the individuals grow and increase in size, so do the 
glands and cement-ducts ; but it seems often to happen, 
that when a specimen is immovably attached, the 
cementing apparatus ceases to act, and the cellular con- 
tents of the duct become converted into a thread of 
transparent tough cement ; the investing membrane, also, 
of the ducts, in Conchoderma sometimes becomes hard 
and mamillated. I have already alluded to the case of 
a Pollicipes, in which both glands and ducts, and even 
a small portion of the two adjoining ovarian tubes, had 
become thus filled up. As in sessile Cirripedes, at every 
fresh period of growth a new cement gland is formed, it 
has occurred to me, that possibly in Pollicipes something 
similar may take place. In sessile Cirripedes, the old 
cement-glands are all preserved in a functionless condi- 
tion, adhering to the membranous or calcareous basis, 
each new larger one attached to that last formed, and 



36 LEPADID.E. 

each giving out cement-ducts, which, bifurcating in the 
most complicated manner, pass outside the shell and thus 
attach it to some foreign body. 

The cement, removed from the outside of a Cirripede, 
consists of a thin layer of very tough, bright-brown, 
transparent, laminated substance, exhibiting no structure 
under the highest powers, or at most a very fine dotted 
appearance, like a mezzotinto drawing. It is of the 
nature of chitine ; but boiling caustic potash has rather 
more effect on it than on true chitine ; and I think 
boiling nitric acid rather less effect. In one single 
instance, namely, in Coronula, the cement conies out of 
the four orifices of the two bifurcating ducts, in the 
shape of distinct cells, which, between the whale's skin 
and the basal membrane, arrange themselves so as to 
make a circular, continuous slip of cement; then the 
cells blend together, and are converted into transparent, 
structureless cement. Cementing tissue or membrane 
would, perhaps, have been a more correct title than 
cement ; but, in ordinary cases, its appearance is so little 
like that of an organised tissue, that I have for this 
reason, and for brevity-sake, preferred the simple term of 
Cement. 

In the larva the cement always escapes through the pre- 
hensile antennae ; and it thus continues to do throughout 
life in most or all of the species of Lepas, Conchoderma, 
Dichelaspis and Ibla. In the first two of these genera, 
the cement escapes from the borders of the lower side of 
the disc or penultimate segment of the antennae, and can 
be there seen radiating out like spokes, which at their 
ends divide into finer and finer branches, till a uniform 
sheet of cement is formed, fastening the antennas and 
the adjoining part of the peduncle down to the surface of 
attachment. In Dichelaspis Warwickii and Scalpellnm 
Peronii, the cement, or part at least, comes out of the 
ultimate segment of the antennae, in the shape of one tube, 
within another tube of considerable diameter and length. 
In Scalpelhm vulgar e, and probably in some of the other 



ATTACHMENT. 37 

species, which live attached to corallines, the cement 
soon ceases to debouch from the antennse, but instead, 
bursts through a row of orifices on the rostral margin of 
the peduncle (PL IX, fig. 7), by which means this margin 
is symmetrically fastened down to the delicate, horny 
branches of the zoophyte. In Pollicipes, the two cement- 
ducts, either together or separately (PL IX, fig. 2, 2 a') t 
wind about the bottom of the peduncle in the most 
tortuous course, at each bend pouring out cement through 
a hole in the membrane of the peduncle. In Ibla the 
lower part of the peduncle is internally filled by cement, 
and thus rendered rigid. In Lep as fascicular is a vesicular 
ball of cement surrounding the peduncle is thus formed 
(PL I, ^g. 6), and serves as a float ! All these curious, 
special adaptations are described under the respective 
genera. How the cement forces its way through the 
antenna?, and often through apertures in the thick mem- 
brane of the peduncle, I do not understand. I do not 
believe, though some appearances favoured the notion, 
that the duct itself debouches and divides, at least this 
is not the case in Coronula, but only that the internal 
chord of cellular matter thus acts and spreads itself out ; 
nor do I understand how, when the antennae and imme- 
diately adjoining parts are once cemented down, any more 
cement can escape ; yet this must take place, as may be 
inferred from the breadth of the cemented, terminal por- 
tion of the peduncle in Lepas and Conchoderma ; and 
from the often active condition in old individuals of the 
cementing organs. 

I have entered on this subject at some length, (and I 
wish I had space for more illustrations,) from its offering, 
perhaps, the most curious point in the natural history of 
the Cirripedia. It is the one chief character of the Sub- 
class. I am well aware how extremely improbable it 
must appear, that part of an ovarian tube should be con- 
verted into a gland, in which cellular matter is modified, so 
that instead of aiding in the development of new beings, 
it forms itself into a tissue or substance, which leaves the 



38 lepadidtE. 

body* in order to fasten it to a foreign support. But on 
no other view can the structure, clearly seen by me both 
in the mature Cirripede and in the larva, be explained, 
and I feel no hesitation in advancing it. I may here 
venture to quote the substance of a remark made by Pro- 
fessor Owen, when I communicated to him the foregoing 
facts, namely, that there was a new problem to solve, 
— new work to perform, — to attach permanently a crus- 
tacean to a foreign body ; and that hence no one could, 
a priori, tell by what singular and novel means this would 
be effected. 

Filamentary Appendages. — These have generally been 
considered to act as branchiae ; they occur at the bases of 
the first pair of cirri in Lepas, Alepas, Conchoderma, 
and in three species of Pollicipes : in Conchoderma there 
are similar appendages attached to the pedicels of the 
cirri (PI. IX, fig. 4>,g — k) ; and in the above three species 
of Pollicipes there is a double row of them on the prosoma : 
their numbers differ in different species (in some there 
being none) of the same genus, and even in different indi- 
viduals of the same species ; they are entirely absent in 
the majority of the genera. These facts would indicate 
that they are not of high functional importance ; and they 
seem so generally occupied by testes (PI. iv, fig. 5), that 
I suspect their function is quite as much to give room 
for the development of these glands, as to serve for 
respiratory purposes. With the exception of the four 
above-named genera, the mere surface of the body and 
of the sack must be sufficient for respiration : in Concho- 
derma aurita the two great expansions of surface, afforded 
by the folded, tubular, ear-like projection s, aid, as I 
believe, towards this end. 

* The protrusion of the egg-bearing pouches in Cyclops and its kindred 
genera, outside the body, offers a feeble analogy with what takes place in 
Cirripedes. Professor Allman ('Annals of Natural History/ vol. xx, p. 7,) 
who has attended to the subject, says that the external egg-bearing pouches 
are " a portion of the membrane of the true ovaries :" if the membrane of 
these pouches had been specially made adhesive, the analogy would have 
been closer. 



MOUTH. 39 

The shape of the body varies, owing to the greater or less 
development of the lower part of the prosoma, the greater 
or less distance of the first from the second pair of cirri, 
and of the mouth from the adductor scutorum muscle, 
(PL IX, fig. 4, and PI. IV, 8a). In all the genera, the body 
is much flattened. I may here mention a few particulars 
about the muscular system. One of the largest muscular 
masses is formed by the adductor scutorum, and by the 
muscles which surround in a double layer (the fasciae 
being oblique to each other) the whole of the upper part 
of the prosoma. From under the adductor, a pair of 
delicate muscles runs to the basal edge of the labrum, so 
as to retract the whole mouth, and two other pair to the 
integument between the mouth and the adductor, so as 
to fold it -. again, there are other delicate muscles in some 
(for instance in Zepas Hillii) if not in all the Lepadidae, 
crossing each other in the most singular loops, and serving 
apparently to fold the membrane between the occludent 
edges of the scuta. Within the prosoma there is a strong 
adductor muscle, running straight from side to side, for 
the purpose, as it appears, of flattening the body. The 
thorax, on the dorsal and ventral surfaces, is well fur- 
nished with straight and oblique muscles (without striae), 
which straighten and curl up this part of the body. The 
muscles running into the pedicels of the cirri, cross each 
other on the ventral surface of the thorax ; the muscles 
within the rami are attached to the upper segments of 
the pedicels. Finally, I may remark that the whole of the 
body and the cirri are capable of many diversified move- 
ments. 

Month. — This is prominent, and almost probosci- 
formed (PL IX, fig. 4 b), and in the abnormal Anelasma 
(PL IV, fig. 2 d), quite probosciformed, — such, also, was 
its character in the larval condition. In outline, it is either 
sub -triangular, or oval with the longer axis transverse ; the 
whole is capable, as well as the separate organs, of con- 
siderable movement, as I have seen in living sessile 
Cirripedes. It is composed (Tab. V, fig. 2) of a labrum, 



40 LEPADIDJE. 

swollen or bullate, often to such an extent as to equal 
in its longitudinal axis the rest of the mouth ; of palpi 
soldered to the labrum ; of mandibles, maxillae, and outer 
maxillae, the latter serving as a lower lip. These organs 
have only their upper segments free, but there are traces, 
clearly seen in the mandibles (PL X, fig. 1, a, b), of their 
being formed of three segments. The two lower seg- 
ments are laterally united, and open into each other, the 
prominence of the mouth being thus caused : this condi- 
tion appears to me curious, and is, to a certain limited 
extent, intermediate between those articulated animals 
which have their tropin soldered into a proboscis, and 
those furnished with entirely free masticatory or prehensile 
organs. The palpi adhere to the corners of the labrum ; 
and I call them palpi only from seeing that they spring 
laterally from above the upper articulation of the man- 
dibles. The prominence of the mouth, measured from 
the basal fold by which the whole is separated from the 
body, is much greater on the half formed by the labrum 
and mandibles, than on the other half facing the cirri. 
The tropin surround a cavity — the supra-cesophageal 
cavity — in the middle of which, between the mandibles 
is seated the orifice of the oesophagus. The oesophagus 
is surrounded by long, fine, muscular fasciae, radiating in 
all directions, opposing the constrictor muscles, and is 
capable of violent swallowing movements, — constriction 
after constriction being seen to run down its whole 
course : there are also some fine muscles attached to the 
membrane forming the supra-cesophageal cavity. The 
trophi serve merely for the prehension of prey, and not 
for mastication. 

The Labrum, as stated, is always bullate or swollen ; 
and sometimes the upper exterior part forms, as in 
Ibla (PI. IV, fig. 8 a, c), and Dichelaspis, an overhanging 
blunt point. The object, I suspect, of this bullate form 
is to give, in the upper part, attachment to longer muscles 
running to the lateral surfaces of the mandibles, and 
lower down to the oesophagus. The crest close over the 



MOUTH. 41 

supra-cesophageal cavity, is generally furnished with small, 
often bead-like teeth. The Palpi are small, their apices 
never actually touching each other; they are more or 
less blunt, not differing much in shape in the different 
genera (PL X, figs. 6 to 8), and clothed with spines. They 
are not capable of movement ; their function seems to be 
to prevent prey, brought by the cirri, escaping over the 
labrum ; I infer this from finding in Anelasma and in 
the male of Ibla, which have the cirri functionless, that 
the palpi are rudimentary. 

The Mandibles (PL X, figs. 1 — 5) have from two to 
ten strong teeth in a single row ; where the number 
exceeds five, several of the teeth are small; the in- 
ferior angle is generally pectinated with fine spines; 
in Lithotrya (fig. 2), the interspaces between the teeth are 
also pectinated. In the same individual there is not un- 
frequently one tooth, more or less, on opposite sides of 
the mouth. Internally, the mandibles are furnished on 
their outer and inner sides with several ligamentous 
apodemes, (in Lithotrya roughened with points (PL X, 
fig. 2), for the attachment of the muscles ; of these (fig. 1), 
there is a chief depressor and elevator, attached at their 
lower ends to near the basal fold of the mouth, and a 
lateral muscle, attached to the broad basal end of the palpi, 
and serving, apparently, to oppose the edge of mandible to 
mandible. The Maxilla in the different genera (PL X, 
figs. 9 to 15) differ considerably in outline ; they are gene- 
rally about half the size of the mandibles ; at the upper 
corner, there are always two or three spines larger than 
the others, and often separated from them by a notch ; 
the rest of the spinose edge is straight, or irregular, or 
step-formed, or with the lowest part projecting, or with 
one or two narrow prominences bearing fine spines. All 
these spines, quite differently from the teeth of the man- 
dibles, are articulated on the edge of the organ, and stand 
in a double row. At a point corresponding with the 
upper articulation of the mandibles, a long, thin, narrow, 
rigid apodeme, projects inwards (fig. 10), and running 



42 LEPADIDvE. 

down nearly parallel to the thin, outer, flexible membrane 
of the mouth, is attached to the corium, and thus serves as 
a support to the whole organ. This apodeme is embedded 
in muscles (PI. X, fig. 1 0) ; there are other large muscles 
attached to the inner side of the organ, and again others 
running laterally towards the mandibles. The apodeme, 
of course, is moulted with the integuments of the mouth. 
The Outer Maxillce (PL X, figs. 16, 17) serve as a lower 
lip; they are thicker than the other trophi; they have 
their inner surfaces clothed with spines, sometimes divided 
into an upper and lower group, and occasionally separated 
by a deep notch : there are often long bristles outside. 
They are furnished with at least two muscles ; in sessile 
Cirripedes I have seen that they are capable of a rapid 
to and fro movement, and I have no doubt that their 
function is to brush any small creature, caught by the 
cirri, towards the maxillae, which are well adapted to aid 
in securing the prey, and to hand it over to the mandibles, 
by them to be forced down the oesophagus. On the ex- 
terior face of the outer maxillae, above a trace of an upper 
articulation, either two small orifices or two large tubular 
projections can always be discovered ; and these, as will 
presently be mentioned, I believe to be olfactory organs. 
Cirri. — The five posterior pair are seated close to each 
other and equidistant ; the first pair is generally seated at a 
little distance, and sometimes at a considerable distance 
from the second pair. The first pair is the shortest ; the 
others, proceeding backwards, increase gradually in length. 
The rami of each pair are either equal in length or slightly 
unequal: those of the first pair are oftenest unequal. 
The number of segments in the posterior cirri is some- 
times very great ; in one species of Alepas, there were 
above sixty segments in one ramus, the other ramus being 
in this unique case (PI. X, fig. 28) small and rudimentary. 
The pedicels consist of two segments, a lower, longer, and 
upper short one (fig. 18, c, d.) In the usual arrangement 
of the spines on the segments of the three posterior pair 
of cirri, there are (figs. 26, 27) from three to six pair of 



CIRRI AND CAUDAL APPENDAGES. 43 

long spines on the anterior face, with generally some 
minute spines (occasionally forming a tuft) intermediate 
between them : on the dorsal surface, in the upper- 
most part of each segment, there is a tuft of short spines 
generally mingled with some longer, finer ones : on the 
inner side of each segment, on the upper rim, there are 
generally a few extremely minute and short spines. From 
the increase of these latter and of the intermediate spines, 
the antero-lateral faces of the segments of the first cirrus, 
and of the lower segments of the anterior ramus of the 
second cirrus (PI. X, fig. 25), are almost always thickly 
paved with brush-like masses of spines. The lower seg- 
ments of the anterior ramus of the third cirrus is generally, 
though not always, thus paved : these paved segments 
are much broader than the others. The posterior rami 
of the second and third cirri are often in some slight 
degree paved, though in other cases they resemble the 
three posterior pair of cirri. The two segments of the 
pedicels have bristles on their anterior faces, essentially 
arranged on the same plan as on the segments of the 
rami : the bristles are generally not so symmetrically 
arranged on the pedicels of the second and third cirri, as 
on the three posterior pair. There are some exceptions 
to the foregoing general rules : in the posterior cirri of 
Alepas cor nut a, there is only one pair of long spines to 
each segment (fig. 28) ; in Bichelaspis Zotvei, there are 
eight pair; in Zep as fascicular is, in old specimens, the 
segments are paved with a triangular brush of spines ; 
the upper segments in Pcecilasma eburnea support small 
oblong brushes; and, lastly, in Pcecilasma jissa (fig. 29), 
and crassa, the spines form a single circle round each 
segment, interrupted on the two sides. These spines are 
often doubly serrated or plumose : many of them on the 
protuberant segments of the first three pair of cirri, are 
sometimes coarsely and doubly pectinated. 

Caudal Jpp enclaves. — These are present (PL X, 
figs. IS to 24) seated on each side of the anus, in all the 
genera, except in Conchoderma, Anelasma, and Scalpellum 



44 LEPADID.E. 

villosum ; they consist of a very small single segment, 
destitute of spines in Lepas, and spinose in Psecilasma, 
Dichelaspis, Oxynaspis, Scalpellum, and some species of 
Pollicipes ; they consist of several segments in Alepas, 
Ibla, Lithotrya, and in some species of Pollicipes. In the 
latter genus, some species have their caudal appendages 
multiarticuiate, though so obscurely articulated, that the 
passage (fig. 22) from several to one segment is seen to 
be easily effected. When the appendage consists of many 
articulations, it is generally about as long as the pedicel 
of the sixth cirrus; but in Ibla quadrivalvis, it is four 
times as long. The segments are narrow, slightly flat- 
tened, much tapering; each (fig. 24) is surmounted by 
a ring of short spines, which are generally longest on 
the apex of the terminal segment. I could never trace 
muscles into these appendages. 

Alimentary Canal. — The oesophagus is of considerable 
length : it is formed of strong, transparent, much folded 
membrane, continuous with the outer integuments, and 
moulted with them : it is surrounded by corium, and as 
already stated, by numerous muscles : at its lower end it 
expands into a bell, with the edges reflexed, and some- 
times sinuous : this bell lies within the stomach, and 
keeps the upper broad end expanded. According to the 
less or greater distance of the mouth from the adductor 
muscle, the oesophagus runs in a more or less parallel 
course to the abdominal surface between the first and suc- 
ceeding pairs of cirri, and enters the stomach more or less 
obliquely. In Ibla alone, it passes exteriorly to, and 
over the adductor scutorum muscle. The stomach lies 
in a much curved, almost doubled course ; it is often a 
little constricted where most bent ; it is broadest at the 
upper end, and here, in Lepas and Conchoderma, there 
are some deep branching caeca; in the latter of these 
two genera, the whole surface is, in addition, pitted in 
transverse lines. The stomach is coated by small, 
opaque, pulpy, slightly arborescent glands, believed to be 
hepatic; these are arranged in longitudinal lines, in all 



ALIMENTARY CANAL. 45 

the genera, except in Alepas, in which they are transverse 
and reticulated : the whole stomach is thus coated. There 
is, also, a coating of excessively delicate, longitudinal and 
transverse muscles without striae. The rectum varies in 
length, extending inwards from the anus to between the 
bases of the second and fifth pair of cirri : it is narrow, 
and formed of much folded transparent membrane, re- 
sembling the oesophagus, continuous with the outer 
integuments, with which it is periodically moulted. The 
anus is a small longitudinal slit, in the triangular piece of 
membrane representing the abdomen, let in between the 
last thoracic tergal arches, as already mentioned under the 
head of the Metamorphoses ; it lies almost between the 
caudal appendages, and opens on the dorsal surface. 
Within the stomach, there can generally be plainly seen, 
in accordance with the period of digestion when the speci- 
men was taken, a thin, yet strong, perfectly transparent 
epithelial membrane, not exhibiting under the highest 
power of the microscope any structure : it enters the 
branching caeca, and extends from the edge of the bell 
of the oesophagus to the commencement of the closed 
rectum, and consequently terminates in a point : it con- 
sists of chitine, like the outer integuments of the animal, 
and by placing the whole body in caustic potash, I have 
dissolved the outer coats of the stomach, and seen the 
bag open at its upper end, perfectly preserved, floating 
in the middle of the body, and full of the debris of the 
food. In most of the specimens which I have examined, 
preserved in spirits of wine, this epithelial lining was some 
little way distant and separate from the coats of the 
stomach ; and hence was thought by M. Martin St. Ange 
to be a distinct organ, like the closed tube in certain 
Annelids. Occasionally, I have seen one imperfect epi- 
thelial bag or tube within another and later-formed one. 
Digestion seems to go on at the same rate throughout the 
whole length of the stomach ; if there be any difference, 
the least digested portions lie in the lower and narrower 
part. The prey, consisting generally of Crustacea, infu- 



46 LEPADIDvE. 

soria, minute spiral univalves, and often of the larvae of 
Cirripedes, is not triturated : when the nutritious juices 
have been absorbed, the rejectamenta are cast out through 
the anus, all kept together in the epithelial bag, which is 
excluded like a model of the whole stomach, with the 
exception of that part coated by the bell of the oesophagus. 
I have sometimes thought that the bag was formed so 
strong, for the sake of thus carrying out the excrement 
entire, so as not to befoul the sack. I believe Lepas can 
throw up food by its oesophagus ; at least, I found in one 
case, many half -digested small Crustaceans in the sack, 
and others of the same kind in the stomach. 

Circulatory System. — I can add hardly anything to 
what little has been given by M. Martin St. Ange : like 
others, I have failed, as yet, in discovering a heart. The 
whole body is permeated by channels, which have not 
any proper coat : there is one main channel along the 
ventral surface of the thorax, dividing and surrounding 
the mouth, and giving out branches which enter the inner 
of the two channels in each cirrus : as Burmeister has 
shown, there are also two channels in the penis. There 
are two dorso-lateral channels in the prosoma, which are 
in direct connection with the great main channel, running 
down the rostral (t. e. } ventral) side of the peduncle. This 
latter main channel branches out in the lower part, and 
transmits the fluid through the ovarian tubes, whence, I 
believe, it flows upwards and round the sack, re-entering 
the body near the sides of the adductor scutorum muscle. 
The main rostral channel (or artery ?) in the uppermost 
part of the peduncle, has a depending curtain, which, I 
think, must act as a valve, so as to prevent the circulating 
fluid regurgitating into the animal's body during the con- 
tractions of the peduncle. 

Nervous System and Organs of Sense. — In most of the 
genera, there are six main ganglia, namely, the supra- 
cesophageal, and five thoracic ganglia ; but in Pollicipes 
mitella there are only four thoracic ganglia. Of these, 
the first thoracic or infra-cesophageal ganglion is con- 



NERVOUS SYSTEM. 47 

siderably the largest and most massive ; it is squarish, 
or oval, or heart-shaped; it presents no trace of being 
formed by the union of two lateral ganglia. Two great 
nerves spring from its under side (a), represented in the 
woodcut on page 49, by dotted lines), and run straight 
down amongst the viscera in the prosoma : these nerves 
are about as large as those forming the collar and those 
running to the second ganglion ; hence, six great nerves 
meet here, two in front, two behind, and two on the 
under side. At the anterior end, over the junction with 
the collar chord, three equal-sized nerves rise on each side, 
with a fourth, smaller one, outside; these go to the 
tropin and to the two olfactory sacks. At the posterior 
end, on each side, a pair of nerves branch out rectangu- 
larly, one of which (a,) goes to the first cirrus, and there 
divides into two branches; of these, the upper runs up 
the cirrus, and the lower one downwards. The other 
nerve ($), proceeding on each side from this first thoracic 
ganglion, runs to the muscles beneath the basal articula- 
tion of the first cirrus. The collar surrounding the oeso- 
phagus is generally very long, sometimes equalling the 
whole thoracic chord ; at a middle point, a small branch 
is sent off, and at the anterior end (e, e), close to the 
supra-cesophageal ganglia, double or treble fine branches 
run to the true ovaria, lying close to the upper end of the 
stomach. The four (or only three) other thoracic ganglia, 
when viewed as transparent bodies, are seen to be solid ; 
but in some of the genera, as in Conchoderma, the outline 
plainly shows, that each consists of a lateral pair fused 
together. The second thoracic ganglion (b) is rather 
small; it is either close to the first, as in PoUicipes 
mitetta and Lep as fascicular is, or far distant, as in Ibla. 
The third (c) and fourth are of about the same size with 
the second : these three ganglia send large branches to 
the second, third, and fourth pair of cirri : other minute 
branches spring from their under sides, and from the 
intermediate double chords. The fifth ganglion is larger 
and longer than the three preceding ones, and gives off 



48 LEPADID.E. 

nerves to the fifth and sixth pair of cirri ; it is clearly 
formed by the union of the fifth, with what ought to have 
formed a sixth ganglion. The two nerves going to the 
sixth cirrus give off on their inner sides, each a great 
branch to the penis. In Pollicipes mitetta, in which 
there are only four instead of five thoracic ganglia, it is 
evident from the outline and position of the nerves going 
to the fourth pair of cirri, that the fourth ganglion is 
fused into the fifth, itself, as we have just seen, nor- 
mally composed of two consecutive ganglia. In this 
Pollicipes there is other evidence of concentration in 
the nervous system, for none of the ganglia show signs 
of being formed of lateral pairs; the second is close to 
the first ; and the abdominal double chord is in part 
separated by a mere cleft ; lastly, as we shall immedi- 
ately see, the same remark is applicable to the supra- 
cesophageal ganglia. 

The latter (d) alone remain to be described ; they 
present far more diversity in shape than do the thoracic 
ganglia; they are almost always seen in outline to be 
laterally distinct, and usually resemble two pears with 
their tapering ends cut off and united ; in a transverse 
line they are as long as the infra- oesophageal ganglion, 
but are much less massive. In Lepas fascicularis (d), 
they are pear-shaped; in Pollicipes mitella they are 
globular, and separated by a third globular ganglion, 
which I believe is the ophthalmic ganglion, presently 
to be described; in Pollicipes spinosus, however, the 
ophthalmic ganglion is, as usual, placed in advance of 
the supra-cesophageal ganglion, which latter, in this one 
species, shows no sign of being formed of a lateral pair 
fused together. In Alepas cornuta the supra-cesophageal 
ganglion consists of two quite distinct ganglia, elongated 
in the longitudinal axis of the body, and separated from 
each other by the whole width of the mouth ; the chord 
which unites them is of the same thickness as the rest of 
the collar. In all the genera, from the front of each 
of the two supra-cesophageal ganglia, a pair of nerves, 



OPHTHALMIC GANGLIA AND EYES. 



49 



(/,/,) united and together as large as the collar nerve, 
rises, and can be traced running unbranched, in a nearly 
straight line, for a length equalling the whole rest of the 
nervous chord, so as to supply the peduncle and the inside 
of the capitulum or sack. At the inner ends of these two 
same ganglia, from a central point where they are united, 
a little central branch rims in front to the adductor 
scutorum and other adjoining muscles ; and still smaller 
fibrils run behind to the oesophageal muscles. 

Ophthalmic Ganglia and Eyes. — Owing to Professor 
Leidy's* discovery of eyes in a Balanus, I was led to 
look for them in the Lepadiclse. Extending from the front 
of the two supra-cesophageal ganglia, two chords may be 
seen in Lepas fascicularis (of which a rude diagram is 
here given), to run into two small, perfectly distinct oval 




Diagram of the anterior portion of the nervous system in Lepas fascicularis. 
A. First thoracic or infra-cesophageal ganglion. B. Second thoracic. 
C. Third thoracic ganglion. D. Supra-cesophageal ganglion. E. The two 
ophthalmic ganglia. F. Double eye. a. Nerve going to first cirrus ; b, to 
the muscles below the first cirrus; c, to the second cirrus; d, to the third; 
e, nerves running to the ovaria ; /, double nerves supplying the sack and 
peduncle. 

* Proceedings of the Academy of Natural Sciences, Philadelphia, 
vol. iv, Jan. 1848. 



No. i, 



50 



LEPADID.E. 



ganglia (e), which are not united by any transverse com- 
missure. From the opposite ends of these two ganglia 
smaller nerves run, and, bending inwards at right angles, 
enter, beyond the middle, an elongated (r), almost black, 
eye, composed of two eyes united together. Although in 
outline the eye appears single, two lenses can be distinctly 
seen at the end, directed upwards and towards the 
ganglia ; two pigment-capsules can also be distinguished ; 
these are deep and cup-formed, and of a dark reddish- 
purple. The following measurements will show the pro- 
portions of the parts in a specimen of the Lepas fascicularis 
having a capitulum -^ths of an inch in length. 

Double eye {Jjg§* * \ \ 
Diameter of single lens . 
Ophthalmic ganglion {^ } ; 



26 

BooB 

13 

BoC<5 
6 

Bono 

Bo5(5 
n 

BooO" 



Supra-cesophageal ganglion, " 

transverse or longest axis > 

of both together 
Supra-cesophageal ganglion, "I 

longitudinal axis of . .J 
Infra-cesophageal ganglion, 1 

transverse axis of .J 

Infra-cesophageal ganglion, \ 

longitudinal axis of . . J 



12fl 

Boo~0" 



45 

BooU 



120 

B003 



114 

Bo0(5 



In Conclioderma aurita the ophthalmic ganglia are 
much smaller, and nearer to the supra-cesophageal gan- 
glion, than in L. fascicularis. In Alepas cornuta the 
ophthalmic chords run towards each other from the two 
distant and separate supra-cesophageal ganglia ; and the 
ophthalmic ganglia, (instead of being quite separate, as in 
L. fascicularis,) are united by their front ends, and the 
two eyes instead of standing some way in front, with 
nerves running to them, are embedded on the double oph- 
thalmic ganglion ; the pigment-capsules here, also, have 
the shape of mere saucers, and are joined back to back, 
with the two lenses projecting far out of them. In neither 
sex of Ibla could I perceive that the eye was double. In 
Pollicipes spinosus the ophthalmic ganglion stands in 
front of the single supra-cesophageal ganglion, and shows 
no signs of being formed of a lateral pair j the eyes them- 
selves, however, differently from, in all the foregoing cases, 
are, though approximate, quite distinct. In Pollicipes 



OPHTHALMIC GANGLIA AND EYES. 51 

mitella I did not see the eyes ; but the ophthalmic gan- 
glion consists, as I believe, of a single globular one, placed 
exactly between the two globular, supra-cesophageal gan- 
glia, all three being of nearly equal size. Professor Leidy 
does not mention the ophthalmic ganglia; hence I infer 
that in Balanus, which is a more highly organised Cirripede, 
they are fused into the supra-cesophageal ganglion. 

In all the genera, the double eye is seated deep within 
the body ; it is attached by fibrous tissue to the radiating 
muscles of the lowest part of the oesophagus, and lies 
actually on the upper part of the stomach ; consequently, 
a ray of light, to reach the eye, has to pass through the 
exterior membrane and underlying corium connecting the 
two scuta, and to penetrate deeply into the body. In 
living sessile Cirripedes, vision seems confined to the 
perception of the shadow of an object passing between 
them and the light ; they instantly perceived a hand 
passed quickly at the distance of several feet between a 
candle and the basin in which they were placed. 

As the infra-cesophageal ganglion sends nerves to the 
tropin and to the first pair of cirri, it must correspond 
to the segments, from the fourth to the ninth inclusive, 
of the archetype crustacean. The state of the supra- 
cesophageal and ophthalmic ganglia appears to me very 
interesting : I do not believe that in any mature ordinary 
crustacean, the first or ophthalmic ganglion can be shown 
to be distinct from the two succeeding ganglia, or to be 
itself composed of a pair laterally distinct. The ganglia, 
corresponding with the second and third segments of the 
body, which should normally support two pair of antennae, 
are in the Lepadidse united together ; but laterally they 
are generally distinct in outline, and are actually separate 
in Alepas : the supra-cesophageal ganglion shows also its 
double nature, by giving rise to a pair of large double 
nerves, evidently corresponding with the two pair of an- 
tennular nerves in ordinary crustaceans. The embryonic 
condition of the whole supra-cesophageal portion of the 
nervous system in the Lepadidae, corresponds with the 



52 LEPADID.E. 

rudimentary state of the only organ of sense supplied by 
it, namely, the eye, which in size and general appear- 
ance has retrograded to the state in which it was in, 
during the first stage of development of the larva; — I 
have used the term embryonic, because, in the embryos of 
ordinary Crustacea, all the ganglia are at first longitudi- 
nally distinct, and laterally quite separate. The conclusion 
at which we before arrived from studying the metamor- 
phoses, namely, that the whole peduncle and capitulum 
consisted of the first three segments of the head, is beauti- 
fully supported by the structure of the nervous system, 
in which these parts are seen to be supplied with nerves 
exclusively from the supra-cesophageal ganglion : now in 
ordinary Crustacea the supra-cesophageal ganglion sends 
nerves to the eyes and the two pair of antennas correspond- 
ing, as is known by embryological dissections, to the first 
three segments of the body. Moreover, it is asserted that 
the carapace which covers the thorax in Crustacea, is not 
formed by the development of the first segment ; and this, 
likewise, may be inferred to be the case with the pe- 
duncle and capitulum in the Lepadidae, as the nerves 
of the ophthalmic ganglia go exclusively to the eyes. 
Finally, I may remark that in Pollicipes, looking to the 
whole nervous system, the state of concentration nearly 
equals that in certain macrourous decapod crustaceans, 
for instance the Astacus marinus, of which a figure is given 
by Milne Edwards. 

Olfactory Organs. — In the outer maxillae, at their bases 
where united together, but above the basal fold separat- 
ing the mouth from the body, there are, in all the genera, 
a pair of orifices (PI. X, fig. 16); these are sometimes 
seated on a slight prominence, as in Lithotrya, or on the 
summit of flattened tubes (PL X, fig. 17), projecting up- 
wards and towards each other, as in Ibla, Scalpellum, 
and Pollicipes. In Ibla these tubular projections rise from 
almost between the outer and inner maxillae. It is impos- 
sible to behold these organs, and doubt that they are of 
high functional importance to the animal. The orifice leads 



OLFACTORY AND ACOUSTIC SACKS. 53 

into a deep sack lined by pulpy corium, and closed at the 
bottom. The outer integument is inflected inwards, (hence 
periodically moulted,) and becoming of excessive tennity, 
runs to near the bottom of the sack, where it ends in an 
open tube: so excessively thin is this inflected membrane, 
that, until examining Anelasma, I was not quite certain 
that I was right in believing that the outer integument 
did not extend over the whole bottom. I several times 
saw a nerve of considerable size entering and blending 
into a pulpy layer at the bottom of the sack of corium ; 
but I failed in tracing to which of the three pair of 
nerves, springing from the front end of the infra -oesopha- 
geal ganglion, it joined. I can hardly avoid concluding, 
that this closed sack, with its naked bottom, is an organ 
of sense ; and, considering that the outer maxillae serve 
to carry the prey entangled by the cirri towards the 
maxillae and manclibles, the position seems so admirably 
adapted for an olfactory organ, whereby the animal could 
at once perceive the nature of any floating object thus 
caught, that I have ventured provisionally to designate 
the two orifices and sacks as olfactory. 

Acoustic (?) Organs. — A little way beneath the basal 
articulation of the first cirrus (PI. IX, fig. 4d, and PL IV, 
fig. 2e), on each side, there maybe seen a slight swelling, 
and on the under side of this, a transverse slit-like orifice, 
o'oth of an inch in length in Conchoderma, but often only 
half that size. In Ibla this orifice is seated lower down 
(PI. IV, fig. 8a, e), between the bases of the first and 
second cirri, which are here far apart : in Alepas cornuta 
it is placed rather nearer to the adductor scutorum 
muscle, namely, beneath the manclibles. The orifice leads 
into a rather deep and wide meatus ; the external integu- 
ment is turned in for a short distance, Aviclening a little, 
and then ends abruptly. The meatus, enlarging upwards, 
is lined by thick pulpy corium, and is closed at the upper 
end; from its summit is suspended a flattened sack of 
singular and different shapes in the different genera. 
This, the so-called acoustic sack of Conchoderma virgata, 



54 LEPADID^E. 

is figured PL IX, fig. 6. The deep and wide notch faces 
towards the posterior end of the animal ; the inferior lobe, 
thus almost cut off, is flattened in a different plane from 
the upper part ; the lobe is lodged in a little pouch of cor- 
responding form, leading from the open meatus in which 
the upper part is included. In Conchoderma aurita, the 
top of the acoustic sack is narrower and more constricted, 
the whole more rounded, and the lobe more turned down. 
In Lepas fascicularis the notch is not so deep or wide, 
and the lobe larger. In Ibla Cumingii the sack is of the 
shape of a vase, with one corner folded over. In Scal- 
pellum vulgare it is small, oval, with the lower end much 
pushed in, and furnished with a little crest. Lastly, in 
Pollicipes mitella it is simply oval. In all cases the sack 
is empty, or contains only a little pulpy matter : it 
consists of brownish, thick, and remarkably elastic tissue, 
formed, apparently, of transverse little pillars, becoming 
fibrous on the outside, and with their inner ends appear- 
ing like hyaline points. The mouth of the acoustic sack 
(removed in the drawing) is closed by a tender diaphragm, 
through which I saw what I believe was a moderately- 
sized nerve enter; I have not yet succeeded in tracing 
this nerve. The first pair of cirri seem, to a certain ex- 
tent, to serve as antennae, and therefore the position of an 
acoustic organ at their bases, is analogous to what takes 
place in Crustacea • but there are not here any otolites, 
or the siliceous particles and hairs, as described by Dr. 
Farre, in that class. Nevertheless, the sack is so highly 
elastic, and its suspension in a meatus freely open to the 
water, seems so well adapted for an acoustic organ, that 
I have provisionally thus called it. In the larva, as I 
have shown, a pouch, certainly serving for some sense, 
I believe for hearing, is seated in quite a different 
position at the anterior end of the carapace. I may 
mention that I found sessile Cirripedes very sensitive of 
vibrations in objects adjoining them, though not, appa- 
rently, of noises in the air or water. In a group of 
specimens, I could not touch one even most delicately 



REPRODUCTIVE SYSTEM. 55 

with a needle, without all the adjoining ones in- 
stantly withdrawing their cirri; it made no difference 
if the one touched had its operculum already closed and 
motionless. 

Reproductive System, — Male Organs. — All the Cirri- 
pedia which I have hitherto examined, with the exception 
of certain species of Ibla and Scalpellum, are herma- 
phrodite or bisexual.*" I shall so fully describe the 
sexual relations of the several species of these two genera, 
under their respective headings, and at the end of the 
genus of Scalpellum, that I will not here give even an 
abstract of the grounds on which my firm belief is based, 
that the masculine power of certain hermaphrodite species 
of Ibla and Scalpellum, is rendered more efficient by 
certain parasitic males, which, from their not pairing, 
as in all hitherto known cases, with females, but with 
hermaphrodites, I have designated Complemental Males. 

The male organs have been well described by 
M. Martin St. Ange, whose observations have since been 
confirmed by R. Wagner, f The testes are small, 
often leaden-coloured, either pear or finger-shaped, or 
branched like club-moss, — these several forms sometimes 
occurring in the same individual ; they coat the stomach, 
enter the pedicels, and even the basal segments of the 
rami of the cirri, and in some genera occupy certain 

* I am compelled to differ greatly from the account given by Prof 
Steenstrup of the reproductive system in the Cirripedia, in his ' Untersuchun- 
gen liber das Yorkommen des Hermaphroditismus,' ch. v, 1846; — a translation 
of which I have seen, owing to the great kindness of Mr. Busk. Mr. Goodsir 
has described ('Edin. NewPhil. Journal/ July 1843,) what he considers the 
male of Balanus ; but I have seen this same parasitic creature charged with 
ova, including larvse ! From the resemblance of the larvae to the little 
crustacean described by Mr. Goodsir, in the same paper, as a distinct parasite, 
I believe the latter to be the male of his so-called male Balanus, and that all 
belong to the same species, allied to Bopyrus. This genus, as is well known, 
is parasitic on other Crustacea ; and it is a rather interesting fact thus to 
find, that this new parasite which is allied to Bopyrus, in structure, is like- 
wise allied to it in habits, living attached to Cirripedia, a sub-class of the 
Crustacea. 

f In ' Midler's Archiv,' 1834, p. 467. I have already several times 
referred to M. Martin St. Ange's excellent Memoir, read before the Academy 
of Sciences, and subsequently, in 1835, published separately. 



56 LEPADIM1. 

swellings on the thorax and prosoma, and in others the fila- 
mentary appendages : the testes seen in the apex in one of 
these appendages in Conchoderma, is represented in PI. IX, 
fig. 5. The two vesicular seminales are very large; they 
lie along the abdominal surface of the thorax, and gene- 
rally (but not in some species of Scalpellum) enter the 
prosoma, where their broad ends are often reflexed ; here 
the branched vessels leading from the testes enter. The 
membrane of the vesicular seminales is formed of circular 
fibres ; and is, I presume, contractile, for I have seen the 
spermatozoa expelled with force from the cut end of a 
living specimen. The two canals leading from the vesi- 
cular generally unite in a single duct at the base of the 
penis ; but in Conc/ioderma aurita, half-way up it. The pro- 
bosciformed penis, except in certain species of Scalpellum, 
is very long ; it is capable of the most varied movements ; 
it is generally hairy, especially at the end ; it is supported 
on a straight unarticulated basis, which in Ibla quadri- 
valvis alone (PL IV, fig. 9 a), is of considerable length; 
in this species, the upper part is seen to be as plainly 
articulated as one of the cirri; in Alepas, the articula- 
tions are somewhat less plain, and in the other genera, 
the organ can be said only to be finely ringed, but these 
rings no doubt are in fact obscure articulations. In the 
females of Ibla Cumingii and Scalpellum ornatum, there 
is, of course, no penis. 

Female Organs. — M. Martin St. Ange has described 
how the peduncle* is gorged with an inextricable mass 
of branching ovarian tubes, filled with granular matter 
and immature ova. In Conchoderma and Alepas, the 
ovarian tubes run up in a single plane (PI. IX, fig. 3,) 
between the two folds of corium round the sack. Here 
the development of the ova can be well followed : a 
minute point first branches out from one of the tubes ; its 

* I may here mention, that in all sessile Cirripedes, the ovarian branching 
tubes lie between the calcareous or membranous basis and the inner basal 
lining of the sack, and to a certain height upwards round the sack : the true 
ovaria and the two duels occupy the same position as in the Lepadidse. 



REPRODUCTIVE SYSTEM. 57 

head then enlarges, like the bud of a tulip on a footstalk ; 
becomes globular; shows traces of dividing, and at last 
splits into three, four, or five egg-shaped balls, which 
finally separate as perfect ova. Within the peduncle, 
the ovarian tubes branch out in all directions, and within 
the footstalks of the branches (differently from what 
takes place round the sack), ova are developed, as well 
as at their ends. Close together, along the rostral 
(i. e., ventral) edge of the peduncle, two nearly straight, 
main ovarian tubes or ducts may be detected, which do 
not give out any branches till about half way down the 
peduncle, where they subdivide into branches, which in- 
osculate together, and give rise to the mass filling the 
peduncle, and sometimes, as we have just seen, sending up 
branches round the sack. These two main unbranched 
ovarian ducts, followed up the peduncle, are seen to 
enter the body of the Cirripede (close along side the 
great double peduncular nerves), and then separating, 
they sweep in a large curve along each flank of the pro- 
soma, under the superficial muscles, towards the bases of 
the first pair of cirri ; and then rising up, they run into 
two glandular masses. These latter rest on the upper 
edge of the stomach, and touch the caeca were such exist ; 
they were thought by Cuvier to be salivary glands. They 
are of an orange colour, and form two, parallel, gut- 
formed masses, having, in Conchoderma, a great flexure, 
and generally dividing at the end near the mouth into 
a few blunt branches. I was not able to ascertain 
whether the two main ducts, coming from the peduncle, 
expanded to envelope them, or what the precise con- 
nection was. The state of these two masses varied 
much ; sometimes they were hollow, with only their 
walls spotted with a few cellular little masses ; at other 
times they contained or rather were formed of, more or 
less globular or finger-shaped aggregations of pulpy mat- 
ter ; and lastly, the whole consisted of separate pointed 
little balls, each with a large inner cell, and this again 
with two or three included granules. These so closely 



58 LEPADIDiE. 

resembled, in general appearance and size, the ovigerms 
with their germinal vesicles and spots, which I have often 
seen at the first commencement of the formation of the 
ova in the ovarian tubes in the peduncle, that I cannot 
doubt that such is their nature. Hence I conclude, 
that these two gut-formed masses are the true ovaria. 
I may add, that several times I have seen in the two 
long, unbranched ducts, connecting the true ovaria and the 
ovarian tubes in the peduncle, pellets of orange-coloured 
cellular matter (*. e., ovigerms) forming at short intervals 
little enlargements in the ducts, and apparently travelling 
into the peduncle. 

The structure here described is quite comformable with 
that which we have seen in the larva ; in the latter, two 
gut-formed masses of equal thickness extended from the 
caeca of the stomach to within the future peduncle, where 
the cement-ducts entered them, and where, after a short 
period, they were seen to expand into a mass of ovarian 
tubes. In the mature Cirripede, the cement-ducts can 
still be found united to the ovarian tubes in the middle of 
peduncle ; and the cause of the wide separation of the true 
ovaria and ovarian tubes, can be simply accounted for by 
the internal, almost complete intersection of the animal, 
which takes place during the last metamorphosis. 

The ova, when excluded, remain in the sack of the 
animal until the larvae are hatched ; they are very nume- 
rous, and generally form two concave, nearly circular, 
leaves, which I have called after Steenstrup and other 
authors, the ovigerous lamella (PL IV, fig. 2 b). These 
lamellae lie low down on each side of the sack : in Concho- 
derma virgata, however, there is often only a single lamella, 
forming a deeply concave cup : in C. aurita there are gene- 
rally on each side four lamellae, one under the other. The 
ova lie in a layer from two to four deep ; and all are held 
together by a most delicate transparent membrane, which 
separately enfolds each ovum : this membrane is often 
thicker and stronger round the margins of the lamellae, 
where they are united, in a peculiar manner, presently to be 



REPRODUCTIVE SYSTEM. 59 

described, to a fold of skin, on each side of the sack : these 
two folds, I have called the ovigenous frcena (PI. IV, fig. 2/). 
M. Martin St. Ange, describes an orifice under the 
carina, by which he supposes the ova to enter the sack ; 
this, after repeated and most careful examinations, I ven- 
ture to affirm does not exist; on the contrary, I have 
every reason to believe that the ova enter the sack in the 
following curious manner. Immediately before one of 
the periods of exuviation, the ova burst forth from the 
the ovarian tubes in the peduncle and round the sack, 
and, carried along the open circulatory channels, are col- 
lected (by means unknown to me) beneath the chitine- 
tunic of the sack, in the corium, which is at this period 
remarkably spongy and full of cavities. The corium 
then forms or rather (as I believe) resolves itself into the 
very delicate membrane separately enveloping each ovum, 
and uniting them together into two lamellae ; the corium 
having thus far retreated, then forms under the lamellae 
the chitine-tunic of the sack, which will of course be of 
larger size than the last-formed one, now immediately to 
be moulted with the other integuments of the body. As 
soon as this exuviation is effected, the tender ova, united 
into two lamellae, and adhering, as yet, to the bottom 
of the sack, are exposed : as the membranes harden, the 
lamellae become detached from the bottom of the sack, and 
are attached to the ovigerous fraena. To demonstrate this 
view, an individual should have been found, with both the 
old and new chitine tunic of the sack, and with the lamellae 
lying between them ; this, I believe, I have seen, but it 
was before I understood the full importance of the fact : 
a great number of specimens would have to be examined 
in order to succeed again, for the changes connected with 
exuviation supervene very quickly. I have, however, 
several times found the ova so loose under the sack, as 
to be detached with a touch from the ovarian tubes ; 
and I have twice carefully examined specimens, which 
had just moulted, as shown by even the mandibles being 
flexible, in which the lamellae had not become united to 



60 LEPADID^l. 

the frsena, but still adhered to the newly-formed chitine 
tunic of the sack ; in these, the ova were so tender, that 
they broke into pieces rather than be separated from the 
membrane of the lamella, itself hardly perfectly deve- 
loped, for pulpy cellular matter adhered outside some of 
the ova. These and other facts are quite inexplicable on 
any other view than that advanced. 

As the lamellae are formed without organic union 
with the parent, they would be liable to be washed out 
of the widely open sack of the Lepadidae, if they had 
not been specially attached to the frcena. These fraena 
consist of a pair of more or less semicircular folds of 
skin, depending inside the sack, on each side of the point 
of attachment of the body. The fraena are often of consi- 
derable size, but in Ibla, they are very minute ; they are 
formed of chitine tunic with underlying corium, like the 
rest of the sack ; on their crests, there is a row, or a set 
of circular groups, or a broad surface, covered, either 
with minute, pointed, bead-like bodies mounted on long 
hair-like footstalks, or with staff-formed bodies on very 
short footstalks. I measured some of the bead-like bodies, 
in Lepas anserifera, and they were -^-oVoth of an inch in 
diameter, and the footstalks three or four times as long 
as the elongated heads. These heads, of whatever shape 
they may be, have an opaque, and, I believe, glandular 
centre ; I could not make out with certainty an aperture 
at their ends, but, I believe, such exists, and they seem to 
secrete a substance, which hardens into a strong membrane, 
serving to unite the crest of the fraenum to the edges of 
the lamellae. In one case, this bit of membrane seemed 
formed of a woven mass of threads. These little glan- 
dular bodies, with the membrane formed by them, are 
cast off at each exuviation, and new glands formed on the 
crest of the fraenum underneath. In some species of 
Pollicipes, (viz., P. cornucojria and elecjans^) the fraena, 
though present and large, are functionless and destitute 
of the glands : I believe, they exist in this same function- 
less condition, and in rather a different position in the 



EXUVIATION ; RATE OF GROWTH. 61 

sessile Cirripedes, and that in tins family they serve as 
Branchiae. 

The above- described method by which Cirripedia lay 
their eggs, namely, united together in a common mem- 
brane, placed between their old outer and new inner 
integuments, and the manner in which the lamellae, 
when thus formed, are retained for a time fastened to 
the fraena, and are then cast off, appears to me very 
curious. In some of the lower Crustacea, it is known, 
that the ova escape by rupturing the ovisacs formed 
by the protruded ovarian tubes, and this is the nearest 
analogy with which I am acquainted. The ova are 
impregnated (as I infer from the state of the vesiculae 
seminales), when first brought into the sack, and whilst 
the membrane of the lamellae is very tender • the long 
probosciformed penis seems well adapted for this end. 
In the male of Ibla Cumingii, which has not a probosci- 
formed penis, the whole flexible body, probably, performs 
the function of the penis : in Scalpettum omatum, however, 
the spermatozoa must be brought in by the action of the 
cirri, or of the currents produced by them. That cross im- 
pregnation may and sometimes does take place, I infer 
from the singular case of an individual, in a group of 
Balani, in which the penis had been cut off, and had 
healed without any perforation ; notwithstanding which 
fact, larvae were included in the ova. 

Exuviation; Mate of Growth; Size. — I have had 
occasion repeatedly to allude to the exuviation of the 
Lepadidae : with the exception of the genus Lithotrya,* in 
which the calcareous scales on the peduncle, together 
with the membrane connecting them, is cast off, neither 
the valves nor the membrane uniting them, nor that 
forming the peduncle with its scales and styles, are 

* The external integuments being moulted in Crustacea, but not in 
the Cirripedia, may appear, at first, an important difference : but we here 
see that non-exuviation is not universal amongst the Lepadidae, and, on 
the other hand, according to M. Joly, ('Annales des Sciences Naturelles,' 
2d series, Zoolog.), there is one true crustacean, the Isaura cycladoides, 
which has a persistent bivalve shell. 



62 LEPADID.E. 

moulted ; but the surface gradually disintegrates and is 
removed, perhaps sometimes in flakes, whilst new and 
larger layers are formed beneath. In Scalpellum, I as- 
certained that the new membrane, connecting together the 
newly-formed calcified rims under the valves of the capi- 
tulnm, was formed as a fold, with the articulated spines 
which it bears, all adpressed in certain definite directions. 
This fold of new membrane, when the old membrane 
splits and yields, of course expands, and thus the size of 
the capitulum is increased. In the peduncle, lines of 
splitting can seldom be perceived, except, indeed, in the 
sub-globular, embedded, downward-growing peduncle of 
Anelasma, as described under that genus. I do not 
understand what determines the complicated lines of 
splitting of the old membrane between the several valves 
of the capitulum, — without it be simply, that along these 
lines alone, the old membrane is not strengthened by the 
new membrane being closely applied under it, the new 
being formed, as we have just said, in a fold, in order to 
allow of increase in size. Although, as I believe, there is 
strictly no exuviation in the outer membranes of mature 
Lepadidoe, it seems that narrow strips of membrane are 
cast off from between the valves, for the few first moults, 
after the final metamorphosis of the larva. I may here 
remark that, in most sessile Cirripecles, the outside mem- 
brane connecting the operculum and shell, is regularly 
moulted. 

The delicate tunic lining the sack, (a mere duplicative 
of that thick one, forming the outside of the capitulum, 
and generally transformed into valves,) and the integuments 
of the whole body, are regularly moulted. With these 
integuments, the membrane lining the oesophagus, the 
rectum, and the deep olfactory pouches, and the horny 
apodemes of the maxillae, are all cast together. I have 
seen a specimen of Lepas, in which, from some morbid 
adhesion, the old membrane lining one of the olfactory 
pouches had not been moulted, but remained projecting 
from the orifice as a brown shrivelled scroll. The new 



EXUVIATION J RATE OF GROWTH. 63 

spines on the cirri (and on the maxillae) are formed within 
the old ones ; but as they have to be a little longer than 
the latter, and as they cannot enter these up to their 
very points, their basal portions are not thus included, 
but are formed, running obliquely across the segments 
of the cirri ; and what is curious, these same basal por- 
tions are turned inside out, like the fingers of a glove 
when hastily drawn off. After the exuviation of the old 
spines, the new spines have their inverted basal portions 
drawn out from within the segments, and turned outside 
in, so as to assume their proper positions. 

All Cirripedia grow rapidly : the yawl of H. M. S. 
Beagle was lowered into the water, at the Galapagos 
Archipelago, on the 15th of September, and, after an 
interval of exactly thirty-three days, was hauled in : I 
found on her bottom, a specimen of Conchoderma virgata 
with the capitulum and peduncle, each half an inch in 
length, and the former -^-ths in width: this is half the size 
of the largest specimen I have seen of this species : several 
other individuals, not half the size of the above, con- 
tained numerous ova in their lamellae, ready to burst 
forth. Supposing the larva of the largest specimen be- 
came attached the first day the boat was put into the water, 
we have the metamorphosis, an increase of length from 
about - 05, the size of the larva, to an whole inch, and the 
laying of probably several sets of eggs, all effected in thirty- 
three days. Prom this rapid growth, repeated exuviations 
must be requisite. Mr. W. Thompson, of Belfast, kept 
twenty specimens of Balanus balanoides, a form of much 
slower growth, alive, and on the twelfth day he found 
the twenty-first integument, showing that all had moulted 
once, and one individual twice within this period. I 
may here add, that the pedunculated Cirripedes never 
attain so large a bulk as the sessile ; Zepas anatifera is 
sometimes sixteen inches in length, but of this, the far 
greater portion consists of the peduncle. Pollicipes 
mitella is the most massive kind ; I have seen a specimen 
with a capitulum 2*3 of an inch in width. 



64 LEPADID^E. 

Affinities. — Considering the close affinity between the 
several genera, there are, I conceive, no grounds for 
dividing the Lepadidse into sub-families, as has been 
proposed by some authors, who have trusted exclusively 
to external characters. In establishing the eleven genera 
in the Lepadidse, no one part or set of organs affords 
sufficient diagnostic characters : the number of the valves 
is the most obvious, and one of the most useful charac- 
ters, but it fails when the valves are nearly rudimentary, 
and when they are numerous : the direction of their 
lines of growth is more important, and fails to be charac- 
teristic only in Scalpellum : with the same exception, the 
presence or abscence of calcified or horny scales on the 
peduncle is a good generic character. For this same 
end, the shape of the scuta and carina, but not of the 
other valves, comes into play. In three genera, the pre- 
sence of filamentary appendages on the animal's body is 
generic ; in Pollicipes, however, they are found only on 
three out of the six species. The number of teeth in the 
mandibles, and the shape of the maxillae, often prove 
serviceable for this end; as does more generally the 
presence of caudal appendages, and Avhether they be 
naked or spinose, uniarticulate or multiarticulate ; in 
Pollicipes alone this part is variable, being uni- and multi- 
articulate; and in one species of Scalpellum they are 
absent, though present in all the others. The shape of 
the body, the absence or presence of teeth on the labrum, 
the inner edge of the outer maxillae being notched or 
straight, the prominence of the olfactory orifices, the 
arrangement of the spines on the cirri, and the number 
and form of their segments, are only of specific value. 

Comparing the pedunculated and sessile Cirripedes, it is, 
I think, impossible to assign them a higher rank than that 
of Families. The chief difference between them consists, 
in the Lepadidse, in the presence of three layers of striaeless 
muscles, longitudinal, transverse and oblique, continuously 
surrounding the peduncle, but not specially attached to 
the scuta and terga ; and on the other hand, in the Bala- 



GEOGRAPHICAL RANGE. 65 

nidae, of five longitudinal bundles of voluntary muscles, 
with transverse striae, fixed to the scuta and terga, and 
giving them powers of independent movement. In the 
Lepadidae, the lower valves, or when such are absent, the 
membranous walls of the capitulum, move with the scuta 
and terga when opened or shut ; and the lower part of the 
capitulum is separated by a moveable peduncle from the 
surface of attachment ; in the sessile Cirripecles, the 
lower valves are firmly united together into an immovable 
ring, fixed immovably on the surface of attachment. I 
will not compare the softer parts, such as the cirri and 
trophi, of the Lepadidae with those of the Balanidae, as 
my examination of this latter family is not fully com- 
pleted : I will only remark, that there is a very close 
general resemblance, more especially with the sub-family 
Chthamalinae. 

Geographical. Mange; Habitats. — The Pedunculated 
Cirripedes extend over the whole world ; and most of the 
individual species have large ranges, more especially, as 
might have been expected, those attached to floating 
objects ; excepting these latter, the greater number in- 
habit the warmer temperate, and tropical seas. Of 
those attached to fixed objects, or to littoral animals, 
it is rare to find more than three or four species in 
the same locality. On the shores of Europe I know of 
only three, viz., a Scalpellum, Pollicipes, and Alepas. 
At Madeira (owing to the admirable researches of the 
Rev. R. T. Lowe), two Paecilasmas, a Dichelaspis, and an 
Oxynaspis are known. In New Zealand, there are two 
Pollicipes and an Alepas, and, perhaps, a fourth form. 
From the Philippine Archipelago, in the great collection 
made by Mr. Cuming, there are a Paecilasma, an Ibla, 
a Scalpellum, Pollicipes, and Lithotrya. Of all the 
Lepadidae, nearly half are attached to floating objects, or 
to animals which are able to change their positions ; the 
other half are generally attached to fixed organic or in- 
organic bodies, and more frequently to the former than 
to the latter. Most of the species of Scalpellum are in- 

5 



66 LEPADID.E. 

habitants of deep water; on the other hand, most of 
Pollicipes,* of Ibla, and Lithotrya are littoral forms. The 
species of Lithotrya have the power of excavating burrows 
in calcareous rocks, shells, and corals ; and the singular 
manner in which this is effected, is described under that 
genus. Anelasma has its sub-globular peduncle deeply 
embedded in the flesh of Northern Sharks ; and I have 
seen instances of the basal end of the peduncle of Con- 
choderma aurita, being sunk into the skin of Cetacea ; in 
the same way the point of the peduncle in the male of 
Ibla, is generally deeply embedded in the sack of the 
female. I believe in all these cases, the cementing sub- 
stance affects and injures the corium or true skin of the 
animal on which the creature is parasitic, whilst the sur- 
rounding parts, being not injured, continue to grow 
upwards, thus causing the partial embedment of the 
Cirripecle. In the case of Anelasma, we have growth at 
the end of the peduncle, and consequently downward 
pressure, and this may possibly cause absorption to take 
place in the skin of the shark at the spot pressed on. 

Geological History. — Having treated this subject at 
length, in the volume of the Palseontographical Society 
for 1851, 1 will not here enter on it : I will only remark, 
that the Lepadidae or Pedunculated Cirripedes are much 
more ancient, according to our present state of know- 
ledge, than the Balanidse. The former seem to have 
been at their culminant point during the Cretaceous 
Period, when many species of Scalpellum and Polli- 
cipes, and a singular new genus, Loricula, existed; 
Pollicipes is the oldest genus, having been found in the 
Lower Oolite, and, perhaps, even in the Lias. The fossil 
species do not appear to have differed widely from 
existing forms. 

* I am informed by Mr. L. Reeve that Pollicipes mitella is eaten on the 
coast of China; and Ellis states ('Phil. Trans./ 1758) that this is the case 
with P. cornucopia on the shores of Brittany. It is well known that the 
gigantic Balamis psitlacus, on the Chilian coast, is sought after as a delicacy; 
and I am assured, by Mr. Cuming, that it deserves its reputation. 



67 



Genus — Lepas. Plate I. 

Lepas. Linnaut.* Systema Naturae, 1767- 
Anatifa. Brugiere.-\ Encyclop. Method, (des Vers), 1789. 
Anatifera. {Lister} et plerumque Auctorum Anglicorum. 
Pentalasmis. (Hill.) Leach. Journal de Physique, July, 1817. 
Pentalepas. De Blainville. Diet, des Sci. Nat., 1824. 
Dosima. /. E. Gray. Annals of Philosophy, vol. x, 1825. 

Valvce 5, approximate : carina sursiim inter terga 
extensa, deorsiini aut furcd infossd aut disco externo 
terminata : scuta subtriangula, umbonibus ad angulum 
rostralem positis. 

Valves 5, approximate : carina extending up between 
the terga, terminating downwards in an embedded fork, 
or in an external disc : scuta sub triangular, with their 
umbones at the rostral angle. 

Filaments seated beneath the basal articulation of the 
first cirri ; mandibles with five teeth ; maxillae step- 
formed ; caudal appendages uniarticulate, smooth. 

Distribution. — Mundane ; attached to floating objects. 

Description. — Capitulum flattened, sub -triangular, 
composed of five approximate valves. The valves are 

* Linnaeus, as is well known, included under this genus both the pedun- 
culated and sessile Cirripedes. According to the rules of the British 
Association, the name Lepas must be retained for part of the genus ; and as 
the sessile division was named Balauus, by Lister and Hill, even before the 
invention of the binomial system, and subsequently, in 1778, by Da Costa, 
and again, in 1789, by Brugiere, there can be no question that Lepas must 
be applied to the pedunculated section of the genus. In this instance it is 
particularly desirable to recur to the Linnean name, as no other name has 
been generally adopted. Had not Lister and Sir J. Hill published before the 
binomial system, their names of Anatifera and Pentalasmis would have had 
prior claims to Lepas. 

f The date of this publication is almost universally given as 1792, appa- 
rently caused by an error in the title-page of the First Part, which has 
consequently been cancelled. The First Part contains Anatifa and Balanus, 
and was published in 1789. The Second Part was published in 1792, and 
has a corrected title-page for the whole volume. 



68 GENUS LEPAS. 

either moderately thick and translucent, or very thin and 
transparent; and hence, though themselves colourless, they 
are often coloured by the underlying corium. Their sur- 
faces are either smooth and polished, or striated, or fur- 
rowed, and sometimes pectinated. They are not subject 
to disintegration ; they are generally naked, except on the 
borders, where they are coated, and held together by 
membrane ; in L. fascicularis, however, the valves are 
covered with thin membrane, bearing very minute spines. 
The manner of growth of the valves will be best des- 
cribed under each. All the valves, even in the same 
species, are subject to considerable variation in shape, 
more especially the terga. 

Scuta. — These valves are sub-triangular in outline, 
with the basal margin straight and rather short; and 
with occludent and tergo-carinal margins more or less 
protuberant ; in L. fascicularis, however, the basal (PL I, 
fig. 6), and occludent margins are slightly reflexed and 
prominent. A ridge, generally runs from the umbo to the 
upper point. Internally, there is no conspicuous pit for the 
adductor muscle ; under the umbones, there is generally 
either on both valves, or only on the right-hand side 
(PL I, fig. 1 <?), a small calcareous projection or tooth, of 
variable size and shape, even in the same species ; it is 
generally largest on the right-hand valve ; these teeth at 
first sight appear to form a hinge, uniting the opposite 
scuta at their umbones, but this is not really the case, 
and their use appears to be only to give attachment to 
the membrane uniting the valves together, and to the 
peduncle. The basal margin is internally strengthened 
by a calcified rim, more or less developed. The umbones 
(and primordial valves when distinguishable,) are seated 
at the rostral angles; during growth the basal margin 
is not added to, and the occludent margin only to small 
extent ; hence the main growth of the valve is at the 
upper end, and along the carina-tergal margin. In 
L. fascicularis, however, the basal reflexed margin is 
slightly added to beneath the umbo. 



GENUS LEPAS. 69 

Terga, — flat, small compared with the scuta, usually of 
an irregular quadrilateral figure, with the two upper or 
occludeut margins very short, in proportion to the two 
(carinal and scutal) lower margins ; all the margins are 
nearly straight. The two occludent margins, generally 
meet each other at about right angles, forming a small 
triangular projection ; in L. fascicularis, however, the 
occludent margin is formed by a single, slightly curved line. 
The umbones (and primordial valves when distinguishable) 
are not seated at the uppermost point, but at the angle 
where the carinal margin unites to the upper of the two 
occludent margins : during growth the terga are added 
to, both on the occludent and on the scutal margins, and 
slightly along the carinal margin ; hence their growth is 
unequally qaaqua-versal, except at one angle of the irre- 
gular quadrilateral figure. 

Carina. — This is always very narrow and curved, con- 
cave within, often carinated and barbed exteriorly ; it ex- 
tends upwards between the terga for one half or two 
thirds of their length : at the lower extremity it ends 
(with the exception of L. fascicularis), in a small fork 
(PI. I, fig. 1, a, b) rectangularly inflected and embedded 
in the membrane, beneath the basal margin of the scuta. 
From comparing this lower part of the carina in L. aus- 
tralis (fig. ha), with the same part in some of the species 
of the allied genus Psecilasma, it would appear that 
the fork is formed by an oblong disc, more and more 
notched at the end, and with the rim between the two 
points more or less folded backwards : conformably with 
this view, in very young specimens of L. australis, instead 
of a large and sharp fork, there is a small disc. The only 
use of the fork appears to be to give firm attachment 
to the membrane uniting the valves and peduncle. In 
Z. fascicularis, instead of a fork, there is a broad, oblong 
disc (figs. 6, 6a), rectangularly inflected; it is much longer 
than the fork, in proportion to the upper part of the 
carina ; the disc is not more deeply embedded than the 
upper part. The umbo (and primordial valve when 



70 GENUS LEPAS. 

distinguishable,) of the carina is seated just above the 
embedded fork (or disc in L. fascicularis), at the point 
where the inflection takes place ; hence the main growth 
of the carina is upwards, — the fork, however, being of 
course, likewise added to at its point : in L. fascicularis, 
the growth is both upwards and downwards. 

Peduncle and Attachment. — The peduncle is generally 
quite smooth : though with a high power its surface may 
be seen to be studded with minute beads, or larger discs, 
of yellowish and hard chitine ; in the young of L. aus- 
tralis, and I suspect of some other species, it is covered 
with very minute spines. The peduncle in this genus 
attains its greatest development. The cement-tissue de- 
bouches, I believe, only through the functionless larval 
antennae, except in one species, L. fascicularis, in which a 
ball of this substance is formed in a most peculiar manner 
round the peduncle (PL I, fig. 6), apparently for the purpose 
of serving as a float, as will be presently described. 

Size and Colour. — The species of this genus are the 
largest of the Pedunculata, with the exception of some 
Pollicipes : even in the smallest species (£. pectin ata), 
the capitulum sometimes attains a length of about half 
an inch. The peduncle varies much in length in the 
same species: in L. anatifera, it is occasionally above a 
foot long. The colours of L. anatifera, L. Hillii, and 
L. anserifera, are very bright and striking ; the membrane 
bordering the valves and that round the top of peduncle 
in two of the species, is of the brightest scarlet-orange ; 
the valves, owing to the under -lying corium, are pale 
blueish-grey, and the interspaces between them dark 
leaden-purple. The cirri and tropin are generally dark 
purple or lead-colour. 

Filamentary Appendages. — These are attached to be- 
neath the basal articulation of first pair of cirri ; they vary 
in the several species, from one to five or six on each 
side, the lowest being always the longest. Several of 
them are occupied by testes. In L. pectinata, generally, 
not even one is developed. They are subject to great 



GENUS — LEPAS. 71 

variation in their proportional lengths, and in number, in 
the same species. These organs have generally been con- 
sidered to serve as branchiae ; I see no reason to believe 
that they are more especially designed for this end, than 
is the general surface of the body. 

Mouth. — The labium is moderately bullate, the longi- 
tudinal diameter of this part equalling about one third, 
or half of that of the rest of the mouth. The palpi are 
moderately developed. The mandibles (PL X, fig. 5) 
have five teeth with the inferior point either broad, or 
very narrow and tooth-like. The maxillae are step-formed 
(PI. X, fig. 9) ; the first step is sometimes indistinct and 
curved ; and in Z.pectinafa, all the steps vary much, and 
are more or less blended together. The outer maxillae 
(like those at PI. X, fig. 16), are internally clothed con- 
tinuously with spines. The olfactory orifices are not at all 
prominent. 

Cirri. — The first pair is placed near the second pair, 
and is of considerable length ; the second has the anterior 
ramus thicker than the posterior ramus, and the seg- 
ments brush-like; the segments (PL X, fig. 26) of the 
four posterior cirri bear from four to six pair of long 
spines, with a row of small intermediate spines : in the 
posterior cirri of L. australis the lateral rim spines are 
much developed ; and in those of L. fascicularis, the 
usual pairs of large spines are lost in a broad triangular 
brush, formed by the increase of the lateral marginal, and 
intermediate spines. 

Caudal Apjoendages (PL X,' fig. 18/5), very small, either 
blunt or pointed, and quite destitute of spines. 

The prosoma is well developed. The stomach is sur- 
rounded in the upper part by a circle of large branching 
caeca. The generative system is highly developed ; the 
testes coating the whole of the stomach, entering the fila- 
mentary appendages and the pedicels of the cirri ; the two 
ovigerous lamellae contain a vast number of ova ; they are 
united to rather large fraena, of which the sinuous margin 
supports either a continuous row or separate tufts of glands. 



72 GENUS — LEPAS. 

Distribution. The species abound over the arctic, 
temperate and tropical parts of the Atlantic, Indian and 
Pacific Oceans, and are always, or nearly always, attached 
to floating objects, dead or alive. The same species have 
enormous ranges ; in proof of which T may mention that 
of the six known species, five are found nearly all over the 
world, including the British coast ; and the one not found 
on our shores, the L. australis, apparently inhabits the 
whole circumference of the southern ocean. 

General Remarks and Affinities. — The first five species 
form a most natural genus ; they are often sufficiently diffi- 
cult to be distinguished, owing to their great variability. 
The sixth species (Z. fascicularis) differs to a slight 
extent in many respects from the other species, and 
has considerable claims to be generically separated, as 
has been proposed by Mr. Gray, under the name of 
Dosima ; but as it is identical in structure in all the 
more essential parts, I have not thought fit to separate it. 
As far as external characters go, some of the species of 
Paecilasma have not stronger claims, than has L. fascicu- 
laris, to be generically separated ; and I at first retained 
them altogether, but in drawing up this generic descrip- 
tion, I found scarcely a single observation applicable to 
both halves of the genus ; hence I was led to separate 
Lepas and Paecilasma. If 1 had retained these two genera 
together, I should have had, also, to include the species 
of Dichelaspis and Oxynaspis ; and even Scalpellum 
would have been separable only by the number of its 
valves ; this would obviously have been highly inconve- 
nient. Although some of the species of Peecilasma so 
closely resemble externally the species of Lepas, yet if we 
consider their entire structure, we shall find that they are 
sufficiently distinct; as indirect evidence of this, I may 
remark that Conchoderma (as defined in this volume), 
includes two genera of most authors, and yet certainly 
comes, if judged by its whole organisation, nearer to 
Lepas than does Paecilasma. 



LEPAS ANATIFERA. 73 



1. Lepas anatifera. Tab. I. fig. 1. (var.) 

L. anatifera. Idnnaus. Systema Naturae, 1767. 

Anatifa vel anatifera vel pentalasmis leevis*, plerumque 
auctorum. 

— engonata (!). f Conrad. Journal Acad. Nat. Sc. Phila- 

delphia, vol. vii, 1837, p. 262, PL xx, fig. 15. 

— dentata (var.) Brugiere. Eucyclop. Meth. (des Vers), 

1789. 
Pentalasmis dentatus (var.) Brown. Illust. Conch., PI. lii, fig. 5. 
Anatifa Martin St. Ange. Mem. sur l'organisation 

des Cirripedes, 1835. 

L. valvis aid Icevibus aut delicate striatis : e duobus 
scutis, dextro solum dente interno umbonali instructo; 
pedunculi parte superior e fused. 

Valves smooth, or delicately striated. Right-hand 
scutum alone furnished with an internal umbonal tooth : 
uppermost part of peduncle dark-coloured. 

Filaments, two on each side. 

Var. (a). Fig. 1. Scuta and terga with one or more 
diagonal lines of dark greenish-brown, square, slightly 
depressed marks. 

Var. (b). (Fig. lb.) Carina strongly barbed. 

Extremely common ; attached to floating timber, vessels, seaweed, bottles, 
&c, and to each other, in the Atlantic Ocean, Mediterranean, West Indies, 
Indian Ocean, Philippine Archipelago, Sandwich Islands, Bass's Straits, 
Van Diemen's Land. 

General Appearance. — Valves white, more or less 
translucent and thick, with a tinge of blueish-grey, from 
the underlying corium ; sometimes brownish cream- 
coloured, rarely with a tint of purple. Surfaces smooth, 

* As this, though the commonest species, has never been defined, I give 
only a few synonyms and references, it being quite impossible to distinguish, 
in any published description, this species from A. Hillii of Leach; this 
latter species I recognise under this name only from having authentic spe- 
cimens from the British. Museum, as Leach overlooked every one of the real 
diagnostic characters. 

f I have used, in conformity with botanists, the mark of interjection, to 
show that I have seen an authentic specimen. 



74 LEPAS ANATIFERA. 

with traces of very fine lines radiating from the umbones, 
sometimes rather plain on the basal part of the scuta. 
Length in proportion to the breadth of the capitulum 
variable, owing to the varying degree to which the scuta 
and terga have their apices produced. Scuta with the 
occludent margin either considerably curved or nearly 
straight. The internal tooth of the right-hand scutum, 
close to the umbo, varies in size and form, being either 
pointed, square, or obliquely truncated on either side, or 
it has a notch on the summit ; internal basal rim of the 
scuta either plainly developed or nearly absent. In many 
specimens (PI. I, fig. 1), on the scuta, or on the scuta 
and terga, (and sometimes more on one side of the indi- 
vidual than on the other,) a nearly straight line, running 
diagonally across the capitulum, of slight, quadrilateral 
depressions, of a dirty greenish colour, with the edges 
blending away, is either conspicuously developed, or can 
only just be discerned. These marks increase in size from 
the umbones to the margins of the valves. There are 
sometimes two or even three rows on the scuta. They 
are formed by the retention of a portion of the chitine 
membrane, which is cast off the rest of the surface ; the 
margins of the valves are occasionally notched slightly on 
the line of marks ; there is no difference along this line in 
the underlying corium. Specimens both with and without 
a barbed carina are thus characterised. Carina; the 
interspace between the carina and the scuta and terga is 
not wide. The carina exteriorly, is either convex and 
smooth, or furnished with knobs or with extremely sharp, 
long teeth (PL I, fig. 1 b) ; small specimens, with the 
capitulum under half an inch in length, are generally most 
strongly barbed.* Apex more or less acuminated; width 
and thickness variable ; sides strongly furrowed. Fork 
(fig. 1 a) generally less wide than the widest upper part 
of the valve, with the two prongs diverging from each 

* Mr. W. Thompson found that 15 specimens, out of about 200, attached 
to a vessel which came from New Orleans into Belfast, had their carinas 
barbed. 



LEPAS ANATIFERA. 75 

other at less than a right angle ; their sharpness and precise 
form variable j rim between them reflexed (figs. 1 a and b), 
making a slight notch behind. Peduncle smooth, wrinkled, 
length in proportion to that of the capitulum varying, from 
barely equalling it, to six or seven times as long. I have 
noticed a specimen including mature ova, with a capitulum 
under half an inch long. 

Filamentary Appendages ; — never more than two on 
each side, with sometimes only one developed ; of variable 
length ; one seated on the flank of the prosoma, under 
the first cirrus ; the second close under the basal articula- 
tion of this cirrus, on the posterior face of a slight swelling : 
these appendages- correspond with g and h in Fig. 4, 
PL IX. 

Mouth. — Mandibles (PL IX, fig. 5), with, as usual, five 
teeth, all pointing downwards. Maxillae (PL IX, fig. 9), 
with the lower step of variable width compared to the two 
upper steps. Cirri; posterior cirri with segments (fig. 26) 
bearing six pair of spines ; intermediate fine spines rather 
long ; first cirrus, anterior ramus longer by only about 
two segments than the posterior ramus ; second cirrus 
with anterior ramus, with very broad transverse rows 
of bristles; spine-bearing surfaces considerably protu- 
berant ; caudal prominences smooth, rounded. 

Si%e. — The largest specimen which I have seen had a 
capitulum two inches in length ; the longest, including 
the peduncle, was sixteen inches. 

Colours. — Calcareous valves already described. Edges 
of the orifice bright scarlet orange ; basal edges of the 
scuta, and sometimes of all the valves, with a torn border 
of orange membrane. Interspaces between the valves dull 
orange-brown. Peduncle darkish purplish-brown, with 
the lower part sometimes pale ; chitine membrane itself 
tinted orange ; in young specimens, peduncle pale, the 
colour first appearing in the uppermost part, close under 
the capitulum ; this upper part is often darker than the 
other parts, and never orange-coloured, as in L. Hillii 
and L. anserifera. Sack internally dark purplish lead- 



76 LEPAS ANATIFERA. 

colour, sometimes with a tinge of orange, darkest under 
the growing edges of the valves j body of animal pale 
purplish lead-colour. The four posterior cirri blackish 
purple; the second, and often the third cirrus, appear 
as if the colour had been laterally abraded off; these 
latter cirri have sometimes a tinge of orange. In very 
young specimens, the cirri are only barred with purple. 
The ova and the contents of the ovarian tubes are of a 
beautiful azure blue, becoming yellow in spirits. 

In museums a vast amount of difference is seen in the 
colours of this species, caused by the method of pre- 
paration : if dried without having been in spirits, and 
subsequently kept dry, the orange tint round the orifice 
is preserved; if kept long in spirits, this is quite lost; 
but sometimes in specimens in spirits the colour of the 
membrane of peduncle is preserved and rendered pinker. 
The colours of the sack and animal are either quite dis- 
charged or rendered extremely dark. The valves them- 
selves also often become more opaque. In some specimens 
well preserved in spirits, the sack and cirri were purplish- 
brown or lead-colour, tinted with dirty green, or orange, 
or bright yellow, or brick -red. 

General Remarks. — Prom the foregoing description it 
will be seen how extremely variable almost every part 
of this species is. I find, in the British Museum, ten 
distinct specific names given by Dr. Leach to different 
varieties, or rather to different specimens, for some of them 
are undistinguishable. A specimen from the Sandwich 
Islands, sent by Mr. Conrad to Mr. Cuming, is marked 
A. engonata. 

In looking over a large collection of specimens in a 
museum, the most distinctive characters appear at first 
to be the colours, the dentation or barbed condition of 
the carina, the row of square marks on the scuta and 
terga, and the more or less produced form of the whole 
capitulum : all these characters are absolutely worthless 
as distinctive characters, and blend into each other. In 
a fresh condition, the colours of this species, and of 



LEPAS HILLII. 77 

L. anserifera and L. Hittii are surprisingly alike, though in 
L. anatifera alone, the uppermost part of the peduncle is 
dark. As far as I have seen, the smoothness of the 
valves, together with the presence of a tooth beneath the 
umbo, on the right-hand scutum, and its entire absence 
on the left side, (in other species it is smaller on this, 
than on the right-hand side,) is an unfailing diagnostic 
mark. I believe this species is always attached to float- 
ing objects, though there are some very young specimens 
in the British Museum, collected by Sir G. Grey, adher- 
ing to sandstone, but this may have been buoyed up by 
some large sea-weed. Mr. Peach has given me the 
particulars of two instances, in which, after gales of wind, 
this species, of nearly full size, adhering to apparently 
freshly broken-ofTLaminarise, has been cast upon the coast 
of England and Scotland. 



2. Lepas Hillii. (PL I, fig. 2). 

Anatifa vel pentalasmis l^evis (!) plerumque auctorum. 
Pentalasmis Hillii (!). Leach. Tuckey's Congo Expedit. p. 413, 

1818. 

— CHELONL& (!) lb. lb. 

Anatifa tricolor (?). Qiwi/et Gaimard. Ann. des Sc. Nat., 1st 
series, torn, x, 1827, PL vii, fig. 7, et Voyage de 
1' Astrolabe, PL xciii, fig. 4. 
— substriata (!). Conrad. Journal Acad. Nat. Sc, Phila- 
delphia, vol. vii, 1837, p. 262, PL xx, fig. 14. 

L. valvis Icevibus ; scutorum dentibus internis umbo- 
nalibus nullis ; carina a cater is valvis, J wrcd etiam a scu- 
torum basali margine, paululum distante ; pedunculi parte 
superior e aut pallida aid aurantiacd. 

Valves smooth; scuta destitute of internal umbonal 
teeth; carina standing a little separate from the other 
valves, with the fork not close to the basal margin of the 
scuta ; uppermost part of peduncle either pale or orange- 
coloured. 

Filaments three on each side. 



78 LEPAS HILLII. 

Extremely common ; attached to ships' bottoms, from all parts of the 
world ; on floating timber ; associated with L. anatifera and L. anserifera. 
Mediterranean. Attached to turtles, in the Atlantic, lat. 30° north. West 
Indies. Falkland Islands. " South Seas/' collected by A. Menzies. Port 
Stephen, Australia. 

General Appearance. — Capitulum laterally flat ; length 
varies in proportion to the breadth; valves white, somewhat 
translucent, moderately thick, very smooth, but with faint 
traces of radiating lines ; in some varieties, surface rather 
irregular along the zones of growth. Scuta without any 
internal teeth, and with scarcely any trace of the internal 
basal rim ; upper angle little acuminated ; the occludent 
margins of the two scuta stand rather separate from each 
other, showing a wide space of corium between them : these 
margins are arched and protuberant, but with the lower 
part a little hollowed out ; basal margin a little curved. 
In one specimen alone, I saw a trace of a diagonal line of 
square coloured marks, like those common in L. anatifera. 
Terga rather broad, with the basal angle not much 
acuminated. The degree of prominence and outline of 
the double occludent margin varies very much. Carina, 
separated by a rather wide space from the scuta and 
terga ; of very varying shape, the upper part not much 
acuminated, generally very flat, sometimes exteriorly 
marked by a central depressed line ; never barbed ; 
occasionally, (in a specimen from Australia,) middle part 
so wide as almost to become spoon-shaped ; on the other 
hand occasionally of nearly the same width throughout ; 
somewhat constricted above the fork. Fork deeply 
embedded as usual ; situated, in fresh specimens, a little 
way beneath the basal margins of the scuta, instead 
of touching them, as in the other species ; forks of vary- 
ing width, not so abruptly inflected as in many species ; 
sometimes much narrower than the upper widest part of 
the valve, sometimes nearly twice as wide ; prongs of fork 
not very sharp, diverging at about a right angle, with the 
rim between them reflexed. The apex of the carina 
extends up between the terga for barely half their length, 



LEPAS HILLII. 79 

instead of up fully three fourths of their length, as in 
L. anatifera. 

The chitine membrane at the base of the capitulum, 
especially at the anterior and posterior ends, is covered 
with beautiful, little, embedded, yellowish beads, about 

th of an inch in diameter ; above this, on each side of 



2000 



the carina, there is a space with similar but smaller little 
spheres, and still higher up still minuter ones ; others 
occur on different parts of the capitulum ; these spaces 
are seen to be distinctly separated from each other, and 
present a beautiful appearance under a high power. 

Peduncle, as long as, or rather longer than, the capitu- 
lum : in one set of specimens, however, it was thrice or 
four times as long as the capitulum. The peduncle, in 
some specimens, was conspicuously covered with trans- 
verse plates of yellowish hard chitine. 

Filamentary Appendages. — Three on each side ; one on 
the flank of the prosoma, with a pair beneath the basal 
articulation of the first cirrus ; relative lengths various, 
but the posterior filament of the pair under the cirrus, is 
the shortest. Mouth; palpi not much acuminated; 
maxillae step-formed, but with the upper or first step in 
some specimens indistinct, or forming a curve. Cirri ; 
the segments of the first cirrus and of the posterior arm 
of the second cirrus are highly protuberant, the protuber- 
ances sometimes equalling half the thickness of the seg- 
ments themselves. Caudal appendages smooth, rounded. 

Size. — The largest specimen which I have seen, in 
the collection of Mr. Cuming, had a capitulum 1-^th of 
an inch long, and 1 \ wide ; therefore not quite equalling 
in size the largest specimens of L. anatifera. 

Colours. — When fresh, valves blueish-grey from the 
underlying corium, edges of all the valves and round the 
orifice, and round the top of the peduncle, bright orange- 
yellow, passing into the finest scarlet, and varying 
slightly in tint in different specimens. Space between the 
carina and the other valves, and between the occludent 
margins of the scuta, rich purplish-brown ; peduncle 



80 LEPAS HILLII. 

either pale or purplish-brown, or only clouded on the 
sides with the same. In young specimens, peduncle 
nearly colourless ; and in those under a quarter of an inch 
long in the capitulum, the top of the peduncle has not 
acquired its orange tint. Sack pale, leaden-purple, body 
the same, but paler and more reddish; cirri (but only 
the tips of first pair) tinted with fine golden orange. 
Immature ova in peduncle beautiful blue. After being 
long kept in spirits, the colours are changed, weak- 
ened, or discharged, as in L. a?iatifera and L. anserifera, 
and the valves become opaque. In some long-kept spe- 
cimens the corium everywhere had become pale brown ; 
more usually it assumes a dirty purplish lead-colour. 

Monstrous Variety, — Amongst a set of ordinary speci- 
mens from a ship from Genoa, sent me by Mr. Stutchbury, 
there were three, one full-grown and two very young, 
with the whole capitulum, (and likewise with the scuta 
and terga taken separately,) not above half the usual 
length in proportion to the breadth. Neither the colours 
nor animal in this variety presented any difference. 

General Remarks. — This species is almost universally 
confounded with L. anatifera. Quoy and Gaimard, how- 
ever, appear to have distinguished it, under the name of 
A. tricolor, from its colours. Leach named it acci- 
dentally, for he specifies not one distinctive character, 
and besides his two published names, he has appended 
two other names to specimens in the British Museum. 
A specimen, from the Sandwich Islands, sent by Mr. 
Conrad to Mr. Cuming, is marked A. substriata. In a 
dry state, from the shrinking of the membranes, and 
consequent approach of the carina to the other valves, 
and of the fork to the basal margin of the scuta, it is 
most difficult to distinguish this species, though so 
decidedly distinct, from L. anatifera; the absence, how- 
ever, of a tooth on the under side of the right-hand 
scutum is at once characteristic. Even in specimens 
kept in spirits, in which there has been no shrinking, 
but in which the colours have changed, and taking into 



LEPAS ANSERIFERA. 81 

account the variation in the carina and upper part of the 
terga, this species is not always readily distinguished 
from L. anatifera, without opening the valves and looking 
for the right-hand tooth of the latter. In fresh specimens, 
the orange ring at the top of the peduncle, and the broad 
purplish interspace between the carina and other valves, 
are characteristic. In all states, the filamentary append- 
ages offer a good character. 



3. LEPAS ANSERIFERA. PI. I, fig. 4. 

L. ansekifeea. Limitetis. Syst. Naturae, 1707. 

Anatifa stkiata. Brug. Encyclop. Meth. (des vers), PL clxvi, 

fig- 3. 
Pentalasmis dilatata \ (young). Leach. Tuckey's Congo 

Expedit.,p. 413, 1818. 
Anatifa sessilis (?). Quoy et Gaimard. Voyage de 1' Astrolabe, 

PL xciii, fig. 31. 
Lepas nauta* Macgillivray : Edin. New Phil. Journ., 

vol. xxxviii, p. 300. 
Pentalasmis anseejferus. Brown. Illust. Conch., 1841, PL li, 

fiff.l. 



■*o* 



L. valvis approximatis leviter sulcatis (tergis prcecipue) ; 
scuto dextro dente forti interno wnbonali, Icevo aut dente 
exiguo, aut merd crista instrncto ; margine occludente 
arcuato, prominente: pedunculi parte superior e aurantiacd. 

Valves approximate, slightly furrowed, especially the 
terga ; right-hand scutum with a strong internal umbonal 
tooth; left-hand with a small tooth, or mere ridge; 
occludent margin arched, protuberant : uppermost part of 
peduncle orange-coloured. 

* Professor Macgillivray does not consider the species, which he has 
described under L. nauta, and which I cannot doubt is the same with the 
present species, as the L. anserifera of Linnseus ; but I find it so named in 
all old collections, and it seems to agree very well with Linnaeus's descrip- 
tion. There has been much groundless confusion about this species ; I have 
no hesitation in giving A. striata, of Brugiere, as a synonym, though I have 
received from Paris the Lepas pecti?iata of this volume, named as the 
A. striata; and on the other hand, Poli has incorrectly called a common variety 
of L. pectinata by the name of L. anserifera. 

6 



82 LEPAS ANSERIFERA. 

Filaments five or six on each side. 

Var. (dilatata, young) ; valves rather thin, finely fur- 
rowed, often strongly pectinated ; scuta broad, with the 
occludent margins much arched, making the space wide 
between this margin and the ridge connecting the umbo 
and the apex : carina often barbed. 

Common on ships' bottoms from the Mediterranean, West Indies, South 
America, Mauritius, Coast of Africa and the East-Indian Archipelago. Cen- 
tral Pacific Ocean. China Sea. Chusan. Sydney. Attached to pumice, 
various species of fuci, Janthinse, Spirulse ; often associated with L. anatifera 
and L. Ilillii, and, in a young state, with L.fascicularis. 

General Appearance. — Capitulum more or less elon- 
gated relatively to its breadth ; in two specimens, with 
scuta of equal width, one was longer than the other by 
the whole of the occludent margin of the terga. Valves 
white, thick, (in young specimens sometimes diaphanous 
and thin,) closely approximate to each other; surfaces 
furrowed to a very variable amount. Terga generally 
more plainly furrowed than the scuta, of which the basal 
portion is generally less furrowed than the upper part ; 
ridges, often rough, generally much narrower than the 
furrows : in half-grown specimens (var., dilatata of 
Leach,) the ridges are frequently denticulated, and there 
is even sometimes a row of bead-like teeth along the 
basal margins of the scuta. The ridges vary much, 
sometimes alternately wide and narrow ; in two speci- 
mens of equal size, there were, in one, thirty- two ridges, 
and in the other only eighteen, on the scutum. 

Scuta, with the occludent margin rounded and pro- 
tuberant to a variable degree, but always leaving a 
rather wide space between the margin, and the ridge 
which rims from the umbo to the apex ; apex pointed. 
Right-hand internal tooth considerably larger than that 
on the left, which is often reduced to a mere ridge ; 
internal basal rim thick, sometimes furrowed along its 
upper edge, but of variable thickness, sometimes not 
extending as far as the baso-carinal angle. Terga, some- 



LEPAS ANSERIFERA. 83 

times equalling, sometimes only two-thirds of, the length 
of the scuta; in young specimens, the two occludent 
margins form a right-angle with each other ^ in older 
specimens they form less than a right-angle, and hence 
the portion of valve thus bounded is unusually protube- 
rant. Carina, within deeply concave ; exterior sides finely 
furrowed longitudinally, generally denticulated ; valve only 
slightly narrowed in above the fork, of which the prongs 
diverge at an angle of 90°, or rather more, and are wider 
than the widest upper part of the valve ; rim between the 
prongs reflexed; the heel or external angle, just above 
the fork, sometimes considerably prominent. I have seen 
only a single large specimen with its carina barbed. 
In half-grown specimens, (var. dilataia, Leach,) the carina 
is often strongly barbed, with the upper point much acumi- 
nated, the fork about twice as wide as the widest upper part, 
and the prongs diverging at rather more than a right-angle. 
In some specimens, especially very young ones, there are 
at the base of the carina, above the fork, some strong, 
downward-pointed, inwardly-hooked, calcareous teeth ; 
such occur also in some specimens along the basal margins 
of the scuta, two of these hooked teeth under the urn- 
bones of the scuta being larger than the rest : specimens 
conspicuously thus characterised came from the Navigator 
Islands ; in these, I may add, the acutely triangular pri- 
mordial valves were quite plain. 

Peduncle, generally about as long as the capitulum ; in 
young specimens generally short. 

Filamentary Appendages, generally five, sometimes six, 
on each side ; one is seated on the side of the prosoma, 
and the four others placed in pairs beneath the basal 
articulation of the first cirrus ; the lowest posterior 
filament of the four generally is the largest. In young 
specimens, having a capitulum only half an inch long, 
the upper pair of the four often is not developed, or 
is represented by mere knobs. The mouth presents 
no distinctive characters. Cirri, with the longer ramus 
of <the first pair almost equal to the shorter arms of the 



84 LEPAS ANSERIFERA. 

second pair; spine-bearing surfaces only slightly protu- 
berant. Caudal appendages smooth, curved, pointed. 

Size. — The largest specimen which I have seen, had a 
capitulunTone inch and a half in length. 

Colours. — The white valves are edged with bright 
orange membrane ; and are so close to each other that 
no interspaces, coloured from the underlying corium, are 
left. Peduncle, dark orange-brown, with the uppermost 
part under the capitulum bright orange all round; the 
chitine membrane itself being thus coloured. Sack, in- 
ternally, dark purplish lead-colour. Body and cirri, 
either nearly white or pale purplish-lead colour, with the 
arms of the second, third, and fourth cirri, and pedicels of 
the fifth and sixth, more or less tinted with orange. A 
specimen preserved during fourteen months in good spirits 
had only a tinge of orange left round the orifice and round 
the upper part of peduncle, and on the cirri. In some 
other specimens, badly preserved, the chitine membrane 
was quite colourless, and sack and cirri dirty lead-colour. 
Fresh ova, peach-blossom-red ; immature ova, in ovarian 
tubes, pale pink. 

Monstrous Variety. — In Mr. Stutchbury's collection, 
there was a specimen, with the scuta, broad, smooth, thin, 
and fragile, without any ridge running from the umbo 
to the apex, and with the occludent margin reflexed. 
This seemed caused by the shell having been attacked by 
some boring animal, and from having supported Balani. 
In the same specimen the first cirrus on one side was 
monstrously thick and curled ; the second cirrus had its 
posterior ramus in a rudimentary condition. In Mr. 
Cuming's Collection, there are small specimens with 
the zones of growth overlapping each other, with thick 
irregular margins, and with the carina distorted. 

This species has cost me much trouble : I have 
examined vast numbers of specimens, from a tenth to 
half an inch in length, attached to light floating objects, 
such as Janthinae and Spirulse from the tropical oceans, 
which all resembled each other, and slightly differed 



LEPAS PECTIN ATA. 85 

from the common appearance of L. anserifera : this 
variety is the Pentalasmis dilatata of Leach; and for 
a long time I considered it as a distinct species. It 
differs from L. anserifera, in the less thickness of the 
valves, in their being more finely and yet plainly fur- 
rowed ; in the greater width of the scuta ; and more 
especially, of that part of the valve lying between the 
occludent margin, and the ridge running from the 
umbo to the apex ; in the less elongation of the area in 
the terga, bounded by the two occludent margins ; and, 
lastly, in the less size of the whole individual. The 
tropin and cirri are absolutely identical. Lately, how- 
ever, in carefully going over a great suite of specimens, 
all the above few distinctive characters broke down and 
insensibly graduated away; and I am convinced that this 
form is only a variety of L. anserifera ; its different aspect 
being caused partly by youth, but chiefly, I suspect, from 
being attached to light objects floating close to the surface 
of the sea. 

The Lepas anserifera can be distinguished by the 
slight furrows on its valves from all the other species, 
excepting L. pectinata: this latter species can be 
readily known, by the close proximity in the scuta 
of the occludent margin, and the ridge extending from 
the umbo to the apex ; by its carina being very narrow 
above the fork ; by the prongs of the fork diverging 
at an angle of from 135° to 180°; by the thinness of 
its valves ; by the coarseness of the furrows on them ; 
and lastly, by there being at most in L. pectinata only 
one filamentary appendage beneath the first cirrus. 



4. Lepas pectinata. PL I, fig. 3. 

Lepas pectinata. Spengler. Skrifter Naturhist. Selbskabet, 2, 
B, 2, H. 5 1793, Tab. X, fig. 2. 
— muricata (var.) Poll. Test. Utriusque Scicil., vol. i, 
PL vi, figs. 23, 29, 1795. 



86 LEPAS PECTINATA. 

Lepas anseeifeba. Poli. Test. Utriusque Scicil., vol. i, PI. vi, 
figs. 25-27. 
— sulcata. Montagu. Test. Brit., PL i, fig. 6, 1803. 
Pentalasmis sulcata. Leach. Encyclop. Brit. Suppl., torn, iii, 
Pl.lvii, 1824. 

— sprauLiE (!) (var.) Leach. Tuckey's Congo Expedit. 

Appendix, 1818. 

— eadula (var.) et sulcatus. Brown. Illust. of 

Conchology, PI. li, figs. 3—6, 1844. 

— inversus. Chenu. Illust. Conchy., PI. i, fig. 14. 
Anatifa sulcata. Quoy et Gaimard. Voyage de 1' Astrolabe, 

PI. xciii, figs. 18, 20 * 

L. valvis tenuibus, crasse sulcatis, scepe pectinatis ; scu- 
torum crista prominente ab umbone ad apicem juxta mar- 
ginem occludentem pertinente : furcce carinalis cruribus 
inter angulos 135° et 180° diver gentibus. 

Valves thin, coarsely furrowed, often pectinated. Scuta 
with a prominent ridge extending, from the umbo to the 
apex, close to the occludent margin ; fork of the carina 
with the prongs diverging at an angle of from 135° to 
180°. 

Filaments absent, or only one on each side. 

Var. (PL I, fig. 3 a), upper part of the terga (bounded 
by the two occludent margins) produced and sharp ; 
surface of all the valves often coarsely pectinated, and 
with the carina barbed. 

Atlantic Ocean, from the North of Ireland to off Cape Horn ; common, 
under the tropics ; Mediterranean : attached to wood, cork, charcoal, sea- 
weed, a reed-like leaf, spirulae, cuttle-fish bones, to a bottle together with L. 
anatifera ; to a ship's bottom, Belfast, ( W. Thompson.) Often associated 
with L. fascicular is. Montagu states ('Test. Brit.,' p. 18) that this species 
is sometimes attached to the fixed Gorgonia flabellum. 

General Appearance. — The capitulum varies consider- 
ably in length compared to its breadth, caused chiefly by 
the greater or less production of the occludent portion of 
the terga ; valves thin, brittle ; the furrowed surface varies 

* I may add, that I have received many specimens incorrectly labelled 
A. striata, which is properly a synonym of L. anserifera. 



LEPAS PECTINATA. 87 

much in character, narrow and broad ridges often alter- 
nating; frequently each ridge (but more especially the 
ridge running from the umbo to the apex of each scutum, 
and sometimes that alone,) is covered with prominent, 
curled, flat, calcareous spines, giving the shell an appear- 
ance like that of many mollusca. Other specimens show 
no trace of these calcified projections. From the thinness 
of the valves and the depth of the furrows, the margins 
of the valves are sinuous. Scuta: the ridge running 
from the umbo to the apex is unusually prominent and 
curved; it runs very close to the occludent margin, so 
that, differently from in all the other species, only a very 
narrow space is left between this margin and the ridge. 
Internal teeth, under the umbones, either sharp and pro- 
minent, or mere knobs ; sometimes that on the right side 
is much larger than that on the left ; sometimes they are 
nearly equal ; sometimes that on the left is scarcely distin- 
guishable. Internal basal rim absent, or barely developed. 

Terga : these valves have a conspicuous notch to receive 
the apex of the scuta ; the two occludent margins either 
meet each other at a rectangle, or at a much smaller angle, 
causing the portion thus bounded to vary much in out- 
line, area, and degree of prominence. This at first led 
me to think that the P. spirula of Leach, in which the 
point is very sharp and prominent, was a distinct species ; 
but there are so many intermediate forms, that the idea 
must be given up. I may remark, that in all the species 
of Lepas, the upper part of the tergum seems particularly 
variable. The degree of acumination of the basal portion 
of the tergum also varies ; the internal surface sometimes 
has small crests radiating from the umbo. 

Carina, broad, within deeply concave ; edges sinuous, 
externally sometimes strongly barbed ; narrow above the 
fork, which latter is wider than the widest upper part of 
the valve; prongs sharp, thin, diverging at an angle of 
from 135° to 180°; the rim connecting the prongs not, 
or only slightly, reflexed. 

Peduncle, narrow, shorter than the capitulum. 



88 LEPAS PECTINATA. 

Filamentary Appendages, none, or only one, short, 
obtuse projection on each side, on the posterior face of 
the swelling under the first cirrus. 

Mouth. — Mandibles, with the inferior point produced 
into a single pectinated tooth, rarely into two pectinated 
teeth ; on one side of one specimen, there were only four 
instead of five teeth. Palpi very narrow. Maxillae highly 
variable ; they may be described as formed of five steps, 
of which the two lower ones are generally united into a 
single one, divided by a mere trace of a notch ; or with the 
three lower steps blended into an irregular, projecting 
surface, and with even the fourth step indistinct. I have 
seen these two extreme forms on opposite sides of the 
mouth of the same individual, — on one side the maxillae 
being regularly step-form, on the other the whole inferior 
part forming an almost straight edge, standing high up 
above the first notch or step which bears the two upper 
great spines. 

Cirri. — First pair rather far removed from the second 
pair, with the longer ramus about three-fourths of the 
length of shorter ramus of second cirrus ; spine-bearing 
surfaces, hardly at all protuberant ; lateral marginal spines 
on the posterior cirri rather long; caudal appendages 
smooth, rounded, extremely minute : penis very spinose. 

Size. — Capitulum in the largest specimen, six-tenths of 
an inch long ; only a few arrive at this size. 

Colours, after having been kept in spirits, — sack and 
cirri, especially first cirrus, clouded with pale purple; 
peduncle brownish ; valves appear blueish in specimens 
not long preserved, but in specimens kept longer they 
become perfectly and delicately white. 

General Remarks. — Under the head of L. anserifera, I 
have made some remarks on the diagnostic characters of 
this species. In the thinness of the valves, — form of the 
carina, with the rim connecting the prongs being not, or 
scarcely, reflexed, — and in the shortness and narrowness 
of the peduncle, there is some approach to L. australis, 
and thence to L. fascicularis. In the form of the maxillae, 



LEPAS AUSTRALIS. 89 

— in one specimen having the mandible on one side 
bearing only four teeth, — and in the frequent absence of 
filamentary appendages, there is some approach to the 
genus Ptecilasma ; but there is no such approach in the 
characters derived from the capitulum. We have seen 
that, as in so many other species of this genus, most 
of the parts are variable, and this is the case to a most 
unusual extent in the form of the maxillae. Dr. Leach 
has attached eight specific names to the specimens 
preserved in the British Museum. 



5. LEPAS AUSTRALIS. PL I, fig. 5. 

L. valvisglabris, tenuibus^fragilibus ; scutorum dentibus 
umbonalibus utrinque internis ; carina parte superior e 
lata, plana, supra fur cam valde constrictd ; fur cm cruribus 
latis, plants, tenuibus, acuminatis, intermedio margine 
non reflexo. 

Valves smooth, thin, brittle; scuta with internal um- 
bonal teeth on both sides. Carina with the upper part 
broad, flat ; much constricted above the fork, which has 
wide, flat, thin, pointed prongs, with the intermediate 
rim not reflexed. 

Filaments, two on each side. 

Common on Laminariae in the whole Antarctic Ocean : Bass's Straits, 
Van Diemen's Land : Bay of Islands, New Zealand, lat. 35° S. : lat. 
50° S., 172° W. : coast of Patagonia, lat. 45° S. : attached to bottom of 
H. M. S. Beagle, lat. 50° S., Patagonia: attached to a Nullipora, (I presume 
a drift piece,) British Museum. 

General Appearance. — Capitulum rather obtuse and 
thick; valves thin, brittle, approximate, either white 
and transparent, or dirty -brown and opaque ; or some- 
times tinted internally with purple (perhaps the effects of 
being preserved in spirits) ; surface plainly marked by 
lines of growth, rarely marked with traces of lines radiat- 
ing from the umbones. Scuta with teeth on both sides, 



i 
4 *^m~ 



90 LEPAS AUSTRALIS. 

nearly equal ; internal basal rim rather wide, sometimes 
furrowed ; basal margin considerably curved inwards. 
Terga rather wide ; basal angle blunt ; angle formed by 
the two occludent margins blunt and rounded. Carina 
{fig. 5 a) with the apex blunt, flat ; the middle part gene- 
rally very broad ; much constricted above the fork, where 
it is internally deeply concave, and externally carinated ; 
fork twice as broad as the broadest upper part of the 
valve ; with the prongs flat, broad, thin, pointed, diverging 
at about an angle of 75°, with the intermediate rim not 
at all reflexed ; the fork generally not deeply imbedded in 
the chitine membrane of the peduncle, so as to be quite 
easily visible externally ; sometimes there is an internal, 
transverse, depressed line on the fork. In young specimens, 
with the capitulum about a quarter of an inch long, the 
fork of the carina is not developed, the lower slightly in- 
flected portion consisting simply of an oval plate, twice 
as wide as the upper part. Until I had carefully ex- 
amined a perfect series, showing the gradual changes in 
this part, I did not doubt that the young specimens formed 
a distinct species, and named it accordingly : the short- 
ness of the penis first made me perceive that the specimens 
were immature. At this early age, I may add, the fila- 
mentary appendages were not developed. Peduncle either 
quite short, or as long as the capitulum, close under which 
it is considerably constricted all round. 

Filamentary Appendages. — Two on each side : one long, 
tapering, placed on the prosoma (in one specimen repre- 
sented by a mere knob), and the second shorter, situated 
on the posterior margin of the SAvelling beneath the first 
cirrus. 

Mouth. — Maxillae, with three large spines at the 
upper angle, and with the first step distinct, but narrow ; 
mandibles with five teeth; in young specimens the in- 
ferior point ends in a single spine ; sides of the supra-oral 
cavity very hairy ; the membrane, forming the inner fold 
of the labrum, yellow and thickened in the form of a spoon. 

Cirri.- — In the posterior cirri there are, at the upper 



LEPAS AUSTRALIS. 91 

lateral edges of the segments on both sides, small spines ; 
the segments in the first cirrus, and in the broad anterior 
ramus of the second cirrus, are hemispherically and con- 
siderably protuberant. Caudal appendages smooth. 

Size. — The largest specimen had a capitulum one inch 
long. 

The Colours (after having been long in spirit) of the 
valves have already been given ; sack and peduncle dirty 
yellowish-brown, with the parts corresponding to the mar- 
gins of the valves much darker brown, or almost black; seg- 
ments of the cirri clouded with dark brown; body and pedi- 
cels of the cirri dirty yellowish. I have reason to believe 
that the colours are totally different in living specimens. 

Monstrous Varieties. — Most of the specimens from lat. 
50° S., on the coast of Patagonia, were more or less 
deformed, with the successive zones of growth overlapping 
each other, and forming coarse concentric ridges. The 
carina in several specimens was laterally distorted. 

I have already remarked that this species has some 
affinity to L. pectinata ; but it is much more closely re- 
lated to L. fascicularis, the affinity being clearly shown 
by the thinness and translucency of the valves, their con- 
vexity, by the width and little acumination of the upper 
part of the carina, by the width of the fork, and by its not 
being deeply imbedded. In young specimens, moreover, 
before the fork is fully developed, there is a remarkable 
similarity between the two species, in the form of this 
lower part of the carina. Again, the narrowness and 
inflection of the peduncle under the capitulum in L. cms- 
trails, and lastly, the lateral marginal spines on both sides 
of the segments of the posterior cirri, all clearly indicate 
this same affinity to L. fascicularis. 

I believe this species is confined to the southern ocean ; 
and perhaps there represents L. fascicularis of the northern 
and tropical seas. It must, judging from the number 
of specimens brought home by Captain Sir J. Ross, and 
from those previously in the British Museum, and from 
those collected by myself, be a very common species. 



92 LEPAS FASCICULARIS, 



6. LEPAS FASCICULARIS. PI. I, fig. 6. 

Lepas FASCICULARIS. Ellis and Solander. Zoophytes, 1786, 

Tab. xv, fig. 5. 

— — Montagu. Test. Brit. Suppl., 1808, 

pp. 5, 164. 

— cygnea. Spengler. Skrifter Naturhist. Selbskabet, Bd. i, 

1790, Tab. vi, fig. 8. 

— dilata. Donovan. British Shells, 1804. 
Pentalasmis FASCICULARIS. Brown. Illust. Conch., 1844, PL li, 

%. 2. 
— spirulicola (!) et Donovani (!) Leach. Tuckey's 

Congo Expedit., p. 413, 1818. 
Anatifa vitrea. Lamarck. Animaux sans Vertebres. 
Dosima fascicularis. (!) J. E. Gray. Annals of Philosophy, 

vol. x, 1825. 
Pentalepas vitrea. Lesson. Voyage de la Coqnille. Mollusca, 

PL xvi, fig. 7, 1830. 
Anatifa oceanica (!) Quoy et Gaimard. Voyage de 1' Astrolabe, 

PL xciii. 

L. valvis glabris, tenuibus, pellucidis; carina rectangule 
flexd, parte inferior e in discum planum oblong um expansd. 

Valves smooth, thin, transparent ; carina rectangularly 
bent, with the lower part expanded into a flat oblong 
disc. 

Filaments, five on each side; segments of the three 
posterior cirri with triangular brushes of spines. 

Var. (Donovani, of Leach.) Carina with the upper 
part flat, spear-shaped, externally with a narrow central 
ridge. 

Var. {Villosa. PL I, figs. 6b, c.) Valves placed rather 
distant from each other ; carina extremely narrow, with 
the upper part of nearly the same width throughout ; 
terga with the lower part much acuminated ; body of 
animal finely villose. 

Coasts of Great Britain and France ; Baltic Sea, according to Montagu 
Southern United States (from Agassiz) ; tropical Atlantic Ocean ; East- 



LEPAS FASCICULARIS. 93 

Indian Archipelago, off Borneo and Celebes ; Pacific Ocean, between the 
Sandwich and Mariana Archipelagos ; New Zealand : attached to fuci, Spirulse 
Janthinse, YeleDas, often to feathers and cork ; often associated with the 
young of L. anserifera, (var. dilatata^) and L. pectinata. 

General Appearance. — Capitulum highly variable in 
all its characters ; thick and broad in proportion to its 
length, but the breadth is variable, — in some specimens, 
the capitulum being longer by one-fifth of its total length 
than broad ; in others, one-fifth broader than long. Valves 
generally approximate ; in some varieties, however, from 
the narrowness of the carina and terga, the valves stand 
far apart, there being an interval between the carina 
and scuta of nearly half the breadth of the latter. Valves 
excessively thin, brittle, transparent, colourless, smooth, 
but generally sinuous along the zones of growth, which are 
conspicuous : valves generally covered throughout by thin 
chitine membrane, which is thickly clothed, especially in 
the interspaces between the valves, with minute spines, 
barely visible to the naked eye. Scuta with the lower 
part of the tergo-carinal margin extremely protuberant ; 
occludent margin, more or less, but slightly reflexed, 
with a depressed line running from the umbo to the 
apex; basal margin much reflexed, but to a variable 
extent and at a varying angle, even up to a right angle, 
— an external rim or collar being thus formed. There 
are no distinct internal teeth, but the basal margin 
under the umbones, is more or less distinctly produced 
into a rounded disc or projection, which is generally 
not so much outwardly reflexed as the rest of the basal 
margin : there is no distinct internal basal rim. The 
primordial valves are generally visible, but they do not 
lie, as in all other species, close to the basal margin, but 
a little above it, — the lower reflexed portion having been 
subsequently developed. Terga flat, with the occludent 
margin slightly arched, and not, as in the foregoing spe- 
cies, formed of two sides ; apex bent towards the carina ; 
width of the lower half highly variable, owing to the 
varying extent to which the scutal margin is hollowed 



94 LEPAS FASCICULARIS. 

out ; in some specimens, the whole lower half beneath the 
apex of the scuta is of nearly the same width throughout ; 
in other specimens this lower part is spear-shaped. The 
widest part of the tergum either equals in width, or is only 
two- thirds of the width of the widest part of the carina 
beneath its umbo. Carina (PL I, fig. ha) highly variable 
in shape, with the part above the umbo either spear- 
shaped and slightly concave within, or nearly flat and 
furnished with a central external ridge ; or the upper 
part (fig. 6 c) is of equal and extreme narrowness through- 
out, and deeply concave within, appearing as if only the 
central ridge had been developed. The part below the 
umbo, (answering to the fork in the foregoing species,) 
is about one-third of the length of the whole valve, and 
generally twice as wide as the upper part, but in the 
variety with the upper part of the carina equally narrow 
throughout, the lower part is thrice as wide as the upper ; 
the disc, or lower part, is generally slightly concave 
within, exteriorly either with or without a central ridge ; 
basal margin rounded ; lateral margin more or less 
curved, according to the form of the upper part. The 
disc is not more deeply imbedded in membrane than is 
the upper part of the valve. The heel or umbo is either 
angular and prominent, or rounded. In very young 
specimens the carina is simply bowed, instead of being 
rectangularly bent. 

Peduncle, — short, narrow, being abruptly inflected all 
round under the basal edges of the capitulum ; lower part 
of very variable shape, being often suddenly contracted 
into a mere thread (fig. 6b), which sometimes widens 
again at the extreme end. The external membrane is 
very thin, and is penetrated by the usual fine tubuli 
leading to the corium; its surface is wrinkled and desti- 
tute of spines, or with extremely few. The peduncle is 
often completely surrounded by a yellowish ball, (of 
which 1 have seen specimens from the coast of England, 
and from off Borneo,) sometimes half as wide as the 
capitulum, composed of very tender, vesicular, structure- 



CAUSE OF BUOYANCY. 95 

less membrane, and of a pulpy substance : perhaps the 
yellow colour may be owing to long immersion in spirits. 
Some authors have supposed that the ball was the ovisac 
of the animal ; and for the first few minutes, deceived by 
the numerous included spores of, as I believe, Bacillarise, 
I thought that this was the case ; others have supposed 
that it consisted of some encrusting algce or other foreign 
organism ; but it is, in reality, a most singular develop- 
ment of the cement-tissue, which ordinarily serves 
to attach Cirripedes by their bases to some extraneous 
object, but here surrounding that object and the pe- 
duncle, gives buoyancy, by its vesicular structure, to the 
whole. The membrane of the ball falls to pieces in 
caustic potash, differently from the chitine membrane of 
the enclosed peduncle, and this shows that there is some 
difference in composition from ordinary cement. The 
ball, when cut in two, exhibits an obscure concentric 
structure. The whole is excreted by the two cement- 
ducts, through two rows of orifices, one on each side of 
the surrounded portion of the peduncle ; and I actually 
traced, in one case, the yellow pulpy substance coming 
out of the cement-ducts. The upper apertures are in 
gradation larger than those below them, and they stand 
a little further apart from each other ; these are figured 
as seen from the outside, much magnified, at PL I, 
fig. 6d. I did not succeed in finding the cement-glands, 
but I followed the ducts, of rather large size, running 
for a considerable distance as usual along and within the 
longitudinal muscles of the peduncle. Nearly opposite 
the uppermost aperture, on each side, the duct passes 
out through the corium, and becomes laterally attached 
to the outer membrane of the peduncle, at which point 
an aperture is formed (as in other cases, by some un- 
known process), thus giving exit to the contents of the 
duct. Beneath this upper aperture the duct runs down 
the peduncle, between the corium and the outer mem- 
brane, till it comes to the next aperture, to which it is 
also attached, and so on to all the lower ones ; but I 



96 LEPAS FASCICULARIS. 

believe no cement tissue continues to pass out through these 
lower apertures. Beneath the lowest aperture the two 
ducts run into the two prehensile antennae of the larva, 
which, as usual, terminate the peduncle. The antennae are 
attached to some small foreign body in the centre of the 
vesicular ball, by the usual tough, light brown, transpa- 
rent cement. The two upper apertures are nearly on a 
level with the outside surface of the ball; and it was 
evident that as the animal grows, new apertures are 
formed higher and higher up on the sides of the peduncle, 
and that out of these, fresh vesicular membrane pro- 
ceeds, and grows over the old ball in a continuous layer. 
It appears that the growth of the vesicular ball is not 
regular, — that it is not always formed, — and that when 
formed the whole, or the lower part, sometimes disin- 
tegrates and is washed away. As that portion of the 
peduncle which is enclosed ceases to grow, and has its 
muscles absorbed, retaining only the underlying corium, 
whereas the upper unenclosed portion, and likewise, (as it 
appears) lower portions once enclosed but since denuded, 
continue to increase in diameter, the peduncle, when the 
vesicular ball is removed, often has the most irregular 
outline, contracting suddenly into a mere thread, and 
then occasionally expanding again at the basal point. 

Frequently two or three specimens have their peduncles 
imbedded in one common ball, of which there is a fine 
specimen in the College of Surgeons (PL I, fig. 6), the 
ball being about one inch and a quarter in diameter, 
with a slice cut off. In this specimen, it is seen that the 
vesicular membrane proceeding from several individuals, 
unites to form one more or less svmmetrical whole, and 
that the original common object of attachment is entirely 
hidden. Dr. Coates* gives a curious account of the infi- 
nite number of specimens, through which he sailed during 
several days, in the Southern Atlantic Ocean : the balls 
appeared like bird's eggs, and were mistaken for some 

* Journal of the Acad. Nat. Sc, Philadelphia, vol. vi, p. 138, 1829. 



LEPAS FASCICULARIS. 97 

fucus, which was supposed to have encrusted the scales of 
the Velellae, to which the Cirripede had originally become 
attached. Several individuals had their peduncles im- 
bedded in the same ball, " which floated like a cork on 
the water." As this species grows into an unusually 
bulky animal, we here see a beautiful and unique contriv- 
ance, in the cement forming a vesicular membranous 
mass, serving as a buoy to float the individuals, which, 
when young and light, were supported on the small 
objects to which they originally had been cemented in 
the usual manner. 

Filamentary Appendages. — Five on each side, of which 
four lie in pairs at the base of the first cirrus (of these, 
only three are sometimes developed), and one on the 
flank of the prosoma. 

Mouth. — Palpi much acuminated. Mandibles with five 
teeth ; the first not far remote from the second ; inferior 
point rather broad and finely pectinated. Maxillae with 
two large, unequal, upper spines, and four regular steps. 

Cirri. — Posterior cirri, with the upper parts of the 
segments slightly protuberant ; in young specimens, the 
spines can be seen to consist of five pairs, placed in two 
converging lines in the upper half of each segment, with 
numerous minute, latero -marginal, and intermediate little 
bristles : in large specimens, all these latter have so in- 
creased in number, that the normal five pair cannot be 
distinguished, and the front of each segment is covered 
by a triangular thick brush of bristles, all pointing in the 
same direction, thus giving a very unusual character to 
the posterior cirri : the dorsal tuft on each segment con- 
sists of six or seven large spines, with from one to three 
dozen fine ones. First cirrus and anterior ramus of second 
cirrus with broad brushes of bristles. The pedicels of 
all the cirri are thickly covered with bristles. Caudal 
appendages smooth, with rounded summits. 

Penis very hairy : vesiculge seminales purple, much 
convoluted, lying within the prosoma; testes dendritic, 
scarcely enlarged at their terminal points, purplish ; 

7 



98 LEPAS FASCICULARIS. 

ovigerous frsena large with sinuous margins, the glan- 
dular beads being arranged in groups. 

She. — The largest specimen (from the coast of Devon- 
shire) had a capitulum 1*6 of an inch long, and 1*2 
broad, and of unusual thickness. 

Colours, after having been in spirits : front surfaces of 
the segments of the cirri and of the pedicels purple. 
In some specimens from off Borneo, parts of the sack 
and the interspaces between the two scuta, were of a fine 
purple. Montagu states, that the whole shell and body 
of animal, when fresh, are pale blue, with the cirri spotted 
with brown. 

General Remarks. — The extreme variability of this 
species is remarkable. In the College of Surgeons, there 
is a group of specimens collected by Mr. Bennett, I 
believe, in the Atlantic, in which the extreme narrowness 
of the carina and of the terga (PI. I, fig. 6, b, c) 
(with consequent wide spaces of membrane left between 
these valves), led me, at first, to entertain no doubt, that 
it was quite a distinct species, which was strengthened 
by finding that the whole surface of the cirri were villose, 
with very minute spines ; hence I called this variety, 
vittosa. On the closest examination, however, I could 
detect no other differences, and the narrowness of the 
carina and terga varied very considerably: moreover, in 
one of the specimens, which was about intermediate in 
the form of its valves between this variety and the com- 
mon form, the surfaces of the cirri were not in the least 
degree villose. Again, in some other specimens, the 
terga were as narrow as in Mr. Bennett's, whilst the 
carina had its usual outline. 

In a var. (called by Leach, P. Donova?ii,) from the 
Atlantic, under the Equator, the carina is remarkable from 
the extreme flatness of the upper part, and from the pre- 
sence of an exterior, narrow, central ridge. In one 
specimen from Jersey, in the British Museum, the carina 
made an extremely near approach to this same form. 

Affinities. — This species is certainly much the most 



GENUS— P.ECiLASMA. 99 

distinct of any in the genns, and Mr. Gray has proposed 
to separate it under the name of Dosima ; but consider- 
ing the close similarity of the whole organisation of the 
internal parts, together with the transitional characters 
afforded by L. austraiis, I think the grounds for this 
separation are not quite sufficient. I have remarked, 
under L. austraiis, on the affinity between that and 
the present species. In the carina terminating in a disc 
(though here not imbedded), there is some slight affinity 
to Pcecilasma eburnea and crassa, and markedly so in the 
arrangement of the bristles on the posterior cirri. In 
the valves being covered with villose membrane, and to a 
certain extent in the form of the carina and of the occlu- 
dent margin of the terga, and especially in the two rows 
of cement -orifices in the peduncle, there is some affinity 
to Scalpellum. 



PtEcilasma. Nov. Genus* Plate II. 

Anatifa. /. E. Gray. Proc. Zoolog. Soc, 1848, p. 44. 
Trilasmis. Hinds. Voyage of the Sulphur. Mollusca, 1844. 

Valva, 3, 5, aid 7, approximates: carina solum ad 

basales apices tergorum externa, termino basali aid 

truncato aid in discum j^ofunde infossum producto : 

scuta pcene ovalia, umbonibus ad angidum rostralem 

positis. 

Valves, 3, 5, or 7, approximate : carina extending only 
to the basal points of the terga ; with its lower end 
either truncated or produced into a deeply imbedded 
disc. Scuta nearly oval, with their umbones at the 
rostral angle. 

Mandibles with four teeth ; maxillae notched, with the 
lower part of edge prominent; anterior ramus of the 

* noKiAoo-, various, and tkaafia, plate or valve. I have not been able to 
adopt Mr. Hinds' name for this genus, as it would be too glaringly incorrect 
to call a five-valved species, a Trilasmis. 



100 GENUS — P.ECILASMA. 

second cirrus not thicker than the posterior ramus ; 
caudal appendages uniarticulate, spinose. 

Generally attached to Crustacea. 

I have already given my reasons for instituting and 
separating this genus from Lepas ; as far as the capi- 
tulum is concerned, the differences between these genera 
certainly appear trivial ; they consist in the carina not 
extending up between the terga, and in the lower end 
being either truncated, or produced into an imbedded 
disc : the terga have a single occludent margin. The 
included animal's body differs in more important re- 
spects ; for both mandibles and maxillae are very dis- 
tinct ; the cirri of some of the species also differ ; and 
the caudal appendages are here always spinose : there 
are no filamentary appendages : and lastly, the habits are 
different. 

The genus may be divided into two sections, firstly, 
P. Kcempferi and P. aurantia, which have their carina? 
basally truncated, the basal angles of their terga cut 
off, and the anterior rami of their second cirri shorter 
than the posterior rami; and, secondly, P. crassa, P.fissa, 
and P. eburnea, which in these several respects are other- 
wise characterised. The P. eburnea, however, differs 
rather more from P. crassa and P. Jissa, than these two 
do from each other ; but certainly not enough to allow of 
the retention of Mr. Hinds' genus of Trilasmis. P. crassa, 
in an especial degree, connects together all the forms. 

General dyjjjearance. — Capitulum oval, more or less 
produced, flat or gibbous ; formed of three, five, or seven 
approximate valves ; the lesser number arising from the 
abortion of the terga, and the greater number from the 
scuta being divided into two segments. Valves mode- 
rately thick, either white or reddish, smooth or striated, 
and sometimes partly covered by membrane, bearing 
minute spines. Scuta oval, of varying proportions ; the 
basal margin is generally narrow, and blends into the 



GENUS PiECILASMA. 101 

carina-tergal margin ; the internal basal rim generally is 
well developed, sometimes with, and sometimes without 
internal teeth beneath the umbones. In P. eburnea, and 
sometimes in P. crassa, there is a line of apparent fissure, 
and in P.fssa of actual disseverment, running from the 
umbo to the apex of each scutum, nearly in the line in 
which a ridge extends in Lepas • the primordial valves 
of the scuta in these three species, are seated at the 
basal angles of the lateral and larger segments. The 
positions of the primordial valves, and the direction of 
growth in the calcified valves, are, in all the species, the 
same as in Lepas. In several of the species attached to 
Crustacea, the two scuta are unequally convex, which is 
caused, as was pointed out to me by Mr. Gray, by that 
valve which lies close and nearly parallel to the body of 
the crab, being least developed. The Terga are either 
quite absent, or rudimentary as in P. crassa, or pretty 
well developed as in the other species ■ the occludent 
margin is single, and not double as generally in Lepas ; 
the basal angle is either pointed or truncated. The Carina 
varies considerably in shape, but never extends up between 
the terga, nor ends downwards in a fork ; in the first 
two species it is truncated; in the others, it terminates 
in a deeply-imbedded oblong disc, which in P. eburnea 
seems almost entirely (but of course not quite) to sepa- 
rate the inside of the capitulum from the peduncle ; 
a similar separation is effected in P.fssa, where the 
imbedded disc is small, by two large teeth on the 
internal basal rims of the two scuta. The carina is 
always narrow, and either solid internally or very slightly 
concave. 

Peduncle, is very short and narrow ; the membrane is 
generally ringed with thicker, yellower portions, and often 
bears very minute spines. 

Size. — All the species are small, with a capitulum not 
exceeding half an inch in length. 

Filamentary Appendages. — None. 

MoutJi. — Labrum generally considerably bullate in 



102 PJ3CILASMA K.EMPIERI. 

the upper part, with a row of teeth on the crest. The 
mandibles have four teeth., with the inferior point narrow 
and spine-like, or rudimentary and absent. The maxillce 
have, under the two or three upper great spines, a deep 
notch itself bearing spines ; beneath this, the lower part 
is straight and considerably prominent, PI. X, fig. 15. 
Outer maxillae are covered on their inner sides con- 
tinuously with spines. 

Cirri. — The first pair is sometimes seated very distant 
from the second. The arrangement of the spines on the 
posterior cirri varies, to an unusual degree within the 
limits of the same genus. We have either the ordinary 
structure of anterior pairs, with single fine intermediate 
spines (as in P. Kampferi and aurantid), or we have the 
pairs increased by one or two additional longitudinal 
lateral rows, as in P. eburnea ; or we have the front 
spines forming a single transverse row, as in P. crassa 
and P.Jissa, PL X, fig. 29, a. The segments in none 
of the species are protuberant; the anterior ramus of 
the second cirrus does not seem to be thicker than the 
posterior ramus, as is usually the case. The rami of the 
second, and of most of the other cirri, are unequal in 
length, — the anterior ramus, contrary to the ordinary 
rule, being longer in P. eburnea, P.jissa, and P. crassa, 
than the posterior ramus by several segments ; I have 
hitherto observed this inequality only in the sessile genus 
Chthamalus. 

The Caudal Appendages are small, uniarticulate, and 
always furnished with bristles. 

Distribution. — Four out of the five species live attached to Crustacea in 
the European and Eastern warmer temperate and tropical oceans ; the fifth 
species was found attached to the dead spines of an Echinus, off New 
Guinea. It is probable that several more species will be hereafter discovered. 



1. P^ECILASMA ICeMPEERI. PI. II, Fig. 1. 

P. valvis 5; camice basi truncatd et cristatd : scuto- 
rum dentibus intemis umbonalibus fortibus : tergo- 



P.EC1LASMA KjEMPFERI. 103 

rum acumine basali truncato, margini occludenti pcene 
p ar allele- . 

Valves 5 ; carina with a truncated and crested base ; 
scuta with strong internal umbonal teeth ; terga with 
the basal point truncated, almost parallel to the occludent 
margin. 

Maxillae with short thick spines in the notch under 
the two upper great spines; caudal appendages with 
scattered bristles on their summits, and along their whole 
outer margins. 

Japan ; attached, in great numbers, to the upper and under sides of the 
Inachus Kampferi of De Haan, a slow-moving brachyourous crab, probably 
from deep water. British Museum. 

General Appearance. — Capitulum rather compressed, 
narrow, and produced. Valves white, tinged with orange, 
smooth, moderately thin, occasionally with faint traces 
of striae radiating from the umbones. Scuta, apex pointed, 
with a very slight ridge running to the umbo; basal 
margin equalling two thirds of the length of the terga, 
with an internal basal rim ; on the under side of each 
valve, beneath the umbo, there is a strong tooth. Out 
of the numerous specimens, all excepting one had then- 
scuta unequally convex, with their occludent margins 
unequally curved, that of the more convex valve at 
the umbo, curling beyond the medial line. The basal 
end of the carina is, likewise, slightly curved laterally, 
and always turns towards the more convex valve. This 
inequality, as Mr. Gray pointed out to me, depends on 
the position of the specimens ; the flatter side lying close 
to the carapace of the crab. Terga, flat, oblong, nearly 
rectangular; occludent margin straight; basal angle, 
truncated, almost parallel to the occludent margin ; in 
width, three or four times as wide as the carina. Carina, 
(fig. 1, a) short, narrow, slightly curved, upper part 
broadest, with the apex rounded, only just passing up 
between the basal broad ends of the terga ; externally 
carinated, internally very slightly concave ; basal end 



104 P^ECILASMA KjEMPFERI. 

abruptly truncated, crested, not deeply imbedded in the 
membrane of the peduncle. 

Peduncle, barely as long as the capitulum, apparently 
(for specimens dry and much shrunk) narrow, surrounded 
by rings or folds of thicker yellowish membrane, of which 
the upper ones retain moderately long spines ; low down 
these rings become confluent ; whole surface finely dotted, 
dots largest on the rings. 

Mouth. — Labrum highly bullate in the upper part, with 
a row of teeth on the crest ; mandibles with four teeth, 
the fourth close to the inferior apex, which is very little 
developed, sometimes making the fourth tooth appear 
simply bifid. Maxillae with two large spines on the 
upper angle, beneath which there is a large depression, 
bearing one rather long and thick, and four short and 
thick, spines ; inferior upraised part with a double row of 
longer and thinner spines. 

Cirri. — Posterior cirri with segments bearing five pairs 
of spines, of which the lowest pair is very minute ; inter- 
mediate spines minute ; spines of the dorsal tuft thin, 
of nearly equal size ; segments not at all protuberant, 
elongated. First cirrus, standing far separated from the 
second (as in Scalpellum), with its nearly equal rami 
rather above half as long as those of the second cirrus. 
Second cirrus with anterior ramus not thicker, and 
scarcely more thickly clothed with spines, than the pos- 
terior ramus, but shorter than it by three or four seg- 
ments ; the spines not forming a very thick brush on the 
anterior ramus. Both rami of third cirrus with a longi- 
tudinal roAV of minute spines, parallel to the main pairs. 
Between the bases of the pedicels of the first pair of cirri, 
there are two closely approximate, conical flattened pro- 
tuberances, like the single one to be described in Ibla, 

Caudal Appendages, about one third of the length of 
the pedicel of the sixth cirrus, with some moderately long 
and strong spines at the end, and down the whole outer 
sides. 

Ova, much pointed. Penis, hairy. 



P^ECILASMA AURANTIA. 105 

Size. — Capitulum in largest specimens half an inch 



long. 



2. PtECILASMA AURANTIA. PL II, Fig. 2. 

P. valvis 5 ; carina basi truncate! : scutis ovatis, 
margine basali perbrevi, dentibus parvis, intemis, umbo- 
nalibus instructo : tergorum acumine basati peroblique 
truncato. 

Valves 5 ; carina with a truncated base ; scuta oval, 
with the basal margin very short, furnished with small 
internal umbonal teeth ; terga, with the basal point very 
obliquely truncated. 

Maxillae with fine spines in the notch under the three 
great upper spines; caudal appendages with scattered 
bristles on their summits, and along only the upper part 
of their outer margins. 

Madeira; found by the "Rev. R. T. Lowe, attached to the rare Homola 
Cuvierii, probably a deep-water crab. British Museum. 

General Appearance. — This species so closely resembles 
P. Kcempferi, that it is superfluous to describe it in 
detail ; and I will indicate only the points of difference. 
When the valves have been well preserved, they are of 
fine pale orange colour, and hence the name above given, 
which was proposed by the Rev. R. T. Lowe. 

Scuta, with the internal umbonal teeth small; basal 
internal marginal rim very prominent, furrowed within ; 
basal margin short, (only equalling half the length of 
terga), owing to the great curvature of the lower part of 
the carino-tergal margin ; hence, the outline of the scuta 
is almost pointed oval. I saw no appearance of ine- 
quality in the two sides. 

Terga, rather smaller in proportion to the scuta, than in 
P. Kcempferi, with the basal end very obliquely truncated, 
so as to appear at first simply pointed, not parallel to the 
occludent margin ; apex considerably more pointed and 
produced than in the foregoing species. 



106 P.ECILASMA AURANTIA. 

Carina, almost of equal narrowness throughout, barely 
concave within ; lower end triangular, abruptly truncated, 
and not crested. 

Primordial valves very plain, with the usual hexagonal 
structure : those of the terga, rounded at both ends, in- 
stead of being square, as in the mature calcified valves. 

Peduncle short, narrow, not half as long as the capi- 
tulum ; paved with minute equal beads, as in the genus 
Dichelaspis. 

Mouth. — Mandibles with the fourth tooth very small ; 
inferior angle rudimentary. Maxillae, with three great 
upper spines, beneath which there is a deep notch bear- 
ing some delicate spines ; inferior upraised part, as in 
P. Kcempferi. 

Cirri. — Rami of first cirrus hardly more than one 
third as long as the rami of the second cirrus, which 
latter rami are unequal in length by only two segments ; 
the posterior ramus being the longer one. 

Caudal Appendages, with only two or three lateral 
bristles, besides those on the summit. 

Size. — Capitulum, three to four tenths of an inch long. 

General Remarks. — This species has the closest general 
resemblance to P. Kcempferi, and is evidently a repre- 
sentative of it. On close examination, however, almost 
every part differs slightly ; the chief points being the 
narrowness of the basal margin of the scuta ; the oblique- 
ness of the truncated basal end of the terga and the 
sharpness of the upper end ; the rudimentary state of 
the inferior angle of the mandibles ; the character of 
the spines on the maxillae \ the proportional lengths of 
the cirri, and the fewness of the spines on the outer 
sides of the caudal appendages. The fact of Madeira 
having this Paecilasma, a representative both in structure 
and habits of a Japan species, is interesting, inasmuch, 
as I am informed by Mr. Lowe, that some of the Madeira 
fishes are analogues of those of Japan. 



P^ECILASMA CRASS A. 107 



3. PiECILASMA CRASSA. PL II. Fig. 3. 

Anatifa crassa. /. E. Gray. Proc. Zoolog. Soc, 1848, p. 44, 
Annulosa, Tab. iii, figs. 5, 6. 

P. valvis 5; camice termino basali in discum par- 
vum infossum producto : scutis converts, dentibus inter nis 
umbonalibus mdlis: tergis {XEne rudimentalibus, vice carina 
latioribus. 

Valves 5 ; carina with the basal end produced into a 
small imbedded disc; scuta convex, without internal 
umbonal teeth; terga almost rudimentary, scarcely broader 
than the carina. 

Spines on the segments of the posterior cirri arranged 
in single transverse rows. 

Madeira; attached to the Homola Cuvierii, Rev. R. T. Lowe. British 
Museum.* 

General Appearance. — Capitulum highly bullate, or 
thick. Valves rather thick, opaque, either pale or dark 
flesh-red, smooth, yet rather plainly striated from the 
umbones. There are a few very minute spines on the 
membranous borders of the valves. 

Scuta highly convex, broadly oval, apex broad rounded; 
basal margin narrow, much curved; no internal, um- 
bonal teeth ; basal internal rim strong, running up part 
of the occludent margin. A slightly prominent ridge, 
either rounded or angular, but in one specimen a 
narrow depressed fissure-like line, runs parallel to the 
occludent margin and ends near the apex in a slight 
notch ; this fact is of interest in relation to the structure 
of the scuta in P. eburnea and P.Jlssa. The scuta are 
either equally or very unequally convex; in the latter case, 
the occludent margin of one valve is curled, so that its 
umbo is not quite medial. 

* It is stated, in ' Zoolog. Proc./ (1848, p. 44,) that this species was 
attached to a gorgonia, from Madeira ; I cannot but suspect that there 
has been some confusion with the Oxynaspis celata from Madeira, which is 
thus attached. 



108 P^ECILASMA CRASSA. 

Terga, minute, almost rudimentary, scarcely broader 
than the carina, and half as long as the chord of its arc ; 
carinal margin slightly curved ; scutal margin straight, 
with a slight prominence fitting into a notch in the scuta ; 
basal end bluntly pointed. 

Carina, (fig. 3, a) rather shorter than the scuta, 
extending up only to the basal ends of the terga; 
moderately curved ; apex moderately sharp ; middle part 
broadest, externally carinated; internally not concave, 
with the inner lamina of shell, at the basal end, pro- 
duced into a very small oblong disc or tooth, which is 
only as wide as the narrowest upper part of the valve. 
The exterior keel does not extend on to this disc, which 
is slightly constricted at its origin. 

Peduncle very short, narrow, ringed, and apparently 
without spines. 

Size. — Capitulum four tenths of an inch long. 

The following parts of the animal are described from 
some small and not well preserved specimens from 
Madeira, which I owe to the kindness of Mr. Lowe. 

Mouth. — Labrum highly bullate in the upper part, 
with large, inwardly pointed, unequal teeth. Mandibles, 
with four large, pointed, equal- sized teeth, with the inferior 
angle very narrow, acuminated like a single spine. 
Maxillae, with three (?) large upper spines, of which the 
middle one is extremely strong and long, beneath which, 
there is a deep notch with a single strong spine, and 
with the whole inferior part square and much upraised, 
so as to stand on a level almost with the tips of the great 
upper spines. 

Cirri in a miserable state of preservation ; first cirrus 
short, second cirrus with rami unequal, and I suspect the 
anterior one the longest ; some of the other cirri also 
have unequal rami. The segments of the posterior 
cirri are not protuberant, they have on their anterior 
faces a single transverse row of bristles : in the upper 
segments, some of the spines in each dorsal tuft (which 
is much spread out), are much thicker, though rather 



P^ECILASMA FISSA. 109 

shorter than those on the anterior face. This peculiar 
structure is common to all five posterior cirri. 

Caudal Appendages. — I can only say that they are 
spinose on their summits. 

Affinities. — This species is allied to P. eburnea in the 
rudimentary condition of its terga ; in the disc-shaped 
basal end of its carina ; and in the presence in some 
specimens, of a fissure-like line on the scuta parallel to 
their occludent margins. Its affinity, however, is closer 
to P. fssa, as is more especially shown by the remark- 
able arrangement of the spines on the five posterior cirri. 



4. P^CILASMA FISSA. PI. II, Fig. 4. 

P. valvis 7; scuto utroque e duobus juxtapositis segmentis 
formato ; segmento altero intus dentato : tergis brevibus, 
ier aut quater carina latioribus: carina termino basali in 
discum parvum angustum infossum producto. 

Valves 7 ; each scutum being formed of two closely 
approximate segments; of which one is internally toothed: 
terga short, three or four times as wide as the carina: 
carina with the basal end produced into a small, narrow, 
imbedded disc. 

Spines on the segments of the posterior cirri arranged 
in single transverse rows. 

Philippine Archipelago; Island of Bohol; parasitic on a spinose crab, 
found under a stone at low water ; single specimen, in Mus., Cuming. 

General Appearance. — Capitulum gibbous, broadly 
oval, nearly a quarter of an inch long. Valves white, 
smooth, moderately thick, marked by the lines of growth. 
The occludent segments of the scuta, and nearly the 
whole of the terga, and the whole of the carina, enveloped 
in lemon-yellow membrane, tinged with orange, but the 
specimen had long been kept dry. 

Scuta formed of two, apparently always separate, 
segments, closely united, so that externally their separa- 



110 P.ECILASMA FISSA. 

tion is hardly visible, and does not allow of movement ; 
the fissure thus formed runs almost in the line connecting 
the umbo and apex, (where in most species a ridge 
extends,) but a little on the carina! side of it. The 
occludent segment is narrowly bow-shaped, pointed at 
both ends, with the upper end projecting slightly beyond 
the apex of the lateral segment, and with the occludent 
margin regularly curved from end to end. The lateral 
segment is large, of an oval shape, with a narrow strip 
cut off on one side. Primordial valves very plain at the 
umbones of the lateral segments, but none are visible on 
the occludent segments ; and this makes me believe that 
these two pieces are normally parts of a single valve; 
having only one specimen of P. Jissa, I was not able to 
make out quite certainly whether the two segments are 
continuously united at their umbones by a non-calcified 
portion of valve, as is certainly the case with Dichelaspis. 
The basal margin of the lateral segment is narrow, 
inflected, and blends with the carino-tergal margin; it 
has an internal, prominent, basal rim, and towards the 
occludent margin a large, prominent; internal tooth. This 
internal basal rim is not parallel to the outer basal 
margin, but rises to a point a little way up the occludent 
margin, in the same manner as in P. eburnea, but in 
a lesser degree; in this latter species the peduncle is 
internally almost cut off by the large disc of its carina ; 
here, on the other hand, it is internally almost cut off by 
these rims and the two large teeth of the lateral segments 
of the scuta. 

Terga sub-triangular, short, nearly half as broad as 
long ; three or four times as wide as the carina, and rather 
wider than the occludent segment of the scuta; occludent 
margin single, arched; carinal margin slightly arched; 
basal angle bluntly pointed. 

Carina very narrow, much arched, running up just 
between the basal ends of the terga ; exterior ridge en- 
veloped in membrane ; heel blunt, prominent ; internally, 
not concave, even slightly convex, produced at the lower 



P^ICILASMA FISSA. Ill 

end into a very narrow, short, imbedded disc, (or rather 
tooth,) which is itself a little curved downwards and 
blunt at the end. 

Peduncle very narrow, about half as long as the 
capitulum ; yellow, finely beaded, plainly ringed, without 
spines. 

Mouth. — Labrum, with a row of minute teeth ; palpi 
narrow. Mandibles with all the lower part narrow ; of 
the four teeth, the second and third are narrow, the 
fourth is pectinated and placed very close to the inferior 
angle, which is produced into a long thin tooth. Maxillae 
unknown. 

Cirri. — First pair lost. The arrangement of the spines 
on all is most abnormal, PL X, fig. 29 : dorsal tuft long, 
arranged in a transverse line and seated in a deep notch ; 
in the sixth cirrus, the spines on the lower segments are 
fine, those on the upper segments are thick and claw- 
like, mingled with some fine spines ; in the four anterior 
cirri the spines of the dorsal tufts are even thicker 
and more claw-like. On the anterior faces, also, of all 
the segments the spines form a single row; they are 
shorter than those composing the dorsal tuft ; hence the 
spines on each segment are arranged in a circle, inter- 
rupted widely on the two sides : this arrangement is 
common to all five posterior cirri. Second cirrus, with 
the anterior ramus one third longer and thinner than 
the posterior ramus (this is the reverse of the usual 
arrangement) ; this longer ramus equals in length the 
sixth cirrus. Third cirrus, with the anterior ramus con- 
siderably longer than the posterior ramus ; in the three 
posterior pair of cirri, also, the anterior rami are a little 
longer than the posterior : except in length, there is 
little difference of any kind between the five posterior 
pair of cirri. Pedicels of the cirri long; rami rather 
short ; segments elongated, not protuberant. 

Caudal Appendages nearly as long as the pedicels of the 
sixth cirrus, thickly clothed with very fine bristles, like a 
camel's-hair pencil brush. 



112 PtECILASMA EBURNEA. 

Affinities. — In the structure of the carina, and more 
especially of the scuta, there is a strong affinity between 
the present and following species ; for we shall imme- 
diately see that in P. eburnea there is evidence of the 
scuta being composed of two segments fused together ; 
and the larger segment is furnished with an internal 
oblique, strong, basal rim. To this same species there is 
an evident affinity in the form of the mandibles and of the 
caudal appendages, and in the anterior rami of the cirri 
being longer than the posterior rami. Notwithstanding 
these points of affinity, I consider that P. fissa is more 
closely related in its whole organisation, as more par- 
ticularly shown in the arrangement of the spines on the 
cirri and in the presence of terga, to P. crassa than to 
P. eburnea. Although in Dichelaspis, the scuta are 
invariably composed of two almost separate segments, 
yet P. fissa shows no special affinity to this genus. 



5. P^CILASMA EBURNEA. PI. II, Fig. 5. 

Trilasmis eburnea. Hinds. Voyage of Sulphur, 1844, vol. i, 
Mollusca, PI. xxi, fig. 5. 

P. valvis 3 ; scutis acumi?iatis, ovatis; ad pedunculum 
pane transverse spectantibus ; dentibus internis umbo- 
nalibus fortibus : tergis nullis : carina termino basali in 
discum amplum oblongum infossum producto. 

Valves 3 ; scuta pointed, oval, placed almost trans- 
versely to the peduncle ; internal umbonal teeth strong : 
terga absent : carina with the basal end produced into a 
large, oblong, imbedded disc. 

Spines on the upper segments of the posterior cirri, 
arranged in three or four approximate longitudinal rows, 
making small brushes. 

Habitat. — New Guinea, attached to the spines of a dead Echinus. Brit. 
Mus., and Cuming. 

General Appearance. — Capitulum flat, pear-shaped, 



PjECILASMA eburnea. 1 13 

placed almost transversely to the peduncle. Valves 
white, smooth, moderately thick. 

Scuta: the basal margin, as seen externally, is narrow, 
and can hardly be separated from the carinal margin ; 
but an internal basal rim, (fig. 5, b) (along which the 
imbedded disc of the carina runs,) shows where, in 
the other species, the basal and carinal margins are 
separated. This basal internal rim is not parallel to the 
external basal margin, but runs upwards to the occludent 
margin, leaving beneath it a large triangular space, to 
which the membrane of the peduncle is attached ; and 
this makes it appear as if the rostral umbones of these 
valves had grown downwards ; but, judging from the 
allied species, P.fissa, I have no doubt that the pri- 
mordial valves really lie on the umbones, and that the 
growth has been in the usual direction, that is, exclu- 
sively upwards. The occludent margin is curved, and 
blends by a regular sweep into the carinal margin, so 
that there is no acute upper angle. A distinct line can 
be seen, as if two calcareous valves had been united, 
running from the umbo to the upper end of the valve, 
thus in appearance separating a slip of the occludent 
margin ; internally this appearance is more conspicuous ; 
this structure is important in relation to that of P. fissa. 
The pointed umbones are divergent, and internally under 
each, there is a large tooth. The two valves are equally 
convex. 

Terga, entirely absent. 

The Carina (Tab. II, fig. 5, a, c), including the disc, 
is three fourths as long as the scuta ; it is placed almost 
transversely to the longitudinal axis of the peduncle ; it is 
narrow and internally convex ; the imbedded disc is very 
large, forming a continuous curve with the upper part of 
the carina j this disc runs along the internal basal rim of 
the scuta, and hence almost separates, internally, the 
peduncle from the capitulum ; it equals one fourth of the 
total length of the valve, and is thrice as wide as the 
upper part; it is oval, externally marked by a central 

8 



114 P^ECILASMA EBURNEA. 

line, and with a slight notch at the end, giving a divided 
appearance to the whole, and indicating how easily a fork 
might be formed from it. The carina is thick, measured 
from the inner convex to the exterior surface, which is 
carinatecl ; heel prominent. 

Peduncle, narrow, very short, not nearly so long as the 
capitulum. 

Mouth. — Labrum considerably bullate, with the lower 
part much produced towards the adductor muscle ; crest 
with small bead-like teeth; palpi small, pointed; man- 
dibles, with the first tooth standing rather distant from 
the second ; inferior angle spine-like and bifid ; maxillae 
(PL X, fig. 15), with two considerable spines (only one is 
shown in the Plate) beneath the upper large pair; the 
inferior upraised part bears seven or eight pair of spines, 
and its edge is not quite straight; close to the main 
notch, lying under the four upper spines, there are two 
minute notches, with the interspace bearing a tuft of fine 
spines and a pair of larger ones. 

Cirri. — The rami in all are rather unequal in length, 
the anterior rami being rather the longest ; the anterior 
rami of the second and third cirri are not thicker than 
the posterior rami. The segments in the three posterior 
cirri are not protuberant ; the upper segments bear three 
or four pair of spines, with some minute intermediate 
ones, and with the lateral marginal spines unusually large 
and long, so as to form, with the ordinary pairs, a third 
or fourth longitudinal row ; hence a small brush is formed 
on each segment. The dorsal tuft is large and wide, so as 
to contain even fourteen spines, of which some are as long 
as those in front. In the lower segments of these same 
posterior cirri, the lateral marginal spines are not so much 
developed (nor is the dorsal tuft), and hence the segments 
can hardly be said to be brush-like. The first cirrus is 
placed rather distant from the second pair. The second 
and third cirri differ from the three posterior pair, only 
in the bristles being slightly more numerous, and in the 
dorsal tufts being more spread out. 



GENUS DICHELASPIS. 115 

Caudal Appendages about half the length of the lower 
segments of the pedicels of the sixth cirrus ; truncated and 
rounded at their ends; thickly clothed with long excessively 
fine bristles, so as to resemble camel-hair pencils. 

The Stomach, I believe, is destitute of caeca ; in it was 
a small crustacean. 

General Remarks. — I was at first unwilling to sacrifice 
Mr. Hind's genus, Trilasmis, which is so neatly cha- 
racterised by its three valves ; moreover, the present 
species does differ, in some slight respects, from the 
other species of Psecilasma; but under the head of 
P. jissa I have shown how that species, P. crassa and 
P. eburnea are tied together. The absence of terga, 
which are rudimentary in P. crassa, (and we shall here- 
after see, in Conchoderma, how worthless a character their 
entire absence is,) and the arrangement of the spines 
in the upper segments of the posterior cirri, are the only 
characters which could be used for a generic separation. 



Genus — Dichelaspis. Plate II. 

Octolasmis. * /. E. Gray. Annals of Philosophy, vol. x, new series, 

p. 100, August 1825. 
Heptalasmis. Agassiz. Nomenclator Zoologicus. 

Vahce 5, qua fere pro septem haberi possent, scuto in 
segmenta plane duo, adangidum auteni rostralem conjuncta, 
diviso : carina pier unique sursiini inter terga externa, 
deorsum aid disco infosso autfurcd aut calyce terminata. 

* From hxrfkoa, bifid, and acnria, a shield, or scutum. The name Octo- 
lasmis was given by Mr. Gray under the belief that there were eight valves. 
Leach (as stated in the 'Annals of Philosophy/) had proposed, in MS., 
the name Heptalasmis, and this is now used in the British Museum by Mr. 
Gray, and thus appears in Agassiz's ; Nomenclator Zoologicus.' Although, 
strictly, there are only five valves, 1 continued to use, in my MS., the term 
Heptalasmis, until I examined the D. orthogonia, where it was so apparent 
to the naked eye that there were only five valves, the scuta in this species 
being less deeply bifid, that I was compelled to give up a name so mani- 
festly conveying a wrong impression, and hence adopted the one here used. 



116 GENUS— DICHELASPIS. 

Valves 5, generally appearing like 7, from each scutum 
being divided into two distinct segments, united at the 
rostral angle ; carina generally extending up between the 
terga, terminating downwards in an imbedded disc, or 
fork, or cup. 

Mandibles, with three or four teeth ; maxillae notched, 
with the lower part of edge generally not prominent; 
anterior ramus of the second cirrus not thicker than the 
posterior ramus, not very thickly clothed with spines ; 
caudal appendages uniarticulate, spinose. 

Distribution. — Eastern and Western warmer oceans in the Northern hemi- 
sphere, attached to Crustacea, sea-snakes, &c. 

Description. — The capitulum appears to contain seven 
valves ; but, on examination., it is found that two of the 
valves on each side, are merely segments of the scutum • 
these are united at the umbo, in three of the species, by a 
narrow, non-calcified portion of valve, where the primordial 
valve is situated ; in D. orthogonia^ however, the junction 
of the two segments is perfectly calcified, and of the 
same width as the whole of the basal segment. The 
capitulum is much compressed, broad at the base, and 
extends a little beneath the basal segments of the scuta. 
The valves are very thin, often imperfectly calcified, and 
generally covered with membrane. They are not placed 
very close together, and in all the species a considerable 
interspace is left between the carina and the two other 
valves : in the D. Grayii the valves are so narrow that 
they form merely a calcified border round the capitulum. 
The membrane between the valves and over them, is 
very thin, and is thickly studded, in some of the species, 
with minute blunt conical points, apparently representing 
spines. The valves in the same species present considerable 
variations in shape ; in their manner or direction of growth, 
and in the position of their primordial valves, they agree 
with Lepas and Paecilasma. 

Scuta. — In three of the species the two segments, 



GENUS — DICHELASPIS. 117 

named the occludent and basal, appear like separate 
valves, but these, by dissection, can be most distinctly 
seen to be united at the rostral angle. The primordial 
valve, formed of the usual hexagonal tissue, is elliptic, 
elongated, and placed in the direction of the occludent 
segment ; calcification commences at its upper point, so 
as to form the occludent segment, and afterwards at its 
lower point, but rectangularly outwards, to form the basal 
segment ; in the minute space between these two points 
of the primordial valve, there is, in four of the species, 
no calcification ; so that the two segments are united by 
what may be called a flexible hinge ; in D. ortltogonia the 
two calcareous segments are absolutely continuous. The 
occludent segment is longer than the basal segment ; it 
either runs close along the orifice, or in the upper part 
bends inwards ; both segments are narrow, except in 
B. Warwickii, in which the basal segment is moderately 
broad ; the two segments are placed at an angle, varying 
from 45° to 90°, to each other. The capitulum generally 
extends for a little space beneath the basal segments of 
the scuta, where it contracts to form the peduncle. 

The Terga present singular differences in shape, and 
are described under the head of each species ; scarcely 
any point can be predicated of them in common, except 
that they are flat and thin. 

The Carina is much bowed, narrow, and internally 
either slightly concave or convex and solid ; the upper 
end extends far up between the terga ; the lower end is 
formed by a rectangularly inflected, imbedded, triangular 
or oblong disc, deeply notched at the end, or as in 
H. Lowei, of a fork, the base, however, of which is wider 
than the rest of the carina, so as to present some traces of 
the disc-like structure of the other two species ; or lastly, 
as in D. ort/wgonia, it terminates in a crescent-formed 
cup. 

Peduncle. — This is narrow, compressed, and about as 
long, or twice as long, as the capitulum; in D.Warwickii 
it is studded with minute beads of yellowish chitine. 



118 GENUS DICHELASPIS. 

Size. — Small, with a capitulum scarcely exceeding a 
quarter of a inch in length. 

Filamentary Appendages. — None. There are two small 
ovigerous fraena, which, in D. Warwickii, had the glands 
collected in seven or eight little groups on their margins. 

Mouth. — Labrum highly bulla te, with small teeth on 
the crest ; palpi small, not thickly covered with spines. 
Mandibles narrow, with three or four teeth. Maxillae 
small, with a notch beneath the two or three great upper 
spines ; lower part bearing only a few pair of spines, 
generally not projecting, but in D. orthogonia largely 
projecting. Outer maxillae, with their inner edges con- 
tinuously covered with bristles. 

Cirri. — First pair short, situated rather far from the 
second pair; second pair with the anterior ramus not 
thicker than the posterior ramus, and hardly more thickly 
clothed with spines than it, excepting sometimes the few 
basal segments. All the five posterior pair of cirri re- 
semble each other more closely than is usual. In 
D. Lowei, the segments of the posterior cirri bear the 
unusual number of eight pair of main spines. 

Caudal Jppendages.— -Uni-articulate, spinose ; in D. 
pellucida they are twice as long as the pedicels of the 
sixth cirrus, but I could not perceive in them any distinct 
articulations. 

Distribution. — Attached to crabs at Madeira, and off Borneo; to sea- 
snakes in the Indian Ocean. The individuals of all the species appear to be 
rare. 

General Remarks. — Foui of the five species, forming 
this genus, though certainly distinct, are closely allied. I 
have already shown, that although the characters separating 
Lepas, Paecilasma, and Dichelaspis are not very im- 
portant, yet if they be neglected these three natural little 
groups must be confounded together. Dichelaspis is 
much more closely united to Paecilasma than to Lepas, 
and, as far as the more important characters of the 
animal's body are concerned, there is no important dif- 



GENUS DICHELASPIS. 119 

ference between them. Consequently, I at first united 
Psecilasma and Dichelaspis, but the latter forms so natural 
a genus, and is so easily distinguished externally, that I 
have thought it a pity to sacrifice it. The carina, (which 
seems to afford better characters than the other valves in 
Dichelaspis,) from generally running up between the terga 
and in ending downwards, in three of the species, in a 
deeply notched disc or fork, more resembles that in 
Lepas than in Paecilasma ; in the manner, however, in 
which the imbedded disc, in D. Wanvic/m and D. Grapi, 
nearly cuts off the inside of the capitulum from the 
peduncle, there is a resemblance to Pcecilasma eburnea. 
In the extent to which the valves are separated from 
each other, in the bilobed form of the scuta, (the two 
segments in Dichelaspis, perhaps, answering to the upper 
and lateral projections in the scuta of Conchoderma vir- 
gata^) and in the basal half of the scuta not descending 
to the base of the capitulum, there is a considerable re- 
semblance to Conchoderma ; in both genera the adductor 
muscle is attached under the umbones of the scuta ; but 
the structure of the mouth and cirri and caudal appendages 
shows that the affinity is not stronger to Conchoderma than 
to Lepas. It appears at first probable, that Dichelaspis 
would present a much closer affinity to Pcscilasmajissa, in 
which, owing to the scuta being formed of two segments, 
there are seven valves, than to any other species of 
that genus ; but in P.fissa the primordial valve is trian- 
gular and is situated on the basal segment, whereas, in 
Dichelaspis, it is elliptic and is seated between the two 
segments, and is more in connection with the occludent 
than with the basal segment ; and this I cannot but think 
is an important difference : in other respects, P. fissa 
shows no more affinity to Dichelaspis than do the other 
species of the genus. Finally, I may add that Dichelaspis 
bears nearly the same relation to Psecilasma, as Con- 
choderma does to Lepas. 



] 20 DICHELASPIS WARWICKII. 



1. Dichelaspis Warwickii. PL II, figs. 6, 6 a, b. 

Octolasmts Warwickii. /. B, Gray. Annals of Philosophy, 
vol. x, p. 100, 1825 ; Spicilegia Zoologica, t. vi, fig. 16, 1830. 

D. scutorum segmento basali duplo latiore quam seg- 
mentum occludens : tergorum parte inferior e paulb latiore 
quam occludens scutorum segmentum. 

Scuta, with the basal segment twice as wide as the 
occludent segment; terga, with the lower part slightly 
wider than the occludent segment of the scuta, 

Mandibles, generally with four teeth. 

Off Borneo, attached to a crab (Belcher) : China Sea. British Museum. 

General Appearance. — Capitulum much compressed, 
elongated, with the valves not very close together, the 
carina being separated by a rather wide space from the 
scuta and terga. Valves variable in shape, very thin and 
translucent, covered by thin membrane, which, over the 
whole capitulum, is studded with minute blunt points. 

Scuta. — Segments without internal teeth or an internal 
basal rim ; the occludent segment long, narrow, pointed, 
not quite flat, sometimes slightly wider in the upper 
part; about one third of its own length longer than 
the basal segment; occludent margin slightly arched; 
basal segment about twice as wide as the occludent seg- 
ment, triangular, slightly convex ; in young specimens 
(PL II, fig. 6 b), the carinal margin of the basal segment 
is protuberant, and the occludent margin hollowed out ; in 
old specimens the occludent margin of the basal segment 
is straight, and the carinal margin much hollowed out. 
In very young specimens the basal segment is very small 
compared to the occludent. 

Terga, variable in shape ; flat, lower part wider than 
the occludent segment of the scuta; occludent margin 



DICHELASPIS WARWICKII. 121 

double, forming a considerable rectangular projection, 
as in the terga of Lcpas ; scutal margin deeply excised at 
a point corresponding with the apex of the scuta, a flat 
tooth or projection being thus formed ; there is some- 
times a second tooth (fig. 6 b) a little above the basal 
point. The terga, in the first variety, somewhat resemble 
in shape the scuta of Conchoderma aurita. 

Carina, much bowed, narrow, slightly concave within, 
(in the Borneo specimen, rather wider and more con- 
cave,) extending up between the terga for half their 
length, terminating downwards in a rectangularly in- 
flected, deeply imbedded, oblong, rather wide, flat disc, 
at its extremity more or less deeply notched. This disc 
is externally smooth ; internally it sometimes has two 
divergent ridges on it; it extends across about two- 
thirds of the base of the capitulum (fig. 6 a, as seen 
from beneath, when the peduncle is cut ofT), to under 
the middle of the basal segments of the scuta. 

Peduncle, narrow, flattened ; united to the capitulum 
some little way below the scuta; about as long as the 
capitulum ; the membrane of which it is composed is 
thin, externally studded with bluntly conical beads of 
yellowish chitine, of which the largest were —^ of an 
inch in diameter; on their internal surfaces these are 
furnished with a small central, circular depression, appa- 
rently for a tubulus ; the arrangement of the beads varied 
in concentric zones. Similar conical points on the capi- 
tulum have an internal concave surface about ^ in 
diameter, with a central circle y^oo in diameter, for the 
insertion, as I believe, of a tubulus. 

Size. — The largest specimen had a capitulum a quarter 
of an inch long. 

Mouth. — Labrum highly bullate ; crest with not very 
minute, blunt teeth, which towards the middle lie closer 
and closer to each other, so as to touch. Palpi rather 
small, with a few very long bristles at the apex. 

Mandibles, narrow, produced, with four teeth, and the 
inferior angle tooth-like and acuminated ; in one spe- 



122 DICHELASPIS WARWICKII. 

cimen, on one side of the mouth, the mandible had only 
three teeth. 

Maxillce, small ; at the upper angle there are two large 
spines and a single small one, beneath which there is a 
deep notch, and beneath this a straight but projecting 
edge, bearing a few moderately large and some smaller 
spines. Outer maxillae sparingly covered with bristles 
along the inner margin. 

Cirri. — First pair far removed from the second pair, 
and not above half their length ; segments rather broad, 
with transverse rows of bristles not very thickly crowded 
together ; terminal segments very obtuse, and furnished 
with thick spines. The segments of the three posterior 
pair have each three or four pair of spines, with a few 
minute spines scattered in an exterior, parallel, longi- 
tudinal row ; dorsal tufts, with four or five long spines. 
The second cirrus has its anterior ramus not thicker, 
but rather shorter than the posterior ramus ; the former 
is only a little more thickly clothed with spines, owing 
to those in the longitudinal lateral row being longer and 
more numerous, than is the sixth pair of cirri. Bristles 
not serrated. 

Caudal Appendages, narrow, thin, slightly curved, about 
half as long as the pedicels of the sixth cirrus ; in young 
specimens, the appendage bore seven or eight pair of long- 
bristles rectangularly projecting; in some older specimens, 
there was a tuft of bristles on the summit, and two 
other tufts on the sides. 

I at first thought that the Borneo specimen was a 
distinct species, but after careful comparison of the ex- 
ternal and internal parts, the only difference which I can 
detect is, that the terga are slightly larger, and that the 
carina, to a more evident degree, is wider, more especially 
in the middle and lower portions. 



DICHELASPIS GRAYII. 123 



2. DlCHELASPIS Grayii. PI. II, fig. 9. 

D. scutorum segmento basalt angustiore quam seg- 
mentum occludens; longitudine pcene dimidid: tergis bi- 
pen?iiformibus, margin e crenato, spina posticd, manubrio 
angustiore quam occludens scutorum segmentum. 

Scuta, with the basal segment narrower than the occlu- 
dent segment, and about half as long as it. Terga like 
a battle-axe, with the edge crenated and a spike behind ; 
the handle narrower than the occludent segment of the 
scuta. 

Mandibles with three teeth ; cirri unknown. 

Attached to the skin of a sea-snake, believed to have been the Hydeus or 
Pelamis bicolor, and therefore from the Tropical, Indian or Pacific Oceans ; 
associated with the Conchoderma Hunteri ; single specimen, in a very bad 
condition, in the Royal College of Surgeons. 

General Appearance. — Capitulum much compressed, 
elongated,, formed of very thin membrane, with the valves 
forming round it a mere border. Valves thin, imper- 
fectly calcified, covered with membrane. 

Scuta formed of two narrow plates at very nearly 
right-angles to each other, one extending along the 
occludent, and the other along the basal margin ; both 
become very narrow at the point of junction, and are 
there not calcified, but are evidently continuous and form 
part of the same valve ; the basal segment is about half 
as long and narrower than the occludent segment, flat 
and bluntly pointed at the end; occludent segment 
slightly curled, and therefore the whole does not lie 
quite in the same plane; narrow close to the umbo, 
with a very minute tooth on the under side ; apex 
rounded. In the upper part, the occludent segments 
leave the membranous margin of the orifice, and run in 
near to the terga, bending towards them at an angle of 
45° with their lower part. I was unable to distinguish 
the primordial valves. 



124 DICHELASPIS GRAYII. 

Terga. — These valves are of the most singular shape, 
resembling a battle-axe, with a flat and rather broad 
handle ; the upper part consists of an axe, with a broad 
cutting crenated edge, behind which is a short blunt 
spike. The spike and cutting edge together answer to 
the double occludent margin of the tergum in Lepas. 
The whole valve is flat, thin, and lies in the same plane ; 
the carinal margin is nearly straight ; the scutal margin 
bulges out a little, and at a short distance above the blunt 
basal point is suddenly narrowed in, making the lower- 
most portion very narrow ; the widest part of the handle 
of the battle-axe, is narrower than the occludent segment 
of the scuta. The two spikes behind the cutting and 
crenated edges of the two terga, are blunt and almost 
touch each other ; above their point of juncture, the mem- 
brane of the orifice forms a slight central protuberance. 

Carina, very narrow throughout, concave within, much 
bowed ; upper point broken and lost, but it must have 
run up between the terga for more than half their 
length ; basal portion inflected at nearly " right angles, 
and running in between, and close below, the linear 
basal segments of the scuta, so as almost entirely to 
cut off internally the peduncle and capitulum. This 
lower inflected and imbedded portion, or disc, gradually 
widens towards its further end, which is, at least, four times 
as wide as the upper part of the carina, and is deeply 
excised, but to what exact extent I cannot state, as the spe- 
cimen was much broken. On each side of this elongated 
triangular disc, there is a slight shoulder corresponding 
to the ends of the basal segments of the scuta; and on 
the upper surface of each shoulder, there is a small tooth 
or projection. The middle part of the disc is barely 
calcified, and is transparent. 

Peduncle, rather longer than, and not above half as 
wide as, the capitulum; the latter being nearly T Vths 
of an inch in length • the membrane of the peduncle is 
thin, naked and structureless. 

Mouth. — Labrum highly protuberant in the upper part, 



DICHELASPIS PELLUCIDA. 125 

with a row of beads on the crest. Palpi small, with few 
bristles. Mandibles, with the whole inferior part, very 
narrow ; three teeth very sharp, with a slight projection, 
perhaps, marking the place of a fourth tooth ; inferior 
angle ending in the minutest point ; first tooth as far 
from the second, as the latter from the inferior angle. 
MaxillcB with a broad shallow notch ; inferior angle much 
rounded, bearing only four or five pair of spines. 

Cirri. — First pair apparently remote from the second 
pair ; all five posterior pair lost ; first pair short, with 
the rami unequal by about two segments ; segments 
clothed with several transverse rows of bristles « terminal 
segments blunt. 



3. DlCHELASPIS PELLUCIDA. PL II, fig. 7. 

D. valvarum singidarum acuminibus superioribus ei 

inferioribus vice intersecantibus : senior urn segmento basali 

multo angnstiore quam segmentum occludens ; lo7igitudine 

fere dimidid : tergis bipenniformibus, margine integro, 

manubrii acumine ad carinamjlexo. 

Valves with the upper and lower points of the several 
valves only just crossing each other. Scuta with the basal 
segment much narrower than the occludent segment, and 
about half as long as it. Terga like a battle-axe, with 
the edge smooth, and the point of the handle bent to- 
wards the carina. 

Mandibles with four teeth ; caudal appendages twice 
as long as the pedicels of the sixth cirrus. 

Indian Ocean ; attached to a sea-snake. 

This species comes very close to the D. Gragii, which 
likewise was attached to a snake ; but I cannot persuade 
myself, without seeing a graduated series, that the differ- 
ences immediately to be pointed out can be due to 
ordinary variation. I am much indebted for specimens 
to the kindness of Mr. Busk. 



126 DICHELASPIS PELLUCIDA. 

General Appearance. — The membrane of the capitulum 
and peduncle is surprisingly thin and pellucid, so that 
the ovarian tubes within the peduncle can be traced with 
the greatest ease. The valves are small, the apices only 
just crossing each other, and are composed of yellow 
chitine, with mere traces of calcification. The capitulum 
is pointed, oval, -15 of an inch long; the peduncle is 
narrow, and fully twice as long as the capitulum. 

Scuta. — The two segments stand at right-angles to 
each other ; the basal segment is linear and pointed, 
fully half as long, but only one third as wide, as the 
occludent segment. The point of junction of the two 
segments is wider than the rest of the basal segment. 
This latter segment lies some little way above the top of 
the peduncle. The occludent segment is bluntly pointed ; 
it is directed a little inwards from the edge of the orifice 
towards the terga ; the apex readies up just above the 
slightly reflexed lower point of the terga. The adductor 
muscle is fixed under the point of junction of the two 
segments. 

The Terga are battle axe-shaped, with the blade part 
very prominent, smooth-edged ; behind the blade there is 
a short upwardly-turned prominence. The lower point 
of the handle of the axe, is bent towards the carina. The 
terguni, measured in a straight line, equals in length 
two thirds of the occludent segment of the scutum, the 
handle being rather narrower than this same segment. 

The Carina is extremely narrow and much bowed ; the 
apex reaches up only to just above the lower bent points 
of the terga. The basal end is rectangularly inflected, and 
stretches internally nearly across the peduncle; it consists 
(fig. la) of a triangular disc of yellow thin membrane, 
four or five times as wide as the upper part of the valve ; 
the end of this disc is hollowed out ; its edges are thick- 
ened and calcified, and hence, at first, instead of a disc, 
this lower part of the carina appears like a wide fork ; 
the tips of the prongs stretch just under the tips of the 
basal segments of the scuta. 



DICHELASPIS PELLUCIDA. 127 

Peduncle. — Its narrowness and transparency are its 
only two remarkable characters. 

Mouth. — All the parts closely resemble those of 
B. Grayii, but being in a better state of preservation I 
will describe them. The labrum is highly bullate, with 
a row of minute teeth on the crest, placed very close 
together in the middle. Palpi small, thinly clothed with 
spines ; mandibles extremely narrow, hairy, with four 
teeth, but the lower tooth is so close to the inferior 
angle, as only to make the latter look double. Maxillae, 
with a very deep broad notch, dividing the whole into 
two almost equal halves ; in the upper part there are 
three main spines. 

Cirri. — The first pair are placed at a considerable dis- 
tance from the second pair ; they are short with equal 
rami, and rather broad segments furnished with a few 
transverse rows of bristles. The five posterior cirri have 
singularly few, but much elongated segments, bearing 
four pair of spines : the two rami of the second pair are 
alike, and differ only from the posterior cirri in a few 
of the basal segments having a few more spines. 

The Caudal Appendages are twice as long as the pedi- 
cels, and nearly half as long as the whole of the sixth 
cirrus ; they have a small tuft of long thin spines at their 
ends, and a few in pairs, or single, along their whole 
length ; at first I thought that they were multi- articulate, 
but after careful examination I can perceive no distinct 
articulations ; I have seen no other instance of so long 
an appendage without articulations. 

Diagnosis. — This species differs from D. Grayii in all 
the valves being shorter, so that their points only just 
cross each other ; but this, I conceive, is an unimportant 
character. In the scuta, the basal segment is here nar- 
rower, but the point of junction of the two segments 
wider than in that species ; in the terga, the edge of the 
axe is smooth instead of being crenatecl, and the handle 
and the point behind are of a rather different shape ; in 
the carina the imbedded basal disc has not shoulders and 



128 DICHELASPIS L0WE1. 

small teeth, as in B. Grayii. Notwithstanding these 
differences, I should not be much surprised if the present 
form were to turn out to be a mere variety. 



4. Dichelaspis Lowei. PL II, fig. 8. 

D. scutorum segmento basali angustiore quam occlu- 
ders segmentum, longitudine fere f : tergorum parte in- 
feriori duplo latiore quam occludens scutorum segmentum. 

Scuta with the basal segment narrower than the occlu- 
dent segment, and about four-fifths as long as it. Terga 
with the lower part twice as wide as the occludent seg- 
ment of the scuta. 

Mandibles with four teeth ; segments of the three pos- 
terior cirri with eight pair of main spines. 

Hab. — Madeira; attached to a rare Brachyourous Crab, discovered by 
the Rev R. T. Lowe. Yery rare. 

General Appearance. — Capitulum much compressed, 
sub -triangular, formed of very thin membrane ; valves im- 
perfectly calcined, and thin. 

Scuta formed of two narrow plates placed at about an 
angle of 50° to each other, and united at the umbo by a 
non-calcified flexible portion. The primordial valve is 
situated at this point, but chiefly on the occlnclent seg- 
ment. The occludent segment is about twice as wide 
and about one fifth longer than the basal segment, which 
latter is rather sharply pointed at its end. The occludent 
segment is slightly arched, a little narrowed in on the 
occludent margin close to the umbo ; its upper end is 
broad and blunt ; it runs throughout close to the edge of 
the orifice of the sack, and its longer axis is in the same 
line with that of the terga. Close to the umbones, on 
the under side of the basal segment, there is, on each 
valve, a longitudinal calcified fold, serving as a tooth. 



DICHELASPIS LOWEI. 129 

Terga broad, with a deep notch corresponding to the 
apex of the occludent segment of the scuta; the part 
beneath the notch is of nearly the same width throughout, 
and is twice as broad as the occludent segment of the 
scuta ; it has its basal angle very broad and blunt. The 
entire length of the terga equals two thirds of that of the 
occludent segment of the scuta ; occludent margin simply 
and slightly curved. 

The Carina is of nearly the same width throughout, 
with the upper part rather the widest, and the apex 
blunt; within convex; it extends up between three fourths 
of the length of the terga, terminating downwards in a 
fork with very sharp prongs, standing at right-angles to 
each other (fig. 8 a.) The fork, measured from point to 
point, is thrice as wide as, and measured across at the 
bottom of the prongs it is wider than, the widest upper 
part of the valve, — a resemblance being thus shown with 
the triangular notched disc in D. Grayii. The points 
of the prong extend under about one fourth of the length 
of the basal segments of the scuta. 

Peduncle rather longer than the capitulum, which, in 
the largest specimen, was ^ths of an inch in length ; 
peduncle narrow, close under the capitulum ; membrane 
thin and structureless. The larger specimen had almost 
mature ova in the lamellae. 

Mouth. — Labrum with a few bead-like teeth on the 
crest, distant from each other even in the central part ; 
palpi rather small, moderately clothed with bristles. 

Mandibles, with four teeth; the inferior angle blunt 
and broad, showing, apparently, a rudiment of a fifth 
tooth ; the first tooth is as far from the second, as is this 
from the inferior angle ; second, third, and fourth teeth 
very blunt, whole inferior part of mandible not much nar- 
rowed. Maxillae small, with a small notch under the 
three upper spines, which are followed by five or six pair, 
nearly as large as the upper spines. 

Cirri. — First pair remote from the second ; their rami 
nearly equal, and about one third of the length of the 

9 



130 DICHELASPIS ORTHOGONIA. 

rami of the second cirrus ; thickly clothed with bristles : 
rami of the second cirrus of equal thickness, but little 
shorter than those of the sixth cirrus ; the three or four 
basal segments of the anterior ramus are thickly clothed 
with spines ; the other segments, and all the segments 
on the third pair, resemble the segments of the three 
posterior pair. These latter are elongated, not pro- 
tuberant, and support eight pairs of spines with very 
minute intermediate spines ; those in the dorsal tufts are 
numerous and long. 

Caudal Appendages nearly as long as the pedicels of the 
sixth cirrus ; oval, moderately pointed, with their sides, 
for one fourth of their length, thickly clothed with long 
very thin spines. 

Affinities. — In the form of the scuta and of the carina 
this species is most nearly allied to D. Grayii or D. pel- 
htcida, in the form of the terga to D. WarwicTcii. 



5. DlCHELASPIS ORTHOGONIA. PI. II, fig. 10. 

D. scutorum basali segmento angustiore quam occludens 
segmentum ; longitudine fere dimidid ; duorwm segmentorum 
junctione calcared : tergorum prominentiis marginalibus 
incequalibus quinque : carina deorsimi in parvo calyce 
lunato terminatd. 

Scuta with the basal segment narrower than the 
occludent segment, and about half as long as it ; junction 
of the two segments calcified. Terga with five unequal 
marginal projections. Carina terminating downwards in 
a small crescent- formed cup. 

Maxillae with the inferior part of edge much upraised. 

Hab. unknown ; associated with Scalpellum rutilum, apparently attached 
to a horny coralline. British Museum. 

The specimens are in a bad condition, not one with 
all the valves in their proper positions, and most of them 
broken ; animal's body much decayed and fragile. 



DICHELASPIS ORTHOGONIA. 131 

General Appearance. — Capitulum apparently much 
flattened ; valves naked, coloured reddish, separated from 
each other by thin structureless membrane. 

The Scuta consist of two bars placed at right-angles to 
each other, with the point of junction fully as wide as 
any part of the basal segment, and perfectly calcified ; 
the primordial valve lies at the bottom of the occludent 
segment. The basal segment is equally narrow through- 
out, and very slightly concave within ; the occludent 
segment widens a little above the junction or umbo, and 
then keeps of the same width to the apex, which is 
obliquely truncated j internally this segment is concave ; 
externally it has a central ridge running along it ; the 
occludent segment is twice as long and twice as broad as 
the basal segment. Both segments are a little bowed 
from their junction to their apices. 

Terga. — These are of a singular shape ; they are about 
three-fourths as long as the occludent segment of the 
scuta, and in their widest part, of greater width than it. 
They consist of four prominent ridges proceeding from 
the umbo, and united together for part only of their 
length, and, therefore, ending in four prominences ; one 
of these, the longest, has the same width throughout, 
and forms the basal point ; a second, very small one, is 
seated high up on the carinal margin just above the apex 
of the carina ; the third and fourth, are nearly equal in 
length, and project one above the other on the scutal 
margin. There are two occludent margins, meeting each 
other at right angles, and forming a prominence, as in 
Lepas ; and this gives to the margin of the valve the five 
prominences. The whole valve internally is flat ; exter- 
nally, it is ridged as described. 

Carina (fig. 10, a, 6), much bowed, narrow, long; 
externally, the central ridge is quite flattened ; internally, 
slightly concave, but scarcely so towards the lower part, 
which is narrow ; the upper part widens gradually, and the 
apex is rounded. The basal embedded portion is as 
wide as the uppermost part, and forms a cnp, unlike any- 



132 D1CHELASPIS ORTHOGONIA. 

thing else known : the outline of this cup is semi-oval and 
crescent-formed ; it is moderately deep ; it is formed by 
the external lamina of the carina bending rectangularly 
downwards and a little outwards, whereas the inner 
lamina of the lower part (which is slightly concave), is 
continued with the same curve as just above, and forms 
the concave chord to the semi-oval rim of the cup. This 
cup, I believe, lies under the points of the basal segments 
of the scuta. 

Peduncle unknown, probably short. 

Length of capitulum, above T Vths of an inch. 

Mouth. — Labrum with the upper part highly bullate, 
and produced into a large overhanging projection ; crest 
with a row of rather large bead-like teeth ; palpi small, 
their two sides parallel, very sparingly covered with long 
bristles. 

Mandibles, narrow, produced, with four teeth, and 
the inferior angle produced into a single strong spine : 
the distance between the tips of the first and second teeth 
almost equals that between the tip of the second tooth 
and of the inferior angle. 

Maxilla with three large upper unequal spines, beneath 
which, there is a deep and wide notch (bearing one spine), 
and the inferior part projects highly, bearing three or 
four pairs of spines, and is, itself, obscurely divided into 
two steps. 

Outer Maxilla, very sparingly covered with bristles ; 
outline, hemispherical. 

Cirri, — The rami of the five posterior pair are extremely 
long, as are the pedicels ; the segments are much elong- 
ated, with their anterior faces not at all protuberant; 
each bears five pair of very long and thin spines, with an 
excessively minute one between each pair ; the dorsal tuft 
consists of very fine and thin spines. The second cirrus 
has its anterior ramus not at all thicker than the posterior 
ramus ; but has an exterior third longitudinal row of 
small bristles. First cirrus, separated by a wide inter- 
val from the second pair ; very short with the two rami 



GENUS — OXYNASPIS. 133 

slightly unequal in length ; the segments are broad, and 
are paved moderately thickly with spines ; the terminal 
spines not particularly thick. 

Caudal Appendages consist of very small and narrow 
plates, about half the length of the pedicels of the sixth 
cirrus, with a few long spines at their ends. 

This well-marked species, I think, has not more affinity 
to one than to another of the previous species : it differs 
from all, in the junction between the two segments of the 
scuta being perfectly calcified ; in the peculiar cup, forming 
the base of the carina ; and lastly, in the inferior part of 
the maxillae projecting. 



Oxynaspis.* Gen. Nov. PL III. 

Valve 5, approximate i scutorum umbones in medio 
marginis occludentis positi : carina rectangulejlexa, sursicm 
inter terga externa, termino basali simpliciter concavo. 

Valves 5, approximate ; scuta with their umbones in 
the middle of the occluclent margin ; carina rectangularly 
bent, extending up between the terga, with the basal end 
simply concave. 

Mandibles with four teeth ; maxillae notched, with the 
lower part of edge nearly straight, prominent ; anterior 
ramus of the second cirrus thicker than the posterior 
ramus ; caudal appendages, uniarticulate, spinose. 

Attached to horny corallines. 

I have most unwillingly instituted this genus ; but it 
will be seen by the following description, that the one 
known species could not have been introduced into Lepas 
or Paecilasma, without destroying these genera, although 
it has a close general resemblance with both As far as the 
valves are concerned, it is more nearly related to Lepas 
than to Paecilasma; but taking the entire animal, its 

* From oZvvw, to sharpen, and ntm-ty, a shield or scutum. 



134 OXYNASPIS CELATA. 

relation is much closer to the latter genus than to Lepas i 
it differs from both these genera in the manner of growth 
of the scuta, which is both upwards and downwards, the 
primordial valve being situated in nearly the middle of 
the occludent margin. In this respect, and in the shape 
of the carina and terga, there is an almost absolute identity 
with Scalpellum ; I may, however, remark that in Scal- 
pellum, the scuta first grow downwards, and afterwards 
in most of the species upwards, whereas here from the 
beginning, the growth is both upwards and downwards. 
In the mouth and cirri, there is rather more resemblance 
to Scalpellum than to Psecilasma and Lepas : in habits, 
also, this genus agrees with Scalpellum, and if it had 
possessed a lower whorl of valves, it would have quite 
naturally entered that genus. It is unfortunate, that so 
insignificant and poorly characterised a form should require 
a generic appellation. In natural position, it appears to 
lead from Scalpellum through Psecilasma to Lepas. 



1. OXYNASPIS CELATA. PL III, fig. 1. 

Madeira; attached in numbers to an Antipathes; Rev. R. T. Lowe. 
Mus., Hancock, 

General Appearance. — The capitulum is rather thin, 
and broad in proportion to its length ; it seems always 
entirely covered by the horny muricated bark of the 
Antipathes, and hence externally is coloured rich brown 
and covered with little horny spines. The membrane 
over the valves is very thin, and is with difficulty sepa- 
rated from the Antipathes j it has, I believe, no spines of 
its own. The corium lining the peduncle is a fine 
purple. All the individuals are attached to the coralline, 
with their capitulums upwards in the direction of the 
branches, and in this respect fig. 1. is erroneous. 

The valves, when cleared of the bark, are white, or are 
strongly tinged with pinkish-orange. The upper parts 
of the scuta and terga are plainly furrowed in lines 



OXYNASPIS CELATA. 135 

radiating from their umbones ; hence their margins are 
serrated with blunt teeth; their surfaces, moreover, are 
sparingly studded with small calcareous points. 

Scuta (fig. 1, a), sub-triangular, with the lower part 
rounded and protuberant, the upper produced and pointed. 
The umbo is situated in the middle of the occludent 
margin, instead of at the rostral angle, as in the foregoing 
genera. The occludent margin is straight, and is bordered 
by a narrow step or ledge, formed of transverse growth- 
ridges, and therefore has its edge serrated : the rostral 
angle is often slightly produced into a small projection. 
The basal margin is short, and forms an angle above a 
rectangle with the occludent margin : the tergal margin 
is straight ; the carinal margin is rounded, protuberant, 
and of unusual length compared to the basal margin. The 
surface of the valve is convex near the umbo ; and beneath 
there is a large deep hollow for the adductor muscle. 

Terj/a (fig. 1, b) large, flat, triangular, as long as the 
scuta or the carina, all three valves being nearly equal in 
length; occludent margin straight, or slightly arched, 
basal angle broad, not very sharp. 

Carina short (fig. 1, c, drawn rather too long), deeply 
concave, rectangularly bent, with the lower part not quite 
as long as the upper, and a little wider : the basal margin 
is truncated, rounded, and slightly sinuous. The umbo 
is situated at the angle, and therefore nearly central. 
The umbo of the terga, I may add, is in the same place, 
as in Lepas. 

The peduncle is very short and narrow, and is, I believe, 
without spines ; it is enveloped by the bark of the Anti- 
pathes. The capitulum in the largest specimens was 
'2 of an inch in length. 

Filamentary Appendages, apparently none. 

Mouth, with the orifice rather inclined abdominally. 

Labrum, with the upper part extremely protuberant, 
forming a projecting horn ; no teeth on the crest. Palpi 
rather small, with only a few bristles at the end. 

Mandibles, with four teeth and the inferior angle 



136 



GENUS CONCHODERMA. 



pointed ■ first tooth as far from the second, as is the latter 
from the inferior angle ; in one specimen, on one side, 
there were five teeth. 

Maxilla with three great spines at the upper angle, 
beneath which a deep notch, and with the inferior part 
much upraised ; this lower part rather rounded at both 
corners, with the upper spines longer than the lower. 

Outer Maxilla with the bristles continuous in front ; 
externally, slightly protuberant, with a tuft of bristles 
longer than those on the front side. Olfactory orifices 
apparently not protuberant ; but all the specimens were 
in a bad state. 

Cirri. — Prosoma very little developed. First cirrus 
very far removed from the second. The three posterior 
cirri are straight and long ; the segments are elongated 
and bear four or five pairs of very long spines, with a 
single minute intermediate spine between each pair ; 
dorsal tufts, with long spines. First cirrus, rami unequal 
by two or three segments, and thickly covered with spines ; 
the first cirrus is short compared to the second, owing to 
the length of the pedicel of the latter, though the longer 
ramus of the first, nearly equals the shorter ramus of the 
second pair. Second cirrus, with its anterior ramus 
shorter by two or three segments than the posterior 
ramus, and thicker than it, with the segments covered like 
brushes with bristles ; posterior ramus, and both rami of 
the third cirrus, a little more thickly clothed with bristles 
than are the three posterior cirri. 

Caudal Appendages, minute, broadly oval, with six or 
seven long bristles on their summits. 



Genus — Conchoderma. Plate III. 

Conch oderma. Olfers. Magaz. der Gesellsch. Natuforsch. 
Freunde zu Berlin, Drittes Quartel, 1814 * 

* The general title to the volume, containing four Quarterly parts, is 
dated 1818 ; but as in the 'Journal dc Physique/ for July, 1817, the editor 



GENUS — CONCHODERMA. 137 

Lepas. Linnceus. Systema Naturse, 1767. 

Branta. Oken. Lehrbuch der Naturgeschichte, Th. 2, p. 362, 

1815. 
Malacotta et Senoclita. Schumacher. Essai d'uu Nouveau Syst. 

des Habitations des Vers., 1817. 
Otion et Cineras. Leach. Journal de Phys., vol. lxxxv, p. 67, 

July, 1817. 
Gymnolepas. De Blainville. Diet, des Sci. Nat., Art. Mollusca, 

1824. 
Pamina. J. E. Gray. Anuals of Philosophy, vol. x, (Second 

Series,) August, 1825.f 

Valvce '2 ad 5, minute, inter se remote : scuta bi- 
aut tri-lobata, umbonibus in medio marginis occludentis 
positis : carina arcuata, terminis utrinque pcene simi- 
libus. 

Valves 2 to 5, minute, remote from each other : scuta 
with two or three lobes, with their umbones in the 
middle of the occludent margin : carina arched, upper 
and lower ends nearly alike. 

Filaments seated beneath the basal articulations of the 
first pair of cirri, and on the pedicels of four or five ante- 
rior pairs ; mandibles, with five teeth, finely pectinated • 
maxillae step-formed ; caudal appendages, none. 

Distribution. — Mundane, throughout the equatorial, temperate, and cold 
seas; attached to floating objects, living or inorganic. 

The Capitulum is formed of smooth membrane, in- 
cluding five small valves, of which the terga and carina 
are often quite rudimentary or absent. Valves minute, 
thin, generally more or less linear, placed far distant from 
each other ; sometimes imperfectly calcified and covered 
by chitine membrane, or imbedded in it. The umbones 

refers to Conchoderma, the Quarterly Part containing this genus must have 
appeared before 1818 : Lamarck gives the year 1814 as the date of the paper 
in question, and I have accordingly followed him. Prom a similar reference 
by the editor, it appears that Schumachers volume appeared before the 
number of the ' Journal de Physique' containing Leach's Paper. _ 

f Under these nine generic names, the two common species of Con- 
choderma have received thirty-three different specific denominations, caused 
partly by changes of nomenclature, and partly from varieties having been 
ranked as species. 



138 GENUS CONCHODERMA. 

of the valves (together with the primordial valves) are nearly 
central, so that they are added to at their upper and lower 
ends ; hence their manner of growth is considerably dif- 
erent from that of the valves in Lepas. The adductor 
muscle is attached to a slight concavity on the under side 
of each scutum, at the point whence the lobes diverge. 

The Terga are placed almost transversely to the scuta ; 
at their lower ends, there is either a very slight prominence 
in the capitulum, or there is a large tubular, folded ap- 
pendage, opening into the sack, and apparently serving 
for respiratory purposes. 

Peduncle, smooth, moderately long; attachment effected 
by the cement-stuff being poured out exclusively, as it 
appears, from the larval antennae. These antennae in 
C. aurita and C. virgata, resemble, in the form of the 
disc and in the long feathered spines on the ultimate seg- 
ment, those in Lepas. 

The Filamentary Appendages are highly developed; 
there are six or seven on each side ; two are attached 
beneath the basal articulation of the first cirrus (as is usual 
in Lepas), and near them there are one or two small 
pap-formed projections of apparently similar nature ; the 
rest of the filaments are attached to the posterior edges 
low down, on the lower segments of the pedicels of the 
cirri. I believe, in all cases, these appendages are occu- 
pied by testes. 

Prosoma, moderately developed. 

Mouth, situated not far from the adductor muscle ; 
labrum considerably bullate, with the crest hairy and 
pectinated with inwardly pointing, approximate, flattened 
teeth : inner fold of the supra-cesophageal cavity slightly 
thickened and yellowish, villose on the sides. 

Palpi of the usual shape, not meeting, moderately 
broad. 

Mandibles, with five teeth, graduated in size, nearly 
equidistant, finely pectinated either on one or both sides 
towards their bases; inferior angle narrow, either pro* 
duced into a fine tooth, or almost rudimentary. 



GENUS — CONCHODERMA. 139 

Maxilla, about -f- ths of the size of the mandibles, step- 
formed, with five steps generally distinct ; at the upper 
angle there are two large unequal spines, of which the 
lower one is the largest, with a third long thin one on 
the first step ; lower spines doubly serrated. Apodeme 
directed inwards and backwards. 

Older Maxillce (PL X, fig. 16) simply arched; the 
membrane of the supra-cesophageal cavity under these 
maxillae is highly bull ate and villose. Olfactory orifices 
not prominent. 

Cirri, — First pair not seated far distant from the 
second pair. The three posterior pair have the anterior 
faces of their segments considerably protuberant, support- 
ing four or five pairs of long bristles ; between which, 
there is a row of minute, fine, upwardly pointing bristles : 
on the lateral upper margins of each segment, there are 
a few very minute spines ; dorsal tuft short, with thick 
and thin spines intermingled. In the first cirrus (of 
which the rami are nearly equal in length), and in the 
anterior ramus of the second cirrus, the faces of the seg- 
ments are highly protuberant, and clothed with thick 
transverse rows of finely and doubly serrated spines : the 
anterior ramus of the second cirrus is considerably thicker 
than the posterior ramus, which latter, together with 
both rami of the third cirrus, differ from the three pos- 
terior cirri only in the intermediate and in the lateral 
marginal spines being slightly more developed. 

Caudal Appendages, absent. 

Alimentary Canal. — The upper part of the stomach has 
four large caeca, of which the posterior one is the largest ; 
the whole surface, also, is covered with minute pits, 
arranged in transverse rows. 

Generative System, developed to an extraordinary de- 
gree. The testes run into all the filamentary append- 
ages, as well as more or less, into the pedicels of the 
cirri : the two vesicular seminales unite tvithin the penis, 
either just beyond its basal constriction, or up one third 
of its length. Penis short, hairy. The ovarian tubes not 



140 GENUS CONCHODERMA. 

only fill the peduncle, but extend in a thin sheet between 
the two folds of coriuni all round the sack, close up to 
the terga. The two ovigerous fraena are present in the 
usual position ; the ovigerous lamellae either form several 
layers, in pairs, one under the other, or are united in a 
single large cup-formed sheet enclosing the whole animal. 

Colours. — The prevailing tint is a dark purplish- 
brown, which forms, or tends to form, broad longitudinal 
bands on the peduncle and capitulum. 

General Remarks. — This genus is intimately related, 
as has been remarked by Professor Macgillivray,* to 
Lepas : if we look to the body of the animal, which from 
being less exposed to external influences must, in the 
Cirripedia, offer the most trustworthy characters, we find 
that in Conchoderma there are additional filamentary ap- 
pendages attached to the cirri, that there are no caudal 
appendages, that the teeth of the mandibles are finely 
pectinated, and that the ovarian tubes run higher up round 
the sack ; in every other respect, there is the closest simi- 
larity, even to the arrangement of the bristles on the 
cirri. In the capitulum, the difference consists chiefly, 
though not exclusively, in the less development of the 
valves, and their consequent wide separation : the scuta, 
however, in Conchoderma, are added to beneath their 
u unbones, or original centres of growth, which is never the 
case, or only to a very slight degree, in Lepas. Concho- 
derma has no very close affinity to any other genus. As the 
majority of authors have ranked the two common species 
under two distinct genera (Otion and Cineras), I may 
observe, that there is no good ground for this separation ; 
in the above few specified points in which Conchoderma 
differs from the genus most closely allied to it, the two 
species essentially agree together. If we take the nearest 
varieties of C. virgata and C. aurita, there is but a very 
slight difference even in the form of their valves, and 
these hold the same relative positions to each other ; the 

* Remarks on the Cirripedia, &c.; ' Edin. New Phil. Journal/ vol. xxxix, 
p. 171. 



CONCHODERMA AURITA. 141 

carina, however, is always less developed in C. aurita ; 
even the colouring in both tends to follow the same 
arrangement. The only obvious distinction between the 
two species, are the ear-like appendages of C. aurita, 
which, however, are not developed in its early age, are 
subject to considerable variation, are of no high functional 
signification, and are indicated in C. virgata by two 
prominences on the same exact spots. On these grounds 
I conclude, that the generic separation of the two species 
is quite inadmissible. 



1. CONCHODERMA AURITA. PL III, &&. 4. 

Lepas aurita. Linn* Systema Naturae, 1767. 

Otion Cuvieranus (!) Blainvillianus (!) Bellianus (! )Dumer- 

illtanus (!) Rissoanus. Leach. Encyclop. Brit., 

vol. iii, Supp., 1824, and Zoological Journal, vol. ii, 

p. 208, July 1825. 
Otion depressa et saccutifera. Coates. Journal Acad. Nat. 

Sci. of Philadelphia, vol. vi, p. 132, 1829. 
Otion auritus. Macgillivray . Edinburgh New Phil. Journal, 

vol. xxxviii, 1815. 
Lepas leporina. Poll. Test, utriusq. Sicil., pi. vi, fig. 21, 

1795. 
Lepas cornuta. Montagti. Linn. Trans., vol. xi, p. 179, 1815. 
Conchoderma AURiTUM et LEPORiNUM. Olfers. Magaz. der 

Gesell. Ereunde zu Berlin, 3d Quartel., p. 177, 1814. 
Branta aurita. Oken. Lehrbuch der Naturgesch., Th. 11, 

p. 362, 1815. 
Malacotta bivalvis. Schumacher. Essai d'un Nouveau Syst., 

&c, 1817. 
Gymnolepas Cuvierii. Be Blainville. Diet, des Sc. Nat., Art. 

Mollusc, Plate, fig. 1, 1824. 



* Many authors (Poli, Montagu, &c. 3 ) have doubted from the strangely 
mistaken description, viz., "ore octovalvi dentato," whether this species 
could be the Lepas aurita of Linnseus. But in the Linnean Society, there is a 
proof plate from Ellis's " Account of several rare Species of Barnacles," in 
'Phil. Trans.,' 1758, with an excellent figure of the C. aurita, and on the 
margin in Linnseus's handwriting is the name Lepas aurita. 



142 CONCHODERMA AURITA. 

C. capitido duohus tiibularibus quasi-auribus instructo, 
pone terga rudimentalia (sape nidld) positis : scutis bilo- 
batis : carina nulla, aid omnino rudimentali : pediincido 
longo, a capitulo distincte separate). 

Capitulum with two tubular ear-like appendages, seated 
behind the rudimentary and often absent terga ; scuta 
bilobed; carina absent, or quite rudimentary; peduncle 
long, distinctly separated from the capitulum. 

Filaments attached to the pedicels of the second cirrus j 
two upper spines of the maxillae pectinated. 

Hab. — Mundane ; extremely common. On ships' bottoms from all parts 
of the world. Arctic Sea. Greenland. Pacific Ocean. Often attached 
to Coronulse on Whales. On slow-moving fish, according to Dr. A. Gould. 
Often associated with C. virgata, and Lepas anatifera, L. Hillii, and 
L. anserifera. 

General Appearance. — The capitulum (seen from above 
in PL III, fig. 4 a) is slightly compressed, almost globular, 
composed of thick membrane, with two large, ear-like, 
flexible, tubular, folded appendages, at the upper end, 
opening into the sack. These appendages are seated 
behind the rudimentary terga when such are present, or 
behind the spots which they would have held if not 
aborted. In a young condition they are tubular, but not 
folded ; and often, according to Prof. Macgillivray, either 
one or both are at first imperforate. They are formed ex- 
ternally of the outer membrane of the capitulum (rendered 
thin where folded), and internally of a prolongation of 
the inner tunic of the sack ; between the two, there is, 
as around the whole sack, a double layer of corium. A 
section across both appendages, near their bases, is given 
in PI. Ill, fig. 4/5, showing how they are folded, — the 
chief fold being directed from below upwards, with a 
smaller fold, not always present, from between the two, 
outwards. The folds sometimes do not exactly corre- 
spond on opposite sides of the same individual ; they are 
almost confined to the lower part, the orifice itself being 
often simply tubular. These appendages are sometimes 
very nearly as long as the whole capitulum : a section 



CONCHODERMA AURITA. 143 

near their bases is sub-triangular. I shall presently make 
some remarks on their functions and manner of formation. 

The Scuta, as well as the other valves, are imperfectly 
calcified : shape, variable. They usually consist of two 
lobes or plates, placed at above a right angle to each 
other, and rarely (fig. 4 c) almost in a straight line ; the 
lower lobe is more pointed and narrower than the upper ; 
the two correspond to the lower and middle lobes in the 
scuta of C. virgata, the upper one being here absent. 

The Terga are developed in an extremely variable 
degree ; they are often entirely cast off and absent. In 
very young specimens, they are of the same length with 
the carina, but after the carina has ceased to grow, the 
terga always increase a little, and sometimes to such a 
degree as to be even thirty or forty times as long as 
carina. When most developed (fig. 4 a) they are not 
above one third as long as the scuta, to which they lie 
at nearly right angles ; they consist of imperfectly calcified 
plates, square at both ends, slightly broader and thinner 
at the end towards the carina, where they are a little 
curled inwards, than at the opposite end ; they are not 
quite flat in any one plane; internally they are slightly 
concave; finally, I may add, they nearly resemble in 
miniature the terga of C. virgata. In full grown specimens, 
the terga almost invariably drop out and are lost; but 
even in this case, a long brownish cleft in the membrane 
of the capitulum, marks their former position. The 
orifice of the capitulum is usually notched between the 
terga, or between the clefts left by them ; on each side 
of the notch there is a slight prominence. In some few 
cases, however, there is no trace of this notch. Behind 
the terga or the clefts, the great ear-like appendages, as 
we have seen, are situated. 

Carina, rudimentary (fig. 4) and often absent; it is 
pointed-elliptical, and is rarely above the ^th of an inch 
long. After arriving at this full size, calcareous matter 
is added to the under surface over a less and less area, so 
that it becomes internally pointed, and finally, in place of 



144 CONCHODERMA AURITA. 

calcareous matter, continuous sheets of chitine are spread 
out beneath it; hence, during the disintegration of the 
outer surface, the carina comes to project more and more, 
and at last drops out ; subsequently, even the little hole 
in which it was imbedded, disintegrates and disappears. 

Peduncle, cylindrical, distinctly separated from the 
capitulum, and generally twice or thrice as long as it : 
the thickness of the outer membrane generally great, but 
variable : surface of attachment variable, either pointed, 
or widely expanded, or formed into divergent projections. 

Filamentary Appendages, seven on each side, highly 
developed, long and tapering ; there are two beneath the 
basal articulation of the first cirrus, and one on the poste- 
rior margin of the pedicel of each cirrus, excepting the 
sixth pair ; the filaments on the pedicels are nearly twice 
as long as the cirri themselves. 

Mouth, — mandibles, with the five teeth nearly equi- 
distant, and towards their bases finely pectinated on both 
sides ; inferior angle rudimentary, often represented by a 
single minute spine : in one specimen, there were only 
four teeth on one side. Maxillae, with fiye steps, not very 
distinct from each other, with the first step much curved. 
The larger of the two upper great unequal spines is 
pectinated, like the teeth of the mandibles; there is a 
third long finer spine beneath the upper large pair. 

Cirri rather short, broad, with the anterior faces of 
the segments protuberant, especially those of the first 
cirrus and of the anterior ramus of the second pair : spines 
on the anterior cirri doubly serrated. Posterior cirri, with 
the intermediate spines between the pairs, long ; dorsal 
tufts, minute. On the lower segment of the pedicels of the 
four posterior cirri, there are two separate tufts of bristles. 

Colours extremely variable ; sometimes five longitudinal 
bands of dark purple can be distinctly seen (as in C. vir- 
gatd) on the peduncle, these bands becoming more or less 
confluent on the capitulum ; at other times, the capitulum 
is more or less spotted, or often nearly uniformly purple : 
the sack, cirri and trophi are, also, purple. 



CONCHODERMA A.UR1TA. 145 

Size. — The largest specimen which I have seen was, 
including the peduncle and ears, five inches in length, 
the capitulum itself being rather above one inch in length, 
and^ths of an inch in breadth. 

General Remarks. — I have come to the same conclusion 
with Prof. Macgillivray, concerning the variability of this 
form, and I believe there is only one true species. With 
respect to Dr. Coates's species, viz., Otion depressa and 
0. saccutifera, though I have not seen specimens, I can 
hardly doubt, from the insufficient characters given, that 
they are mere varieties. 

With respect to the ear-like appendages, we shall pre- 
sently see in C. virgata, that at corresponding points on 
the capitulum (Tab. Ill, fig. 25), there are two slight, 
closed prominences. According to Professor Macgillivray, 
in C. aurita, every gradation can be followed by which 
the appendages, at first closed, become tubular and open. 
The opening would ensue, if the corium became absorbed 
at the bottom of the appendages whilst still imperforate, 
for then the inner tunic would be cast off at the next 
moult and would not be re-formed, whilst the outer 
membrane would gradually disintegrate together with the 
other external parts of the capitulum, and not being 
re-formed at this point, an aperture would at last be left. 
These appendages have no relation to the generative 
system : the ovarian tubes, which surround the sack do 
not extend into them ; nor do the ovigerous lamellae. I 
believe, that their function is respiratory : the corium 
lining them is traversed by river-like circulatory channels, 
and their much-folded, tubular and open structure must 
freely expose a large surface to the circumambient water. 
Why this species should require larger respiratory organs 
than any other, I know not. In this species, moreover, 
the filamentary appendages are developed to a greater 
extent than in any other cirripede ; in most genera, the 
surface of the body and of the sack suffices for respiration. 



10 



146 CONCHODERMA VIRGATA. 



2. CONCHODERMA VIRGATA. PL III, fig. 2. PI. IX, fig. 4. 

Lepas vikgata. Spengler. Skrifter Naturhist. Selbskabet., B. i, 
1790, Tab. vi, fig. 9. 

— coriacea. Poll. Test, utriusque Sicil., PI. vi, fig. 20, 1795. 

— membranacea. Montagu. Test. Brit. Supp., p. 164, 1808, 

et Linn. Trans., vol. xi, Tab. xii, fig. 2. 
Conchoderma virgattjm. Olfers. Magaz. Gesells. Naturfor. 

Freunde, Berlin, 1814, p. 177, (3d Quartel).* 
Branta virgata. Oken. Lehrbuch derGesell, Th. ii, p. 362, 1815. 
Senoclita fasciata. Schumacher. Essai d'un Nouveau Syst., 

1817. 
Cineras vittata. Leach. Encyclop. Brit. Supp., Tom. iii, Plate. 

1824. 

— cranchii (!) chelonophilus (!) Olpersii (!). Leach. 

Tuckey's Congo Expedition, p. 412, 1818. 

— megalepis (!) Montagui (!) Rissoanus. Leach. Zool. 

Journal, vol. ii, p. 208, 1825. 

— membranacea. Macgillivray . Edin. New Phil. Journal, 

vol. xxxix, p. 171, 1845. 

— bicolor. Risso. Hist. Nat. des Productions, &c., 1826, 

Tom. iv, p. 383. 

— vittatus. Brown. Illust. of Conch., 1844, PL li, figs. 

16—18. 

Gymnolepas Cranchii. Be Blainville. Diet, des Sci. Nat. Hist., 

1824. 
Pamina trilineata (!) (Var. Monstr.). J". E. Gray. Annals of 

Phil., vol. x, 1825. 

C. scutis trilobatis : tergis intils concavis, apicibus in- 
trorsum leviter curvatis : carina modicd, leviter curvatd : 
pedunculo in capitulmn coalescente. 

Scuta three-lobed : terga concave internally, with their 
apices slightly curved inwards : carina moderately de- 
veloped, slightly curved : peduncle blending into the 
capitulum. 

No filament attached to the pedicel of the second cirrus. 

Var. chelonophilus (PI. Ill, fig. 2 c). Terga, minute, 
nearly straight, solid, acuminated at both ends, placed 
far distant from the other valves: carina, either minute 

* See page 136 respecting this date. 



C0NCH0DERMA VIRGATA. 147 

and acuminated at both ends, or moderately developed 
and slightly arched and blunt at both ends : lateral lobes 
of the scuta broad : valves imperfectly calcified. 

Hub. — Muudaue : extremely common on ships' bottoms from all parts of 
the world. Falkland Islands. Galapagos Islands, Pacific Ocean. Attached 
to sea-weed, turtle and other objects. Often associated with Conchoderma 
aurita, Lepas anatifera, L. Hillii, and L. anserifera. 

General Appearance, — Capitulum, flattened, gradually 
blending into the peduncle; summit square, rarely ob- 
tusely pointed. Membrane, thin. Valves, thin, small, 
sometimes imperfectly calcified, very variable in shape and 
in proportional length, and therefore, situated at variable 
distances from each other, but always remote and im- 
bedded in membrane. 

Scuta, trilobed, consisting of an upper and lower lobe 
(the latter generally the broadest), united into a straight 
flat disc, with a third lobe standing out from the middle 
of the exterior margin, generally at an angle of from 
50° to 70° (rarely at right angles) to the upper part, and 
generally (but not always) bending a little inwards. The 
shape of the lateral lobe varies from rounded oblong to an 
equilateral triangle ; as it approaches this latter form, it 
becomes much wider than the upper or lower lobes. In 
one specimen, and only on one side, the scutum (fig. 2 d) 
presented five points or projections. In some specimens, 
the scuta are very imperfectly calcified, and consist of 
several quite separate beads of calcareous matter of irre- 
gular shape, held together by tough brown membrane. 

Terga, extremely variable in shape, placed at nearly 
right angles to the scuta: beyond their carinal ends 
(fig. 2 b), the capitulum presents two small prominences, 
which are important as indicating the position of the 
homologous, ear-like appendages in C. aurita* The 
upper ends of the terga are imbedded in membrane, and 
project freely like little horns for about one third of their 
length : this free portion exactly answers to the pro- 

* These have also been observed bv Dr. Coates; see 'Journal of Acad. 
Nat. Sci. Philadelphia,' vol.vi, p. 134,1829. 



148 CONCHODERMA VIRGATA. 

jecting portion, bounded by the two occludent margins, 
in the terga of Lepas. The freely projecting portion is 
generally curled inwards, and the carinal portion more 
or less outwards, — the form of the letter S being thus ap- 
proached ; but the curvatures are not exactly in the same 
plane. The whole valve is generally of nearly equal width 
throughout, the carinal part being a very little (but in some 
specimens considerably) wider; internally, it is deeply 
concave ; both points generally are blunt and rounded. In 
some rare varieties (Cineras c/ielonop/iilus of Leach, fig. 2 c), 
the terga are much smaller and flat, with both points sharp, 
the whole upper portion being much and abruptly at- 
tenuated, and internally, without a trace of a concavity. 
Generally, the terga are about two thirds of the length 
of the scuta, rarely only half their length ; generally, 
they are separated from the apices of the scuta by about 
their own length, rarely by twice their own length. 
Generally, the terga are shorter than the carina, but 
sometimes a very little longer than it : generally they are 
distant by one third or one fourth of their own length 
from the apex of the carina, rarely by their entire length. 

Carina (fig. 2 a), lying nearly parallel to the scuta, con- 
cave within, very slightly bowed, of nearly the same width 
throughout, but with the lower third beneath the umbo, 
generally a trace wider than the upper part. Length, 
variable, generally rather longer (sometimes by even one 
third of its own length) than the scuta, but sometimes 
equalling only three fourths of the length of the scuta ; 
generally longer than the terga. Upper and lower points 
rounded ; in rare varieties, both ends are sharply acumi- 
nated. The carina and terga are generally most acuminated 
where they are smallest and least perfectly calcified ; and 
consequently, in this same state, the valves stand furthest 
apart. 

Peduncle, flattened, gradually widening as it joins the 
capitulum, to which it is generally about equal in length, 
or a little longer. 

Filamentary Appendages. — Six on each side (PI. IX, fig. 4), 



CONCHODERMA V1RGATA. 149 

of which one (h) is seated on the posterior margin of a 
swelling, beneath the basal articulation of the first cirrus, 
and this is the longest ; the second (y) is short and thick, 
and is seated a little lower on the side of the prosoma, 
(near to this, there are also two little pap-like eminences ;) 
the third (*) is seated on the posterior margin of the pedicel 
of the first cirrus, above the basal articulation ; the fourth, 
fifth, and sixth (j, k, I) in similar positions on the pedicels 
of the third, fourth, and fifth cirri. These three latter 
filaments are shorter and smaller than the first three. 
At the base of the second cirrus, which has no proper 
filament, there is a swelling as if one had been united to it. 

Mouth. — Mandibles, with the basal edges of the five 
teeth pectinated by minute, short, strong spines on 
one side; inferior angle extremely short. In one 
specimen, there was a minute pectinated tooth between 
the first and second; in another, the second tooth was bifid 
on its summit ; in another, the fourth was rudimentary. 

Maxillce, with five steps : sometimes each step com- 
mences with a spine rather larger than the others ; at the 
upper angle, there are two large unequal spines (neither 
pectinated,) with a third longer and thinner, seated a 
little below. Outer maxilla (PI. X, fig. 16), simple. 

Cirri, with twice as many segments in the sixth cirrus as 
in first; spines on the first and second cirri doubly serrated. 

Colours (when alive). — Capitulum and peduncle grey, 
with a tinge of blue, with six black bands, tinged with 
purplish brown. The two bands near the carina become 
confluent on the peduncle, and sometimes disappear ; 
the carina is edged, and the interspace between the 
two scuta, coloured with the same dark tint. The whole 
body and the pedicels of the cirri are dark lead-colour, 
with the segments of the cirri almost black : in some 
specimens, the colour seems laterally abraded from the 
cirri. Ova white, becoming in spirits pinkish, and then 
yellow. The dark bands on the capitulum and peduncle 
become in spirits purple ; but are sometimes discharged ; 
the general grey tint disappears. Professor Macgillivray 



150 CONCHODERMA VIRGATA. 

states that many individuals are light-brown or yellowish- 
grey, with irregular brown streaks, or crowded dots : 
he states that in very young specimens the colours are 
paler, and the valves spicular. 

Size. — The largest specimen which I have seen, had a 
capitulum rather above one inch long and three fourths 
of an inch wide : growth very rapid. 

Monstrous Variety. — In the British Museum, there is 
a dried and somewhat injured specimen of a monstrous 
variety, the Pamina trilineata of J. E. Gray : it differs 
from the common form only in having a tubular projec- 
tion, just behind the notch separating the upper points of 
the terga ; this tube springs from over the terga, and is, 
therefore, in a different position from the ear-like append- 
ages in ConcJioderma aurita. It does not open into the 
sack : the membrane composing it appears to have been 
double in the upper part, and to have been lined with 
corium : in short, this tube seems to have been an ex- 
crescence or tumour, of a cup or tubular form. 

General Remarks. — It will have been seen how much 
subject to variation the valves of this species are. When 
I first examined the Cineras cJielonophilus of Leach, from 
36° N. lat., Atlantic Ocean, and found in many specimens, 
both old and young, that the terga were very small, flat, 
acuminated at both ends, with a projecting shoulder on 
the carinal margin, and situated at about their own 
length from the apex of the carina, and at twice their own 
length from the scuta; and when I found the carina 
acuminated at both ends, and the scuta very imperfectly 
calcified, with the lateral lobe broad, flat, and standing 
out at right angles ; and lastly, when I found the whole 
capitulum bluntly pointed, instead of being square on 
the summit, I had not the least doubt, that it was a 
quite distinct species. Afterwards, I found in the Cineras 
Olfersii of Leach, from the South Atlantic, the same form 
of terga ; but within slightly more concave or furrowed, 
and not nearly so small, and therefore not placed at above 
half so great a distance from the other valves ; and here, 



CONGHODERMA VIRGATA. 151 

the carina had its usual outline, as had nearly the scutum 
on one side, whereas, on the other side, it presented a 
new and peculiar form, having five ridges or points, and 
was imperfectly calcified ; seeing this, it was impossible 
to place much weight in the precise form or size (and 
therefore, relative separation,) of the calcified valves ; and 
on close examination, I found every part of the mouth 
and cirri identical in Leach's Cineras chelonophilus and 
C. Olfersii, and in the common form. Therefore, I con- 
clude, that C. chelonophilus, and still more C. Olfersii, 
are only varieties ; the terga presenting the greatest, yet 
variable, amount of difference, namely, in their acumina- 
tion and flatness. We know, also, that in the species 
of the closely allied genus of Lepas, the terga are very 
variable in shape, and this is the case, even in a still 
more marked degree, in Conchoderma aurita. Professor 
Macgillivray, 1 may add, has come to a similar conclusion 
regarding the extreme variability of the valves of this 
species. 

As the varieties here mentioned are very remarkable, 
and may perhaps turn out to be true species, I think they 
are worth describing in some detail : I will only further 
add, that we must either make several new species, or 
consider, as I have done, several forms as mere varieties. 



C. virgata, var. chelonophilus of Leach. PI. Ill, fig. 2 c. 

Atlantic Ocean, 35° 15' N., 16° 32' W. On the Testudo caretta. 

Capitulum not above half an inch long, composed of very 
thin membrane, with six bands (as stated by Leach) of 
faint colour; summit bluntly pointed; valves very small, 
far distant from each other ; the scuta are imperfectly cal- 
cified, the central part of the umbo consisting of thick, 
brown chitine, with imbedded shelly beads ; terga and 
carina perfectly calcified. 

Scuta trilobed, flat, within slightly concave, upper lobe 



152 C0NCH0DERMA VIRGATA. 

rather more acuminated than the lower; lateral lobe 
triangular in outline, twice as wide as either the upper 
or lower lobes ; lying in the same plane with them, and 
standing out at almost exactly right angles. 

Terga, flat ; placed obliquely to the scuta, and barely 
half as long; separated from them by nearly twice their 
own length ; upper and lower points acuminated ; the 
umbo on the carinal margin forms a projecting shoulder ; 
the scutal margin is straight, they are separated by nearly 
their own length from the apex of the carina. 

Carina narrow, very slightly arched, within slightly 
concave, both points acuminated ; lower third rather wider 
than the upper part ; in length equalling three fourths of 
the scuta, and longer by one third than the terga ; about 
as wide as the latter. 

Filaments, Cirri, and Mouth exactly as before. 

In some specimens sent to me by the Rev. R. T. Lowe 
from off the Testudo caretta, taken near Madeira, the 
scuta have their lateral lobes broad and nearly rect- 
angular : the carina extends nearly to between the terga : 
the terga are nearly straight, somewhat pointed at both 
ends, distant from the scuta, almost solid within, with 
their upper points bowed outwards : the whole capitulum 
is bluntly pointed, as in the var. c/te nop Zulus, to which 
form this makes a rather near approach. 



C. virgata, var. Olfersii. 

Cineras Olfersii. Leach. Tuckey's Congo Expedition. 
Hab. South Atlantic Ocean. 

Scuta, unlike on the opposite sides of the same indi- 
vidual, on one side with a single lateral lobe as usual, 
but this very narrow, on the other (fig. 2 d), with five 
lobes or projections. 

Terga slightly concave within, separated by a little more 
than their own length from the tips of the scuta, and by 
one third of their own length from the tip of the carina. 



CONCHODERMA HTJNTERI. 153 

Carina longer than the scuta by about one fifth or one 
sixth of its own length, blunt at both ends, considerably 
bowed. 

Again, I possess a group of remarkably fine specimens 
given me by Mr. L. Reeve, from the southern ocean, (as 
I infer from a young Lepas australis adhering to them,) in 
which all the individuals, young and old, are characterised 
as follows : — Scuta, with the lateral lobe generally broad, 
but to a very varying extent, with the upper and lower 
lobes extremely sharp. Terga separated from the scuta, 
by one and a fourth of their own length, and by their 
own length from the carina; somewhat acuminated at 
both ends, nearly straight, with a very slight shoulder 
near the umbo. Carina equalling the terga in length, and 
about three fourths of the length of the scuta ; neither the 
upper nor lower point much acuminated. All the valves 
most imperfectly calcified : in one specimen, the scutum 
on one side was simply horny, without a particle of cal- 
careous matter. The summit of the capitulum nearly 
intermediate in outline between the common square, and 
bluntly-pointed form of var. ckelonopkilus. I compared 
the cirri and trophi with those of a common variety, and 
could detect not the smallest difference. This variety 
differs from var. Olfersii, in the less development of its 
carina, and from ckelonopkilus, in the greater development 
of its carina, and especially of its terga* It would appear 
as if the great variability of the valves was connected with 
the absence of calcareous matter. 



3. CONCHODERMA HUNTERI. PL III, fig. 3. 

Cineras Hunteri. R. Owen. Cat. Mus. Coll. of Surgeons, 
(1830), Invert. Parti., p. 71. 

C.valvis angustis: scutis trilobatis, prominentia later ali 
non latiore quam inferior : tergorum parte superior e pcene 
rectangule secundum aperture marginem fleccd .- carina 
valde arcuatd : pedunculo brevi, in capitulum coalescente. 



154 CONCHODERMA HUNTERI. 

Valves, narrow : scuta, trilobed, with the lateral lobe 
not wider than the lower one : terga, with the upper part 
bent almost rectangularly along the margin of the orifice : 
carina considerably arched : peduncle short, blending into 
the capitulum. 

No filament attached to the pedicel of the second 
cirrus. 

Var. — Carina absent; scuta, with the upper lobe 
absent; terga, with the rectangular projection little de- 
veloped. 

Attached to the skin of a snake, probably the Hydeus or Pelamis bicolor, 
and therefore from the tropical Indian or Pacific Oceans. Mus. Coll. of 
Surgeons.* 

Capitulum, with the membrane very thin ; summit ob- 
tusely pointed. Valves linear and thin. 

Scuta, elongated, flat, with the upper projecting lobe 
rather more acuminated than the lower, and equalling it 
in length ; lateral lobe not wider than the lower, and 
about as long as it, forming an angle of about 55° with 
the upper one. 

Terga, of somewhat variable length, generally about 
half as long as the carina, narrow, and of nearly equal 
width throughout ; lower point sharp ; externally convex ; 
internally solid, with a trace of a central depressed line; 
the upper fourth part generally a little bowed out of the 
plane of the lower part, and abruptly bent at rather above 
a right angle along the occludent margin of the orifice. 
These valves are situated at about half their own length 
from the upper points of the scuta. 

Carina considerably arched, extending to the lower 
points of the terga, or running up between them for even 
half their length ; equally narrow throughout ; scarcely 
broader than the terga ; both points rounded ; internally 
concave ; the lower point does not extend as far down as 
that of the lower lobe of the scuta. 

* I owe to the kindness of Professor Owen, an examination of these 
specimens, and information regarding them. 



CONOHODERMA HUNTERI. 155 

Peduncle, narrow, shorter than the capitulum, which, 
in the largest specimen was -^ths of an inch long. Lon- 
gitudinal purple bands appear to have originally existed 
on the peduncle. 

Filamentary Appendages, tropin and cirri all similar 
to the same parts in C. virgata ; but perhaps the anterior 
faces of the segments in the posterior cirri are rather less 
protuberant ; perhaps also the first cirrus is rather shorter 
in proportion to the sixth cirrus. 

Variety [monstrous). — Amongst the specimens, I found 
one very young one, in which the scuta had not upper 
lobes, so that in outline they exactly resembled the scuta 
in the quite distinct C. aurita: there was not even a rudi- 
ment of a carina: the tergum, on one side, was externally 
bordered by a projecting, semi-circular, calcified disc ; and 
the upper points of both terga showed only traces of the 
rectangular projection, which is the chief characteristic of 
C. Hunteri. From these traces alone, and from the 
specimen being mingled with the others, do I here 
include this variety. 

General Remarks. — I have very great doubts whether 
I have acted rightly in considering this as a species; but 
as there were many specimens, old and young, all differing 
remarkably from the common species, this form anyhow 
deserves description. The points by which it can be dis- 
tinguished from C. virgata, are — the almost rectangular 
manner in which the upper portion of the tergum is bent 
outwards and along the orifice of the sack — the narrow- 
ness of all the valves, and especially of the lateral lobes 
of the scuta, — and lastly, the greater curvature of the 
carina, which in some specimens runs up far between the 
terga; had this last character been constant, it would 
have been an important one, but such is far from being 
the case. Great as are these differences in the valves, 
and though common to many specimens, they are not 
sufficient to convince me that it is a true species, and I 
should not be at all surprised at varieties, intermediate 
between it and the common form, being hereafter found; — 



156 GENUS ALEPAS. 

had a name not been already attached to it, I should not 
have given one. In the monstrous variety described, we 
see to what an extent the valves may vary. The C. Hunteri 
approaches nearest to the var. of C. virgata, called by 
Leach Cineras cJielonophilus, for in both, the top of the capi- 
tulum is bluntly pointed and the terga are solid within ; 
in the Var. c/ielonop/iilus, the terga and carina are minute, 
whereas here, though very narrow, they are much elon- 
gated. Certainly C. chelonophilus has almost as strong 
a claim to rank as a species as C. Hunteri ; but in the 
former, by the aid of other varieties, the differences were 
almost reduced to the peculiarities in the terga — the 
valves, the most subject to variation. In C. Hunteri we 
have other differences, and the form of the terga is even still 
more peculiar. I have, therefore, provisionally attached 
to it the specific name by which it is designated in the 
Museum of the College of Surgeons. From having been 
long kept in spirits, all aid from colour is lost. 



Genus — Alepas. PL III. 

Alepas. Sander Rang. Manuel des Mollusques, 1829. 

Anatifa. Quoy et Gaimard. Voyage de 1' Astrolabe, 1831. 

Triton. Lesson. Voyage de la Coquille, 1830. 

Cineras. Lesson. Secundum Sander Rang. 

Capitulum aut sine valvis, aut scutis corneis, pane 
abditis. 

Capitulum without valves, * or with horny, almost 
hidden, scuta. 

Filaments seated beneath the basal articulations of the 
first pair of cirri ; mandibles, with two or three teeth ; 

* Any one not attending to the characters derived from the softer parts of 
the Balanidae and Lepadidse, might easily confound with Alepas the genus 
Siphonicella (genus nov.), which, undoubtedly, though having the external 
appearance of a pedunculated cirripede, belongs to the Balanina3, and is closely 
related to Coronula. 



GENUS ALEPAS. 157 

maxillae notched, with the lower part irregular, projecting ; 
caudal appendages multi-articulate. 

Attached to various living objects, fixed or floating. 

Capitulnm either entirely destitute of valves, or with 
transparent horny scuta, not containing any calcareous 
matter, and almost hidden in membrane. These scuta 
are formed of a lower and a lateral lobe, placed at above 
right angles to each other ; they are added to by successive 
layers, and closely resemble in shape the scuta of the 
Conchoderma aurita. The orifice in A. tubulosa projects 
so much as to be almost tubular. In A. parasita and 
A. minuta it does not project, and is either moderately 
large, or very small in proportion to the length of the 
capitulum ; from contraction it is much wrinkled. The 
membrane forming the capitulum is smooth and very 
transparent ; it contains very few tubuli, except under 
certain irregular projections in A. cornuta. 

The Peduncle is rather short and narrow; it blends 
into the capitulum, and is not, in some of the species, 
separated from it by any distinct line; the surface of 
attachment is rather wide. Within the peduncle we have 
the three usual layers of striae-less muscles ; namely, the 
innermost and longitudinal, which run lower down than 
the others ; the middle and transverse; and, lastly, the ex- 
terior, oblique muscles, which cross each other (becoming 
transparent) on the rostral central line. These several 
muscles run up from the peduncle and surround the 
capitulum ; from the transparency of the membranes 
they can be seen from the outside : they are particu- 
larly conspicuous round the orifice, which they probably 
serve to close. There is, in all cases, the usual adduc- 
tor scutorum muscle (with transverse striae), which is 
attached under the horny scuta, where such exist. The 
fact of the striae-less muscles of the peduncle surrounding 
the whole capitulum, has been observed only in one other 
genus, namely Anelasma. In consequence of this struc- 



158 GENUS — ALEPAS. 

ture, the capitulum must possess considerable powers of 
contraction. 

The antennae of the larva in the Alepas cornuta and 
A. minuta have the sucking disc nearly circular, with the 
spines unusually plain on the distal as well as proximal 
margin. Basal segment broad, much constricted where 
united to the disc. The ultimate segment has on the 
middle of the outer margin, in A. cornuta, two minute 
spines, which I have not observed in any other cirripede : 
on the summit there are the usual spines. 

Size. — Three of the species are small. 

Filamentary Appendages. — These are rather small; 
there is only one on each side, situated on the posterior 
margin of a slight swelling, beneath the basal articulation 
of the first cirrus ; and therefore in the position in which 
the filaments are most constant in Lepas, and where they 
likewise occur in Conchoderma. 

Body. — The prosoma is either pretty well developed 
or is small, according as the first cirrus is placed near to, 
or far from the second cirrus. 

Mouth. — Labrum moderately bullate, with the lower 
part more or less produced ; crest with blunt, bead-like 
teeth, and short hairs. 

Palpi (PI. X, fig. 8), acuminated and narrow to an 
unusual degree. 

Mandibles, with two or three teeth, and the inferior 
angle acuminated ; the lateral bristles unusually strong, 
so as to give the main teeth the appearance of being pec- 
tinated. 

Maxillce, widely notched, with three great upper spines ; 
the part beneath the notch projecting, and either straight 
or irregular. 

Outer MaxillcB, with the inner bristles either continuous 
or divided into two groups : exteriorly there is a smaller 
or larger prominence, with long bristles. The olfactory 
orifices are either slightly, or not at all protuberant. 

Cirri. — In the three posterior pair, the segments have 
their bristles arranged in a transverse row, either in the 



GENUS — ALEPAS. J 59 

form of a narrow brush, or consisting only of a single 
pair with two or three minute, intermediate, and lateral 
marginal spines. The anterior ramus of the second cirrus 
is thicker, and more thickly clothed with spines than is 
the posterior ramus : this latter ramus, however, and both 
rami of the third cirrus, are rather more thickly clothed 
with spines than are the three posterior pair. The unique 
case in A. cornida of the inner rami of the fifth and sixth 
cirri being rudimentary (PI. X, fig. 28) will be minutely 
described under that species. 

Caudal Appendages, thin, tapering, multi- articulate, 
about as long as the pedicels of the sixth cirrus. 

Stomach. — The oesophagus runs in a somewhat sinuous 
course, and enters the top of the stomach obliquely. There 
are no caeca. The biliary envelope presents a reticulated 
structure, instead of the usual longitudinal folds. 

Generative System. — The penis is hairy, not very long, 
and ringed or articulated in an unusually plain manner ; 
the space between each ring being about one fourth of the 
diameter of the penis : the unarticulated basal portion or 
support is here remarkably long. The vesicular seminales 
are long, tortuous, and enter the prosoma. The ovarian 
tubes are of wide diameter : in A. comuta they surround 
the whole capitulum. The ovigerous fraena are small, con- 
stricted at the base, and square on the free margin, which 
is studded with minute glandular beads, borne on the finest 
footstalks. 

Range. — Southern shores of England, Mediterranean, Atlantic, West 
Indies, New Zealand, attached to various objects. A. parasita has been 
always taken on Medusae.* 

Affinities. — This genus differs from all, except Anelasma, 
in the manner in which the striae-less muscles of the pe- 
duncle run up and surround the capitulum, and likewise 

* It appears that Solander (Dillwyn Des. Cat., vol. i, p. 34) observed a 
species of this genus adhering to a Medusa on the coast of Brazil. Mr. 
Cocks informs me that an Alepas, apparently A. parasita, has been cast on 
shore near Ealmouth, attached to a Cyaneea'; and that two other specimens 
adhered to the bottom of a vessel arriving at that port from Odessa. 



160 ALEPAS MINUTA. 

in the reticulated character of the biliary envelope of the 
stomach. To Conchoderma, especially to C. aurita, there 
is a manifest affinity in the form of the horny scuta : there 
is also some affinity to this same genus in the presence of 
filamentary appendages though here little developed, and 
in the circular form of the disc of the larval antenna?, and, 
lastly, in the ovarian tubes in A. cornuta surrounding the 
capitulum. There is quite as close, if not closer affinity 
to Ibla, in the following peculiarities, — in the curved oeso- 
phagus, — in the general character of the cirri and trophi, 
with the olfactory orifices in one species in some degree 
prominent, — in the multi- articulated caudal appendages, 
— and in the plainly-articulated penis, with its elongated 
unarticulated support, though both these characters are 
exaggerated in Ibla. Lastly, the scuta in Ibla, though 
not at all resembling in shape those of A. cornuta, are 
formed without calcareous matter; and again, in Ibla, 
the muscles of the peduncle run up to the bases of the 
valves, and so almost surround the space in which the 
animal's body is lodged. 

The four species of Alepas appear to form two little 
groups; viz. A. parasita and A. minuta on the one hand, 
and A. cornuta and A. tubulosa on the other. 



1. Alepas minuta. Tab. Ill, fig. 5. 

Alepas minuta. Philippi. Enumeratio Mollusc. Sicilian 183(5, 

Tab. xii, fig. 23. 

— A. Costa. Esercitazionc Accadem., vol. ii, 

part I, Naples, 1840, PI. iii, fig. 5 (secundum 
Gueriu in Revue Zoolog., 1841, p. 250.) 

— Chenu. Blust. Conch., PI. iii, figs. 8 — 10. 

A. aperturd non promlnente, capituli longitudinis vios 
tertiam partem ce quant e : scutls cornels, pane absconditis : 
longltudlne tot a ad quart am unci ce partem. 

Orifice not protuberant, one third of the length of the 



ALEPAS MINUTA. 161 

capitulnm : scuta horny, almost hidden. Total length 
quarter of an inch. 

Outer maxilla^ with the spines in front continuous ; 
posterior cirri, with several long spines arranged in a 
transverse row on each segment ; caudal appendages 
longer than the pedicels of the sixth cirrus. 

Sicily ; attached to a Cidaris :* island of Capri (A. Costa) . 

Capitulum oval, blending insensibly into the peduncle ; 
moderately flattened ; composed of thin structureless 
membrane, with the exception of two horny, almost quite 
hidden scuta. Orifice situated near the summit, and in 
a line, which is oblique to the longitudinal axis of the 
peduncle ; much wrinkled ; barely one third of the length 
of the whole capitulum. 

The Scuta, consist of yellowish, transparent, horny, 
laminated chitine, without any calcareous matter ; exter- 
nally covered by the common integument of the capi- 
tulum ; these valves are placed very near to each other, 
close under the orifice, and therefore high up on the 
capitulum ; the membrane between them is smooth and 
unwrinkled : thev are formed of two rather acuminated 
lobes, joining each other at above a right angle ; one lobe 
(the longer one) stretching nearly transversely across the 
capitulum, the other running down parallel to its rostral 
margin : in shape and position they resemble the scuta of 
Conchoderma aurita ; and if another lobe had been de- 
veloped it would have run along the orifice, and then 
these valves would have resembled the scuta of Concho- 
derma virgata. In a specimen with a capitulum ^ths of 
an inch long, the scuta from point to point were ^th of 
an inch in length. 

Peduncle, much wrinkled, about one third in diameter 
of the capitulum, and shorter than it ; at the base it is 
generally expanded into two or three finger-like pro- 

* I am greatly indebted to Professor J. Muller, of Berlin, for kindly 
lending me specimens. 

11 



162 ALKPAS MINUTA. 

jections. Length of the largest specimen, about one fourth 
of an inch. Colour, according to A. Costa in the work 
above cited, " rufo-flava vittata;' but after spirits the 
whole becomes uniformly yellowish. 

Filamentary Appendages, situated beneath the basal 
articulation of the first cirrus, on the posterior edge of 
the usual enlargement ; acuminated, about two thirds of 
the length of the shorter ramus of the first cirrus. 

Prosoma well developed. 

Mouth. — On each side there are two slight promi- 
nences; one under the mandibles, the other transverse 
nearer to the adductor muscle. 

Zabrum, placed near the adductor muscle, with the 
upper part not more bullate than the lower part ; crest 
with a row of blunt teeth, and many fine bristles growing 
chiefly outside the teeth ; there are many fine bristles 
on the inner or supra-cesophageal fold of the labruni. 

Palpi not nearly touching each other, pointing towards 
the adductor: much hollowed out on their inner sides, hence 
narrow and acuminated, with doubly serrated bristles. 

Mandibles, with three teeth and the inferior angle 
ending in a single sharp spine ; whole inferior portion 
narrow ; first tooth as far from the second, as the latter 
from the inferior angle ; owing to the presence of short 
thick spines projecting from the sides of the jaw, the lower 
edges of the second and third teeth appear pectinated. 

Maxilla, nearly two thirds of the width of the man- 
dibles ; beneath the three larger upper spines there is a 
considerable notch, and the whole lower part is very 
slightly upraised ; edge irregular, with obscure traces of 
either two projections, or perhaps of four steps. 

Outer Maxillce, with bristles in front continuous; 
exteriorly there is a slight prominence near each olfactory 
orifice, with a tuft of long bristles. 

Cirri not much elongated ; first pair placed not quite 
close to the second ; five posterior cirri nearly equal in 
length ; pedicels long, with irregularly scattered spines, — 
those on the pedicel of the first cirrus beautifully and 



ALEPAS PARASITA. 163 

conspicuously feathered. The segments of the three 
posterior pair are not very short or broad ; very slightly 
protuberant, each with a long transverse, crescentic, 
narrow brush of bristles, which stand two or three 
deep in the middle, but on the sides are single : dorsal 
tufts long, and in the upper segments the spines are thick 
and claw-like. This structure is common to all the cirri. 
First cirrus with the rami unequal in length by two 
segments ; from the shortness of the pedicel, this cirrus is 
much shorter than the second, but its rami are about two 
thirds of the length of those of the second cirrus. Second 
cirrus (and in a less degree the third cirrus), with the 
anterior ramus a shade broader than the posterior ramus, 
and rather more thickly covered with spines than are the 
three posterior cirri. Fifteen segments in the sixth cirrus ; 
nine in the longer ramus of the first cirrus. 

Caudal Appendages, rather longer than the pedicels of the 
sixth cirrus, composed of seven cylindrical, tapering seg- 
ments, each with a circle of very fine bristles on its summit. 

The acoustic (?) sacks are situated some way below the 
basal articulations of the first cirrus. 



2. ALEPAS PARASITA. 

Alepas parasita. Sander Rang. Man. des Mollusq., p. 364, 

Pl.viii, fig. 5, 1829* 
Anatifa univalvis. Quoy et Gaimard. Armales des Sciences, 

Nat., torn, x, p. 234, 1827, PL vii, fig. 8. 
— paeasita. Quoy et Gaimard. Voyage de P Astrolabe, 

PI. xciii, 1834. 
Triton (Alepas) fasciculatus. Lesson. Voyage de la Coquille. 

Mollusc. PL xvi, fig. 6, torn, ii, part I, 
1830, p. 442. 



* M. Sander Rang rejects the specific name " univalvis" as signifying a 
generic character, and he has been followed in this by MM. Quoy and 
Gaimard themselves. This, according to the Rules of the British Associa- 
tion, would hardly have been a sufficient reason, but it appears that A. para- 
sita, like A. minuta, has a pair of horny scuta or valves ; and, therefore, the 



164 ALEPAS PARASITA. 

A. aperturd non prominente, capituli longitudinis § 
cequanie : scidis corneis : longitudine totd ad 2 uncias. 

Orifice not protuberant, equalling two thirds of the 
length of the capitulum : scuta horny. Total length two 
inches. 

Animal unknown. 

Parasitic on Medusae, Mediterranean and Atlantic Oceans : south shore of 
England (?) * 

I have not seen this species, and have drawn up the 
above specific character from the Plates and brief 
descriptions in the Voyages of the Coquille and Astrolabe. 
M. Lesson thinks that his species differs from that of 
M. Quoy and Gaimard ; but as the peculiar yellow colour 
of the capitulum, general shape, short cirri, habits and 
range, are all common to both, I believe that they are 
identical. There is, however, one singular difference, 
namely, that the cirri are coloured bright blue in the 
Plate in the Voyage of the Astrolabe, and yellowish 
in that in the Voyage of the Coquille : this possibly may 
have resulted from the drawing in the latter case having 
been made from a specimen long kept in spirits. 

M. Lesson says that there are seven pair of cirri, from 
which I infer that this species has a pair of long, articu- 
lated, caudal appendages : he asserts that each cirrus has 
ten segments ; the cirri are short and little curled. 
M. Lesson remarks, that " deux languettes bifurques 
occupent le bas de 1'ouverture ovale*/ I can hardly 
doubt but that these are horny scuta of nearly the same 
shape as in A. minuta. The whole animal seems to be 
extremely transparent, and of a " jaune-citron clair.' 3 
MM. Quoy and Gaimard, however, remark, that different 
specimens vary from white to yellow. Entire length two 
inches, of which the capitulum is fourteen French lines. 
The peduncle is narrow and short. 

name univalvis is too obviously false to be retained. With respect to the 
generic name Triton, I fully believe that it was applied by Linnaeus to the 
cast-off exuviae of sessile Cirripedes. 
* See Eoot-note, p. 159. 



ALEPAS CORNUTA. 165 



3, ALEPAS CORNUTA. PI. Ill, fig. 6. 

A. aperturd parvd, leviter prominente : scutis nidlis : 
capitulo plerumque tribus, parvis, conipressis eminetitiis 
secundum carinalem margin em instructo. 

Orifice small, slightly protuberant ; capitulum without 
horny scuta ; generally with three small flattened pro- 
jections along the carinal margin. 

Outer maxillae with the inner bristles divided into two 
groups ; segments of the posterior cirri extremely nu- 
merous, each with one pair of main spines ; inner rami 
of the fifth and sixth cirri rudimentary. 

St. Vincent's, West Indies, attached to an Antipathes, collected by the 
Rev. L. Guilding. 

Capitulum globular, slightly flattened, smooth, trans- 
lucent, entirely destitute of valves ; orifice slightly pro- 
jecting or tubular, parallel to the longitudinal axis of the 
peduncle, with the edges sinuous ; it appears more tubular 
than it really is, from the convexity of the part of the 
capitulum immediately beneath the orifice. Three small, 
flexible, horny, irregular prominences project from the 
carinal margin ; one at the bottom of the capitulum ; a 
second about half-way up it ; and a third generally close 
to the orifice ; but their positions vary a little, and the 
prominences vary still more in shape and size, being 
either rounded and very small, or much flattened and 
considerably prominent ; they are imperforate ; in the 
membrane under them a few tubuli may be seen, which 
are not elsewhere visible ; their summits are roughened 
with very minute points and beads of chitine ; others, 
still minuter, are scattered over the whole capitulum. 

Peduncle short, narrower than the capitulum, into 
which it insensibly blends ; strongly wrinkled ; surface of 
attachment wide ; position with respect to the branches 
of the coralline, various. 



166 ALEPAS CORNUTA. 

Size and Colour, — The largest specimen, including the 
peduncle, was half an inch in length, and ^ths of an inch 
across the capitulum; colour, after having been long 
in spirits, brownish-yellow. 

Filamentary Appendages, one on each side, short, 
tapering and pointed; seated on the posterior margin 
of a slight swelling beneath the basal articulation of 
the first cirrus ; they are about equal in length to the 
pedicels of this cirrus. 

The Mouth is directed abdominally ; labrum much 
produced downwards, so as to be far separated from the 
adductor muscle ; moderately bullate, forming about one 
third of the longitudinal axis of the entire mouth ; upper 
part forming a slightly overhanging prominence ; crest 
with a row of blunt, bead-like teeth, and externally to 
them there are numerous curved short bristles. 

Palpi (PI. X, fig. 8,) unusually narrow, a little hollowed 
out along their inner margins ; pointing towards the 
adductor muscle ; thickly covered with doubly serrated 
bristles. 

Mandibles, with either two or three teeth ; inferior angle 
narrow and tooth-like ; both sides covered w r ith strong 
bristles or spines, projecting beyond the toothed edge. 

Maxillce, with two large upper spines, and a third 
rather distant from them ; beneath these, there is a wide 
notch or hollow ; inferior part square, projecting, bearing 
six pair of moderately long spines, (of which the central 
one is the longest,) mingled with finer ones. 

Outer Maxillce, with a semicircular outline; the serrated 
bristles in front are divided into two groups ; externally 
there is a rounded and very considerable projection 
covered with long bristles. Olfactory orifices slightly 
prominent, approximate, seated within and just beneath 
the rounded projections at the base of the maxillae. 

Body. — Prosoma little developed ; thorax small. 

Cirri, extremely long, but slightly curled, capable of 
being protruded so as almost to touch the base of the 
peduncle or the surface of attachment ; segments short, 



ALEPAS CORNUTA. 167 

extraordinarily numerous. In the three posterior cirri 
(excepting the rudimentary rami), each segment sup- 
ports two long, slightly serrated spines, with two or three 
minute intermediate ones, and with one or two very 
short, thick spines on the inner and upper lateral margins : 
dorsal tufts with only two or three long, fine, unequal 
spines. All the segments are extremely flat, broad, short, 
with their anterior faces not protuberant ; the greater 
number of the segments, especially the lower ones, have 
very obscure articulations, to be seen only with a high 
power, and these can be capable of little or no movement. 

First Cirrus placed far from the second, with the top 
of its pedicel on a level with the top of the lower seg- 
ment of the pedicel of the second cirrus ; rami short, 
barely half the length of those of the second cirrus ; 
unequal, the anterior ramus being only two thirds of the 
length of the posterior one ; the shorter ramus contains 
thirteen inverted-conical segments, with one side rather 
protuberant; the longer ramus contains twenty-three 
thinner segments ; the segments on both rami are clothed 
with bristles, arranged in two or three rows, forming 
narrow transverse brushes. 

Second Cirrus, with its pedicel long, and its rami nearly 
equalling in length those of the sixth pair ; the two rami 
of nearly equal length ; the anterior one rather thicker 
than the posterior one ; this posterior ramus has fifty-five 
segments ! The bristles on the second and third cirri 
are arranged on the same principle as on the three 
posterior pair ; but from an increase in size and number 
of the little intermediate bristles between the main pairs, 
and of those on the lateral rims, the segments, especially 
the basal ones, of the anterior ramus of the second cirrus, 
are clothed with thin brushes of bristles ; these same 
bristles, on the posterior ramus of the second, and on both 
rami of the third cirrus, can hardly be said to form 
brushes, though longer and more numerous than those 
on the three posterior pair of cirri. 

Fifth and Sixth Cirri. — These resemble each other, 



168 ALEPAS CORNUTA. 

and have their inner or posterior rami in an almost rudi- 
mentary condition. In the sixth cirrus (PL X, fig. 28) 
the outer ramus (a) has actually sixty-three segments, 
whereas the rudimentary ramus (k) has only eleven, nearly 
cylindrical segments. These are furnished with extremely 
minute spines, of which those on the dorsal face are 
longer than those on the anterior face ; the spines on 
the summit of the terminal segment are the longest; 
the segments are not half as thick as the normal ones in 
the outer ramus. The rudimentary ramus is only one 
seventh part longer than the pedicel which supports 
both it and the normal ramus. In the fifth cirrus, 
the rudimentary ramus is rather longer, and has thirteen 
segments, resembling those in the rudimentary ramus of 
the sixth. In the fourth cirrus there is no trace of this 
peculiar structure, the rami being equal in length and 
strength. The two rudimentary rami on each side are 
nearly straight, and seem incapable of movement; they 
project out behind the normal rami, and closely resemble 
in general appearance, the two caudal appendages ; hence 
this cirripede, at first sight, appears to be six-tailed. 

Pedicels of Cirri. — The pedicel of the first pair is very 
short; that of the second is the longest; those of the pos- 
terior cirri decreasing in length. Upper segments short ; 
lower segments in the second, third and fourth cirri, irre- 
gularly and rather thickly clothed with bristles, but in the 
fifth and sixth cirri, there is a regular double row of main 
spines, with some minute intermediate ones : hence there 
is a difference, both in the rami and in the pedicels, between 
the fourth cirrus and the fifth and sixth, and this is a 
unique case. On the dorsal surface of the pedicel of the 
second cirrus, there is a tuft of much feathered fine spines. 

Caudal Appendages. — Each consists of eight much ta- 
pering, very thin segments, furnished with a few short 
simple spines round their upper margins, and with a 
longer tuft on the terminal short segment; basal seg- 
ments twice as thick as the middle ones. In length, 
these caudal appendages equal the pedicels of the sixth 



GENUS ANELASMA. 169 

pair of cirri, and are a very little shorter than the rudi- 
mentary rami of these same cirri. 

General Remarks. — Having examined this species first 
in the genus, I fully anticipated that the very remarkable 
character of the inner rami of the fifth and sixth cirri 
being rudimentary, and serving the same function (if any) 
with the caudal appendages, would have been generic ; but 
this is not the case, for Alepas cornuta cannot be separated 
from A. minuta without violating a clear natural affinity. 



4. Alepas Tubulosa. 

Quoy et Gaimard. Voyage de l'Astrolabe, PI. xciii, fig. 5, 1834. 

A. aperturd parvd prominente et tubulosa : scutis etpro- 
minentiis secundum marginem carinalem, nullis. 

Orifice small, tubular, protuberant ; capitulum without 
horny scuta or projections along the carinal margin. 

Animal unknown. 

New Zealand, Tolaga Bay. Attached to a living Palinurus. 

I have given the above brief character from the plate, 
and imperfect description in the voyage of the Astrolabe. 
The small and distinctly tubular orifice, and the smooth 
carinated edge of the globose capitulum, appear suffi- 
ciently to distinguish this species from A. cornuta. The 
colour is stated to have been white with violet tints. 
Length, two (French) lines. 

Anelasma. Gen. Nov. PI. IV. 

Alepas. Loven. Ofversigt of Kongl. Vetenskaps-Akad. Eord- 
handlinger: Porsta Argangen. Stockholm, 1844, 
p. 192, Tab. 3. 

Capitulum sine valvis: aperturd ampld: pedunculus 
fimbriatuSy sub-globosus, infossus. ^ 



170 ANELASMA SQUALICOLA. 

Capitulum without valves ; aperture large ; peduncle 
fimbriated, sub-globular, imbedded. 

Cirri without spines; outer maxillae and palpi rudi- 
mentary, spineless ; mandibles minute, with several small 
teeth irregularly placed; maxillae minute, with very mi- 
nute irregularly scattered spines. No caudal appendages. 

I owe to the great kindness of Professor Steenstrup, an 
examination of this very curious cirripede, well described 
and figured by Loven, who considered it an Alepas. It 
lives parasitic, with its peduncle imbedded in the skin of 
sharks, in the North Sea. According to the principles of 
classification which I have followed, this cirripede cannot 
possibly remain in Alepas, and must form a new genus ; 
for some time, indeed, I thought that a new family or 
sub-family ought to have been instituted for its reception ; 
but when I considered that its highly peculiar characters 
are all negative, as the non-articular, non-spinose structure 
of the cirri, and that no new or greatly modified functional 
organ is present, I concluded that it might properly 
remain amongst the Lepadidae. We shall, moreover, 
hereafter see that the male of Ibla, which, of course, must 
remain in the same family with the female, is, in some 
analogous respects, even more abnormal than Anelasma. 



1. Anelasma squalicola. PI. IV, figs. 1 — 7. 

Alepas squalicola. Love?/, ut supra. 
North Sea. Parasitic on Squalus. 

Capitulum, destitute of valves ; oval, much flattened ; 
the double membrane composing it, thin, highly flexible, 
coloured externally and internally, by the underlying 
corium, of a blackish purple ; aperture, extremely large, 
extending from the upper end of the capitulum, to close 
above the peduncle, gaping, and not protecting (in the 
dead condition) the cirri and mouth. 



ANELASMA SQUALICOLA. 171 

The Peduncle is about half as long as the capitulum, 
but, according to Loven, this part varies in length ; it is a 
little narrower than the capitulum; colourless, from being 
imbedded in the shark's skin ; sub-globular ; basal end 
almost hemispherical. Total length of animal 1*3 J dia- 
meter of peduncle *4 of an inch. 

The external membrane of the capitulum is not nearly 
so thick as is usual in other Cirripedes, and is, therefore, 
unusually flexible. The internal membrane, on the other 
hand, is very much thicker than is usual, being only a 
little thinner than the outside coat ; this circumstance, as 
well as the similarity in colour on both sides, is evidently 
due to the remarkable openness of the sack, and conse- 
quent exposure of its inside. The inner membrane, 
when viewed under a high power, is seen to be covered 
with the minutest spines ; the external membrane is 
structureless, except that there are a few rows of very 
minute beads of hard chitine, like those which occur on 
the capitulum of Conchoderma aurita. Loven, however, 
states that there are imbedded in the outer membrane, 
scattered, minute, dendritic, calcareous particles. Of 
these, I could see no trace. There is a very thin muscular 
layer between the two coats, all round the capitulum, and 
this layer becomes rather thicker round the base, near the 
peduncle. The adductor muscle, occupying its usual 
place close below the mouth, is thinner than in any other 
Cirripede of the same size seen by me ; nor does it end so 
abruptly at each extremity, as is usual : where attached 
to the outer coat, no impression is left. It is a singular 
fact, that in this Cirripede alone, the fibres of the adductor, 
and of the muscles of the cirri, and of the tropin of the 
mouth, are destitute of transverse striae ; but it is not 
singular, that the muscles surrounding the capitulum 
should, also, be destitute of striae, for this is the case 
with the muscles which, running up from the peduncle, 
surround the capitulum in Alepas, and partly surround 
it in Conchoderma. It must not be inferred from the 
absence of transverse striae in the muscular fibres of the 



172 ANELASMA SQUAJJCOLA. 

adductor and of the cirri and tropin, that they are involun- 
tary, but only that they are in an embryonic condition, 
for I find in the natatory larva, that all the muscles, with 
the exception of some connected with the eyes, are simi- 
larly destitute, and yet perform voluntary movements. # 

Although in the dead state, the aperture of the capitu- 
lum seems to be always gaping, yet I have little doubt, 
that the living animal can fold the flexible membrane, 
like a mantle, round its thorax and cirri, and thus pro- 
tect, though feebly compared with most Cirripedes, these 
organs. I suspect that the mouth is always exposed. 

Peduncle. — The membrane of the peduncle is thin j the 
whole surface is sparingly and quite irregularly studded 
with minute, much-branched filaments (PL IV, fig. 3, 
highly magnified) ; these are occasionally as much as Jth of 
an inch in length ; the degree of branching varies much, 
but is generally highly complex ; the ordinary diameter 
of the branches is about o^th of an inch ; their tips are 
rounded, and even a little enlarged, and frequently torn 
off, as if they had been attached to or buried in the flesh 
of the shark, in which the whole peduncle is imbedded. 
These filaments are formed of, and are continuous with 
the external transparent membrane of the peduncle, and 
they contain, up to the tips of every sub-branch, a hollow 
thread of corium, prolonged from the layer internally 
coating the whole peduncle. In all other Lepadidse, the 
peduncle increases in length, chiefly at the summit where 
joined to the capitulum, and in diameter, throughout 
nearly its whole length, except close to the base; but, 
owing to the constant disintegration of the outer surface, 
the old outside coat does not split in defined lines, like 
the membrane of the capitulum. In Anelasma, however, 
owing to the imbedded position of the peduncle, the old 
outer coats are preserved, the lines in which they have 

* Dr. C. Schmidt in his Contribution to the comparative Anatomy 
of the Invertebrate animals, &c, (translated in Taylor's Scientific Memoirs, 
vol. v, p. 1,) says that in young Crustacea, " we find plain primitive fibres, 
which subsequently acquire the transversely striated aspect." 



ANELASMA SQUALICOLA. 173 

split during continued growth being thus exhibited : those 
in the uppermost part almost symmetrically surround the 
peduncle, showing that here, as in other Lepadidse, has 
been one regular line of growth ; but in the lower part 
the lines are extremely irregular; and what is almost 
unique, it appears that the blunt basal end is constantly 
increasing in length and breadth, and, apparently, at a 
greater rate than any other part. I judge of this latter 
fact, from the whole bottom of the peduncle being covered 
with numerous curved, or nearly circular, lines of natural 
splitting, the nature of which can be best understood 
by examining the much-enlarged drawing (PL IV, fig. 3) 
of a small portion (taken by chance) of the membrane 
of the base, seen from the outside, and bearing some of 
the simplest branched filaments : other branches, as may 
be seen, have been cut off. This manner of growth ex- 
plains the broad, blunt basal termination of the peduncle, 
so unlike that in other Lepadidse. New membrane is 
formed, not continuously as in other cases, under the 
whole surface of the old membrane, but in irregular 
patches ; thus the portion marked (a) runs under (b), but 
not under the little circles (<?, c), for these are the last- 
formed portions and underlie the membrane (a) and (5). I 
do not understand how the splitting of the old membrane 
is effected ; but no doubt it is by the same process by which 
the membrane of the capitulum in other genera, as in 
Scalpellum, splits symmetrically between the several 
valves. In the branched filaments it is particularly dif- 
ficult to understand their growth, for it is not possible, 
after examining them, to doubt that they continue to 
increase, and send off sub-branches, which it would 
appear probable, penetrate the shark's flesh like roots. 
I may remark that one, or more commonly two or three 
branched filaments stand nearly in the centre of each 
circular line of exuviation or splitting. The branched 
filaments first commence as mere little pustules, and 
these appear to be most numerous at the bottom of the 
peduncle. 



174 ANELASMA SQUALICOLA. 

The final cause of the downward growth of the bottom 
of the peduncle, is obviously to allow of the animal bury- 
ing itself in the shark's body, in the same way as Coro- 
nula and Tubicinella become imbedded by the downward 
growth of their parietes in the skin of Cetacea. The 
only other genus of Lepadidse, in which the growth of the 
peduncle is at all analogous, is Lithotrya, in this genus, 
however, the animal burrows mechanically into soft rock 
or shells. 

I looked in vain for cement, or for the cement-glands, 
(but the specimen was in an extremely unfavorable state 
for finding the latter) or for the prehensile antennae of 
the larva. No doubt this Cirripecle at first becomes 
attached in the same way as others, but after early life, I 
suspect it is retained in its place, by being so deeply im- 
bedded in the shark's body, and perhaps by the root-like 
branched filaments. The irregular growth and splitting 
of the membrane at the base of the peduncle, where the 
prehensile antennae of the larva must originally have been 
situated, would account for not finding them. 

The inside of the peduncle (fig. 2 g) was gorged, in the 
specimen examined by me, with immature ova. The in- 
nermost muscular layer consists of longitudinal bundles of 
unusual size, but placed rather far apart from each other ; 
these do not extend to the very base of the peduncle, and 
at the upper end they curve inwards, almost to the middle 
of the under side of the diaphragm, separating the 
peduncle and capitulum. Outside these longitudinal 
muscles, there are delicate transverse ones, but apparently 
there are no oblique muscles in the upper part of the pe- 
duncle, as in other Lepadidae; near the bottom, the 
transverse muscles form a thicker layer with many of the 
bundles running in oblique lines. 

Mouth. — Loven has not described this part quite accu- 
rately, owing to his not having used high enough magni- 
fying powers. He states that the tropin are soft and 
functionless, which is far from the case. The whole 
mouth (fig. 2d), is unusually small ; it is, to a certain 



ANELASMA SQUALICOLA. 175 

extent, probosciformed, and being curved a little down- 
wards, projects slightly over the adductor muscle, to 
which it is closely placed. The labrum does not project 
more beyond the general surface of the body, than in 
many other Cirripedes, but the probosciformed structure 
is caused by the elongation of the surface fronting the 
thorax. The summit of the mouth stands above the level 
of the top of the pedicels of the first pair of cirri. The 
labrum is slightly hollowed out in the middle of its upper 
margin ; it can scarcely be called bullate, in which it 
differs from all other Lepadidse; on the other hand, the 
outer and inner folds of the labrum are not so close 
together as in Balanus. On each upper corner, there is, 
as usual, a small rounded prominence, close to which 
there is a second slight, rounded, spineless swelling ; 
these latter represent the quite rudimentary Palpi. 

The Mandibles (figs. 4, 5) are more highly developed 
than the other tropin ; they are, however, very minute, the 
toothed edge being only about -j-J-Jb- th of an inch in length, 
measured in its longest direction ; the edge is unusually 
thick, with the teeth placed rather on one side ; this organ, 
when viewed on the labrum side (fig. 5), shows two large 
teeth placed low down, with the inferior angle pectinated 
and broadlv truncated : but when viewed on the other or 
maxillae side (fig. 4), several large and small teeth, placed 
alternately and irregularly in pairs, are seen extending 
along the whole edge. The mandibles are furnished, as 
usual, with three principal sets of muscles attached to the 
basal fold of the mouth. 

The Maxilla (fig. 7) are still smaller than the man- 
dibles; the spinose edge being only the -^th of an inch in 
length ; the edge, instead of being square, and furnished 
with a double row of long spines, as in all other Cirripedes, 
is rounded, thick, club-shaped, and with the side facing the 
mandibles, thinly and irregularly strewed with short, thick, 
very minute spines ; there is a large broad apodeme (a), 
in the usual place, but it is much more transparent and 
flexible than common : there are also the usual muscles. 



176 ANELASMA SQUALICOLA. 

In other cirripedes, the mandibles alone seem to force the 
prey down the oesophagus ; but here, the mandibles and 
maxillae equally stand over the orifice, and their adjoining 
spinose faces and edges, seem excellently adapted to force, 
by their united action, any minute living creature down 
the passage. 

The Outer Maxilla are almost in as rudimentary a 
condition as the palpi ; they are quite spineless ; viewed 
externally, they appear like two smooth, blunt, very 
minute projecting points ; but viewed internally, the 
membrane forming the supra-cesophageal hollow seems to 
be united actually to their tips, so that they do not project 
at all. I was surprised to find that the longitudinal 
muscles going to these organs were developed, in pro- 
portion to the other muscles, quite as fully as in ordinary 
cirripedes: hence, these two little outer maxillae, no doubt, 
serve as an under lip, and possess the usual backward 
and forward movement. 

The surface of the probosciformed mouth facing the 
first pair of cirri, has a deep central longitudinal fold, and 
rather more than half-way down, a transverse fold ; just 
above this latter fold, and therefore quite below the outer 
maxillae themselves, the two olfactory orifices are seated ; 
these are unusually large, and the sack into which they 
lead, is most unusually large and deep. In this Cirripede, 
I was first enabled to observe that the membrane lining 
the sack is tubular, and open at the bottom. 

Cirri. — There are, as usual, six pair, and not of very 
small size ; they have a shapeless and rudimentary ap- 
pearance ; they are coloured, like the rest of the body, 
blackish purple: they are quite spineless, and not articu- 
lated, but their anterior faces are either obscurely or very 
plainly lobed, so that in some (for instance in the third 
pair, PI. IV, fig. 6), nine or ten prominent steps could be 
counted, manifestly representing so many segments. The 
rami are equal in length in the first pair, and slightly 
unequal in the second and third pair; these two latter 
are longer than either the first or three posterior pair. 



ANELASMA SQTJALICOLA. 177 

There is a small interspace as usual between the first and 
second pair of cirri. Internally, the cirri are occupied, 
even up to their tips, by delicate striae-less muscles. 
The external membrane of the thorax and limbs, when 
examined under a very high power, is seen to be covered 
with minute toothed scales, as in most Cirripedes. 

The thorax is articulated as usual : the posterior part, 
however, is smaller, and tapers more suddenly than in 
other species, and this corresponds with the smaller 
size and more rudimentary condition, of the three pos- 
terior pair of cirri, compared with the anterior pair. 
The prosoma is hardly at all developed. The orifice 
(PI. IV, fig. 2 e) of the acoustic (?) sack, beneath the first 
cirrus, is unusually large. 

There are no filamentary appendages. 

Alimentary Canal. — The membrane lining the oeso- 
phagus is unusually thin : it is furnished with the ordinary 
constrictor muscles, and others radiating from them like 
spokes of a wheel. The stomach is lined by unusually 
prominent biliary folds, which in the duodenum are trans- 
verse, sending forth, however, short folds at right angles ; 
and these latter, in the proper stomach, become so much 
developed that the folds appear longitudinal. The rectum 
extends inwards, about as far as the base of the fourth 
pair of cirri, but is very short, owing to the little develop- 
ment of the three posterior segments of the thorax. 
The anus is seated in its usual place, at the dorsal 
basis of the penis, and is hidden by loose folds of skin ; 
but there are no distinct caudal appendages. The stomach, 
in the specimen examined, was quite empty. 

Reproductive Organs. — The penis (fig. 2, c) is thick, 
short (about twice as long as the sixth cirrus), constricted 
at the base, ringed, spineless, with the terminal aperture 
large ; internally it is well furnished with muscles. The 
two vesiculae seminales, appeared to be unusually small ; 
and one was much smaller than the other ; they do not 
(I believe) become united into a common tube, till near 
the apex of the penis. They were empty ; and, I presume, 

12 



178 ANELASMA SQUALICOLA. 

from the state of the ova, that their contents had lately 
been discharged. The whole thorax was filled with a 
white, fibrous and cellular mass, consisting perhaps of the 
testes in their undeveloped state. The individual dis- 
sected by me, appeared to have been defective in its last 
act of reproduction, for there were only two or three ova 
attached to the fraenum on one side, and not very many on 
the other. The ova are much less elongated than is usual ; 
they are of a remarkable size, namely T f f T ths of an inch 
in their longer diameter ; the membrane by which they 
are united into a pair of lamellae is remarkably strong ; 
the fraenum (PI. IV, fig. 2f) on each side is large, strong, 
with rounded edges, pale coloured and hence conspicuous ; 
on the side nearest the body, the whole surface is covered 
with club-shaped glands, having very short foot-stalks, 
and being in total length ?T 5 TT ths of an inch ; these 
glands secrete a reticulated layer of gut-formed fibres, 
attached to the ovigerous lamellae. In the specimen de- 
scribed by Loven, the lamellae (fig. 1, and fig. 2, b, b) appear 
to have been very large : and in that examined by myself, 
the peduncle was gorged with immature ova, showing 
that the female reproductive powers were ample, though 
at the foregoing period, only a few eggs had been formed. 
Habits. — According to Loven, this species lives im- 
bedded in the skin of Squalus maximus and sjpinax, in 
the North Sea : I suspect that it is not closely com- 
pressed in its cavity, otherwise, I do not see the use of 
the two layers of muscles round the whole peduncle ; it 
probably adheres to the sides of the cavity by the tips of 
the branched, root-like filaments ; owing to the flexible 
nature of the capitulum, this Cirripede can offer little in- 
sistence to the water, and, therefore, is little likely to be 
torn out of its cavity. I have no doubt that it can fold 
the membrane of the capitulum, like a cloak, round its 
thorax and cirri ; but it certainly can offer far less resist- 
ance, than other Cirripedes, to any enemy. This creature 
must obtain its food, and considering its productiveness 
much food must be required, in a manner quite different 



ANELASMA SQUALICOLA. 179 

from nearly every other member of its Order. As the 
whole of the peduncle is imbedded, and as the mouth is 
probosciformed, with the labrum a little curled over the 
adductor muscle, 1 conclude that this Cirripecle can reach 
minute animals crawling by on the surface of the shark's 
body. 

It must be borne in mind that the mouth, as in all 
Cirripedes, has the power of independent movement, and 
that the mandibles and maxillae are here beautifully adapted 
to catch and force down any small living creature into 
the muscular oesophagus; the rudimentary outer maxillae, 
moreover, no doubt have the power of scraping, like a lip, 
anything towards these prehensile organs. It will here- 
after be seen, that the male of Ibla Cumingii, in which 
the cirri are quite rudimentary, obtains its food in a 
somewhat analogous manner, though in this case the 
whole peduncle moves, and not merely a probosciformed 
mouth : it deserves attention, that in the male Ibla and 
in Anelasma, in neither of which the cirri are prehensile, 
the palpi are rudimentary and useless. I am tempted 
to believe, that the largely developed olfactory sacks, 
and perhaps, likewise, acoustic (?) sacks, in Anelasma, 
replace, by giving notice of the proximity of prey, the loss 
of tactile cirri. It should be remembered that all Cirripedes 
subsist on animals which happen to swim or float within 
reach of the cirri ; but here it is only those which happen 
to crawl within reach of the probosciformed mouth. It 
would, however, be rash to assert that the cirri in Anelasma, 
considering their muscular though feeble structure, may 
not be of some slight use, when thrown over the prey, 
in preventing its escape. 

Professor Steenstrup informs me that, from late obser- 
vations, it appears that this animal always adheres to the 
shark's body in pairs. I regret extremely that I have not 
been able to examine a pair : that the individual examined 
by me was bisexual, I can hardly doubt, though the male 
organs certainly were feebly developed ; it appears pro- 
bable, that the individual described by Loven was like- 



180 GENUS IBLA. 

wise bisexual : but after the facts presently to be revealed 
regarding the sexes in Ibla and Scalpellum, it is quite 
possible that the male and female organs may be developed 
in inverse degrees in different and adjoining individuals. 
The genus Anelasma is, I think, properly placed be- 
tween Alepas and Ibla. In several of its characters, such 
as the absence of calcareous valves, the broad blunt end 
of the peduncle, the spineless cirri, the small size of the 
tropin, and more especially the absence of transverse striae 
in those muscles, which in mature cirripedes are thus 
furnished, we see that this genus is in some degree in an 
embryonic condition. 



Genus — Ibla. Pis. IV, V. 

Ibla. Leach. Zoolog. Journal, vol. ii, July, 1825. 

Anatifa. C-uvier. Mem. pour servir, Mollusques, Art. 

Anatifa, 1837. 
Tetkalasmis. Cuvier. Regne Animal, 1830. 

(Fcem. et Herm.) Valvce 4, cornece : pedunculus spinis 
cornets, persistentibus vestitus. 

(Fern, and Herm.) Valves four, horny: peduncle clothed 
with persistent, horny spines. 

Body partly lodged within the peduncle ; mandibles 
with three teeth ; maxillae with two obscure notches ; outer 
maxillae pointed ; olfactory orifices prominent ; caudal 
appendages multiarticulate. 

Male and Complemental Male, parasitic within the sack 
of the female or hermaphrodite ; mouth and thorax seated 
on a long tapering peduncle, but not enclosed within a 
capitulum ; mouth with normal trophi, but palpi small and 
almost rudimental ; cirri ruclimental, reduced to two pairs ; 
penis reduced to a pore; caudal appendages rudimentary. 

Attached to fixed littoral objects : Eastern Hemisphere. 

General Remarks. — As there are only two species as 



GENUS — IBLA. 18 L 

yet known, and as these resemble each other in every 
respect most closely, a generic description would be a 
useless repetition of the full details given under Ibla 
Cum'mgii. I have taken this latter species as the type, 
from having, owing to the kindness of Mr. Cuming, 
better and more numerous specimens. Ibla and Litho- 
trya are the only two recent genera in which the body 
of the animal is lodged within the peduncle ; but there 
is no distinction of any importance, though useful for 
classification, between the capitulum and peduncle ; and 
these two parts, as we have seen, tend to blend together 
in some species of Conchoderma and Alepas. The entire 
absence of calcareous matter in the valves and spines of 
the peduncle, at first appears very remarkable; but we have 
seen a similar fact in Alepas, and there is an approach to 
it in some varieties of Conchoderma aurita and C. virgata. 
In all four valves of Ibla, the umbones, or centres of 
growth, are at their upper points. The horny spines on 
the peduncle, are the analogues of the calcareous scales in 
Scalpellum and Pollicipes ; and in this latter genus, two 
of the species have their scales, almost cylindrical, placed 
irregularly, with new ones forming over all parts of the 
surface, and not exclusively at the summit, — in which 
several respects there is an agreement with Ibla. The 
shape of the body (*. e. thorax and prosoma, PL IV, fig. 8 a) 
is peculiar ; but it is only a slight exaggeration of what we 
have seen in several genera, and shall meet again in some 
species of Scalpellum. The presence of hairs on the outer 
membrane of the prosoma is a peculiarity confined to this 
genus amongst the Lepadidae, though observed in the 
sessile genus, Chthamalus. The caudal appendages in the 
I. quadrivalvis attain a greater length than in any other 
species of the family, being four times the length of the 
pedicels of the sixth cirrus. A far more important pecu- 
liarity is the fact of the oesophagus, in both species, running 
over or exteriorly to the adductor scutorum muscle, instead 
of, as in every other species, close under this muscle. I 
took great pains in ascertaining the truth of this singular 



182 GKNUS IBLA. 

anomaly : the course of the oesophagus is approximately 
represented in PL IV, fig. 8 a by faint dotted lines. 
The stomach has no caeca; the biliary folds are longi- 
tudinal ; there is a marked constriction at the line corre- 
sponding with the junction of the thorax and prosoma. 
There are no filamentary appendages. 

The generative system gives the chief interest to this 
genus. We here first meet with Males and Females 
distinct ; and, within the limits of this same restricted 
genus, the far more wonderful fact of hermaphrodites, 
whose masculine efficiency is aided by one or two Com- 
plemental Males. The complemental and simple males 
closely resemble each other, as do the female and herma- 
phrodite forms ; but under the two following species I enter 
into such full and minute details on these remarkable 
facts, that I will not here dilate on them. I may add that, 
at the end of the genus Scalpellum, I give a summary of 
the facts, and discuss the whole question. The penis 
(PL IV, fig. 9 a) in the hermaphrodite, I. quadrivalvis, 
is singular, from the length of its unarticulated support, 
and from the distinctness of the segments in the articu- 
lated portion. 

As ovigerous fraena occur in the usual place in i". quad- 
rivalvis, though much smaller than in any other species, I 
have no doubt that they occur in I. Cumingii, although 
I failed in observing them. The glands on the margin, 
in L quadrivalvis, are singular, from not being borne on 
a long, hair-like footstalk. 

Affinities. — Ibla, though externally very different in 
appearance from Scalpellum, is more nearly related to 
that genus than to any other; in both genera some 
species have the sexes separate, the imperfect males being 
parasitic on the female, and other species are bisexual or 
hermaphrodite, but aided by parasitic complemental 
males. In Scalpellum, again, the oesophagus pursues a 
sinuous course, resembling that in Ibla, though it does 
not pass exteriorly to the adductor scutorum muscle. 
The disc of the prehensile antennae of the larva, in 



1BLA CUM1NGI1. 188 

both genera, has an unusual oblong form, like a mule's 
hoof; there is also an affinity between the two genera in 
the size and form of the ova, in the prominent orifices of 
the olfactory cavities, and in the peduncle not being 
naked ; though, in these two latter respects, in the 
structure of the cirri, and in the multiarticular caudal 
appendages, there is an equal affinity to Pollicipes and 
Lithotrya. I have already shown that Alepas is likewise 
related to Ibla. 



1. Ibla Cumingii. PL IV, fig. 8. 

I. {/cem.) valvarum marginibus lateralibus, et superficie 
interio?~e, camlets : pedunculi spinis ple?*umque annulis 
cceruleo-fuscis. 

Fern. — Valves coloured, along the lateral margins and on 
the upper interior surface, blue : spines on the peduncle, 
generally ringed with blueish-brown. 

Caudal appendages barely exceeding in length the 
pedicels of the sixth cirrus : rami of the first cirrus 
unequal in length by about two segments. 

Male, — with scarcely a vestige of a capitulum : maxillae 
with fewer spines than in the female. 

Ha b. — Philippine Archipelago, Island of Guiniavas ; invariably attached 
to the peduncle of Pollicipes mitella, in groups of two or three together ; 
Mus. Cuming. Tavoy, British Burmah Empire ; Mus. A. Gould of Boston. 

FEMALE. 

The capitulum is formed of four valves, but is hardly 
distinct from the peduncle. The latter includes, in 
its wide upper part, the animal's body. The valves, 
namely, a pair of scuta and terga, are composed of an 
extremely hard, horny substance, or properly chitine, and 
do not contain any calcareous matter ; they are extremely 
flat or thin, and both pairs project freely, like curved 
horns, to a considerable height above the sack enclosing 



184 IBLA CUMINGII, 

the body : the terga project about twice as much as the 
scuta, and their flat apices generally diverge a little. The 
tips of the valves are frequently broken off; their surfaces 
are plainly marked or ribbed by the layers of growth, 
which are wide apart. The bases of the valves externally 
are hidden by the long spines of the peduncle. 

Scuta. — These are shorter and broader than the terga ; 
their internal (PL IV, fig. 8 b') growing or corium- covered 
surfaces are slightly concave, triangular, with the basal 
margin longer than the other margins and slightly ex- 
cised in the middle : there is no depression for the strong 
adductor muscle : the internal surface of the free horn- 
like portion, has a small central fold (formed by an oblique 
crest) running from the summit of the triangular growing 
surface to the tip of the valve : in perfect specimens, the 
growing and the free horn-like portions (the latter repre- 
sented much too long in fig. 8 a and b') are about equal 
in length : the basal portion of one side of the scutum 
overlaps the tergum. 

Terga. — The internal growing surface (fig. 8 b') is 
almost diamond-shaped, and less in area than the scuta : 
external surface rounded ; internal surface of the free 
horn-like portion, slightly concave. 

Colour and Structure of Valves. — The external surfaces 
of the scuta and terga are yellow along the middle, plainly 
marked by zones of growth, and finely ribbed longitudi- 
nally: the internal surfaces and sides of the horns of the two 
valves, are coloured fine blue or purple ; in the terga, how- 
ever, the internal surface is mottled with yellow. In some 
specimens, especially in one from Tavoy, each zone of 
growth was only very narrowly edged with blue. When 
a thin layer is removed from one of the valves, the dark 
blue or rather purple appears by transmitted light a 
beautiful pale blue j and it is a very singular fact, that 
this blue portion is permanently turned by very gentle 
pressure into a fiery red ; the same singular effect is 
produced by muriatic and acetic acids. This blue part is 
much harder than the yellow; the latter exhibits, under 



FEMALE. 185 

a high power, a folded structure, and is penetrated by a few 
tubuli, whereas the harder blue portion has a cellular or 
scaled appearance. The spines of the peduncle exhibit, 
in a smaller degree, similar phenomena. 

Peduncle. — This, as already remarked, cannot be 
distinctly separated from the capitulum ; it is much 
compressed ; it is composed of unusually thin and deli- 
cate membrane, transversely wrinkled and thickly clothed 
with long cylindrical horns or spines of chitine. These 
horns (fig. 8 c) are not the analogues of the spines which 
are articulated on the external membranes of many 
Pedunculated and Sessile Cirripedes, but of the calcified 
scales on the peduncle of Scalpellum and Pollicipes ; for 
they pass through the membrane (the underlying corium 
being marked by their bases) and are persistent, being 
added to, like the valves, during each successive period 
of growth. Their bases are concave, so that a section of 
the layers of growth exhibits a series of pointed cones, 
one within another. Each spine is nearly cylindrical, 
irregularly curled, and nodose or slightly enlarged at 
intervals : the apex smooth and pointed ; the exterior 
surface longitudinally and finely ribbed, like the valves. 
The spines increase irregularly in size from the bottom 
to the top of the peduncle, those at the carinal and rostral 
ends being generally the longest ; they point upwards and 
hide the bases of the valves. They are not arranged sym- 
metrically, and new ones are formed over all parts of the 
peduncle. They are formed of the same substance as 
the valves, and do not contain any calcareous matter. 
These horns are yellowish, generally ringed with pale and 
dark blueish brown, which on pressure becomes slightly 
opalescent with pale blue and fiery red : sometimes only 
the upper horns are thus ringed, and in rare instances all 
are simply yellowish. The muscles of the peduncle run 
up to the bases of the four valves. 

Surface of Attachment. — The cement appears to pro- 
ceed from only two points. In some specimens, a con- 
siderable length of one side of the peduncle was fastened 



186 IBLA CUMINGII, 

to the surface of attachment, the horns or spines being 
enveloped in the cement. The prehensile antennae of the 
larva will presently be described under the male. 

The length of an average specimen, including the pe- 
duncle and valves, is about half an inch, and the width 
across the widest part one fifth of an inch. Mr. Cuming 
has one specimen an inch in length, but this is owing 
to the peduncle being unusually tapering. In a specimen 
kept some years in spirits, the cirri, trophi, caudal ap- 
pendages, and corium under the membrane between the 
scuta, were all dark purple; the sack and corium of 
peduncle clouded with purple, and the prosoma pale- 
coloured. 

The Body (PL IV, fig. 8 d) is small compared with the 
capitulum and peduncle ; it is much flattened ; the pro- 
soma is of a very peculiar shape, being square, the sides 
of equal length, and, in an average-sized specimen, ^th 
of an inch long. The peculiar shape arises from the 
great distance between the first and second cirrus — from 
the mouth being far removed from the adductor scutorum 
muscle — and lastly, from the lower part of the prosoma 
being not at all protuberant. The thorax which supports 
the cirri is also unusually small, plainly articulated, and 
separated from the prosoma by a deep fold. The thin 
membrane of the prosoma is studded with some fine, 
pointed hairs, about ^ths in length, and articulated on 
little circular discs. 

Mouth, placed at a considerable distance from the 
adductor, and directed in an unusual manner towards the 
ventral surface of the thorax : the tropin are arranged, 
in a curved line, facing the thorax (see PI. V, fig. 2, 
for this part in the male), and therefore less laterally 
than is usual. 

Labrum (PI. IV, fig. 8 d opposite c) highly bullate ; 
the upper part produced into a blunt point : on its crest 
there are no teeth. 

Palpi (fig. 8 d opposite d) small, blunt and rounded 
at their ends ; inner margins slightly concave. 



FEMALE. 187 

Mandibles (PL X, fig. 4), with three teeth, of which the 
first is much larger than the second and third, and distant 
from them : inferior angle produced and pectinated ; upper 
edges of the second and third teeth finely pectinated. 

Maxilla (PL X, fig. 11) small, slightly but distinctly 
indented by two notches, supporting, besides the three 
upper great 'spines, three pairs of moderately long spines 
and some finer ones : apodeme short, thick. 

Outer Maxilla, unusually pointed, with the inner 
bristles not very numerous, continuously arranged ; exter- 
nally, the bristles are longer. Olfactory orifices, tubular, 
projecting, flattened, square on the summit, smooth : they 
point upwards and obliquely towards each other : they 
arise more laterally than in the other genera, namely out- 
side the bases of the outer maxillae, and between them 
and the inner maxillae. 

Between the bases of the first pair of cirri, there is a 
conical prominence, clothed with bristles and coloured 
purple : it projects nearly as high as the top of the lower 
segment of the pedicel of the first cirrus : it lies over the 
infra-cesophageal ganglion, and serves, I suspect, to fill up 
a little interval between the outer maxillae. 

Cirri long, little curved : the first pair (PL IV, fig. 8 a) 
is situated at an extraordinary distance from the second ; 
hence its basal articulation is on a level with the upper 
articulation of the pedicel of the second cirrus. In the 
three posterior cirri, the segments are laterally very flat, 
with their anterior surfaces not protuberant; each sup- 
ports three pairs of thin, non-serrated bristles, of which 
the second pair is much shorter than the upper, and the 
lowest pair minute • between each pair there is a minute, 
rectangulary projecting bristle ; dorsal tufts consist of two 
or three spines, of which one is longer than the others. 
The two bristles forming each pair, are not of equal 
length ; for in the rami of each cirrus, the inner row of 
bristles is much shorter than the outer ; and this seems 
to be connected with the flatness of the whole animal, 
and the consequent little power of divergence in the rami 



188 1BLA CUMINGII, 

of the cirri. The first cirrus is rather short, with the rami 
unequal in length by about two segments : the anterior 
ramus is shorter and thicker than the other : segments 
numerous, each clothed with several rows of bristles. 
The second cirrus has the anterior ramus thicker and 
more thickly clothed with spines than the posterior ramus ; 
this latter is rather more thickly clothed with spines 
than are the three posterior cirri : the third cirrus is in 
all these respects characterised like the second cirrus, 
but in a lesser degree. The pedicels of the second and 
third cirri are thickly and irregularly clothed with spines ; 
in the three posterior pairs, the spines are placed in two 
regular rows, with some minute intermediate spines. 

Caudal Appendages (PL IV, fig. 8 a',/), multiarticulate, 
thin, tapering, in one specimen equalling, in another just 
exceeding, in length the pedicels of the sixth cirrus. In the 
latter specimen there were thirteen segments, of which the 
basal segments were broader and shorter than the upper ; 
these latter are slightly constricted round the middle, so 
that they resemble, in a small degree, an hour-glass. 
Their upper margins are surrounded by rings of bristles ; 
the terminal segment being surmounted by one or two 
very fine bristles much longer than the others. The two 
appendages are closely approximate ; each arises from a 
narrow elongated slip, attached to the side of the pedicel 
of the sixth cirrus. 

Nervous system. — I examined the upper part of the 
nervous chord, in order to ascertain whether the infra- 
cesophagean ganglion, which is of a globulo-oblong shape, 
was far separated from the second ganglion ; and this I 
found to be the case, in accordance with the distance of 
the first cirrus from the second. I may here remark, that 
in S. quadrivalvis I discovered the eye, which, though in 
all probability really double, appeared to be single ; it was 
situated near to the supra-cesophageal ganglion ; and this 
ganglion was situated near to the adductor scutorum 
muscle, and at a considerable distance from the labrum. 
The aperture leading into the acoustic (?) sack, is situated 



MALE. 189 

much lower down than is usual (PI. IV, fig. 8d), namely, 
at the length of the pedicel of the first cirrus beneath its 
basal articulation. 

Ge?ierative system. — The specimens here described, of 
which I examined six, are exclusively female ; they have 
no trace of the external, probosciformed penis, or of the 
two great vesicuke seminales, or of the testes : on the other 
hand, the ovarian tubes within the peduncle are developed 
in the usual manner, and owing to the large size of the ova, 
are of large diameter, and hence very distinct : I detected, 
also, the true ovaria at the upper edge of the stomach. 

MALE. Plate V, figs. 1 — 8. 

Of the above-described Ibla Cumingii I dissected six 
specimens, four from the Philippine Archipelago,* and 
two from the Burmah Empire, and none of them, as we 
have just seen, possessed the probosciformed penis, the 
vesiculse seminales, or the testes, so conspicuous in other 
Cirripedes ; on the other hand, all were furnished with 
the usual branching ovarian tubes and sometimes with 
ova, and consequently were unquestionably of the female 
sex. Within each of these specimens there was attached 
within the sack, in a nearly central line, at the rostral 
end, (PI. IV, fig. 8 a\ h, magnified five times,) a flattened, 
purplish, worm-like little body, projecting about the ^th 
of an inch : in one of the six individuals, there was a 
second similar little creature attached at the carinal end 
of the sack. Before giving the reasons which I think con- 
clusively prove that these little animals are the Males of 
the ordinary form of the Ibla Cumingii, it will be con- 
venient to describe their structure in detail. 

The whole consists of a long, much flattened peduncle, 
separated from the mouth and thorax by an oblique fold, 
(PI. V, fig. 1 k, b), which is conspicuous on the dorsal 

* I am deeply indebted to the liberality and kindness of Mr. Cuming, in 
allowing me to cut up four specimens of this new species ; and to Dr. Gould, 
of Boston, TJ. S., for the examination of the Burmese specimens. 



190 IBLA CUMINGII, 

margin under the cirri, and can be traced with difficulty 
to the ventral margin. The thorax, itself rudimentary, 
and supporting rudimentary cirri, is in some individuals, 
as in the one represented (fig. 1, magnified 32 times), 
covered by, or received in the oblique fold k, just men- 
tioned : in other individuals the thorax is drawn out. and 
then the fold shows merely as a notch on the dorsal margin, 
and the basal articulations of the cirri stand some little way 
above it. The basal edge of the large, well-developed 
mouth can be traced all round, and on the ventral margin 
(b), is generally marked by a slight notch. The dimen- 
sions and proportions vary much : the longest specimen, 
including the imbedded portion, was ^th, and the shortest 
barely ^ths of an inch in length ; the width of the widest 
portion varied from ^ ths of an inch : the specimen 
figured (PI. IV, fig. Sa, and PI. V, fig. 1,) is a broad, 
short individual. Generally, the middle of the peduncle 
is rather wider than the upper part. 

Peduncle — The main part of the animal, as may be 
seen in the drawing, consists of the peduncle, of which 
the imbedded portion tapers more or less suddenly in a 
very variable manner, and is of variable length, — in one 
specimen being one fourth of the entire length, and in 
another consisting of a mere minute blunt point. The 
free upper part of the animal is bent in various directions, 
in relation to the imbedded portion. The latter passes 
obliquely through the chitine membrane and corium, 
lining the sack of the female, and running along amidst 
the under-lying muscles and inosculating fibrous tissue, 
is attached to them by cement at the extremity. The 
peduncle is often, but not in the individual represented, 
much constricted at the point where it passes through 
the skin of the female, and generally at several other 
points, especially towards the extremity (see fig. 1) ; the 
stages of its deeper and deeper imbedment being thus 
marked. The constrictions are, I believe, simply due to the 
continued growth of the male, whilst the hole through 
the membrane of the female does not yield. The imbed- 



MALE. 191 

lxient, which is considerable only when the lower part 
of the peduncle is almost parallel to the coats of the sack, 
seems caused by the growth and repeated exuviations 
of the female ; I believe, that the larva attaches itself 
to the chitine tunic of the sack, and that the cement, by 
some unknown means, affects the underlying corium, so 
that this particular portion of the tunic is not moulted 
with the adjoining integuments, and that the growth of 
the surrounding parts subsequently causes this portion 
to be buried deeper and deeper : it is, I believe, in the 
same way as the end of the peduncle in Con c7io derma 
aurita, sometimes becomes imbedded in the skin of the 
whale to which it is attached. 

The outer tunic of the peduncle is thin and structure- 
less : in the fold (fig. 1 h) under the cirri, there is a central 
triangular gusset of still thinner membrane, corresponding 
in position to the membrane connecting the two terga in 
the female, and there subjected to much movement. 1 
may here remark, that this fold, in its office of slightly pro- 
tecting the thorax and in its position, evidently represents 
the capitulum with its valves, enclosing the whole body 
of the female. The outer tunic is lined by corium, mot- 
tled with purple, and within this there are two layers of 
striae-less muscles, transverse and longitudinal, as in all 
pedunculated Cirripecles. The corium extends some way 
into the imbedded portion of the peduncle, and conse- 
quently, the outer tunic there continues to be added to 
layer under layer, and as it cannot be periodically moulted, 
it becomes much thicker than in the upper free part of 
the animal : the corium, however, does not extend to the 
extreme point, so that in it growth of all kind ceases. 

Antennce. — The peduncle terminates (PI. V, fig. 1 e) 
in the two usual, larval, prehensile antennae, which it is 
very difficult to see distinctly; they are tolerably well 
represented in fig. 5, greatly magnified. Their extreme 
length, measured from the basal articulation to the tip 
of the hoof-like disc, is ^ths of an inch, the disc itself 
being ^ths of an inch. The disc is slightly narrower 



192 IBLA CUMINGII 



than the long basal segment, from which it is divided 
by a broad conspicuous articulation ; its lower surface 
is flat and its upper convex, altogether resembling in shape 
a mule's hoof ; its apex is fuzzy with the finest down ; 
it bears a narrow ultimate segment, thrown, as usual, 
on one side ; this segment supports on its rounded 
irregular summit, at least five, I believe, judging from the 
structure of the same part in the male larva of Ibla quadri- 
valvis, six or seven spines, longer than the segment itself : 
one long spine arises from the under side of the disc, 
near the base of the ultimate segment, and points back- 
ward : there is also a single curved spine on the outside, 
near the distal end of the basal segment. These organs 
were imbedded in a heart-shaped ball or cylinder of 
brown, transparent, finely laminated cement, and thus 
attached to the fibrous tissue of the female. The two 
cement-ducts (fig. \f) were very plain, each about ^th of 
an inch in diameter, containing the usual inner chord 
of opaque cellular matter. I traced them at the one end 
into the prehensile antennae as far as the disc ; and at the 
other, up the peduncle for about one fourth of its length, 
where I lost them, and could not discover with certainty 
any cement glands. I may, however, here mention, that 
I found in the lower half of the peduncle, numerous, 
yellowish, transparent, excessively minute, pyramidal 
bodies, with step-formed sides ; of these two or three 
often cohered by their bases like crystals ; I have never 
seen anything like these in other Cirripedes, but it has 
occurred to me that they may possibly be connected with 
the formation of the cement : for in the last larval con- 
dition of Lepas, the cement-ducts run up to the gut- 
formed ovaria, filled at this period with yellowish, grape- 
like, cellular masses, without the intervention of cement 
glands, and I can imagine that similar masses, not being 
developed into functional ovaria, might give rise to the 
yellow pyramidal bodies. 

Mouth. — The mouth is well developed ; it is repre- 
sented as seen vertically from above, in PI. V, fig. 2, mag- 



MALE. 1 93 

nified about 60 times ; the positions of the cirri and the 
outline of the thorax are accurately shown by dotted 
lines ; a lateral view is given in fig. 1 . In the specimen 
figured, the longitudinal diameter of the mouth, including 
the labrum, was T ^th of an inch. The muscles of the 
several tropin have transverse striae, and are the strongest 
and most conspicuous of any in the body. The labrum 
is largely bullate, with its summit slightly concave ; the 
tropin are arranged in a remarkable manner, in a semi- 
circular line, so as to be opposed to the labrum rather than 
to each other : there are no teeth or spines on the crest 
of the labrum, which overhangs the oesophageal cavity. 

The Palpi (fig. 2 b and fig. 3) are very small, dark 
purple, bluntly pointed, with a few small bristles at the 
point; they do not extend beyond the knob at each 
corner of the labrum, which is here present, as in all 
other Lepadidse; they are much smaller than in the female, 
though of a similar shape, and consequently, their points 
are much further apart: within their bases, the lateral 
muscles of the mandibles are, as usual, attached ; they are 
represented in fig. 3, as seen from the inside, with the 
eye on a level with the concave summit of the labrum. 
The rudimentary condition of the palpi is connected, as 
remarked under the Anelasma squalicola, with the absence 
of efficient cirri. 

The Mandibles (fig. 7) are well developed; they so 
closely resemble those of the female that it is superfluous 
to describe them : they are, however, smoother, without 
any trace of the teeth being pectinated, and with the 
inferior point smaller : measured in their longer direction, 
they are 5555th of an inch in length, and, therefore, a little 
less than one third of the size of those of the female. 
These organs have the usual muscles well developed, and 
the usual articulations. 

The Maxilla (fig. 8) have a rather rudimentary ap- 
pearance; yet they have the same size relatively to the 
mandibles, as in the female, the spinose edge being ^th s 
of an inch in length. These organs resemble, to a cer- 

13 



194 IBLA CUMINGII, 

tain extent, those of the female, differing from them in 
being less prominent, — in the outline being more rounded, 
with the notches even less distinct, — and in the spines 
being fewer. The apodeme is short and broad. 

The Outer Maxilla (tig. 6) are pointed, with a small 
tuft of bristles at the apex ; they are much less hairy 
than in the female, but have nearly the same unusual 
shape. Outside their bases, and between them and 
the inner maxillae, the two well-developed, tubular, flat- 
tened, square- topped, olfactory orifices, project in exactly 
the same remarkable position as in the female ; these are 
not represented in fig. 2, though sometimes they can be 
very distinctly seen, when the mouth is viewed from 
vertically above. 

Thorax and Cirri. — The thorax is in a rudimentary 
condition: I did not observe the usual articulations. The 
whole, as seen from vertically above, is of small size, 
compared with the mouth ; the outline is accurately shown 
by dotted lines in Tab. 5, fig. 2, together with the posi- 
tions of the two pair of cirri, the caudal appendages, and 
anus. The posterior end of the thorax does not rise to 
the level of the summit of the mouth; and the thorax 
seems of no service, excepting perhaps as a sort of outer 
lip to protect the mouth. The cirri are in an extreme 
state of abortion, and evidently functionless; they are 
lined with purplish corium, without the vestige of a 
muscle ; they are usually distorted and bent in different 
directions ; they vary in size, and even those on opposite 
sides of the same individual, sometimes do not corres- 
pond, and do not arise from exactly corresponding points 
of the thorax. There are always two pair of cirri, which, 
as I conclude from the position of the excretory orifices, 
answer to the fifth and sixth pair in other Cirripedes. 
Each cirrus (fig. 4) usually carries only one ramus, placed 
on a large basal segment, evidently corresponding to the 
pedicel of a normal cirrus. The posterior are larger 
than the anterior cirri, which latter spring from points a 
little lower down on the thorax. In the posterior cirrus 



MALE. 195 

figured, the great basal articulation or pedicel, almost 
equals in length, and much exceeds in thickness, the four 
segments of the ramus ; these segments are furnished on 
their upper dorsal edges with little brushes of spines, but 
have not even a trace of the normally larger and far more 
important anterior spines. In one specimen, the anterior 
cirrus had a large pedicel, carrying three segments, like 
those of the posterior pair ; but in another specimen, one 
of the three segments showed traces of being divided into 
two, thus making four imperfect segments; whilst on the 
corresponding side of this same individual there were only 
two ill-formed segments, with their few spines differently 
arranged. Again, in a third specimen, the great basal 
segment of the anterior cirrus on one side, bore, exteriorly 
to the usual ramus, a single segment furnished with 
bristles, and evidently representing a second ramus ; thus 
showing that the great basal segment certainly answers 
to a pedicel. I may here add, that on the integuments of 
these cirri, I observed with a high power, the serrated scale- 
like appearance common in other Cirripecles. Directly 
between the bases of the sixth cirrus, there is a very 
minute papillus, which, under the highest power, can be 
seen to consist of two closely approximate, flattened 
points ; these, I have no doubt, are the caudal appen- 
dages in an extremely rudimentary condition, for I traced 
the vesiculae seminales to this exact spot : close outside 
these rudimentary points, on a slight swelling, is the 
anus. It will presently be seen that in the male of the 
closely allied Ibla qitadrivalvis, the nature of these caudal 
appendages admits of no doubt, for in this species they 
consist of more than one segment, are spinose, and close 
under them towards the mouth, there is a perfectly distinct 
papillus, representing the usual proboscifonned penis. 

Alimentary Canal. — The oesophagus is very narrow, 
and of remarkable length ; from the orifice under the 
mandibles, it first runs back (in this respect not well 
represented in PI. V, fig. 1,) under the bullate labrum, 
and then straight down the peduncle, where it terminates 



196 IBLA CTJMINGII 



in the usual bell- shaped expansion, entering one side of 
the small globular stomach ; the latter, at its lower end, 
is slightly constricted, and then is rather abruptly up- 
turned. The rectum is of unparalleled length, and ex- 
tremely narrow; it can be best detected after the dis- 
solution by caustic potash of the softer parts, when its 
inner coat of chitine can be seen to be continuous, in the 
ordinary manner, with the outer integuments of the thorax, 
The anus, as already stated, is seated on a slight swelling, 
and consists of a small longitudinal slit (f, fig. 2), placed 
close outside the two very minute caudal appendages. 

Organ of Sight. — In all the specimens, a little below 
the fold separating the mouth from the peduncle, and near 
the abdominal (or rostral) edge, a black ball (c f fig. 1), 
about lith of an inch in diameter, is conspicuous. When 
dissected out, it is somewhat conical in form, and appears 
to consist of an outer coat, with a layer of pigment-cells 
of a dark purple colour, surrounding a transparent, rather 
hard lens, apparently leaving a circular orifice at the 
summit, and forming a short tube at the base, sur- 
rounding what I believe to be a nerve. I was not able 
to perceive that this eye consisted of two eyes united, 
which the analogy of other Cirripedes makes me suppose 
probable, although in the ordinary and hermaphrodite 
Ibla quadrivalvis, the eye also appeared single. It is 
seated under the two transparent muscular layers, close 
upon the upper end of the stomach, and this is the exact 
position, as stated in the introductory discussion (p. 49), 
in which the eyes of pedunculated Cirripedes are com- 
monly situated. 

Generative System. — Within the muscular layer all 
round the upper part of the peduncle, and surrounding 
the stomach, there are numerous, little, rather irregular 
globular balls, with brown granular centres, so closely 
resembling the testes in other Cirripedes, though of 
smaller size, that I cannot doubt that this is their nature : 
they were much plainer, larger, and more numerous in 
some specimens than in others. The vesicular seminales 



MALE. 197 

can seldom be made distinctly out ; but having cut one 
specimen transversely across the thorax, they were as 
plain as could be desired, lying parallel and close to each 
other above the rectum, (the animal being in the position 
as drawn,) and therefore in their normal situation. Each 
had a diameter four times as great as that of the rectum. 
In this individual the contents seemed (whether from 
decomposition or state of development, or from my not 
having used high enough power, I know not,) merely 
pulpy ; but I have since found, in another specimen, 
masses of the most distinct spermatozoa, with the usual 
little knots on them, associated with numerous cells, about 
as large as and resembling those which I have examined in 
living Cirripedes, and from which I have every reason 
to believe the spermatozoa are developed. The vesiculae 
seminales unite and terminate under the two extremely 
minute caudal appendages, and here I think I saw an orifice; 
but there is certainly no projecting, probosciformed penis. 
Having dissected the six specimens with the utmost 
care, and having scrupulously examined the ovaria in 
other Cirripedes during their early stages of development, 
even before the exuviation of the larval locomotive organs, 
and in specimens of smaller size than the male Ibla, I 
am prepared to assert that there are no ovaria, and that 
these little creatures are exclusively males. It should be 
borne in mind, that in some of the specimens there were 
perfect spermatozoa in the vesiculae seminales (as likewise 
in some of the males of I. quadrivalvis), and, therefore, 
if these individuals had been hermaphrodites, their ova 
would have been, at this period, well developed, and ready 
for impregnation : in this state it is almost impossible that 
they could have been overlooked. Moreover, it is probable 
that such ova would not have been very small, for the 
larvae whence the parasitic males are derived, attain (as 
might have been inferred from the known dimensions of 
their prehensile antennae, and as we shall show actually is 
the case in I. qiiadrivalvis,) the size common amongst 
ordinary Cirripedia. 



198 IBLA CUMINGII, 

Concluding Remarks. — That these animals are true 
Cirripedes, though having so different an external appear- 
ance from others of the class, admits of not the least 
doubt. The prehensile antennae, enveloped in cement and 
including the two cement -ducts, would have been amply 
sufficient, without other parts — for instance, the mouth, by 
itself perfectly characteristic with each organ, together with 
the whole alimentary canal, constructed on the normal plan, 
— to have proved that they were Cirripedia. Under the 
head of the closely-allied Ibla quadrivalvis, we shall, more- 
over, see that the males are developed from larvae, having 
every point of structure — the peculiar quasi-bivalve shell, 
the two compound eyes, the six natatory legs, &c, — 
characteristic of the Order. But in some respects, the 
males are in an embryonic condition, though unquestion- 
ably mature, as shown by the spermatozoa ; — thus, in the 
thorax and mouth opening throughout their whole width 
into the cavity of the peduncle, that is, homologically into 
the anterior part of the head, and in the viscera being there 
lodged instead of in the thorax and prosoma, there is a 
manifest resemblance to the larva in its last stage of develop- 
ment : the absence of a probosciformed penis, the spine- 
less peduncle, the food being obtained without the aid of 
cirri, and the length of the rectum, are likewise embryonic 
characters. Not only are these males, as just remarked, 
Cirripedia; but they manifestly belong to the Pedunculated 
Family. If a specimen had been brought to me to class, 
without relation to its sexual characters, I should have 
placed it, without any hesitation, next to the genus Ibla ; 
if the mouth alone had been brought, I should assuredly 
have placed it actually in the genus Ibla : for let it be 
observed how nearly all the parts resemble those of Ibla 
Cumingii, excepting only in size and in being less hairy. 
The tropin are arranged in the same peculiar position 
as in the female ; the labrum is largely bullate, without 
teeth on the crest ; the palpi, though relatively smaller, 
are of the same shape ; so are the mandibles ; the maxillae 
are more rounded and less prominent, but have the same 



MALE. 199 

exact size relatively to the mandibles ; the outer maxillae 
have the same, quite peculiar pointed outline, and the 
olfactory orifices are tubular, and hold the same unusual 
position. It is most rare to find so close a resemblance 
in the parts of the mouth, except in very closely allied 
genera, and often species of the same natural genus 
differ more. Again, in the long oesophagus and con- 
stricted stomach there is a resemblance to Ibla. In the male 
of Ibla quadrivalvis, the caudal appendages are multi- 
articulate ; now, this is a character confined to four genera, 
namely, Ibla, Alepas, Pollicipes, and Lithotrya. I may 
add, that large tubular olfactory orifices are confined to 
the same genera, together with Scalpellum. Lastly, it 
particularly deserves notice, that the prehensile antennae, 
in having a hoof-like and pointed disc, with a single spine 
on the heel, much more closely resemble these organs in 
Scalpellum, certainly the nearest ally of Ibla, than in any 
other genus ; they differ from the antennae in Scalpellum, 
only in the ultimate segment not having a notch on one 
side. These organs, unfortunately for the sake of com- 
parison, were not found in the female and ordinary form 
of Ibla. The full importance of the above generic resem- 
blance in the antennae, will hereafter be more clearly seen, 
when their classificatory value is shown in the final dis- 
cussion on the sexual relations of Ibla and Scalpellum. 

Here, then, we have a pedunculated Cirripede very 
much nearer in all its essential characters to Ibla than to 
any other genus, and exclusively of the male sex ; and this 
Cirripede in six specimens, from two distant localities, 
adhered to an Ibla exclusively of the female sex. May 
we not, then, safely conclude that these parasites are the 
males of the Ibla Cumingii ? Considering that, in the same 
class with the Cirripedia, there is a whole family of crus- 
taceans, the Lerneidae, in which the males, compared with 
the females to which they cling, differ as much in appear- 
ance as in Ibla, and are even relatively smaller, I should 
not have added another remark, had there not been under 
the head of the following species, and of the next genus 



200 IBLA CUM1NGII, 

Scalpellum, a class of allied facts to be advanced, which 
in some respects support the view here taken, but in 
others are so remarkable and so hard to be believed, that 
I will call attention to the alternative, if the above view 
be rejected. The ordinary Ibla Cumingii must have a 
male, for that it is not an hermaphrodite can hardly be 
questioned, seeing how easy it always is to detect the 
male organs of generation ; and we must consequently 
believe in the visits of a locomotive male, though the 
existence of a locomotive Cirripede is improbable in the 
highest degree. Again, as the little animal, considered by 
me to be the male of I. Cumingii, is exclusively a male, 
(for there were no traces of ova or ovaria, though the 
spermatozoa were perfect,) we must believe in a loco- 
motive Cirripede of the opposite sex, though the existence 
in any class of a female visiting a fixed male is unknown :* 
in short, we should have hypothetically to make two loco- 
motive Cirripedes, which, in all probability, would differ 
as much from their fixed opposite sexes, as does the Cirri- 
pede, considered by me to be the male of I Cumingii, 
from the ordinary form. This being the case, I con- 
clude that the evidence is amply sufficient to prove that 
the little parasitic Cirripede here described, is the male 
of Ibla Cumingii. 

If we look for analogies to the facts here given, we 
shall find them in the Lerneidse already alluded to, but 
in these the males are not permanently attached to the 
females, only cling, I believe, to them voluntarily. The 
extraordinary case of the Hectocotyle, originally described 
as a worm parasitic on certain Cephalopoda, but now 
shown by Kolliker to be the male of the species to which 
it is attached, is perhaps more strictly parallel. So again 
in the entozoic worm, the Heteroura androphora the 

* It deserves notice, that in the class Crustacea, both in the Lerneidae 
and in the Cirripedia, the males more closely resemble the larvae, than do the 
females ; whereas amongst insects, as in the case of the glow-worm in 
Colcoptera, and of certain nocturnal Lepidoptera, it is the female which 
retains an embryonic character, being worm-like or caterpillar-like, without 
wings. But in all these cases, the male is more locomotive than the female. 



MALE. 201 

sexes cohere, but are essentially distinct : " this singular 
species, however," according to Professor Owen,* " offers 
the transitional grade to that still more extraordinary 
Entozoon, the Syngamus trachealis, in which the male is 
organically blended by its caudal extremity with the 
female, immediately anterior to the slit-shaped aperture 
of the vulva. By this union a kind of hermaphroditism 
is produced ; but the male apparatus is furnished with its 
own peculiar nutrient system ; and an individual animal 
is constituted distinct in every respect, save in its terminal 
confluence with the body of the female. This condition 
of animal life, which was conceived by Hunter as within 
the circle of physiological possibilities, has hitherto been 
exemplified only in the single species of Entozoon, the 
discovery of the true nature of which, is due to the sagacity 
and patient research of Dr. C. Th. Von Siebold." In 
Ibla, the males and females are not organically united, 
but only permanently and immovably attached to each 
other. We have in this genus the additional singularity 
of occasionally two males parasitic on one female. 

I have used the term parasitic, which perhaps ought 
strictly to be confined to cases where one creature derives 
its nutriment from another, inasmuch as the male is in- 
variably and permanently attached to and imbedded in 
the female, — from its being protected by her capitulum, 
so that its own capitulum is not developed — and from 
its feeding on minute animals infesting her sack. The 
male Ibla must seize its prey, guided probably by its 
well- developed olfactory organs, through the movement 
of its long, flexible body, furnished with muscles, and 
with the mouth seated on the summit. We have already 
seen one instance of a Cirripede, the Anelasma, obtaining 
its food without the aid of cirri, by means of its pro- 
bosciforaied, flexible mouth. The eye can serve only to 
announce to the male when the female opens her valves, 
allowing occasionally some minute prey to enter. In 

* Cyclopaedia of Anatomy and Physiology, p. 142. 



20.2 IBLA CUM1NGII. 

ordinary Cirripedes the penis is long, articulated, and 
capable of varied movements, I presume for the purpose 
of impregnating each separate ovum : the male Ibla has 
no such organ ; and no doubt the whole body, furnished 
like the penis with longitudinal and transverse muscles, 
serves the same purpose ! I may remark, that it seems 
surprising that so small a male should secrete sufficient 
semen to impregnate the ova of the female, but the ova 
are not nearly so numerous in Ibla as in most genera of 
Cirripedes ; and the smallness of the males in some para- 
sitic Crustacea has already been alluded to. The male 
must always be younger than the female, for the latter 
must first grow large enough for the larva of the male to 
crawl into her sack. Whether the male lives as long as 
the female I know not, but he certainly lives for a con- 
siderable period and increases in size, as shown by the 
depth to which the end of the peduncle is imbedded. 
Moreover we shall see, under the next species, that the 
male is metamorphosed from a larva, not one sixth of its 
own size. 

In the male Ibla, abortion has been carried to an ex- 
traordinary and, I should think, almost unparalleled 
extent. Of the twenty-one segments believed to be nor- 
mally present in every Crustacean, or of the seventeen 
known to be present in Cirripedes, the three anterior 
segments are here well developed, forming the peduncle : 
the mouth consists as usual of three small segments : 
the succeeding eight segments are represented by the 
rudimentary and functionless thorax, supporting only 
two pair of distorted, rudimentary and functionless cirri : 
the seven segments of the abdomen have disappeared, 
with the exception of the excessively minute caudal 
appendages ; so that, of the twenty-one normal segments, 
fifteen are more or less aborted. The state of the cirri 
is curious, and may be compared to that of the anthers 
in a semi-double flower; for they are not simply rudi- 
mentary in size and function, but they are monstrous, and 
generally do not even correspond on opposite sides of the 



IBLA QUADR1VALVIS. 203 

same individual. As males in other classes of the animal 
kingdom often retain some female characters, so here 
(though the case is not strictly analogous*) the male pos- 
sesses the cementing apparatus, which homologically is 
part of an ovarian tube modified. 

The individuals in every other genus (with the exception 
of Scalpellum), in the several families, in the three Orders 
of Cirripedia, are hermaphrodite or bisexual. Why, then, 
is Ibla unisexual ; yet, becoming, in the most paradoxical 
manner, from its earliest youth, essentially bisexual? 
Would food have been deficient, and was the seizure of 
infusoria by another and differently constructed individual, 
necessary for the support of the male and female organs ? 
The orifice of the sack of the female is unusually narrow ; 
would the presence of testes and vesiculae seminales have 
rendered her thorax and prosoma inconveniently thick ? 
Seeing the analogous facts in the six, differently-con- 
structed species of the allied genus Scalpellum, I infer 
there must be some profounder and more mysterious 
final cause. 



2. Ibla quadrivalvis. PL IV, fig. 9. 

Anatifa quadrivalvis. Cuvier. Mem. pour servir . . . Mollusq. 

1817, Art. Anatifa, Plate, figs. 15, 16. 
Lbla cuvieriana. /. E. Gray. Annals of Philosophy, vol. x, 

New Series, Aug. 1825. 
— J". K Gray. Spicilegia. Zoolog. Tab. iii, fig. 10. 

Tetralasmis hirstjtus. Cuvier. Regne Animal, vol. iii, 1830, 
Anatifa hirsuta. Quoy et Gaimard. Voyage de l 5 Astrolabe, 

PL xciii, figa3. 7—10, 1834. 



* Certain plants offer a closer, though not perfect, analogy. Thus, in the 
florets of some compositous flowers, the pistil, besides its proper female 
functional end, serves to brush the pollen off the anthers ; while, in the florets 
of some other compositse (see the account of Silphium in \ Ch. K. Sprengel 
Das entdeckte Geheimniss der Natur'), the pistil is functionless for its 
proper end, the flower being exclusively male, but its style is developed, 
and still serves as a brush. So in the male Ibla, part of the ovaria, in a 
modified condition, is still present, and serves as a cementing apparatus. 



204 IBLA QUADRIVALVIS, 

I. (Herm.), valvis et pedunculi spinis sub-flavis : basal 7 
tergorum angulo, introrswn spectanti, hebete, quia mar go 
carinalis inferior longius quam margo scutalis prominet. 

Hermaph. — Valves and spines on the peduncle yellow- 
ish : basal angle of the terga, viewed internally, blunt, 
owing to the lower carina! margin being more protu- 
berant than the scutal margin. 

Caudal appendages four times as long as the pedicels 
of the sixth cirrus : rami of the first cirrus unequal in 
length by about six segments. 

Comple mental Male, with a notched crest on the 
dorsal surface, forming a rudiment of a capitulum : 
maxillae well furnished with spines. 

Kangaroo Island, South Australia (Mus. Brit., given by Cuvier to Leach) ; 
Adelaide, South Australia (Mus. Stutchbury) ; King George's Sound, Voyage 
of Astrolabe; New South Wales, attached to a mass of the Galeolaria 
decumbens, (Mus. Hancock). 

HERMAPHRODITE. 

All the external parts so closely resemble those of 
I. Cumingii, that it would be superfluous to describe 
more than the few points of difference. The horny 
substance of both scuta and terga is uniformly yellow ; 
though in dryed specimens, from the underlying corium 
being seen through the valves, these generally have a 
tinge of blue. 

The Scuta, viewed internally, are less elongated trans- 
versely ; they have their basal margins slightly more 
hollowed out, and the fold on the upper free and horn- 
like portion rather deeper. 

The Terga, viewed internally, have the apex of the 
growing or corium-covered surface higher relatively to 
the scuta than in I. Cumingii; and the basal angle is 
much broader, owing to the lower carinal margin being 
much more protuberant than the scutal margin. The 
spines on the peduncle are all yellowish-brown, and are 
rather longer than in Z Cumingii. I observed in three 
or four specimens, that the lowest part of the peduncle 



HERMAPHRODITE. 205 

had become internally filled up with the usual, brown, 
transparent, laminated cement, cone within cone, so that 
this lower part was rendered rigid and stick -like ; this, 
latter effect, I apprehend, is the object gained by the forma- 
tion of cement within the peduncle, of which I have not 
observed any other instance. The entire length of the 
largest specimen was one inch ; some other specimens were 
only half this size. 

The thorax and prosoma are of the same shape as in 
I. Cumingii, and in the largest specimen, about one tenth 
of an inch square ; the prosoma, as in that species, is hairy. 
In the Mouth, all the parts are closely similar to those of 
/. Cumingii, but one third larger ; the crest of the labrum 
is a little roughened with minute points : the palpi are 
squarer and blunter at their extremities : the mandibles 
have their second and third teeth nearly equal in size to 
the first, and they do not appear pectinated : the maxillae 
have their spinose edge very nearly straight : the outer 
maxillae are pointed. The olfactory orifices are similarly 
situated, and of similar shape ; they are dark coloured. 

Cirri. — These also are similar to those of I. Cumingii; 
the segments, however, of the three posterior cirri have 
each four pair of spines, placed very close together in a 
transverse direction. First cirrus has its two rami un- 
equal in length by about six segments. The anterior 
rami of the second and third cirri are thicker, and more 
thickly clothed with spines, than the posterior rami, to 
perhaps a greater degree than in I. Cumingii. In the 
posterior cirri, the upper segments of the pedicels are 
nearly as long as the lower segments. 

Caudal Appendages, four times as long as the pedicel 
of the sixth cirrus, and three fourths of the length of the 
rami of this same cirrus : segments thirty-two in number, 
and therefore as many as those forming the sixth cirrus : 
the upper segments are much thinner and longer than 
the basal segments ; each furnished with a circle of short 
bristles ; whole appendage excessively thin and tapering : 
the two closely approximate. 



206 IBLA QUADRIVALVIS, 

Colour. — From some well-preserved dryed specimens 
in Mr. Stutchbury's possession, it appears that the sack, 
cirri and tropin, were dark blue, as in I. Cumingii; after 
being long kept in spirits, these parts become brown. 

Generative System. — The penis (PL IV, fig. da) is very 
singular in structure ; it is of the ordinary length, but 
of small diameter ; it tapers but little ; it consists of a 
moveable articulated, and a fixed unarticulated portion ; 
this latter is smooth, much flattened, not divided into 
segments, and projects straight out under the caudal 
appendages ; it is about one third of the length of the 
entire penis ; it corresponds with a part present in all 
Cirripedes, but here surprisingly elongated. The articu- 
lated portion consists of separate segments, twenty in 
number, quite as distinct as those of the cirri ; each one 
is oblong, being longer by about a third part than broad ; 
each has a few short bristles round its upper margin ; 
the terminal segment has a circular brush of bristles. 
The vesiculae seminales are easily seen, though they are 
narrow ; they are slightly tortuous ; they enter the pro- 
soma, and lie on each side of the stomach ; their outer case 
has a ringed structure, but is not fibrous ; the contents 
in the best specimen consisted of a mass of spermatozoa, 
which I saw with perfect distinctness. The testes are 
unusually large and egg-shaped. 

Ova, spherical, ^ths of an inch in diameter, united as 
usual into two ovigerous lamellae. The ovigerous fraena 
are extraordinarily small, and might be very easily over- 
looked ; their length, in a full-sized specimen, was only 
5^ths of an inch, and they projected only ^ths from the 
inner surface of the sack. The glands on their margin, 
to which the lamellae adhere, are pointed oval, with 
an extremely short footstalk, and that rather thick ; the 
entire length of gland and footstalk, being only ^ths of 
an inch. The larvae, in their first stage of development, 
offer the usual characters, and closely resemble those of 
Scalpellum ; the probosciformed mouth, however, is re- 
markably prominent, and the limbs unusually thick. 



COMPLEMENTAL MALE. 207 

Affinities. — This species most closely resembles I. 
Cumingii, and cannot be distinguished externally, except 
by the absence of the blue colour on the marginal and 
interior portions of the valves ; and this can hardly be 
ascertained without separating and cleaning them, owing 
to the blueness of the underlying corium. Internally 
some slight differences may be perceived in the form of 
the valves. Considering these so slight differences, it is 
highly remarkable that this species should be hermaphro- 
dite, whilst J. Cumingii is unisexual. There is a greater, 
though still slight, difference in the included animal's 
body ; the palpi in L quadrivalvis are blunter, the man- 
dibles smoother, the olfactory orifices darker-coloured ; 
the rami of the first cirrus more unequal, the spines 
more numerous on the segments of the posterior cirri, and 
lastly and most conspicuously, the caudal appendages 
are very much longer relatively to the length of the sixth 
cirrus, than in Ibla Cumingii. 

COMPLEMENTAL MALE. 

I have examined one specimen of the hermaphrodite 
/. quadrivalvis, preserved in spirits from Kangaroo Island, 
and one dry from Adelaide, both places in South Australia, 
and four from an unknown locality, purchased from 
Mr. Sowerby ; and within five out of these six specimens, 
males were attached. In one of them, two males of dif- 
ferent ages were included, one adhering to the peduncle 
of the other : in I. Cumingii, also, it may be remem- 
bered, there was a case of two males parasitic on one 
female. I may add that I opened another quite young 
specimen, from Adelaide, not counted with the above, and 
it was without a male. The males in the five specimens 
were attached low down, at the rostral end, almost in a 
horizontal position, stretching across the bottom of the 
sack ; one of them, however, was placed considerably on 
one side. One individual which I measured, was ^ths of 
an inch in length, and —ths in width in the widest part, 



208 IBLA QUADRIVALVIS, 

namely, about half down the peduncle. I may state, for 
the sake of comparison, that the hermaphrodite to which 
this individual was attached, was, including the peduncle 
and capitulum, one inch in length, that is, six times as 
long as the male, and one fifth of an inch in width, that 
is, four times as wide. The above measurements show 
that the male of this species is rather more than twice 
as large as that of I. Cumingii. In consequence of this 
greater size, I dissected, with the utmost care, the one 
specimen which was excellently preserved in spirits, and 
found every part, with a few exceptions, so exactly the 
same as in the male of I. Cumingii, only larger and more 
conspicuous, that it will be sufficient to indicate the few 
points of difference. 

The most conspicuous difference is, that the oblique 
fold separating the thorax and peduncle is more plainly 
developed, projecting at the point corresponding to h in 
fig. 1, PL V, Troths of an inch ; in the middle the fold is 
notched ; it can be traced more easily than in I. Cumingii, 
running beneath and parallel to the basal edge of the 
mouth, to the ventral margin of the body. In the mouth 
there is hardly any difference ; the maxillae, however, 
have two notches even plainer than in the hermaphrodite 
/. quadrivahis, or than in the male I. Cumingii, but the 
depth of such notches is always a variable character ; 
there are also more spines on the edge in the male of the 
present species, than in /. Cumingii. Both mandibles 
and maxillae in the male I. quadrivalvis, are larger than in 
the male I. Cumingii, to a greater degree than the larger 
proportional size of the body in the former will account 
for ; and this, likewise, is the case with these same organs 
in the hermaphrodite I. quadrivalvis compared with the 
female I. Cumingii. The tubular olfactory orifices are 
situated in the same peculiar position as in the herma- 
phrodite, and as in both sexes of L Cumingii : they are 
3^th of an inch in diameter, and about as thick as one of 
the lower segments in the rami of the sixth cirrus. 

The thorax, as in the male of I. Cumingii, is quite 



COMPLEMENTAL MALE. 209 

rudimentary, and serves as a mere flap to protect the 
mouth. In the three specimens carefully examined, the 
posterior cirri had each only one ramus, whilst the anterior 
cirri generally had two : in one specimen, one of the rami 
in the anterior cirrus was formed of five segments, and 
the other ramus of three segments, both rami being sup- 
ported on a uni-articulated pedicel ; but on the opposite 
side of the same individual, the anterior cirrus was repre- 
sented by a mere knob. The longer ramus of the anterior 
cirrus, in the best-developed individual, barely exceeded 
in length the mandibles measured along the line of the 
teeth ! In one specimen between the bases of the pos- 
terior cirri, there were two perfectly distinct caudal appen- 
dages ; these, like the cirri, are in a quite rudimentary con- 
dition; one was Troths of an inch in length, and consisted 
of three segments, the upper edges of which had short 
spines ; the other was shorter, uni-articulated, but spinose. 
In a second specimen, these appendages were quite 
aborted. Close under them, on the inside or towards the 
mouth, (that is, in the normal position,) there was a 
rudimentary but quite distinct penis, with the apex pro- 
jecting freely, and with the sides distinguishable from the 
ventral surface of the thorax, for the length of -^th of an 
inch : the corium lining this little penis made the terminal 
orifice plainly visible. The vesiculse seminales lie in the 
usual position, and are conspicuous ; they are slightly 
tortuous, with their ends blunt : in the specimen so well 
preserved in spirits, they were filled with a mass of sper- 
matozoa, perfectly distinct ; and the whole cavity of the 
body was lined with globular and pear-shaped testes. 
Assuredly there was no vestige of ovarian tubes. From 
the greater size and excellent preservation of this specimen, 
which rendered the examination of the generative system 
so easy, I was able to examine the contents of the stomach, 
in which I found the delicate epithelial coat, separated as 
usual, and containing cellular matter, on which the animal 
had preyed, but the nature of which I was unable to 

14 



210 IBLA QUADRIVALVIS, 

make out. The anus was much plainer than in the 
male of I. Cumingii. I saw the eye distinctly. I could 
not distinguish the orifices of the acoustic (?) sacks ; and 
I think I should have seen them, if they had existed. 

Prehensile Antenna. — I examined these in the larvae 
presently to be mentioned, and therefore they were in 
better condition than in the mature animal when 
cemented. Their total length, measured along the out- 
side, from the basal articulation to the end of the disc, is 
sloths or ^ths of an inch — that is, one third longer than 
in I. Cumingii ; whilst the hoof-like disc itself is ^ths, or 
only g^oth of an inch longer than this same part in 
I. Cumingii : the apex of the disc is downy, or bears 
some excessively minute spines. The ultimate segment 
has its end irregularly rounded, with the spines obscurely 
divided into two groups, the outer group consisting of two 
or three longer and thinner spines, and the inner group of, 
as I believe, five rather shorter spines : the longer spines 
equal in length the whole ultimate segment. I could not 
perceive that they were plumose, as in many other genera. 
A single, rather thicker and long spine, pointing back- 
wards, is attached to the under side of the disc, nearly 
opposite to the point where the ultimate segment is arti- 
culated on the upper convex surface. Another single, 
curved spine is attached on the outer side of the basal 
segment, near its distal end. 

Development of the Male. — In the specimen before al- 
luded to, which included two males, one of these was only 
the i&ths of an inch in length, and therefore between one 
fifth and one sixth of the size of the mature male. It had, 
probably, undergone only one exuviation since its meta- 
morphosis, for the larva is nearly as long, namely, Tilths 
of an inch. In this young male, the mouth formed one 
third of the entire length : it was attached, not as in every 
other case to the sack of the hermaphrodite, but low 
down to the peduncle of the other male. 

In the sack with these two males, there were certainly 



COMPLEMENTAL MALE. 211 

four, I believe five, larvae, which in every main point of 
structure resembled the larvae of other pedunculated 
Cirripedes. From the peculiar form of their prehensile 
antennae, differing in no respect, except in the propor- 
tional lengths of the segments, from the same organ in 
the male /. Currdngii^ I can feel no doubt that these were 
the larvae of the male I. quadrivalvis ; — for a moment's 
reflection will show how excessively improbable it is, that 
several larvae of some other Cirripede, and that a Cirri- 
pede intimately allied to the parasitic male Ibla, should 
have forced themselves, without any apparent object, into 
the sack of the hermaphrodite Ibla. The larvae, though 
not yet attached, were on the point of attachment, 
so that the single eye of the mature animal could be 
distinctly seen, lying near to the two great compound eyes 
of the larva. We have also just seen, that one male quite 
recently here had undergone its metamorphosis. The 
larvae are T f§oths of an inch in length, and rather more than 
-^oths in width in the widest part : they are boat-shaped, 
the dorsal edge forming the keel of the boat ; the ante- 
rior end is only a little blunter than the posterior end ; 
the quasi-bivalve carapace is smooth. All the essential 
points of structure in the larvae of other Cirripedes at 
this stage, could be distinctly here seen, — such as the 
two compound eyes, with the apodemes to which they 
are attached, and the two oblong sternal plates whence 
the apodemes spring, — the adductor muscle, — the six 
natatory legs, with long plumose spines, — the abdomen, 
with its three small segments and the caudal appendages, 
— the prehensile antennae already described, — and, lastly, 
the two little (auditory ?) sacks at the an tero- sternal edges 
of the carapace, but not so near the anterior extremity as 
in Lepas. The four or five larvae, after having undergone 
in the open sea the several preparatory metamorphoses 
common to the class, must have voluntarily entered the 
sack of the hermaphrodite : ultimately would they, on 
finding two males already attached there, have retired, 
and sought another individual less well provided ; or 



212 IBLA QUADRIVALVJS, 

would they all have remained, and so formed a polyandrous 
establishment, such as we shall presently see occurs some- 
times in Scalpellum? This must remain quite uncertain. 

In this same hermaphrodite specimen of I. quadri- 
valvis, the two ovigerous lamellae contained some hundreds 
of larvae in the first stage of development, which were 
liberated from their enveloping membranes by a touch of 
a needle : they were about the y^ths of an inch in length, 
and presented all the usual characters of larvae at this 
period. What a truly wonderful assemblage of beings 
of the same species, but how marvellously unlike in 
appearance, did this individual hermaphrodite present ! 
We have the numerous, almost globular larvae, with 
lateral horns to their carapaces, with their three pair of 
legs, single eye, probosciformed mouth and long tail : — 
we have the somewhat larger larvae in the last stage of 
development, much compressed, boat-formed, with their 
two great compound eyes, curious prehensile antennae, 
closed rudimentary mouth and six natatory legs so diffe- 
rent from those in the first stage : — we have the two 
attached males, with their bodies reduced almost to a 
mouth placed on the summit of a peduncle, with a minute, 
apparently single eye shining through the integuments, 
without any carapace or capitulum, and with the thorax 
as well as the legs or cirri rudimentary and functionless : 
— lastly, we have the hermaphrodite, with all its com- 
plicated organisation, its thorax supporting six pairs of 
multi-articulated two-armed cirri, and its well-developed 
capitulum furnished with horny valves, surrounding this 
wonderful assemblage of beings. Unquestionably, without 
a rigid examination, these four forms would have been 
ranked in different families, if not orders, of the articu- 
lated kingdom. 

Concluding Remarks. — If the creature which I have con- 
sidered as the male of Ibla Cuniingii be really so, and the 
evidence formerly given seems to me amply conclusive, 
then the animal just described, from its close affinity in 
every point of structure with the former, assuredly is the 



COMPLEMENTAL MALE. 213 

male of Ibla quadrivahis. But feeling strongly how im- 
probable it is, that an additional or complemental male 
should be associated with an hermaphrodite, I will make 
a few remarks on the only possible hypothesis, if my view be 
rejected, — namely, that the two parasites considered by me 
to be exclusively males, are not so, but are independent her- 
maphrodite Cirripedes, the female organs and ova (which, 
if present, would have been nearly mature, judging from 
the presence of spermatozoa in both species) having been 
overlooked by me in every specimen : and again, that in 
the animal described as the female I Cumingii, I have, 
though minutely dissecting several specimens, and find- 
ing far smaller parts, such as the organs of sense and 
nervous system, entirely overlooked all the conspicuous 
male organs, though when I came to /. quadrivahis, and 
naturally expected to find it likewise exclusively female, a 
single glance showed me the great probosciformed penis, 
and by the simplest dissection the vesiculae seminales and 
testes were exhibited. Such an oversight is scarcely cre- 
dible; but even if assumed, we have to believe in the 
extraordinary circumstance of the two parasites being 
species of an independent genus, not only the very next 
in alliance to the animals to which they are attached, but 
in certain most important points, namely, the organs 
of the mouth, actually deserving a place in the very 
same genus. Moreover, the two parasites differ from 
each other, not only in about the same slight degree, but 
in a corresponding manner, as do the two Iblas to which 
they are attached ; thus the mouths of Ibla quadrivahis 
and I. Cumingii are closely similar, (the difference being 
barely of specific value,) so are the mouths of the two 
parasites ; but the parts are larger in the hermaphrodite 
I, quadrivahis, than in I. Cumingii, so are they in the 
parasites. Again, the most conspicuous character in 
I. quadrivahis, is the number of segments in the caudal 
appendages, far exceeding those in the other species of 
Ibla, as well as of every other pedunculated Cirripede, 
and the parasite of this species has articulated spinosc 



214 IBLA QUADRIVALV1S. 

appendages, far larger than the barely visible, non-articu- 
lated pair in I Cumingii. 

Considering the whole case, there seems no room to 
doubt the justness of the conclusion arrived at, under the 
former as well as under the present species, namely, that 
these little parasites are the males of the two species of 
Ibla to which they are attached ; — wonderful though the 
fact be, that in one case, the male should pair with an 
hermaphrodite already provided with efficient male organs. 
It is to bring this fact prominently forward, that I have 
called such males, Complemental Males ; as they seem to 
form the complement to the male organs in the herma- 
phrodite. We look in vain for any, as yet known, analogous 
facts in the animal kingdom. In the genus Scalpellum, 
however, next in alliance to Ibla, in which, consequently, 
if anywhere, we might expect to find such facts, they 
occur; and until these are fully considered, I hope the 
conclusions here arrived at, will not be summarily rejected. 
Although the existence of Hermaphrodites and Males 
within the limits of the same species, is a new fact 
amongst animals, it is far from rare in the Vegetable 
Kingdom : the male flowers, moreover, are sometimes in 
a rudimentary condition compared to the hermaphrodite 
flowers, exactly in the same manner as are the male Iblas. 
If the final cause of the existence of these Complemental 
Males be asked, no certain answer can be given ; the 
vesiculse seminales in the hermaphrodite of Ibla quaclri- 
valviSy appeared to be of small diameter ; but on the 
other hand, the ova to be impregnated are fewer than in 
most Cirripedes. No explanation, as we have seen, can 
be given of the much simpler case of the mere separa- 
tion of the sexes in Ibla Cumingii ; nor can any expla- 
nation, I believe, be given of the much more varied 
arrangement of the parts of fructification in plants of 
the Linnean class, Polygamia, 



GENUS — SCALPELLUM. 215 



Genus — Scalpellum. Pis. V, VI. 

Scalpelltjm. Leach. Journ. de Physique, t. lxxxv, July, 1817. 

Lepas. Linn. Systeina Naturae, 1767. 

Pollicipes. Lamarck. Animaux saus Vertebres, 1818. 

Polylepas. Be Blainville. Diet, des Sc. Nat., 1824. 

Smilium (pars geueris). Leach. Zoolog. Journal, vol. 2, July, 

1825. 
Calantica (pars geueris). /. E. Gray. Anuals of Philosophy, 

vol. x, (new series,) Aug. 1825. 
Thaliella (pars geueris). /. E. Gray. Proc. Zoolog. Soc, 1848. 
Anatifa. Quoy et Gaimard. Voyage de l'Astrolabe, 1826 — 34. 
Xipiiidium (pars geueris). Dixon. Geology of Suffolk, 1850. 

{Herm. et Fcem.) Valvis 12 ad 15 : lateribus verticilli 
inferioris quatuor vel sex, lineis incrementi pier unique 
convergent 5 us : sub-rostrum rarissime adest : pedunculo 
squamifero, rarissime nudo. 

(Herm. and Fern.) Valves 12 to 15 in number : latera 
of the lower whorl, four or six, with their lines of growth 
generally directed towards each other : sub-rostrum very 
rarely present : peduncle squamiferous, most rarely naked 

Filamentary appendages, none : labrum, with the upper 
part highly bullate : tropin, various : olfactory orifices, 
more or less prominent : caudal appendages, uniarticulate 
and spinose, or none. 

Males, parasitic at or near the orifice of the sack of the 
female or of the hermaphrodite : thorax enclosed within 
a capitulum, furnished with three or four rudimentary 
valves, or with six perfect valves : peduncle either short 
and distinct, or confounded with the capitulum : some- 
times mouth and stomach absent, and cirri non-prehen- 
sile ; sometimes mouth and cirri normal. 

Generally attached to horny corallines, in the warmer temperate seas over 
the whole world. 

I have felt much doubt in limiting this genus : the six 
recent species which it contains, differ more from each 
other than do the species in the previous genera. Mr. 



216 GENUS SCALPELLUM. 

Gray lias proposed or adopted generic names for four of 
the species, and a fifth certainly has equal claims to this 
same rank. These genera have been founded almost 
exclusively on the number of the valves ; and oddly 
enough, the numbers have generally been given wrongly, 
namely, in Scalpellum, Calantica, Thaliella, and Xiphi- 
dium. Scalpellum blends through S. villosum into 
Pollicipes ; and this latter genus has an equal right with 
Scalpellum, to be divided into sub-genera, three in number. 
Hence, no less than eight genera might be made out of the 
twelve recent species of Scalpellum and Pollicipes, and 
their formation, in some degree, be justified ; but, in my 
opinion, this inordinate multiplication of genera destroys 
the main advantages of classification. At one time, I 
even thought that it would be best to follow Lamarck, 
and keep the twelve recent species in one genus ; but 
considering the number of fossil species, I believe the 
more prudent course has been followed, in retaining the 
two genera Scalpellum and Pollicipes ; more especially 
as I can hardly doubt, that several other species will be 
hereafter discovered. 

Having so lately described in the Memoirs of the 
Palseontographical Society, the fossil species, I will not 
here further allude to them, than to state, that out of the 
fifteen species therein described, S. magnum comes very 
close to the recent S. vulgar e, and that several Eocene 
and Cretaceous species, such as S. quadrat urn 7 S. fossula, 
and S. maximum, are allied to S. rutilum and S. ornatum. 
Scalpellum villosum, a recent species, has stronger claims 
than any other species to be generically separated ; and 
its habits, in not being attached to horny corallines, are 
also different, but the identity of its Complements Male 
with that of S. Peronii, and its numerous points of resem- 
blance in structure with the other species, have deter- 
mined me not to separate it. Scalpellum Peronii, villo- 
sum, and rostratum, in having a sub-carina, — in the 
rostrum being pretty well developed, — and in the Com- 
plemental Male being pedunculated, and furnished with 



GENUS — SCALPELLUM. 217 

a functional mouth and prehensile cirri, may be separated 
from 8. vulgar e^ ornatum and rutilum; but even between 
these two little groups, 8. rostgratum is in some respects 
intermediate, namely, in having three pairs of latera, and 
more especially in the rudimentary condition of the 
valves of its Complemental Male, and in the position in 
which the male is attached to the hermaphrodite. The 
three species in the second little group, namely, S. vulgar e, 
8. ornatum, and 8. rutilum, are more nearly allied to 
each other in all their characters, especially in the cha- 
racters drawn from their Males, than are the other three 
species. 8. ornatum and 8. rutilum are considerably 
nearer to each other than any other two of the species. 
Upon the whole I conclude that the six species must be 
thrown either into five or into four genera (the first three 
species making one genus), or all into one genus, and this 
latter has appeared to me the preferable course. The 
separation even of Scalpellum and Pollicipes, as already 
stated, is hardly natural. The fact of these genera having 
existed from a remote epoch, and having given rise during 
successive periods to many species now extinct, is probably 
the cause that the few remaining species are so much 
more distinct from each other, than is common in the 
other genera of Lepadidse. Whenever the structure of 
the whole capitulum in the fossil species is well known, 
and as soon as more species, recent and fossil, shall have 
been discovered, then probably the genus Scalpellum will 
have to be divided into several smaller genera. 

Description. — The Capitulum is much compressed, 
and generally produced upwards; it is formed of from 
twelve to fifteen valves, which are rather thin, and 
with the exception of 8. ornatum, almost entirely covered 
by membrane, bearing spines : the valves are seldom 
locked very closely together. A sub-rostrum exists only 
in 8. villosum, which species leads on to Pollicipes : in 
8. vulgar e the rostrum is rudimentary and hidden. The 
scuta, terga and carina, are much larger than the other 
valves : these five valves seem to differ essentially from 



218 GENUS SCALPELLUM. 

the others in being at first developed under the form of 
the so-called primordial valves : the other valves com- 
mence by a small indistinct brown spot, very different 
from the hexagonal tissue of the primordial valves : I 
saw this very clearly in young specimens of S. vulgar e. 
At first, the scuta, terga and carina, grow exclusively 
downwards (and permanently so in most fossil species), 
and therefore the growth of the scuta and carina is in an 
absolutely opposite direction to what it is in Lepas, 
Psecilasma and Dichelaspis. After a short period the 
scuta are added to at their upper ends ; the portion thus 
added, stands at a rather lower level, and projects in a 
rather different direction from the first-formed part of 
the valve, giving to it, in some respects, the appearance 
of having been broken and mended. This structure is 
common to S. vulgare, S. rostratum and S. Peronii. The 
upper Latera (except in S. villosum) grow in the same 
manner, namely, at first exclusively downwards, and then 
both upwards and downwards. The rostral and carinal 
latera (with the same exception of S. villosum) have their 
um bones seated laterally, at opposite ends of the capitu- 
lum, — the umbones of the rostral latera being close to 
the rostrum, and those of the carinal pair close to the 
carina, and consequently their chief growth is directed 
towards each other. The carina in all the species, except 
S. villosum, is either bowed or angularly bent ; in the 
latter case the lower half is parallel to the peduncle, and 
the upper half, extending far up between the terga, is 
parallel to their longer axes. In some of the species the 
carina is added to almost equally at both ends; in 
8. ornatum it grows but little at the upper end, and to a 
varying degree in different individuals according to their 
age ; in 8. rutilum the umbo is at the apex, and there is 
consequently no upward growth ; lastly, in jS. villosum 
the carina widening much from the apex to the basal 
margin, grows exclusively downwards, and a portion of 
the apex projects freely, — characters all common to the 
carina in the genus Pollicipes. The upper latera occur 



GENUS — SCALPELLUM. 219 

in all the species ; in the lower whorl there are either 
two or three pair of latera, in the former case the infra- 
median pair being absent. The latera differ considerably 
in shape in the different species. 

The Peduncle is generally rather short, and, with the 
exception of S. Peronii, is covered with calcified scales. 
These scales are generally small, and placed symmetri- 
cally in close whorls, in an imbricated order, with each 
scale corresponding to the interspace between two scales 
in the whorls above and below. In S. ornatum, the 
scales are so wide, transversely, that there are only four 
in each whorl. In S. villosum, the scales are spindle- 
shaped and arranged somewhat irregularly in transverse 
rows, not very near to each other. New calcareous scales 
originate only round the top of the peduncle, and they 
continue to grow only in the few upper whorls ; and as 
the peduncle itself continues to increase in diameter by 
the formation of new inner membranous layers and the 
disintegration of the old outer layers, the calcareous scales 
come in the lower part of the peduncle to stand further 
and further apart. In the earliest stage of growth there 
are no calcareous scales on the peduncle in S. vulgare ; 
they first appear under the carina. Spines are articu- 
lated in great numbers on the surface of the peduncle in 
S. vulgar e, S. Peronii, and S. villosicm, and very short ones 
on that of S. roslratum. 

Attachment, — All the species, except S. villosum, are 
attached to horny corallines : the singular means of 
attachment in S. vulgare will be described under that 
species, and is probably common to several of the other 
species. The larva in most, or in all cases, when it pro- 
ceeds to attach itself, clings head downwards to the 
branch, and hence the capitulum comes to be placed 
upwards, with its orifice fronting the branch and the 
carina outwards. The sucking disc of the prehensile 
antennse of the larva, in the five species examined, was a 
little pointed, and in shape resembled the hinder hoof 
of a mule : this may perhaps be accounted for by the 



220 GENUS SCALPELLUM. 

narrowness of the branches of the corallines, to which it 
has to adhere : a large circular disc, as in Lepas, would 
have been worse than useless : the ultimate segment in 
most or all the species, has on its inner side (the segment 
being supposed to be extended straight forward) a notch 
or step, bearing, I believe, two spines. 

Size and Colour. — Some of the species attain a medium 
size, others are small. The valves are generally clouded 
red or pink, but sometimes white. 

Mouth. — The various parts vary far more than in any 
genus hitherto described. The labrum is highly bullate, 
with the upper part forming a rounded overhanging 
projection, and with the lower part much produced, so 
that the mouth is placed far from the adductor scutorum 
muscle, and consequently the orifice is directed more 
towards the ventral surface of the thorax than in most 
other Cirripedes : on the crest of the labrum there are 
some very small teeth in several of the species, but not 
in all. The mandibles have either three or four main 
teeth, generally with either one or two small teeth inter- 
mediate between the first and second large teeth, and 
in the case of S. Peronii, with small teeth between all 
the larger ones. The maxillae have their edges furnished 
with many spines, and are either straight or have the 
inferior part prominent and step-formed. The outer 
maxillae have the spines on their inner edges either con- 
tinuous or divided into two groups, of which latter struc- 
ture we have not hitherto had any very well characterised 
example. The olfactory orifices are either highly or 
moderately protuberant. 

In most of the species the prosoma is little developed, 
and the first cirrus is placed far from the second. The 
Cirri are generally but little curled, and have elongated 
segments, with long, generally serrated spines : the first 
cirrus varies in proportional length ; the second and 
third cirri have both their rami more thickly clothed with 
spines than are the three posterior cirri, the spines being 
generally arranged in three or four longitudinal rows : 



GENUS SCALPELLUM. 221 

the cirri, however, of S. villosum in all respects resemble 
closely the cirri of Pollicipes sertus and P. spinosus. 

The Caudal Appendages are uniarticulate, small, and 
clothed with spines : in S. villosum, however, differently 
from in all other allied forms, there are no appendages. 

The Stomach, in those species which 1 opened, is desti- 
tute of caeca. There are no filamentary appendages. 

Generative System. The ova are nearly spherical, and 
remarkably large, as was stated to be the case in the in- 
troductory discussion, in which the larva of S. vulgare, 
in the first stage of development, was described : the 
ovigerous fraena are small. The testes are large, but the 
vesiculse seminales in some of the species extraordinarily 
small. Scalpellum ornatum, and perhaps S. rutilum, 
are unisexual ; the other species are hermaphrodite, but 
most or at least some of the individuals, are furnished 
with Complement al Males. These latter are fully de- 
scribed under each species, so I will here only remark, 
that S. ornatum, which alone (excepting perhaps S. rutilum) 
is unisexual, has less claim than the other species to be 
generically separated : we have seen also, in Ibla, that 
similar sexual differences occur in two most closely allied 
species. It is very singular how much more some of 
the Males and Complemental Males in Scalpellum differ 
from each other, than do the female and hermaphrodite 
forms ; this seems due to the different stages of embryonic 
development at which the males have been arrested. 
In the males, however, of S. rostratum, S. Peronii, and 
S. villosum, compared one with another, but not with the 
males of the other species, the parts of the mouth and 
apparently the cirri, resemble each other more closely, 
than do the same organs in the hermaphrodites. At the 
end of this genus I shall give a summary on the highly 
remarkable sexual relations both in Scalpellum and Ibla. 

Distribution. — The species seem distributed over the whole world, but as 
far as we can trust our present scanty materials, are most common in the 
warmer temperate regions. The S. vulgare ranges from the Norwegian 
seas to Naples. Most of the species are inhabitants of deep water. 



222 SCALPELLUM VULGARE. 

Affinities. — In the preliminary remarks, we have seen 
how this genus blends into Pollicipes ; and under the 
head of Oxynaspis, I have shown its close affinity to 
that genus. If, indeed, we take Pollicipes spinosus, and 
destroy all but six of the already minute and almost 
rudimentary latera, we shall, as far as the capitulum 
is concerned, convert it into a Scalpellum, closely 
similar to S. villosum. If we take any species of Scal- 
pellum, (excepting S. villosum and S. rutilum,) and destroy 
all the valves, bat the scuta, terga and carina, we shall 
convert it into an Oxynaspis. Lastly, I have shown 
under Ibla, that in several most remarkable peculiarities 
of structure, there is a manifest affinity between Scal- 
pellum and that genus. 

Geological History. — Full details on this subject have 
been given in the Memoirs of the Palseontographical 
Society. I will here only state, that the oldest known 
form of Scalpellum occurs in the Lower Green Sand. 



[f SUB-CARINA NULLA.] 

1. Scalpellum Vulgare. PL V, fig. 15. 

Scalpellum vulgare. Leach. Encyclop. Brit. Suppl., vol. iii, 

1824. 

Lepas Scalpellum. Linn. Systema Naturae, 1767. 

— Poli. Test, utriusque Siciliae, PI. vi., fig. 10. 

1795. 

Pollicipes Scalpellum. Lamarck. An. sans Vertebres, 1818. 

Polylepas vulgare. Be Blainville. Diet. Sc. Nat., Plate, 

fig. 4. 1824. 
Scalpellum l^eve, var. Leach. Zoolog. Journal, vol. ii, p. 215, 

1825. 
— SiciLLffi, var. Chenu. Illust. Conch. PI. iv, fig. 9. 

Scalpellum vulgare, (et var.) Brown. Illust. of Conch., 1844, 

PL li, figs. 7 to 20. 

S. (Hem.) valvis 14, si rostrum p eerie rudimentale 
includatur : lateribus superioribus incequaliter ovatis. 



HERMAPHRODITE. 223 

(Herm.) Capitulum with 14 valves, including the 
rudimentary rostrum : upper latera irregularly oval. 

Mandibles, with four or live teeth : maxillae, with the 
edge straight, bearing numerous spines. 

Complemental Male flask-formed, with four rudi- 
mentary valves; no mouth; cirri not prehensile; attached 
to the occludent margin of the scutum, near the umbo. 

Great Britain, Ireland, France, Norway, Naples. Attached to horny 
corallines, at from twenty to thirty, sometimes even to fifty fathoms in depth, 
according to Eorbes and MacAndrew. 

HERMAPHRODITE. 

Description. — Capitulum much flattened with the apex 
produced, of a pale brown colour, sometimes faintly 
tinted purple, composed of 14 valves, of which the ros- 
trum is rudimentary and barely visible externally; valves 
thin, white, translucent, smooth, slightly marked by the 
lines of growth, separated from each other by rather 
wide interspaces of colourless membrane, which is thickly 
clothed by small, articulated spines of unequal length. 
The valves, excepting sometimes their umbones, are also 
covered with membrane, bearing spines, placed in rows 
parallel to the lines of growth ; the spines are particularly 
numerous round the orifice of the sack. 

Scuta slightly convex, thrice as long as broad ; upper 
part much acuminated; occludent margin almost straight; 
basal margin nearly at right angles to the occludent mar- 
gin ; the tergal margin is separated from the lateral 
margin by an angle more or less prominent ; a slight 
curved ridge runs from the umbo to this angle, and this 
deserves especial notice, inasmuch as it indicates the out- 
line which the valve assumed in its earliest growth, and 
which is permanently retained in most of the older fossil 
species. Along the occludent margin, there is a trace of 
a ledge, developed in a variable degree, and which is 
noticed only on account of the plainly visible ledge along 
this same margin, in the allied genus Oxynaspis. The 



224 SCALPKLLUM VULOARE. 

umbo, or centre of calcification, is seated close to the 
occludent margin, and at about one fourth of the length 
of the valve from the apex. Internally, (fig. 15, a, 
PI. V,) the part above the umbo is flat ; and beneath this 
upper part, there is a large rounded hollow (d) for the 
adductor muscle : a fold or indentation (a) running down- 
wards from the umbo, extends in a very oblique line 
across the occludent margin. This fold is of high inte- 
rest as giving lodgment to the Complemental Males, and 
will hereafter often be referred to. 

Terga, triangular, flat ; occludent margin, very slightly 
arched. 

Carina much bent, with the umbo placed at barely 
one third of the entire length of the valve from the apex. 
Two very slight ridges can be perceived, one on each side, 
running from the umbo to the basal margin, and sepa- 
rating the roof from the parietes of the valve ; these 
ridges are of great use in distinguishing the fossil carinae 
of Scalpellum, from the carinas of Pollicipes. The part 
above the umbo is formed by the upward production of 
a marginal slip along each side of the valve, which slips 
in the fossil species (C in the woodcut, fig. 1, given in 
the Introduction,) I have designated as the intra-parietes. 
The lower part of the valve gradually widens from the 
umbo downwards ; internally, the whole is deeply con- 
cave, and continuously curved. The angle varies at 
which the upper and lower portions externally meet each 
other; bnt is never less than 135°. . The upper part of 
the carina runs up between the terga for three-quarters 
of their length ; the basal margin does not extend down 
low enough to pass between the carinal latera. 

Mostrum, (fig. 15$', seen externally, and highly magni- 
fied,) minute, almost hidden by the enveloping membrane 
and by the small prominent umbones of the rostral latera ; 
in area equalling about one fourth of the rostral latera ; 
externally pyramidal, with the upper side rather longer 
than the lower ; internally slightly concave, square, 
with the upper margin and sometimes with the lower 



HERMAPHRODITE. 225 

margin, slightly hollowed out. Umbo of growth nearly 
central. 

Upper Latera, flat, irregularly oval, with an almost 
rectangular shoulder under the basal angle of the terga ; 
in area, about one third larger than the largest valve 
of the lower whorl ; the exact degree of elongation of the 
oval figure varies a little. Umbo seated a little above 
the central point. 

Lower Whorl, — 'Rostral Latera, nearly twice as long as 
broad, lying under the basal margins of the scuta: 
umbo seated over the rostrum ; opposite end, towards 
which the valve widens either sensibly or but little, is 
either square or rounded ; in area, less than any of the 
other valves, excepting the rostrum ; in breadth, equalling 
either half or one third of the height of the infra-median 
latera ; growth, directed chiefly towards the infra-median 
latera. The freely-projecting umbo is about one sixth 
part of the entire length of the valve. 

Infra-median Latera, rather larger than the carinal 
latera; their shape varies from elongated pentagonal 
with the angles rounded, to oval, with the longer axis 
directed upwards. The umbo is seated a little above the 
middle of the basal margin, so that there is some little 
growth downwards, but the main growth is upwards. 
The upper point generally stands a little above that of 
the carinal latera. 

Carinal Latera, flat, less in area than the infra-median 
latera; basal margin nearly straight; carinal margin 
slightly hollowed out, terminal margin arched and protu- 
berant. The umbones of the two valves almost touch each 
other under the middle of the carina; main growth 
towards the infra-median latera and upwards ; umbones 
projecting not above one fifth of the entire length of the 
valve. 

Peduncle, much flattened, rarely as long as the capi- 
tulum, with the upper end nearly as wide as it ; the lower 
end is either blunt, or tapers to a very fine point. The 
calcareous scales are transversely elongated, and are about 

15 



226 SCALPELLUM VULGARE, 

four times as wide as high j their internal surfaces are 
slightly concave, and their external, convex ; the two ends 
are pointed. Viewed internally, the scales approach in 
shape to rhomboids. There are, in a medium-sized speci- 
men, about twenty scales in each whorl, their tips over- 
lapping each other : the whorls are placed not very near 
each other and at rather unequal distances, except round 
the uppermost part, where, being in process of formation, 
they are packed closely together. The membrane uniting 
the scales, supports numerous transverse rows of articu- 
lated spines, varying from ^th to^th of an inch in length, 
and each furnished with a long sinuous tubulus, To^th 
of an inch in diameter, running through the membrane 
to the underlying corium. 

Attachment. — Specimens are attached to various horny 
corallines, and occasionally to the peduncles of each 
other.* In both cases, supposing the coralline to be 
erect, the capitulum is placed upwards, with its orifice 
towards the branch to which it is attached, and conse- 
quently with its carina outwards. Where several are 
crowded in a group, their peduncles often become twisted 
and their positions irregular, with their orifices facing 
in any direction. This uniform position is simply the 
consequence of the larva attaching itself head-downwards, 
and from the position of the prehensile antennas, neces- 
sarily with its sternal surface parallel and close to the 
branch of the coralline ; hence the dorsal surface, which 
afterwards is converted into the carina, faces outwards. 
The peduncle, as already stated, often tapers, at its basal 
extremity, to a sharp point. In very young specimens, 
for instance in one with a capitulum only ^th of an inch 
in length, the method of attachment is the same as in 
Lepas and many other genera, namely, by cement pro- 
ceeding exclusively from the antennae of the larva ; but 
in older and full-grown specimens, instead of the whole 

* Mr. Peach, (Transact. Brit. Assoc, 1845, p. 65,) states that this is 
sometimes the case in Cornwall ; and I have seen a similar instance in a fine 
group from Naples. 



HERMAPHRODITE. 227 

bottom of the peduncle becoming flattened and broadly 
attached, which would be here impossible, the cement is 
poured out through a straight row of orifices along the 
rostral edge, thus causing, by an excellent adaptation, a 
narrow margin to adhere firmly to the thin and cylin- 
drical branches of the coralline. These orifices are repre- 
sented, magnified seven times, in PI. IX, fig. 7, in which 
the lower attached portion of the peduncle is split 
open and exhibited; they are circular, and stand at 
regular intervals, in a straight line ; the higher orifices 
are larger, but further apart from each other than the 
lower ones ; in one fall-grown specimen, I counted ten of 
these orifices in a length of exactly a quarter of an inch. 
At each period of growth, the corium recedes a little 
from the attached portion of the peduncle ; of which 
portion, the greater part is thus left empty and as inca- 
pable of further growth, as are the larval antennae at the 
the extreme point : in the specimen figured, the corium 
extended a little below the upper orifice. The prehensile 
antennae, however, I must remark, do not strictly rise 
from the extreme point of the peduncle, but at a little 
distance from it, on the rostral surface ; this simply 
ensues from the antennae in the larva, being situated on 
the sternal surface, close to, but not actually on the front 
of the head. The two cement glands are seated high up 
on the sides of the peduncle, and remote from each other; 
they are small, unusually globular and transparent. The 
two cement-ducts (fig. 7 a a) proceeding from them, are 
booths of an inch in diameter, and run in a zig-zag line ; 
at the point where they pass through the corium to enter 
the lower attached portion of the peduncle, they become 
closely approximated, and partially imbedded in the 
membrane of the peduncle. Together they run along 
the rostral edge, giving out through each orifice a little 
disc of brownish cement, and finally they enter the larval 
antennae. The peduncle, just above the attached por 
tion, where still lined by corium, no doubt increases in 
diameter at each period of growth, and must, I presume, 



228 SCALPELLUM VULGARE, 

become pressed against the almost parallel branch of 
the coralline. The corium, at this same period, shrinks, 
or is absorbed^ and the two cement-ducts come in con- 
tact with, and adhere to, the inner surface of the outer 
membrane of the peduncle ; and then, by a process which 
I do not understand in this or any other Cirripede, 
apertures are formed both in the ducts and through the 
membrane, so that the cement passes through, firmly 
fastening the outer surface of the peduncle with its cal- 
careous scales and spines, to the coralline. 

The structure of the larval prehensile antennae will be 
most conveniently described when we come to the Coni- 
plemental male ; and figures (10 — 12, PL V) will be given. 

Size and Colours. — Montagu states ( c Test. Brit.,' p. 18) 
that British specimens rarely have a capitulum '62 of an 
inch in length; I have, however, seen an Irish specimen, 
'7 long; and several specimens, from the Bay of Naples, 
•8 long, and including the peduncle, 1*3 in length. The 
valves in all the specimens are white, and the mem- 
brane connecting them either nearly white, or dirty pale 
yellowish, or purplish-brown. Within the sack the 
corium under the valves is tinted pale purple, and two 
very faint bands of the same colour can generally be dis- 
tinguished running down the two sides of the peduncle. 
Body, coloured yellowish- white, with the upper segments 
of the pedicels of the cirri, tinted in front with purple. 

Body, much flattened, the prosoma is very little de- 
veloped ; the mouth placed far from the adductor muscle, 
and is directed in a remarkable manner towards the 
ventral surface of the thorax : the first pair of cirri stands 
far separated from the second pair. 

Mouth. — Labrum with the upper part highly bullate, 
forming an overhanging projection equalling the longi- 
tudinal axis of the mouth ; basal margin much produced ; 
crest with a row of bead-like teeth. 

Palpi rather small, with their external margin straight, 
and internal margin oblique : the bristles on the two 
palpi just meet each other. 



HERMAPHRODITE. 229 

Mandibles, with five or six teeth, with the second, (or 
second and third, when there are six teeth,) smaller than 
the others ; in two specimens, there were five teeth on one 
side and six on the other; inferior angle rather broad 
and strongly pectinated. 

Maxilla with the edge nearly straight, without any 
notch, but with the inferior portion very slightly pro- 
jecting; there are twelve or thirteen pairs of unequal 
spines, of which some of the middle ones are rather 
longer than the others, and almost as long as the two 
upper great spines. 

Outer Maxilla. — On the inner margin the bristles are 
divided into two separate tufts ; exteriorly, near the base, 
there is a distinct rounded swelling with bristles. The 
olfactory orifices are highly protuberant, approximate, 
flattened, scarcely tapering towards their upper ends. 

Cirri. — The five posterior pair are elongated, very 
little curled, with short pedicels ; their segments are 
long, not at all protuberant in front, bearing five or six 
pairs of long, slightly serrated spines, with a very minute 
tuft of bristles between each pair, and with some short 
lateral spines on the inner side of each segment ; on the 
fourth pair of cirri, these lateral spines are considerably 
developed; dorsal tufts consist of fine spines, with one 
much longer than the others. First pair short, separated 
by a wide interval from the second; rami unequal in 
length, by between two and four segments ; longer 
ramus having nine segments, scarcely half as long as the 
rami of the second cirrus ; shorter ramus with seven 
segments ; in the same individual there were twenty 
segments in the sixth cirrus. The segments in the 
shorter ramus of the first cirrus are oblong in a trans- 
verse direction, and may be compared to a set of shields 
placed transversely and strung together ; in the longer 
ramus the segments are longitudinally oblong ; in both 
they are thickly covered with spines. Second cirrus; the 
anterior ramus is a little broader than the posterior ramus, 
with the segments bearing about five rows of bristles ; 



230 SCALPELLUM VULGARE, 

fifteen segments in the shorter ramus. Third pair, with 
the two rami equal in thickness, and with the segments 
differing very little from those of the posterior cirri, 
excepting that the serrated spines in the external lateral 
rows are rather larger. The fourth pair is remarkable by 
having, on the inner side of the upper edge of each seg- 
ment, a little tuft of minute smooth spines, flattened, and 
a little enlarged near their ends, so as to be spear-shaped ; 
I could not see these singular spines on the other cirri. 
The lower segments of the pedicels of all the cirri, except- 
ing the sixth pair, are remarkable from having their inner 
edges, in the middle, produced into a considerable, abrupt, 
rounded projection, irregularly covered with spines. 

Caudal Appendages, (PL X, fig. 21,) very small, 
flattened, of nearly the same width throughout ; in a 
medium-sized specimen, only -j-J-o-th of an inch in length; 
each bears from ten to twenty small bristles placed dis- 
tantly from each other, of which those on the rounded 
apex are the longest. 

Generative System. — The penis is remarkably acumi- 
nated ; the vesicular seminales are unusually small, and 
enter only for a short distance into the prosoma; the 
testes are large. The ovarian tubes are of large diameter ; 
the ova are nearly spherical and large, namely, -^^-o-ths of 
an inch in diameter ; they are not numerous, and lie in 
single layers in the two lamellae. The ovigerous fraena 
are well developed, and lie under the scuta; one I 
measured was xf^ths of an inch in length and T tb-ths in 
width ; the margin is obliquely truncated and slightly 
sinuous. This species breeds late in the autumn, and 
even in mid- winter ; I have examined a specimen from 
Cornwall with ova containing larvae, taken on the 26th 
of October; again, in another specimen from Belfast, 
sent to me by Mr. Thompson, taken in January, there 
were ova in the lamellae, and therefore no doubt impreg- 
nated; and on February the 12th I received from Mr. Peach, 
from Cornwall, specimens so very young that they must 
have become attached during the first days of the month. 



COMPLEMENTAL MALE. 231 

Varieties. — The specimens from near Naples, (which I 
owe to the kindness of the Rev. F. W. Hope,) are some- 
what larger, and differ slightly from those of Britain : 
they form, I imagine, the S. Sicilice of Chenu. After 
carefully examining them internally and externally, I 
think it is quite impossible to consider them specifically 
distinct, for although in several specimens, the valves 
were placed a little further apart from each other, — the 
upper latera a little more elongated, — the carinal latera 
rather narrower in their upper half, — the infra-median 
latera rather more rounded, — and, lastly, in the scuta, 
the tergal margin extended almost in the same line wdth 
the lateral margin ; nevertheless in other specimens, I 
could perceive no difference whatever. It is, however, 
remarkable that in several full-grown Neapolitan speci- 
mens there were no Complemental males, whereas I have 
never seen a single full-grown British specimen without 
such being present. In some specimens in the British 
Museum, without any given locality, I have observed 
considerable variation in the breadth of the carinal and 
rostral latera. 



COMPLEMENTAL MALE. PI. V, figs. 9 14. 

When first dissecting Scalpellum vulgare, I was sur- 
prised at the almost constant presence of one or more 
very minute parasites, on the margins of both scuta, close 
to the umbones : these are represented, but rendered 
darker and therefore more conspicuous than in nature, 
in the drawing, PL V, fig. 15, w T hich is three times the 
natural size. I carelessly dissected one or two specimens, 
and concluded that they belonged to some new class or 
order amongst the Articulata ; but did not at that time 
even conjecture, that they were Cirripedes. Many months 
afterwards, when I had seen in Ibla, that an hermaphrodite 
could have a complemental male, I remembered that I 
had been surprised at the small size of the vesiculae 
seminales in the hermaphrodite S. vulgar e, so that I 



232 SCALPELLUM VULGARE, 

resolved to look with care at these parasites ; on doing 
so, I soon discovered that they were Cirripedes, for I 
found that they adhered by cement, and were furnished 
with prehensile antennae, which latter, I observed with 
astonishment, agreed in every minute character, and in 
size, with those of S. vulgare : the importance of this 
agreement will not at present be fully appreciated. 
I also found, that these parasites were destitute of a 
mouth and stomach ; that consequently they were short- 
lived, but that they reached maturity ; and that all were 
males. Subsequently the five other species of the genus 
Scalpellum were found to present more or less closely 
analogous phenomena. These facts, together with those 
given under Ibla (and had it not been for this latter 
genus, I never probably should have even struck on 
the right track in my investigation,) appear sufficient to 
justify me, in provisionally considering the truly wonderful 
parasites of the several species of Scalpellum, as Males and 
Complemental Males. When these parasites are fully 
described, will be the proper time to discuss and weigh 
the evidence on their sexual relations and nature. I will 
now describe the parasite of S. vulgare. 

General Appearance. — Shape, flask-like, compressed 
(PI. V, fig. 9, magnified 36 times), with a short neck : 
the outline is usually symmetrical, but sometimes is a little 
distorted on the under side. The creature is imbedded 
more than half its length or depth in the transparent, 
spine-bearing chitine border of the scutum of the herma- 
phrodite. Its length, or longer axis, varies from i^-ths ; 
its breadth, or transverse axis, is 6 4°o 7 ths ; and its thickness, 
for it is much flattened, is only ^ths of an inch. On the 
summit, there is a fimbriated orifice (a), the size of which 
can rarely be made out quite distinctly, owing to the 
extreme thinness of the membranous edges. A little 
way beneath the orifice, there are four little blunt, bristly 
points (b), generally rather more than the ^th of an inch 
in length ; they are rather variable in size, and seem to 
be of no functional importance ; directly beneath them, 



COMPLEMKNTAL MALE. 233 

there are four little calcareous beads (as mav be known 
by their dissolving with effervescence in any acid, and 
breaking easily under the needle) ; these are the ^ths of 
an inch in their larger external diameter ; they are rather 
deeply imbedded in the outer integument, and taper a 
little downwards ending in a concave terminal point, into 
which a minute tubulus enters, like those passing into 
and through the valves of ordinary Cirripedia : along the 
axis of imbeclment, they are often ^ths of an inch in 
length. These calcareous beads or rudimental valves are 
seated in pairs, at the two ends of the flattened animal, 
so that when the animal is laid on one side, the upper 
bead in each pair exactly covers and hides the lower one. 
The outer integument is composed of chitine, as may be 
inferred from boiling caustic potash having no effect on 
it ; the upper part is thicker than the imbedded portion 
and is wrinkled transversely; it is covered with minute 
spines n^oooths of an inch in length, either single or in 
groups of two and three, (PL V, fig. 14.) This outer 
tunic is lined by corium, sometimes slightly mottled 
with dull purple; and this by delicate, longitudinal, 
striaeless muscles, running from the base up to the under 
edge of the orifice ; these longitudinal muscles are crossed, 
at least, in the upper part, by still finer transverse muscles. 
Thorax and Abdomen. — When the external integument 
is cut open, the thorax (PL V, fig. 13) is found lodged 
within an inner sack or rather tube, extending from near 
the bottom of the animal, up to the external orifice. The 
whole thorax is sometimes forced through the orifice, owing 
perhaps to the action of the spirits of wine and conse- 
quent endosmose, and is thus well displayed without dis- 
section. The thorax tapers a little, is much flattened and 
straight ; its length ; together with the terminal abdominal 
lobe, is about 5 §oths of an inch ; it is formed of very 
thin, most finely hirsute membrane, transversely wrinkled 
and so extensible, that when everted by the internal 
muscles being seized, it stretches to twice its former 
length ; in this condition, five transverse articulations are 



234 SCALPELLUM VULGARE, 

displayed. The abdominal lobe is smooth, and cannot 
be stretched, or turned inside out by pulling the above 
muscles. On the thorax, corresponding with the inter- 
spaces between the five transverse articulations, there are 
four pair of short limbs, but their bases, I believe, are 
prolonged across the inner or ventral surface of the thorax, 
so as almost to touch each other. These limbs, I believe, 
have no articulations, except, perhaps, where united to the 
thorax. The anterior or lowest limb, on each side, sup- 
ports two or sometimes only a single spine ; this pair 
is rather smaller than the second, and is placed a little 
more distant from it, than are the upper pairs from each 
other. The second pair differs from the upper two, only 
in having its three spines a very little shorter. The two 
upper or posterior pair exactly resemble each other ; each 
has two spines on the summit, and a third seated lower 
down, on a little notch on the outer side, but with its 
point on a level with the others. The points of the spines 
of the two upper limbs, stand on a level with the ex- 
ternal spines at the end of the abdomen. All the spines 
are of excessive tenuity and sharpness ; they are straight, 
long, and not plumose. 

The abdominal lobe is square, and from not being 
wrinkled, has a different appearance from the thorax : 
on each of the posterior angles, there are three mode- 
rately long, very sharp spines, with the tips of the outer 
pair bent a little inwards ; in the middle between them, 
there are two little spines, and a little below and outside 
these latter, on the ventral surface, there are two other 
longer spines with their tips bent inwards ; and again, 
lower down, two other pair, one beneath the other, of 
short spines. Perhaps, the three pair of spines on the 
ventral surface, mark the three segments, which are 
distinct on the abdomen of the larva in the last stage 
of its development, in Lepas and other genera. In the 
same way, it is probable that the lateral spine on the 
notch in each limb, marks the point where, in the larva, 
there is an articulation. Altogether, there are seven 



COMPLEMENTAL MALE. 235 

pairs of spines on the abdomen, and eleven pairs on the 
thoracic limbs. 

A little way beneath the lower or anterior pair of limbs, 
the thorax is abruptly bent, and becomes confluent with 
the lower internal parts of the whole animal. Here, the 
very delicate membrane of chitine which lines the sack or 
tube, extending from the external orifice, can be seen to 
be continuous, as in all Cirripedes, with the outer tunic 
of the thorax. Within the thorax, there are some longi- 
tudinal muscles, without transverse striae, which, I believe, 
enter the short limbs, but not the abdomen, as I infer from 
the latter not being everted when they are pulled. At 
their lower ends these muscles terminate abruptly, and 
from being contracted are often a little enlarged. They 
extend a short way beneath the lower pair of limbs, and 
are, I suspect, attached to the outer integument of the 
animal, near the base. 

After the most careful dissection of very many speci- 
mens, and their examination in many different methods 
(as by caustic potash, &c), I can venture positively to 
assert that there is no vestige of a mouth, or masticatory 
organs, or stomach : I did not see any anus, but I will 
not affirm that such does not exist. 

In the upper part of the animal, lying under the 
superficial muscles, and close beneath the upper line 
of their attachment, I found in all the specimens, an 
eye, of a pointed oval form, rather less than the i^ths 
of an inch in diameter, formed of an outer capsule, lined 
with purple pigment-cells, and surrounding, as it appeared, 
a lens. The eye is not introduced in fig. 9, for I could not 
see it, except by dissection, and therefore do not know 
its exact relative position. 

Generative System. — The contents of the animal, be- 
tween the sack containing the thorax and the outer inte- 
guments, and directly under the thorax, varied much in 
condition : in young and , lately attached specimens the 
whole consisted of a pulpy mass with numerous oil- 
globules ; in other specimens, apparently more mature, 



236 SCALPELLUM VULGARE, 

there were vast numbers of cells, sometimes cohering in 
sheets, about To^hs of an inch in diameter, and having 
darkish granular centres ; these I believe to be the testes, 
for in a specimen presently to be mentioned, in which 
the vesicula seminalis was gorged with spermatozoa, I 
found adhering to its outside, a mass of cells of exactly 
the same diameter, but now empty and transparent instead 
of having brownish centres. Lastly, in several other 
specimens, at the very bottom of the sack -formed animal, 
there was a brownish, pear-shaped bag, of different sizes 
in different individuals, and occasionally broader even than 
the thorax. This bag contained either pulpy matter, or 
a great mass of spermatozoa. Before being disturbed, 
these spermatozoa lay parallel to each other in flocks, and 
they yielded to the needle in a peculiar manner, so that I 
found (having had experience with these bodies in living 
Cirripedia) I could almost tell before examination under 
the compound microscope, wmether or not I should see 
spermatozoa. Many had distinct heads,* which were two 
or three times as broad as the filamentary bodies ; the 
latter when placed between glass were the o^th of an 
inch in diameter. I compared these spermatozoa with 
others taken out of the vesiculae seminales of the individual 
hermaphrodite S. vulgare, to which the parasite was 
attached, and could not perceive the slightest difference 
in them. The brownish pear-shaped bag, or vesicula 
seminalis, the coat of which seems fibrous, could some- 
times be distinctly traced, sending a chord or prolonga- 
tion far up the thorax : at the end of the abdominal lobe, 
no doubt there is an orifice ; and this, I believe, I once 
distinguished. Owing to this chord, the bag often 

* I do not understand the development of the spermatozoa in Cirripedia : 
in a recent Chthamalus and Balanus, I found the greater number had a little 
filament in front of the head or nodular enlargement, which latter varied in 
size and in shape from globular to that of a spindle. The filament before the 
head, also, varied in proportional length; ;t did not project in exactly the same 
straight line with the hinder part, and some of the spermatozoa were entirely 
without this filament in front; — such is the case with the spermatozoa here 
described. 



COMPLEMENTAL MALE. 237 

adheres to the thorax, when the latter is dissected out of 
the general integuments ; in this condition, I twice clearly 
made out that it was single : in one other specimen, how- 
ever, there appeared to be two small vesiculae seminales. 
By using a condenser and very brilliant light, the outline 
of the vesicula seminalis could sometimes be distin- 
guished before dissection, at the bottom of the sack-formed 
animal ; and such was the case in the specimen drawn 
in fig. 9. 

Although I have dissected, at least, thirty specimens, 
taken at different times of the year, and from different 
localities, and when many of the specimens were mature 
and ready for the impregnation of ova, as clearly shown 
by the presence of innumerable spermatozoa, I have never 
seen even a trace of an ovum or ovaria. 

Antennce and Attachment. — The prehensile antennas 
(PL V, fig. 10), are seated a little above the very base 
of the sack-like animal ; and this might have been expected 
from the antennas in the larva, being seated on the ven- 
tral surface, not at the very extremity of the head. By a 
very strong light, they can sometimes just be seen whilst 
the parasite is attached to the hermaphrodite (the scutum 
of the latter having been cleaned on the under side), and 
are thus represented in fig. 9. They are formed of thicker 
membrane than the general integument of the body : the 
second segment, or disc, is pointed and hoof-like ; when 
seen in profile (fig. 11), the upper convex surface has a 
uniform slope with the upper surface of the basal seg- 
ment ; it is furnished with a single backward pointing 
spine, attached, I believe, on the under side, nearly oppo- 
site the articulation of the ultimate segment : at the apex, 
there are some excessively minute hairs or down. The 
ultimate segment projects rectangularly outwards as usual, 
and has on its inner side, rather beneath the middle, 
a conspicuous notch (fig. 12), which bears two or three 
long, non-plumose spines ; on the summit there are three 
or four rather shorter spines. On the outside of the great 
basal segment there is a single spine curving backwards. 



SttoS 



9-10 



238 SCALPELLUM VULGARE, 

The importance of the following measurements (in frac- 
tions of an inch) will hereafter be seen. 

Length of whole organ, from end of disc to the further \ 3s . 3s 

margin of the oblique basal articulation . . j BoDO 

Length of whole organ, to the inner margin of the oblique \ , 

basal articulation . . . J B3 
Breadth of basal segment, measured half-way between the i 
basal and second articulations, — the limb being viewed I 
from vertically above . J 
Length of hoof-like disc, measured from the apex to the 1 

middle of the articulation with the basal segment J 6o ^° 

Breadth of ditto ..... 5505 

Length of ultimate segment . g^o 

Breadth of „ beneath the notch . . 55 7 m 

Breadth of „ above the notch . . ^ m 

I did not see the cement-ducts, which, perhaps, was 
owing to the corium extending from the inside of the 
whole animal some way into the antennae, thus rendering 
them rather less transparent than in common Cirripedes. 
That the ducts and cement-glands exist, is certain, for the 
antennae in every case were enveloped in a little irregular 
mass or capsule of the usual, brown, transparent, lami- 
nated cement. When several of these parasites were 
attached close together, the cement ran up between them. 

I may here state, that I found on one Scalpellum, three 
males very lately attached, and not as yet imbedded in 
the chitine border; they were white, opaque, pulpy, and 
full of oily globules ; the lower part was considerably 
more pointed, and extended further beyond the prehensile 
antennae, than in the older and imbedded specimens. 
There were distinct remnants of two great reddish-brown 
eyes, showing that in this respect the larvae of the male in 
their last stage of development, are characterised like the 
larvae of other Lepadidae. The male larva would, pro- 
bably, be a little larger than the male itself; but yet 
compared with the larva in the earliest stage, there can 
have been unusually little increase of size during the 
several intermediate metamorphoses ; I judge of this from 
the dimensions of the larva of the hermaphrodite in the 
first stage, namely, ^ths of an inch, exactly the size of 
some of the smaller males. In the allied genus lbla, 



COMPLEMENTAL MALE. 239 

the increase is also less than is usual, namely, from ^ths 
of an inch, the diameter of the ovum, to only y—ths of 
an inch, the length of the boat-shaped larva, just before 
its final metamorphosis. 

Habits and Concluding BemarJcs. — The males are im- 
bedded in the spinose chitine border of the occludent 
margin of the scuta, exactly over an oblique fold or 
notch (Hg. 15 a a), close by the umbo. This fold has no 
direct relation to the males, but being present is taken 
advantage of by them ; for it occurs in the young her- 
maphrodite, before the attachment of the males, and in 
species of the genus in which the males are attached 
to other parts. It occurs, also, in fossil species of 
Pollicipes, and in these it seems caused by the upper 
inner part of the valve being rendered more and more 
prominent during growth : in the present species, I sus- 
pect, its origin is connected with the formation of a 
ridge bounding the outer side of the pit for the adductor 
scutorum muscle : we shall see in the next species, that 
this fold is of the highest importance in relation to the 
position of the Males. The transparent chitine border 
of the scuta is broad, and fills up the fold in the shell, so 
that the outline of the occludent margin is not affected 
by it : in the drawing (fig. 9) some of the inner layers of 
chitine (e e), which dipped into and filled up the fold, 
have been removed, that the lower part of the animal 
might be more plainly exhibited. The chitine bears 
numerous spines of various lengths, which must afford 
some protection to the males, rudely arranged in lines, 
parallel to the edge of the valve, indicating the successively- 
formed layers of chitine ; each spine has a fine, tortuous 
tubulus connecting its base with the under-lying corium. 
The extreme outer edge of the border is thin, forming a 
kind of lip, close beneath which the delicate tunic lining 
the sack is attached. During continued growth, the 
valve is added to in thickness, and so is the chitine 
border, and likewise in breadth. It appears that the 
larva of the male must attach itself on the under side 



240 SCALPELLUM VULGARE, 

of this border, on the edge of the tunic of the sack, and 
that by the action of the cement, the corium beneath 
is killed (as I believe always is the case with other para- 
sitic Cirripedia), whereas on both sides, the chitine con- 
tinues to be added to, so that the male, excepting the 
upper and always projecting portion, becomes imbedded 
at first laterally, and ultimately all round : I have seen 
specimens in several different stages of imbedment. 
Hence, in old specimens, with a thick and broad chitine 
border, it might and does come to pass that one male is 
imbedded (the valve being laid flat) directly beneath 
another. 

I have examined a great number of specimens from 
various localities, taken at different times of the year, — 
some dozen specimens from Cornwall,* and several from 
unknown localities in various collections ; some from 
Ireland, from the Shetland Islands, from Norway, and 
from near Naples. Every one of these specimens, with 
the exception of some of the Neapolitan ones, had para- 
sitic males attached to them : I must also except very 
young specimens, on which they never occur. On a 
Cornish specimen, with a capitulum a little more than 
one fifth of an inch in length, it may be mentioned as 
unusual that there were three males. In young speci- 
mens there is generally one male on each scutum, but 
sometimes there are two, and sometimes none on one 
side. In large old Cornish specimens I have counted 
on the two sides together, six, seven, and eight males, 
and in one Irish specimen no less than ten, seven all 
close together on one valve and three on the other, but 
I do not suppose that all these were alive at the same 
time. In the Neapolitan specimens, however, which are 
the largest that I have seen, there was in no case more 

* I am greatly indebted to Mr. Peach for liis unwearied kindness in pro- 
curing me fresh specimens. Mr. W. Thompson allowed me to dissect one, 
possessing particular interest, out of his three Irish specimens. Professor 
Forbes procured me a specimen from the Shetland Islands, and Professor 
Steenstrup was so kind to take pains to send me some Scandinavian 
specimens. 



COMPLEMENTAL MALE. 241 

than two j and ont of seven or eight specimens, four had 
not any male ; so that it would appear there is something 
in this locality hostile to the development of the parasitic 
males. I have noticed only one instance (that given in 
fig. 9) in which the males were imbedded a little way 
apart ; generally they touch each other, and are cemented 
together : where there are several males, they occur at dif- 
ferent levels, as measured from the under or upper surface 
of the chitine border : in one instance of four males ad- 
hering to one valve, I distinctly perceived that the lowest 
one was white, pulpy, and recently attached; the two 
above, which were placed close together and between the 
same laminae of chitine, were mature ; and the third still 
higher up, was dead, empty, transparent, and half de- 
cayed : in some other instances, I have found the upper- 
most parasites dead, and, together with the surrounding 
chitine, partially worn away. 

The larva of the male must have a different instinct 
from the larva of the hermaphrodite ; for the latter 
attaches itself head downwards to a coralline, whilst the 
male larva crawling on the scuta of the hermaphrodite, 
discovers, I presume by eye-sight, the fold in the shell 
beneath the translucent border of chitine, and there inva- 
riably attaches itself. Its object in choosing this par- 
ticular spot, I believe, simply is that the depth or thick- 
ness of the chitine is there greater, and sufficient for its 
imbedment, which would hardly be the case elsewhere. 
This parasite has, as we have seen, no mouth or stomach, 
and indeed, considering its fixed position and the non~ 
prehensile condition of its limbs or cirri, a mouth would 
have been of no service to it, without it had been ex- 
traordinarily elongated. The male must live on the 
nourishment acquired during its locomotive larval con- 
dition ; and its life no doubt is short, but yet not very 
short, as I infer from the depth to which mature specimens 
are buried in the chitine border. The full development 
of the spermatozoa consumes, I suppose, some con- 
siderable lapse of time. The thorax and limbs, though 

16 



242 SCALPELLUM VULGARE, 

furnished with muscles, are obviously, as already re- 
marked, of no use for prehension ; these parts serve, 
probably, to defend the little creature, when its eye 
announces the passing shadow of some enemy, and for 
this purpose they are well adapted from the extreme 
sharpness of the spines. The thorax, into which I traced 
the vesicula seminalis, no doubt also serves for the emis- 
sion and first direction of the spermatozoa ; and hence, 
perhaps, its singularly extensible structure. I have already 
remarked, that in specimens preserved in spirits, the 
thorax is often largely protruded, and bent down at 
right angles to the orifice. I presume this is caused by 
endosmose ; nevertheless it deserves notice, that it was 
in these protruded specimens that the vesicula seminalis 
was most conspicuously gorged with spermatozoa. I 
suspect the longitudinal and transverse muscles lining the 
upper part of the outer integuments of the whole animal, 
can be of little use to the creature, without it be to aid 
in the protrusion of the thorax, and perhaps in the violent 
expulsion of the spermatozoa, thus causing them to reach 
the ovigerous lamellae within ihe sack of the hermaphro- 
dite. It is also probable, that the action of the cirri of 
the hermaphrodite, would tend to draw inwards the sper- 
matozoa in the right direction. In one specimen, the 
spermatozoa in the hermaphrodite and in the male were 
mature at the same time; in another this was not the 
case ; and as the males, apparently, become attached at 
all periods of the year, this want of coincidence in maturity 
must often occur. Can the males retain their sperma- 
tozoa, till told by some instinct, that the ova in the sack 
of the often fecundated hermaphrodite are ready for im- 
pregnation ; or are the spermatozoa sometimes wasted, 
as must annually happen with such incalculable quantities 
of the pollen of many dioecious plants ? 

This little Cirripede is, in many respects, in a partially 
embryonic condition. There is no separation between 
the capitulum and peduncle j there is no mouth ; and the 
thorax, throughout its whole width, opens into the anterior 



COMPLEMENTAL MALE. 243 

part of the animal : the limbs differ greatly from those 
both of the mature Cirripede and of the larva, but come 
closest to the latter : the preservation of the abdomen is 
a well-marked embryonic character. On the other hand, 
the four rudimentary calcareous valves, the narrow orifice, 
the hirsute outer integument, the two muscular layers, the 
single eye, and male internal organs, are all characteristic 
of the fully-developed condition. The four little valves, 
as I believe, represent the scuta and terga, though they are 
placed considerably below the orifice : the little bristly 
points have no homological signification, and are absent 
in the male of the following closely allied species. The 
four pairs of limbs answer to the four posterior cirri, 
as may be inferred from their proximity to the abdominal 
lobe, and from the three posterior pairs closely resembling 
each other, and differing a little from the first pair ; this 
latter pair corresponds with the third pair in the herma- 
phrodite form of Scalpellum. If I am right in believing 
that only a single vesicula seminalis is ordinarily developed 
in the male, this is a special and singular character. 

As stated in the beginning of this description, from 
the one great fact of the absolute correspondence of the 
prehensile antennae of the parasite, with those of the her- 
maphrodite Scalpellum vidgare, together with its fixed 
condition, its short existence, and exclusively male sex, I 
have thought myself justified in provisionally considering 
it as the Complemental Male of the Cirripede to which it 
is attached ; but I hope final judgment will not be passed 
on this view, until the whole case is summed up at the 
end of the genus.* 

* I trust, before long, that some naturalist, with more skill than I pos- 
sess, will examine these parasites on Scalpellum vulgare, which unfortunately is 
the only species of the genus that can be easily obtained. Fresh specimens, 
or those preserved in spirits of wine, are necessary. The action of boiling 
caustic potash is very useful in cleaning the prehensile antennae. If these 
latter organs are sought in the hermaphrodite for the sake of comparison, 
young specimens, adhering to clean branches of a coralline, should be pro- 
cured, and caustic potash used. 



244 SCALPELLUM ORNATUM, 



2. SCALPELLUM ORNATUM. PI. VI, fig 1. 

Thaliella ornata. /. K Gray. Proc. Zoolog. Soc, 1848, p. 44, 
Annulosa, Plate. 

S. (Fcem.) valvis 14, mb-rufis: lateribus superioribus 
quadranti-formibus, arcu crend profunda, notato. 

(Fern.) Capitulum with 14 reddish valves : upper latera 
quadrant-shaped, with the arched side deeply notched. 

Mandibles with three teeth ; maxillae narrow, bearing 
only four or five pair of spines. 

Males, two, lodged in cavities on the under sides of 
the scuta ; pouch-form eel, with four unequal, rudimentary 
valves : no mouth : cirri not prehensile. 

Algoa Bay, South Africa. Attached to Sertularia and Plumularia. British 
Museum.* 

FEMALE. 

Capitulum oblong, with the upper portion much pro- 
duced ; valves, 14, thick, naked, closely locked together, 
irregularly clouded with pale crimson ; the membrane 
connecting the valves is not furnished with spines. On 
most of the valves there are furrows and ridges diverging 
from the umbones, and the lines of growth are plainly 
marked : in the valves of the lower whorl, the umbones 
are slightly protuberant. 

Scuta, convex, unusually thick, oblong, quadrilateral, 
with the occludent margin the longest; lateral margin 
slightly hollowed out. The umbo (and primordial valve) 
is situated at the uppermost point of the valve, and con- 
sequently the growth is exclusively downwards. On the 
under side (PL VI, figs. 1 b' and lc'), in about the middle 
of the valve, there is a pit (a) for the adductor scutorum 
muscle, the depth and distinctness of which varies a little ; 

* I am greatly indebted to Mr. Bowerbank for specimens of this extremely 
interesting species ; also to Mr. Morris, to whom Mr. Bowerbank had given 
some of the original specimens. 



FEMALE. 245 

above the pit, and between it and the apex, there is a 
transverse, oblong, deeper depression (b), within which, 
the male is lodged. A small portion of the apex of the 
valve projects over the terga. 

Terga, large, nearly equalling the scnta in area, flat and 
sub-triangular ; the scutal margin is not quite straight. 
The apex of the valve is thick and solid, and must have 
projected freely for a length equalling one third of the 
occludent margin. 

Carina, laterally broad, angularly bent ; slightly widen- 
ing from the apex to the base ; internally, deeply concave. 
The position of the umbo varies, in young specimens it is 
seated at the uppermost point, and consequently in such 
there is no upward growth ; in older specimens, from the 
junction and upward production of that part on each side 
of the valve, which I have called in fossil specimens the 
intra-parietes, the valve is added to above the umbo, 
but to a lesser degree than in S. vulgare. Slight ridges 
separate the roof from the parietes, and the parietes from 
the intra-parietes. 

Hostrum, minute, narrow, widening a little from the 
apex downwards, inserted like a wedge between the 
umbones of the rostral latera, and hardly projecting above 
their upper margins, so as to be easily overlooked : 
internally concave. 

Upper Latera (fig. 1 a), quadrant-shaped, with a deep 
square notch cut out of the arched margin, which notch 
receives the upper point of the carinal latera ; the surface of 
the valve between the notch and the umbo is depressed.* 

Rostral Latera, small, gradually widening from the 
umbo to the opposite end, which is obliquely rounded. 

Infra-median Latera, approaching to diamond-shaped, 
placed obliquely to the longer axis of the capitulum ; or 
the upper part may be described as spear-shaped. 

* The only valve which I have seen at ail like this, is a fossil specimen 
from the Upper Chalk of Scania ; this is described in my memoir on the 
Fossil Lepadidse (Palseontographical Society), under the name of Scalpellum 
solidulum (Tab. 1, fig. 8, e,f), and is perhaps erroneously there considered 
as a carinal latus. 



246 SCALPELLUM ORNATUM, 

Carina! Latera : these appear as if formed of two 
valves united together ; the upper portion, widening as it 
ascends in a curved line, terminates in a rounded margin, 
which enters the deep notch in the upper latera ; the 
other and lower portion is shorter, and terminates in a 
square margin abutting against the infra-median latera ; 
the umbones of the carinal latera project beyond the line 
of the carina. 

Direction of the Lines of Growth in the Valves. — This 
should always be carefully observed, on account of the 
great diversity there is in this respect between the different 
species, especially when the recent are compared with the 
older fossil species ; moreover one of the chief characters 
between the genus Scalpellum and Pollicipes, depends on 
the direction of the lines of growth. In the scuta, terga, 
rostrum, and upper latera of the present species, the chief 
growth is downwards; in the carina, in mature specimens, 
it is both upwards and downwards; in the carinal latera, 
both upwards and towards the infra-median latera ; in the 
infra-median latera chiefly upwards ; and, lastly, in the 
rostral latera, towards the infra- median latera. 

Peduncle, short, not half as long as the capitulum ; 
calcareous scales imbricated as usual, tinged red, almost 
crescent-shaped, acuminated at both ends, of remarkable 
length, so that in each whorl there are only four scales : 
a full-sized scale equals in length one of the rostral latera. 
The tips of two scales, in one whorl, lie under the middle 
points of the carina and rostrum ; and in the whorl, both 
above and below, a single much curved scale occupies 
this same medial position. The peduncle does not seem 
to have been attached in any definite position to the horny 
coralline, as is the case with S. vulgare. 

Length of capitulum in the largest specimen *2 of an 
inch. 

The Mouth is directed towards the ventral surface of the 
thorax. The Labrum is far removed from the adductor 
muscle, with the upper part forming an overhanging pro- 
jection ; I believe there are some very minute bead-like 



FEMALE. 247 

teeth on the crest. Palpi, small, narrow, thinly clothed 
with bristles. 

Mandibles, with three teeth, of which the first is dis- 
tant from the second ; inferior angle not much acuminated, 
pectinated on both edges. 

Maxilla, small, narrow, produced, without any notch, 
with two large upper spines, of which one is much 
thicker than the other; on the convex upper margin 
there are some minute tufts of very small hairs. 

Outer MaxUlce, with few bristles, arranged in a con- 
tinuous line on the anterior surface ; on the external 
surface there is a tuft of long bristles. Olfactory orifices 
situated laterally, forming two flattened, tubular pro- 
jections. 

Cirri. — First pair placed not far from the second j the 
three posterior pair not very long, with their segments 
elongated, not protuberant, bearing four pair of non- 
serrated spines, with a single short bristle between each 
pair ; dorsal tufts small, with one spine longer than the 
others. First cirrus rather short, segments not very 
broad; second cirrus with the rami nearly equal in length, 
anterior ramus rather thicker than the posterior ramus, 
with three longitudinal rows of spines. 

Caudal Appendages. — These are minute, rather broad, 
not half as long as the lower segments of the pedicels of 
the sixth cirrus, with four very long spines at the tip. 

Penis. — There is no trace of a probosciformed penis in 
the four specimens examined j and as this organ is pre- 
sent in every ordinary cirripede, with the exception of Ibla 
Cumingii which we know to be exclusively female, so we 
may infer with some confidence that the form here de- 
scribed is female, although it is impossible in specimens 
once dried to demonstrate the absence of the vesiculae 
seminales and testes. 

Affinities. — This is a very distinct species; it is, how- 
ever, much more nearly related to S. rutilum, than to any 
other species ; and next to this, to S. vidgare; from this 
latter species it chiefly differs in the large scales of the 



248 SCALPELLUM ORNATUM, 

peduncle, in the scuta not being added to at their upper 
ends, and in the membrane covering and connecting the 
valves being spineless ; but there is a greater difference in 
the trophi and in the cirri. The peduncle of S. ornatum 
presents some resemblance to that of the singular creta- 
ceous genus, Loricula. 

MALE. 

All the specimens, as already stated, were dry, but in 
an excellent state of preservation, so that after having 
been soaked in spirits, they could be minutely examined. 
In the four which I opened, I found, in a transverse pouch 
on the under side of each scutum, a male lodged ; in a 
fifth dead and bleached specimen, the cavities in the shell 
for the reception of the males, were present; and in a 
sixth young specimen, also dead, cavities were in process 
of formation. As compared with plants, the relation of 
the sexes in this species may be briefly given, by saying 
that it belongs to the class Diandria monogynia. I will 
first describe the males themselves, and then the cavities 
in the shell of the female. The males differ in every point 
of detail, from the complemental males of S. vulgare, but 
yet present so close a general resemblance, that a com- 
parative description will be most convenient. 

The general shape of the whole animal is rather more 
elongated, and I suspect flatter, but this latter point 
could not be positively ascertained in dry specimens. 
The entire length is greater, being in the largest specimen 
TtVu (instead of at most 4V0), and the width, -$hv of an inch. 
The orifice is not fimbriated ; the four bristly points over 
the calcareous beads are absent. The whole outer in- 
tegument is much thinner, owing evidently to its pro- 
tected position, and is not covered by little bristles, but 
with an extremely high power, minute points arranged in 
transverse lines can be distinguished. The calcareous 
beads, or rudimentary valves, are thin and regularly oval. 
It is remarkable that in all the specimens, two on one 



MALE. 249 

side were smaller than the two on the other side, — the 
smaller beads being ^iio, and the larger, suo of an inch 
in diameter ; therefore more than twice the size of one of 
the beads in S. vtdgare, which are only WV o externally in 
diameter. From the position of the eye, close to one 
margin, near the upper end of the flattened animal, and 
from the manner in which the little limbs and spines 
lay between two of the beads at the opposite end, it was 
manifest that these latter, one large and one small, cor- 
responded with the terga of the other cirripedes, and that 
the other two, near the eye, answered to the scuta. The 
valves being of unequal sizes on the right and left-hand 
sides of the animal, is probably connected with one side 
being pressed against the hard, shelly valve of the female ; 
in the same way as the valves in certain Psecilasmas, 
are smaller and flatter on the side nearest to the crus- 
tacean to which they are attached. The eye, in being 
slightly notched on the upper and lower edge, shows 
signs of really consisting of two eyes, which I believe is 
always normally the case ; it is rather larger, in the pro- 
portion of 13 to 1 1, being tjMW of an inch in diameter, 
than in S. vulgar e; and from the almost perfect trans- 
parency of the integuments, is far more conspicuous than 
in that species. Hence when the valves of the female are 
opened, the black little eye is the first part of the male 
which catches the attention. No vestige of a mouth could 
be discovered. 

Thorax and Abdomen. — The thorax, as in S. vulgare, 
is highly extensible, and when stretched exhibits the 
same five transverse folds or articulations; when con- 
tracted, it is broader, so that even the truncated end of the 
abdomen is wider than the lower (properly anterior) end 
of the thorax in S. vidgare. Its thin outer integument 
is studded with excessively minute points in transverse 
rows. The four pair of limbs are longer than in S. vidgare ■, 
but the spines on them much shorter and thicker ; each 
limb (including the first) supports three spines, of which 
one is seated on a notch low down on the outside, and 



250 SCALPELLTJM ORNATUM, 

is longer than the other two ; of these two, the one on 
the same side with the notch, is a little longer than the 
other. The spines on the first and second pair of limbs 
are considerably shorter than those on the third pair, and 
these latter, are a little shorter than those on the fourth 
or posterior pair. Hence, the spines on the thoracic 
limbs, compared with those of S. vulgar e, present consi- 
derable differences, both in their relative and absolute 
dimensions. The abdominal lobe is in proportion rather 
shorter ; its end is less abruptly truncated, and supports 
a row of, I believe, six moderately long, and basally 
thick spines ; these spines are not so long as those sur- 
mounting the fourth pair of limbs. On both lateral 
margins of the abdomen, rather on the ventral face, there 
is a row of, I believe, seven long spines, but it is very diffi- 
cult to count the spines in specimens which have been 
once dried. I was able to distinguish that the two lower 
pair of spines on the ventral surface, are seated a little 
way one below and within the other, as in JS>. vulgar e. 
The abdominal spines altogether form quite a brush, and 
there are certainly several more than in S. vulgare, and 
those on the two sides are much longer. 

Antennce. — The disc is hoof-like, with the upper sur- 
face forming a straight line with the upper edge of the 
basal segment ; the apex is pointed and clothed with some 
fine down ; there is a single spine pointing backwards, 
which rises from the lower flat surface. The ultimate 
segment was hidden in laminae of cement; and I was 
not able to make out its structure. There is a single 
spine on the outer edge of the basal segment, in the 
usual position. The entire length of the limb, measured 
from the end of the disc to the further margin of the basal 
articulation, is t£ths of an inch ; measured to the inner 
margin, it is ^ths of an inch ; the disc itself is ^ths of 
an inch long ; these measurements differ a little both ab- 
solutely and proportionally, compared with those of the 
antennae of 8. vulgare. 

Cavities in the Scuta of the Female for the reception 



MALE. 251 

of the Males. — These extend nearly parallel to the tergal 
margin, transversely across the valves, for three fourths 
of their width ; they are seated above the depression for 
the adductor muscle, and are more conspicuous than it; 
they are deep and well defined, and each exactly contains 
one male. The males are placed with their orifices in a 
little notch in the occludent margin, and their prehensile 
antennae at the further end. The distance to which the 
cavities extend across the valve, and their distance from 
the upper or tergal margin, varies a little, but chiefly 
in accordance with the age of the specimens ; for the valve 
continues to increase in width, whilst the size of the 
cavity remains the same. The occludent margin of the 
scutum in the largest female, was '1 of an inch in length ; 
of another, in which there was a fully developed cavity, 
*084 ; of a third, in which there was no cavity, only a 
slight concavity, with a preparatory impression, the length 
of the occludent margin was *062. The larger and 
smaller of these three valves, are drawn of their proper 
proportional sizes, in PI. VI, figs. 1 5', 1 c. The pre- 
paratory impression (fig. 1 c, b), consists of a narrow, not 
quite straight, extremely slight furrow, of slightly irregular 
width, bordered on each side by a very minute ridge, 
which is distinctly continuous with the inner edge of the 
occludent margin, both above and below the cavity. The 
furrow appears to have been formed by calcareous matter 
not having been deposited along this line, during the 
thickening or growth of the internal surface of the valve : 
I suspect, that it originates at a single period of growth, 
for I could see no signs of successively-formed transverse 
lines. I believe that it is strictly homologous with the 
fold, over which the complemental male is attached in 
8. vulgare, but carried, for a special purpose, much further 
across the valve and rectangularly inwards, for in structure 
and position both are identical. In comparing the internal 
views of the scuta in S. vulgar e and S. ornatum (PI. V, 
fig. 15 a\ and PI. VI, fig. 1 c), it must be borne in mind, 
that the latter should be compared, as clearly shown by 



252 SCALPELLUM ORNATUM. 

the lines of growth, with that portion alone of the scutum 
in S. vulgare, which lies under the curved ridge connecting 
the umbo and tergo-lateral angle. The deep cavity in 
which the male is lodged, is formed subsequently to the 
preparatory furrow, simply by the gradual thickening of 
the surrounding surface of the valve, more especially of a 
ridge just above the pit for the adductor muscle, and of 
another broad ridge just beneath the tergal margin. The 
deepest part of the cavity lies parallel to the tergal margin 
along the upper side, and here, in the older valves, the 
preparatory furrow can by care be distinctly traced. In 
conformity with the shape of the cavity, the orifice or notch 
in the occludent margin of the scutum, is situated at the 
point where the preparatory furrow sweeps round and 
enters. I believe that the cavity is lined by membrane, 
and that between the cavity and the body of the female, 
there is a complex membranous layer, — a pouch or bag 
being thus formed. An imaginary section of this pouch 
(with the thickness of all the parts extremely exaggerated 
and in a reversed position) is given in PI. VI, fig. 1 d'\ a 
is the shell ; w the cavity, converted, as I believe, into a 
pouch by, firstly, the delicate tunic (c) lining the sack of 
the female ; secondly, a double layer (d) of corium ; and, 
thirdly, by a special, rather thick membranous layer (5), 
which thinning out round the cavity coats only part of 
the under surface of the scutum. This latter membrane 
I have not seen in any other Cirripede, and I believe it 
is nothing but the tissue, here not calcified, which, in a 
calcified condition, ordinarily forms the valves. On this 
view, the males may be said to be lodged in pouches, 
formed in the thickness of the valves. 

Concluding Bemarks. — The males from the absence of 
a mouth (and no doubt of a stomach), must necessarily be 
short-lived, and, I suppose, are periodically replaced by 
fresh males. # In one instance, the remnants of the two 

* It is possible, though opposed to all analogy, that the females may be 
short-lived, and breed only once, in which case the males would not have 
to be periodically replaced. 



SCALPELLUM RUTILUM. 253 

great compound eyes of the larva, could be seen at the end 
of the pouch, opposite the orifice. The larva?, I conclude, 
crawl in at the orifice, one side of which is formed, as we 
have seen, of yielding membrane, and scratch out the dead 
exuviae of the former occupant : certainly, the males are 
less firmly attached to their pouches, though some small 
quantity of cement is excreted, than are other Cirripedes 
to the objects to which they are attached. The small 
size of the female, and her valves not being thickly edged 
with chitine, accounts for the males having pouches spe- 
cially formed for them, instead of being, as in S. vulgare, 
laterally imbedded in the chitine-border of the scuta. 
In hereafter weighing the evidence on the nature of the 
parasites in Ibla and in Scalpellum, the fact of the valves 
of the supposed female being here modified for the special 
purpose of lodging the males, will be seen to be important. 
If we imagine the male parasites to be extraneous animals, 
and that by adhering to the sack of the Scalpellum, they 
injure the corium and thus prevent the growth of the shell 
over an area exactly corresponding to their own size, 
and so form for themselves cavities ; yet what can be said 
regarding the preparatory furrows ? surely these narrow 
lines cannot have been produced by the pressure of the 
much broader parasites. Must we not see in the furrows, 
the first marking out, if such an expression may be used, 
of the habitation for the male, which has to be specially 
formed by the independent laws of growth of the female ? 



3. Scalpellum pojtilum. PL VI, fig. 2. 

S. (Foem. an Herm.) valvis 14 subrujis : carina? tecto 

piano, utrinque crista rotunda fa instructo; margine basali 

truncato: lateribus sujperioribiis latitudine duplo longioribus. 

(Fern, or Herm.) Capitulum with 14 reddish valves : 
carina with the roof flat, bordered on each side by a 
rounded ridge ; basal margin truncated : upper latera 
twice as long as broad 



£So. 5 



254 SCALPELLUM RUTILUM, 

Mandibles with three teeth : maxilla? narrow, bearing 
only four or five pair of spines : segments of the second 
and third pair of cirri with one side wholly covered with 
spines. 

Males, two, lodged in hollows, on the under sides of 
the scuta ; pouch-formed, with four (?) rudimentary valves ; 
no mouth; cirri not prehensile. 

Hab. unknown; associated with Dichelaspis orthogonia. British Museum. 
FEMALE OR HERMAPHRODITE. 

There is only a single specimen in the British 
Museum, and this had nearly all its valves separated, 
and many of them in fragments : from its state of decay, 
I think the specimen must have been dead, when origi- 
nally collected. 

Description. — The capitulum consists of fourteen valves, 
including from analogy a rostrum.* Valves, apparently 
covered with membrane, bearing some thin spines on the 
margins; clouded with a fine, though pale, orange tint ; 
surfaces plainly marked with lines of growth. 

Scuta, elongated, nearly three times as long as broad; 
apex, pointed ; basal margin extremely oblique, forming 
an acute angle with the occludent margin ; the lateral 
margin is slightly hollowed out, and is separated from the 
tergal margin by a large rectangular projection or shoulder. 
The occludent margin is nearly straight ; externally, there 
is a slight ridge running down the middle of the valve, 
from the apex to the baso-lateral angle ; and a second 

* In my first, and as I thought careful examination of the separated 
valves (my only materials) of this species, I mistook one of the triangular 
rostral latera for the rostrum, and hence was unfortunately led into an 
error in my c Monograph on the Fossil Lepadidae of Great Britain,' in which 
I state that the present species has only twelve valves in the capitulum ; 
and I inferred from this, that S. quadratum, S.fossula, &c, had only twelve 
valves ; I still believe this to be correct, but the existence of fourteen valves 
in S. rutilum and S. ornatum, the recent species to which the above fossils 
are most closely allied, no doubt is a strong argument in favour of this 
higher number. 



FEMALE OR HERMAPHRODITE. 255 

ridge running from the apex to the tergo-lateral angle. 
The lines of growth do not end abruptly at the tergo-lateral 
angle, as is the case with S. ornatum and several fossil 
species, but run up a little way along the tergal margin. 
The umbo is seated at the uppermost point, and, there- 
fore, the main growth is downwards. There is a large 
rounded depression for the adductor muscle (a, fig. 2 a), 
and higher up, opposite the tergo-lateral angle, there is 
another hollow (b), for the lodgment of the males ; this 
latter is of nearly the same shape as the hollow for the 
adductor musle, but rather more conspicuous than it. 
From the appearance of the under surface of the scuta, it 
might read ly have been thought, that there had been two 
adductor muscles. 

Terga, of large size, longer than the scuta, flat, trian- 
gular, with the whole inferior part much produced and 
spear-like. A portion of the apex, must have projected 
freely above the sack. 

Carina (PI. VI, fig. 2 b'\ simply bowed (i. e., not rec- 
tangularly bent), with the umbo (and primordial valve) 
seated at the upper point ; rather massive, narrow, only 
slightly increasing in width from the upper to the lower 
end ; the two sides are flat, and at right angles to the 
roof, which is bordered on each side by a rather broad, 
square-topped ridge (see section fig. 2 c)\ or the roof may 
be said to have a square-edged furrow running from the 
apex to the basal margin, and widening downwards; 
these two ridges have their lines of growth oblique, and 
hence have a twisted appearance; the central depressed 
portion of the basal margin, which is square or truncated, 
descends lower down than the two ridges. The sides of 
the valve close to the apex are broad, and consist, as I 
believe, of intra-parietes, as well as of parietes, but these 
parts are not separated from each other by ridges, as is 
commonly the case, more especially with the fossil species. 
I have described the carina in some detail, on account 
of its resemblance to that of the cretaceous 8. fossula, 
S. trilineatum,, and S. quadricarinatum. 



256 SCALPELLUM RUTILUM, 

Rostrum, unknown ; but one probably existed. 

Upper Latera, of large size, elongated, quadrilateral, 
approaching to diamond-shaped, with the angles rounded, 
nearly twice as long as broad; almost flat; upper half 
acuminated, lying between the scuta and terga; the 
lower half broad, forming a rectangular projection lying 
between two latera of the lower whorl. The umbo is 
near the apex, the greater part of the growth being down- 
wards, but the valve is added to a little, round the two 
sides of the apex ; these additions do not take place in the 
early stages of growth, (as explained under S. vulgare,) 
and, therefore, they form a depressed rim. 

Rostral Latera, almost exactly triangular, curved; 
basal margin furnished with a just perceptible rim. 

Infra-median Latera, quadrilateral, sides unequal in 
length ; the carino-basal margin being the longest ; in 
area not quite twice double the rostral latera; directed 
obliquely upwards. 

Carinal Latera, sub -triangular, produced upwards, 
with the apex rounded, and the two lateral margins hol- 
lowed out ; the basal margin exceeds a little in length 
the basal margin of the rostral latera. The umbones of 
these two latera are seated at their basal outer angles, so 
that the growth of the valves is towards each other and 
upwards. The umbo of the infra-median latus is seated 
at the baso-rostral angle, and hence the growth is obliquely 
upwards. The umbones of the rostral latera must have 
been close together, over the unknown rostrum. 

Length of capitulum about ^th of an inch. 

Peduncle, only small fragments are preserved; the 
calcified scales are small, closely imbricated, several of them 
together only equalling in length the basal margin of 
the rostral latera. Each scale is thin, transversely elon- 
gated ; basal imbedded portion straight ; upper margin 
rounded. 

Mouth. — Labrum with the upper part highly bullate, 
forming an overhanging projection ; palpi apparently small 
and narrow. 



FEMALE OR HERMAPHRODITE. 257 

Mandibles, narrow, produced, with three teeth; inferior 
angle pectinated, as is sometimes the third tooth ; the 
distance between the tips of the first and second teeth 
equals that between the second tooth and the inferior 
angle. 

Jfaxilla, extremely narrow, produced, without any 
notch ; spinose edge exactly one third of the length of 
the mandibles : beneath the two upper great spines there 
are only three or four pair of spines ; on the convex 
upper margin there are some minute tufts of the smallest 
hairs. 

Outer Maxilla, rounded with the inner margins very 
sparingly but continuously covered with bristles. I could 
not ascertain whether the olfactory orifices were tubular. 

Cirri. — These consisted, in the one specimen, of merely 
small fragments. The segments of the posterior cirri are 
elongated, not protuberant, and support, I believe, five 
pair of non-serrated spines, and an exterior row of very 
minute spines : dorsal spines fine and long. Either the 
second or third cirri, or probably both 5 are remarkable for 
having the whole of one side of each segment covered 
with irregular rows of long spines. Moreover, in the upper 
segments of these same cirri, between each separate dorsal 
tuft, there is placed one or two long bristles. The first 
cirrus appears to have had very broad segments, and these 
are singular from the spines in the dorsal rows, being ex- 
tremely long. In some of the cirri, several of the basal 
segments are soldered together. 

Caudal Appendages, lost. 

From the state of the specimen, it was quite impossible 
to ascertain whether the individual here described was an 
hermaphrodite or female ; from the analogy of its nearest 
congener, 8. ornatum, the latter is the most probable ; but 
the genus Ibla shows how the sexes may differ in the 
most closelv-allied forms. 

Affinities. — From the hollows on the under sides of the 
scuta, for the lodgment of the males ; from the umbones 
of the scuta and of the carina being situated on the apices 

17 



258 SCALPELLUM RUTILUM. 

of these valves ; and from all the characters of the mouth, 
S. rutilum is much more closely allied to JS. ornatum than 
to any other species. 

MALE, OR COMPLEMENTAL MALE. 

In the concavity or hollow above the depression for the 
adductor muscle (PL VI, fig. 2a), I found males, but in 
so extremely decayed a condition, that they could hardly 
be examined. On one side, however, I distinctly saw the 
larval prehensile antennae, with pointed, hoof-like discs ; 
and part of the thorax, with its small limbs and long 
spines, as in S. vulgare or S. ornatum. I also saw clearly 
the eye. The four calcified beads or rudimentary valves, 
I believe, were present ; but in removing the specimen, 
the whole fell to pieces and was lost. The outer integu- 
ment was covered with rather thick, very minute bristles, 
each about Tojooth of an inch in length, and therefore only 
half the length of those on the complemental males of 
S. vulgare. The cavities for the males are not formed, 
as in S. ornatum, by the thickening of the internal surface 
of the valve round a defined space, but by the scutum 
being externally convex and internally concave down the 
middle, hollows being thus produced both for the lodg- 
ment of the males and for the attachment of the adductor 
muscle. These hollows are separated from each other by 
a slight transverse ridge. I do not know at which point 
of the margin of the valve, the orifice of the male is situated, 
but I presume close under the apex. In this species, as 
in S. ornatum, there can be no question that the scuta of 
the female are specially modified by their own growth for 
the reception of the males. It must be added that, as it 
was not possible to ascertain whether the ordinary form 
of S. rutilum was hermaphrodite or female, so it must 
remain doubtful whether the parasites are males or 
complemental males; but the former, I think, is most 
probable. 



SCALPELLUM ROSTRATUM. 259 

[f t SUB-CARINA PRESENTE.] 
4. SCALPELLUM ROSTRATUM. PL VI, fig. 7. 

S. (Herm.) valvis 15: rostro permagno : later urn paribus 
quatuor : pari superiore pentagono. 

(Herm.) Capitulum with 15 valves : rostrum very large : 
four pair of latera ; upper latera pentagonal. 

Mandibles with four teeth; maxillae with the inferior 
angle prominent. 

Complemented Male, attached between the mouth 
and adductor scutorum muscle; pedunculated; capitulum 
bearing a pair of elongated scuta and a rudimentary 
carina ; mouth and cirri prehensile. 

Philippine Archipelago; Island of Bantayan. Attached to a horny 
coralline : 20 fathoms. Mus. Cuming. 

HERMAPHRODITE. 

Capitulum, with the upper part narrow and produced. 

Valves, 15 in number, placed close together, clouded 
pale red, covered with membrane, which is thickly clothed 
with minute points. 

Scuta rather small, oval, with the upper end pointed ; 
rather convex ; basal and lateral margins blending into 
each other; the upper produced portion above the umbo 
is small ; there is a deep pit for the adductor muscle, and 
there is a fold on the occludent margin in the usual 
position ; occludent margin not straight. 

Terga large, one third of their own length longer than 
the scuta ; flat, sub -triangular ; the three margins are not 
quite straight ; the carinal margin projects a little above 
the apex of the carina, and the scutal margin is excised 
to fit the upper part of the scuta. 

Carina bowed, internally deeply concave ; upper por- 
tion above the umbo, about one fourth of the total length, 
extending between the terga for two thirds of their length, 



260 SCALPELLUM R0STRATUM, 

up to the slight prominences on their carinal margins : a 
ridge separates, on each side, the parietes from the tectum. 

Rostrum (fig. 7 a) unusually large, about two thirds of 
the length of the scuta, and twice as long as the rostral 
pair of latera; internally concave, externally carinated; 
outline of the upper portion acutely triangular, of the 
lower portion rounded ; umbo seated at the upper end. 

Upper Latera pentagonal, with the apex rounded. 

Rostral Latera flat, four-sided, with the basal margin 
the longest, and the baso-carinal angle produced. 

Infra-median Latera nearly equalling in area the upper 
latera ; not descending so low down as the rostral and 
carinal latera ; outline of lower half semi-oval, of upper 
half rectangular. 

Carinal Latera flat, four-sided, with the basal margin 
the longest, and slightly protuberant ; baso-rostral angle 
produced ; whole valve larger than the rostral latus, but 
closely resembling it in form. 

Siib-carina minute, not above one third of the size of 
the rostral latera, which are the smallest of the other valves ; 
internally deeply concave ; externally solid, pyramidal, 
standing out beyond the surface of the carina, with the 
umbo at the apex. 

The umbones of the four pair of latera are seated a little 
above the centre in each valve, on the summit of a raised 
triangular portion ; this arises from the valve at first 
growing only downwards, and when added to at the 
upper end, the new part forms a ledge at a lower level 
round the old part, which had already acquired some 
thickness. 

Peduncle, short, about half the length of the capitulum ; 
narrow ; thickly clothed with minute, longitudinally elon- 
gated, spindle-shaped, calcareous scales or beads, which 
project but little. 

Length of the capitulum, rather under f 3 ths of an inch. 

In a Young Specimen, with its capitulum, together with 
the peduncle, only ^th of an inch long, the scuta, terga, 
and carina are very large in proportion to the valves of the 



HERMAPHRODITE. 261 

lower whorl. The latter project more, and are externally 
more pointed, as in the genus Pollicipes. The rostrum 
is well developed; the infra-median latera, in proportion, 
are the least of all the valves. The carina is straight and 
pointed, and not, relatively to the scuta, quite so long. 
The scuta are rather broader in proportion to their length, 
which would naturally follow from less having been added 
to their apices, — these valves at first growing only down- 
wards. The membrane covering and connecting the 
valves is furnished with long thin spines. 

Mouth. — Labrum placed far from the adductor scuto- 
rum muscle, with the upper part exceedingly prominent ; 
apparently there are no teeth on the crest. Palpi blunt. 

Mandibles, narrow, with four teeth, of which the second 
is not smaller than the others ; inferior angle sharp and 
produced, barely pectinated. 

MaxillcB. — Under the two or three great upper spines, 
there is a tuft of fine bristles ; the inferior part of the 
edge is step-like, and much upraised. 

Outer Maxillce, with the inner edge deeply notched, 
and the bristles arranged in two quite distinct tufts ; the 
bristles on the outer surface are long. Olfactory orifices, 
thin, tubular, and projecting. 

Cirri. — The first pair is placed far from the second ; 
the three posterior pair are long and straight, with their 
segments much elongated, not protuberant, bearing four 
or five pair of long spines, with little intermediate tufts 
of minute spines, and with the minutest spines on 
the lateral upper edges. Dorsal tufts with one spine ex- 
tremely long, equalling a segment and a half in length ; 
the others very short. Spines all serrated. First cirrus 
not very short ; rami nearly equal, with the four terminal 
segments of both tapering ; all the basal segments much 
thicker, and thickly covered with bristles. Second cirrus 
(as well as the third in a less degree), with the anterior 
ramus thicker than the posterior ramus, and with all the 
lower segments in both rami thickly clothed with three or 
four longitudinal rows of spines. 



262 SCALPELLUM ROSTRATUM, 

Caudal Appendages, spinose, uni-articulate ; but the 
specimen was injured, and I could not exactly make out 
their shape : I believe it was oval, and thickly fringed with 
fine spines. 

Penis, very small, almost rudimentary, narrow, and 
hairy, scarcely exceeding in length the pedicel of the sixth 
cirrus. 



COMPLEMENTAL MALE. PI. VI, fig. 5. 

Before describing the parasite of the present species, 
which departs entirely from the character of the males of 
the three preceding species, it is proper to state that I 
consider it to be a Complemental Male simply from 
analogy, as will hereafter be more fully shown at the end 
of the genus. Had a specimen of the parasite been 
brought to me without any information, I should have 
concluded that it was an immature individual of a new 
genus of pedunculated Cirripedes, remarkable from the 
rudimentary condition of the valves, and exhibiting, in 
one important character, namely, in the form of the 
larval prehensile antennae, an alliance to Scalpellum. 
Had I been then told that three individuals in a group, 
had been found attached to S. rostratum, not outside 
the valves, but to the integument, in a central line, 
between the labrum and the adductor scutorum muscle, 
in such a position that when the Scalpellum closed its 
valves, these parasites were enclosed within the capitulum, 
my surprise would have been great ; for it is very im- 
probable that this singular and unparalleled position 
was accidental in this one group of specimens, inas- 
much as there seems to be a relation between the naked 
condition of the capitulum of the parasite, and the pro- 
tection afforded to it by the capitulum of the Scalpellum. 
It further becomes apparent on reflection, that these 
minute parasites, though having the appearance of im- 
maturity, can not increase in size, or but little, for if they 
did grow, and acquired an ordinary size, they would 



COMPLEMENTAL MALE. 263 

either be killed by the pressure of the scuta of the 
Scalpellum, or they would destroy the latter, and in doing 
so soon lose their own support, and thus necessarily perish! 

The one full-grown specimen of S. rostratum, in Mr. 
Cuming's collection, was in a good state of preservation, 
but dry. The three parasites were attached, as stated, 
close under the labrum, between it and the adductor 
muscle. They are constructed like ordinary Cirripedia, 
and have a mouth, thorax and cirri, enclosed in a capitu- 
lum, supported on a peduncle of moderate length and 
narrow. The entire length of the capitulum and peduncle, 
as far as could be ascertained in the shrivelled condition 
of the specimens, was ^ths, and the greatest width of the 
capitulum yj^ths of an inch. Both capitulum and pe- 
duncle are hirsute with spines, nearly j^th of an inch in 
length, mingled with shorter hairs in little rows of three 
and four together. The figure (5) in PI. VI is merely 
a restoration, as accurate as could be made from the 
much shrivelled specimens. There are only three valves, 
— namely, an oval carina (a), seated rather high up on the 
capitulum, in a rudimentary condition and only T~th of 
an inch in length, and a pair of scuta ; these latter consist 
of a narrow, slightly curved plate, ^ths in length, 
broadest at the lower end, where the breadth is T™ ths 
of an inch. The prehensile antennas, at the end of the 
peduncle, have pointed hoof-like discs : I was not able to 
make out the other parts. It deserves notice, that in 
the young specimen of the ordinary form of S. rostratum, 
^th of an inch in length, and therefore only thrice as 
long as the parasites, all the valves were perfect, and 
seemed to have followed the ordinary law of development. 

Mouth. — The largely bullate labrum is placed far from 
the adductor, in the same manner as in the hermaphrodite. 
The mandibles have three large sharp teeth, with the 
inferior point very sharp and small, so that there is one 
less tooth than in the hermaphrodite. The maxillae have 
two or three large upper spines, the others being very 
thin ; I believe the lower part is upraised and step-like, 



264 SCALPELLUM PERONII, 

as in the hermaphrodite. The outer maxilla? are bilobed 
in front, with a few short bristles on the outer side near 
the bottom. I was not able, from the dried state of the 
specimens, to discover whether the olfactory orifices were 
tubular. Altogether it was apparent, from this imperfect 
examination, that there was a close similarity between 
the mouth of the parasite and of the hermaphrodite. 

The Thorax is unusually elongated. 

Cirri. — The first pair is very short, and is distant 
from the second. All have the appearance of immaturity, 
with their pedicels very long in proportion to their rami ; 
the latter are slightly unequal in length, even in the 
sixth pair. There appeared to be six segments in the rami 
of the sixth pair, each segment bearing two or three pair 
of long spines. 

Caudal Appendages, with two or three little spines on 
their summits. 

Penis, short, blunt, thick at the apex, with one or two 
spines on it. I did not see any ovaria, but this could 
hardly have been expected in specimens in a dried con- 
dition, without they had happened to have been in a 
gorged condition. Certainly there were no ova. 

In the general summary at the end of the genus, I 
shall give my reasons for believing this parasite to be the 
Complemental Male of the Scalpellum rostratum. 



5. Scalpellum Peronii. PI. VI, fig. 6. 

Smilium Peronii. /. K Gray. Annals of Philosoph., new series, 

torn, x, 1825. 
— — SpicilegiaZoologica,tab.iii,fig.lO, 

1830. 
Anatiea obliqua. Quoy et Gaimard. Voyage de P Astrolabe, 

PL xciii, fig. 16, 1823—1834. 
Pollicipes obliqtja. Lamarck. Au. sans Vertebres (2d edition). 

8. (Herm.) valvis 13 : later um paribus tribus; pari sape- 
riore multum elongato : pedunculi squamis calcareis nullis. 



HERMAPHRODITE. 265 

(Herm.) Capitulam with 13 valves : three pair of latera ; 
upper latera much elongated : peduncle without calcareous 
scales. 

Mandibles with 10 or 11 unequal teeth : maxillae witli 
the edge nearly straight, bearing numerous spines. 

Complemental Male, attached externally, between the 
scuta and below the adductor muscle; pedunculated; ca- 
pitulum formed of six valves, with the carina descending 
far beneath the basal angle of the terga ; mouth and cirri 
prehensile. 

Swan River, Australia, attached to a coralline ; Mus. Cuming. Port 
"Western, Bass's Straits, as stated in the Voyage of the Astrolabe. Mus. Brit. 

HERMAPHRODITE. 

Capitulam formed of 13 valves; namely, two scuta, 
two terga, a carina and sub-carina, a rostrum, a pair of 
upper latera, and two pair of lower latera ; these latter 
valves, with the sub-carina and the rostrum, make a 
whorl of six pieces. The upper part of the capitulum is, 
as usual, produced. The upper valves are separated (in 
specimens which have not been dried) by rather wide 
interspaces of membrane; they are covered (excepting, 
generally, their umbones,) by membrane, which in the 
interspaces is clothed with fine spines. The spines, or 
the marks where they were once articulated, are visible 
over nearly the entire surface of the membrane covering 
the valves. The spines are particularly numerous round 
the orifice of the sack. The whole capitulum, (in a dried 
condition), is coloured dull purplish-red, which is only in 
part due to the underlying corium, for the valves them- 
selves are pale red. After having been long kept in spirits, 
the whole capitulum becomes colourless. The valves are 
smooth, faintly marked by lines of growth. The umbones 
of the lower valves project outwards, giving a denticu- 
lated appearance to the base of the capitulum. 

Scuta, slightly convex, oblong, breadth about two 
thirds of the length, almost quadrilateral, with the 



266 SCALPELLUM PERONII, 

upper portion produced into a flat projection ; this pro- 
jection is almost spear-shaped, being constricted a little 
on each side below the apex. There is a deep pit 
for the adductor muscle. The umbo is near the apex, 
the part above not being above one fifth of the whole 
length of the valve. As in S. vidgare, the growth is at 
first downwards, and subsequently a little upwards and 
downwards, thus producing the upper, small, spear-like 
projection, which lies at a lower level than the umbo. 
There is a fold on the occludent margin. 

Terga, large, flat, triangular ; carinal margin slightly 
hollowed out ; occludent margin slightly arched, with a 
small portion protuberant to a variable amount. The 
apex is slightly curved towards the carina. 

Carina, long, internally deeply concave, angularly bent, 
the lower portion slightly longer and wider than the upper 
part ; the two halves meet each other at about an angle 
of 135°; the upper half is parallel to the longer axis of 
the terga, between which it extends for three fourths of 
their length. The external surface is rounded, except near 
the umbo, where the edge is carinated ; growth almost 
equally upwards and downwards ; the parietes and tectum 
are not separated by ridges. 

The Sub-carina lies close under the carina, and is placed 
almost transversely to the longer axis of the capitulum ; 
external surface arched and smooth, the whole having the 
shape of half of a cone, with the apex a little curved 
outwards ; seen internally, it may be said to be formed 
of two triangular wings placed at right angles to each 
other ; basal margin straight ; in size equalling the 
carinal latera. 

Rostrum, lying almost transversely to the longer axis 
of the capitulum, under the basal margins of the scuta ; 
in shape (fig. 6 a) closely resembling the sub-carina, but 
about one third larger than it ; larger also than either the 
rostral or carinal latera ; seen externally, appears like a half 
cone ; seen internally, is formed of two triangular wings 
(with curved edges), placed at right-angles to each other. 



HERMAPHRODITE. 267 

Upper Latera, internally flat, oblong, twice as long as 
broad ; upper end square, truncated ; upper half rather 
wider than the lower half; fully twice as large as either 
of the lower latera. The basal points extend below the 
basal margins of the scuta. The umbo is placed a little 
above the centre. 

Rostral Latera, minute, scarcely exceeding one third 
of the size of the carinal latera, and very much less than 
the rostrum; they are placed transversely under the basal 
point of the upper latus, or rather between it and the 
baso-lateral angle of the scutum ; basal margin, as seen 
internally, straight ; upper margin arched ; rostral angle 
produced ; internally flat ; the whole valve is very thick 
and solid, so that the umbo which lies at the rostral end, 
projects rectangularly outwards. 

Carinal Latera, oblong, nearly quadrilateral, with the 
upper angle produced; placed obliquely, parallel to the 
lower half of the upper latera ; umbo slightly prominent, 
seated near the apex, with three rounded ridges proceed- 
ing from it ; internal surface very slightly concave. 

Peduncle and Attachment. — The peduncle is short, not 
equalling the capitulum in length. The whole surface is 
most thickly clothed with minute spines, which are 
not visible when the specimen is dry ; I think it pro- 
bable that they may sometimes all drop off" before a new 
period of exuviation. The peduncle does not (at least 
in the specimens which I have examined, which were 
grouped in a bunch) taper at the lower end to a point ; 
and after careful examination, I feel sure that the cement 
does not debouch from several successively formed orifices, 
as in jS. vulgare and as in some Pollicipes, but only 
from the two original orifices in the prehensile antennae 
of the larva. In these latter organs, the sucking disc is 
hoof-like and pointed, and is narrower than the basal 
segment. The ultimate segment has on its inner side 
(supposing this segment stretched straight forwards,) a 
notch or step bearing at least three spines. The pro- 
portions of the different parts differ slightly from those 



268 SCALPELLUM PERONII, 

in 8. vulgare ; but, as I shall hereafter have to give all 
the measurements, I do not think them worth repeating 
here. In the one large group of specimens examined by 
me, in Mr. Cuming's possession, all were attached sym- 
metrically to the coralline, as in the case of 8. vulgare, 
capitulum upwards, and their carinas outwards. 

Length of capitulum about three quarters of an inch ; 
width about half an inch ; entire length, with peduncle, a 
little more than one inch. 

The Mouth is placed far from the adductor muscle. 

Labrum, with its basal margin much produced ; upper 
part highly bullate, forming a rounded projection equalling 
the longitudinal axis of the rest of the mouth; crest 
without any teeth. 

Palpi, triangular, with the two margins, thickly clothed 
with bristles ; on each side of the mouth, near where 
the palpi are united to the mandibles, there is a slight, 
orbicular, shield-like swelling. 

The Mandibles (PL X, fig. 3) have nine or ten very 
unequal teeth, with the inferior angle rather broad and 
pectinated; of these, there are four main teeth, of which 
the second is always the smallest, and between the four, 
one or two small teeth are interpolated ; so that the total 
number is either nine or ten, and often varies on the two 
sides of the same individual, as likewise does the shape 
of the inferior angle. 

Maccillce, with the edge nearly half as long as that of 
the mandibles, supporting from seventeen to twenty pairs 
of spines ; the upper pair is only slightly larger than 
the others ; a part near the inferior angle projects slightly 
beyond the rest of the nearly straight edge. The 
apodeme, at its base or point of origin, is unusually 
broad and flat. 

Outer Maxilla, large and triangular. The inner margin 
is slightly concave, and continuously covered with short 
spines. The outer margin is bilobed, as in 8. vulgare, 
with the basal part supporting a great tuft of long bristles, 
of which the greater number turn outwards, and almost 



HERMAPHRODITE. 2G9 

cover the olfactory orifices. The latter are slightly pro- 
minent, placed some way apart from each other, with 
the above-mentioned tufts of bristles between them. All 
the spines of the tropin are in some degree donbly 
serrated. 

Cirri. — The first pair is seated rather far from the 
second pair, and the prosoma being little developed, the 
shape of the body nearly resembles that of S. vulgare. 
The posterior cirri are elongated, very little curled, with 
the segments much flattened, not at all protuberant, 
bearing from five to seven pair of long serrated spines, 
with a few small spines in an exterior row ; between each 
pair there is a very minute tuft of small bristles ; the 
upper lateral rim of each segment is toothed with small 
spines ; spines of the dorsal tufts, long, serrated. First 
pair, elongated, having numerous segments, namely, 
seventeen, whilst the sixth pair in the same individual 
had only twenty-one segments ; rami nearly equal ; seg- 
ments short, nearly cylindrical, thickly clothed with long 
serrated spines. The second and third pair are nearly 
equal in length ; they have their anterior rami slightly 
thicker than their posterior rami, both being much more 
thickly clothed with spines, than are the three posterior 
pair of cirri. Pedicels, rather short, with their inner 
edges not forming a projection, as in S. vulgare. 

Caudal Appendages (PL X, fig. 20), uni- articulate, flat, 
rounded at their ends and moderately long ; clothed most 
thickly, like brushes, with very fine bristles, which latter 
are serrated, and are longer than the appendages them- 
selves. 

Penis, of small size, narrow, pointed, and thickly 
clothed with delicate hairs ; in length equalling only one 
fourth of the sixth cirrus. 

Ovigerous Frana, small> semicircular ; entire edge 
thickly covered with glands. Ovarian tubes, within the 
peduncle, fully developed as usual. 

Affinities. — This species differs from all the others in 
the absence of calcareous scales on the peduncle ; but it 



270 SCALPELLUM PERONII, 

has no other character which at all justifies its generic 
separation. In the shape of the scuta and carina it 
comes nearest to 8. vulgare. Taking all the characters 
together, it is scarcely possible to say to which of the 
other species it is most closely allied, having close affini- 
ties with all. In the entire structure, however, of the 
Complemental Male, immediately to be described, this 
species certainly comes nearer to S. villosiim than to any 
other species. I may add, that in S. vittosum the latera 
are almost rudimentary, and therefore tend to disappear, 
whereas in S. Peronii it is the calcareous scales on the 
peduncle which have actually disappeared. 

COMPLEMENTAL MALE. PL VI, fig. 3. 

I examined, owing to the great kindness of Mr. Cuming, 
six dry specimens of the hermaphrodite S. Peronii, from 
Swan River, and one in spirits from another locality, in 
the British Museum. Out of these seven specimens, only 
three appeared to have had parasites attached to them, and 
these I infer, from reasons to be more fully given at the 
end of the genus, are Complemental Males. One of the 
three specimens, however, had two males close together. 
These parasites were firmly cemented to the integument of 
the hermaphrodite, in a fold, in a central line between the 
scuta, a little below (the animal being in the position in 
which it is figured) the adductor scutorum muscle, and 
therefore some way below the umbones of these valves. 
When the scuta are closed, the parasites, from their small 
size, are enclosed and protected. In every detail of struc- 
ture, they are obviously pedunculated Cirripedia. 

The Capitulum (PI. VI, fig. 3) has six valves ; namely, a 
pair of scuta and of terga, a carina, and a rostrum, all united 
by finely-villose membrane, furnished near the orifice with 
some much longer and thicker spines. The capitulum is 
truncated in a remarkable manner, the orifice not being, 
as in the hermaphrodite, in the same line with the 
peduncle, but almost transverse to it, and therefore almost 



COMPLEMENTAL MALE. 271 

parallel to the surface of attachment. The largest speci- 
men measured transversely, through the scuta and terga, 
was Troths of an inch in breadth ; another was only ^ths 
to sloths : this latter specimen, measured longitudinally, 
from the base of the carina to the tips of the terga, was 
Tgjfeths of an inch. A scutum of the largest specimen 
was J^ths in length. The scuta and terga are broadly 
oval, with the primordial valves very plain at their upper 
ends. I may here mention, that in a central line between 
the scuta, I observed the apparently single, minute, black 
eye, as in ordinary Cirripedia. 

The Carina is straight, triangular, and internally slightly 
concave ; its basal margin descends far below the basal 
points of the terga. 

The Hostrum is shorter, and internally more concave 
than the carina : I believe it projects more abruptly out- 
wards than is represented in the figure. 

The Peduncle commences some little way below the scuta: 
it is narrow and very short : it is finely villose : it is 
lined by delicate transverse striaeless muscles, within which 
there are the usual stronger, longitudinal muscles. The 
base is flat and truncated. I examined, and carefully 
compared, the prehensile antennae with those of the 
hermaphrodite, and found every part and every measure- 
ment the same. The full importance of this identity will 
hereafter be more fully insisted on. The antennae are 
represented of their proper proportional size in fig. 3. 

Mouth. — The labrum, as in the hermaphrodite, is highly 
bullate, and far removed from the adductor scutorum 
muscle. The Palpi are small and triangular, with their 
blunt apices clothed with a very few scattered bristles. 

Mandibles, with only three teeth, and the lower angle 
minute, slightly pectinated; the first tooth is distant 
from the second, and larger than it. Width of the whole 
organ, *0021 of an inch. 

Maxillce, bearing only a few spines, furnished with a long 
apodeme; beneath the upper large pair there is a notch, 
under which there are two spines of considerable size and 



272 SCALPELLUM PERONII. 

a small tuft of fine bristles ; width '001 of an inch, and 
therefore only -^th of the size of the same organ in the 
hermaphrodite : the relative sizes of the maxillaB and 
mandibles are the same in the male and hermaphrodite. 

Outer Maxilla blunt, triangular, with a few thinly- 
scattered bristles on the inner face ; those on the out- 
side being longer. 

Cirri. — The First pair is far removed from the second ; 
the rami are very short, barely exceeding the pedicel 
in length ; they are formed of only four segments, each 
bearing a pair of spines ; but on the end of the terminal 
segment, there are three spines, of which the central 
one is very long. Second pair also short. In the sixth 
pair there are five or six elongated segments, each bearing 
three pair of long spines ; dorsal tufts large. The cirri 
are furnished with transversely-striated muscles. 

The Caudal Ajopendages exist as two very minute plates, 
with a few bristles at their apices. 

The Penis is not acuminated, with four bristles at the 
end ; it is short, equalling only the lower segment of the 
pedicel of the sixth cirrus. In the one specimen pre- 
served in spirits, I unfortunately omitted to search for the 
vesiculae seminales ; I cannot doubt that such existed, but 
it would have been important to have ascertained whether 
they contained spermatozoa. I made out, most distinctly, 
that there was no trace of ovarian tubes within the pedun- 
cle ; and my assertion may be believed when I state, that I 
traced the two much finer and more transparent cement- 
ducts, from the prehensile antennae up to the body of the 
animal : in Lepas I have repeatedly detected, with ease, 
the ovarian tubes within the peduncle, before the calcifi- 
cation of the valves had even commenced, and therefore 
at a much earlier period of growth than in these parasites. 
Consequently I am prepared to affirm, that these parasites 
are not females, but that, as far as can be judged from 
external organs, they are exclusively males. 

Concluding Remarks. — In comparing the capitulum of 
the hermaphrodite with that of the complemental male 



COMPLEMENTAL MALE. 273 

(PL VI, figs. 6 and 3), we must be struck with the diffe- 
rences in their shape, in the number, relative sizes, and 
forms of the several valves. It should, however, be borne 
in mind, that the scuta and carina in the hermaphrodite 
at first grow exclusively downwards ; so that if we remove 
the upper portions subsequently added, the difference in 
shape in these valves is not so great as it at first appears. 
The rostrum in the male is of much larger relative size ; 
whilst of the upper latera there is not a trace, although 
in the hermaphrodite these valves are larger than the 
rostrum. The terga, compared with those of the herma- 
phrodite, differ more essentially than do the other valves ; 
and the manner in which the primordial valves project, 
shows that from the first commencement of calcification, 
the lines of growth have followed an unusual course. The 
great breadth and shortness of the terga is evidently re- 
lated to the shortening of the whole capitulum, and the 
transverse position of the orifice ; and this shortening of 
the capitulum, no doubt, is rendered necessary for its 
reception and protection within the shallow furrow be- 
tween the scuta of the hermaphrodite. Finally, if we 
compare the internal parts of the hermaphrodite and 
male, the differences are considerable, though partly 
to be accounted for by the youth of the latter : the form 
and position of the labrum, and the distance between the 
first and second pair of cirri, is the same in both ; but 
the mandibles and maxillae differ considerably. 

To put the case as I have before done, if a specimen 
of one of these parasites had been brought to me to class 
without any information of its habits, — the downward 
direction of growth in all the valves, the presence of a 
rostrum, the villose outer integument, all the details of 
the prehensile antennae, the form of the animal's body, 
and the position of the labrum, would have convinced me 
that, though a quite new genus, it ought to have stood 
close to Scalpellum, and nearer to it than to Ibla. 



18 



274 SCALPELLUM VILL0SUM, 



6. SCALPELLUM VILLOSUM. PL VI, fig. 8. 

Pollicipes villosus on Plate (tomentosus in text). Leach. 

Encyclop. Brit., Suppl., vol. iii, 1824, 

PL lvii. 
— villosus.* Q.B.Sowerby. Genera of Shells, Pollicipes, 

fig. 3, 1826. 
Calantica Homii. /. IE. Gray. Annals of Phil., vol. x, p. 100, 

1825. 

8. {Herm.) valvis 14 : sub-rostro prasente : carina pcene 
recta: laterum paribus tribus ; pari superior e triangulo. 

(Herm.) Capitulum with 14 valves : sub-rostrum 
present : carina nearly straight : three pair of latera ; 
upper latera triangular. 

Mandibles with four teeth, of which the second is the 
smallest : maxillae with a projection near the inferior 
angle : no caudal appendage. 

Complemental male, attached externally between the 
scuta, below the adductor muscle ; pedunculated ; capitu- 
lum formed of six valves, with the carina not descending 
much below the basal angles of the terga : mouth and cirri 
prehensile. 

Eastern Seasf (?) attached to shells and rocks. Mus. Brit. ; College of 
Surgeons; Cuming. 

HERMAPHRODITE. 

Capitulum with fourteen valves, consisting of a pair of 
scuta and of terga, a carina, (which five valves are much 

* As Mr. Sowerby has adopted the name villosus, I have followed him ; 
though as tomentosus is used through some mistake by Leach in the text, 
both names have equal claims as far as priority is concerned. 

In Lamarck, c Animaux Sans. Vert.,' the P. villosus of Sowerby is made 
synonymous with Anatifa villosa of Brugiere, which is certainly incorrect, 
although the A. villosa of this latter author is not positively known. 

f No habitat is attached to any of these specimens; but Mr. Sowerby 
informs me that he has seen specimens attached to the Modiola albicostata of 
Lamarck, which shell is said by the latter author to be found in the seas of 
India, Timor, and New Holland. 



HERMAPHRODITE. 275 

larger than the others,) a rostrum, sub-rostrum, sub- 
carina, and three pair of small latera. All the valves are 
covered by membrane, as are the calcareous scales on the 
peduncle ; and this membrane everywhere is densely 
clothed with spines. The upper valves are not very 
thick ; they stand rather close together. The eight valves 
of the lower whorl are more solid, and are placed far 
apart; they are small, tending to become rudimentary. 
None of the valves are added to at their upper ends, in 
which respect this species differs remarkably from the 
others of the genus, and approaches in character to 
Pollicipes. 

Scuta, with a deep hollow for the adductor muscle, 
triangular, with the basal margin elongated, and pro- 
tuberant. 

Terga, large, flat, triangular, basal point blunt, with 
the carinal margin slightly hollowed out, and the scutal 
margin protuberant. Apex solid. 

Carina, rather longer than the terga, straight, gradually 
widening from the upper to the basal end, deeply concave. 
In young specimens the upper part is slightly bowed 
inwards. Apex solid. 

Sub-carina, with the inner surface crescent-shaped; 
the umbo points transversely outwards ; in width it 
exceeds the largest of the latera. 

Rostrum, triangular, internally (fig. 8 a) concave ; basal 
margin slightly hollowed out, and deeply notched ; rather 
less in width than the carina; short, with the umbo 
pointing upwards and outwards. In young specimens 
the apex curves a little inwards. 

Bub-rostrum, with the inner surface transversely elon- 
gated (fig. 8 b), slightly crescent-shaped, about two thirds 
as wide as the rostrum. The apex points transversely 
outwards. 

Latera, three pair ; the middle pair apparently corre- 
sponds with the upper latera of the other species of the 
genus. The two other pair of latera, together with the 
rostrum and sub-carina, form a whorl. The sub-rostrum 



276 SCALPELLUM VILL0SUM, 

lies by itself, a little beneath this whorl. The latera are 
smaller than the rostrum or the sub-carina. They are 
placed far distant from each other ; their inner surfaces 
are triangular ; their umbones point upwards ; the rostral 
pair is smaller than the other two pair, which are of 
equal size. The exact position of the rostral latus differed 
on the two sides of the specimen examined ; apparently 
its normal position is at the baso-lateral angle of the scuta. 

Peduncle, wide at the summit, longer than the capi- 
tulum ; calcified scales small, not arranged very regularly ; 
flattened, spindle-shaped, rather far separated from each 
other ; imbedded in membrane, so that even their summits 
are rarely uncovered. The surface of the membrane is 
thickly clothed with spines, which are strong, thick, 
yellow, pointed, and furnished with large tubuli running 
to the underlying corium. These spines are arranged in 
groups of from three or four, to five or six. Besides these 
larger spines, the whole surface is villose with very 
minute colourless spines, not above ^th of the length of 
the larger ones. The surface of attachment is broad. 
This species, not being symmetrically attached to a coral- 
line, the peduncle does not curve, as in most of the other 
species, towards the rostrum. 

The capitulum is above half an inch in length. 

Mouth. — The labrum is much produced downwards, 
but yet the mouth is not very far distant from the adduc- 
tor muscle : the upper part is builate, forming a small 
overhanging point, and in longitudinal diameter equals 
the rest of the mouth. Palpi blunt. 

Mandibles with four teeth, strong, short, thick, the 
second tooth much smaller than the others ; inferior angle 
broad, pectinated. 

Maxilla with a long, rather sinuous edge, which, near 
the inferior angle, has a narrow projecting point, bearing 
rather finer spines ; there is, also, apparently, a very 
minute tuft of small spines close under the two large 
upper spines : there are, altogether, about twenty pair of 
spines, without counting the smaller ones. 



HERMAPHRODITE. 277 

Outer Maxilla, with the inner edge slightly concave, 
continuously covered with bristles ; exteriorly, with a 
prominence covered with longer bristles. Olfactory orifices 
prominent, protected by a slight punctured swelling be- 
tween the bases of the first pair of cirri. 

Cirri. — Prosoma moderately developed ; first pair of 
cirri rather far removed from the second pair. The seg- 
ments of the three posterior pair are not elongated, short, 
slightly protuberant in front, bearing four or five pairs of 
strong spines ; a little below each pair, there is an inter- 
mediate tuft of very fine straight bristles, of which the 
upper tuft is the largest ; on the lateral upper rims there 
are some short, strong spines ; dorsal tufts rather small 
and thick ; spines all more or less serrated, especially on 
the broad basal segments of the three anterior cirri. 
Pedicels of the cirri not particularly protuberant in front. 
First cirrus with rami, slightly unequal in length ; not 
short ; basal segments much thicker and more protuberant 
than the upper segments. Second cirrus ; anterior ramus 
with six or seven basal segments highly protuberant, and 
crowded with spines ; posterior ramus with about six seg- 
ments, similarly characterised. Third cirrus with the 
anterior ramus having six, and the posterior ramus five 
segments, also similarly characterised. 

Caudal Appendages absent, there being only a slight 
swelling on each side of the anus. 

The oesophagus runs parallel to the labrum, and enters 
obliquely the summit of the stomach, which is destitute 
of caeca : the biliary envelope is longitudinally plicated. 

There are no filamentary Appendages. 

Testes large, branched like a stag's horns, attached in 
a sheet to the ventral surface of the stomach : the vesiculae 
seminales enter the prosoma, and have their reflexed ends 
not very blunt. The Penis is rather narrow, with the 
terminal half plainly ringed, and bearing tufts of fine 
bristles arranged in circles, one tuft below the other ; on 
the basal half there are only a few scattered minute 
bristles. 



27S SCALPELLUM V1LL0SUM 



Affinities. — In the downward growth of all the valves, 
in the presence of a sub-rostrum, in the shape of the 
scuta, carina, and more especially of the triangular latera, 
in the form of the peduncle, with its irregularly- scattered 
calcified scales, in the shape of the animal's body, in the 
structure both of the mandibles and maxillae, in the 
arrangement of the spines, both on the anterior and pos- 
terior cirri, Scalpettum villosum most closely resembles, or 
rather is identical with, Pollicipes. Had it not been for 
the fewness of the valves forming thecapitulum, and from 
the presence of Complemental Males, I should have placed 
this species alongside of Pollicipes spinosus and sertus. 
In not having caudal appendages, 8. villosum differs from 
all the species of Scalpellum and Pollicipes ; but this 
organ is variable to an unusual degree in Pollicipes. 

COMPLEMENTAL MALE. PL VI, fig. 4. 

From the kindness of Professor Owen, Mr. Gray, and 
Mr. Cuming, I have been enabled to examine six speci- 
mens of this species ; and on two of them I found Comple- 
mental males. They were attached in the same position 
as in 8. Peronii ; namely, beneath the adductor muscle, 
in the fold between the scuta, so as to be protected by 
the latter when closed. This parasite is six-valved, and has 
a close general resemblance with that of S. Peronii, but 
differs in very many points of detail. It is represented 
of the natural size at a fig. 4. The capitulum is ^ths 
of an inch, measured across the scuta and terga ; and 
the same measured from the base of the carina to the top 
of the capitulum ; hence it is broader, by a quarter of the 
above measurement, and considerably higher than the 
male of S. Pero7iii. From the capitulum being higher, 
that is, not so much truncated, the orifice is placed more 
obliquely. The membrane connecting the valves is 
finely villose, and is besides furnished with spines, con- 
spicuously thicker and longer than those on the male 
S. Peronii. The scuta and terga are much more elongated, 



COMPLEMENTAL MALE. 279 

a scutum being here ^ths of an inch in length. The 
carina descends only just below the basal points of the 
terga, instead of far below them. The rostrum is a little 
broader and more arched than the carina ; it is y—ths in 
length, and therefore more than two thirds of the length 
of the carina, the latter being -fifths of an inch from the 
apex to the basal margin. The primordial valves, with 
, the usual hexagonal tissue, are seated on the tips of the 
scuta, terga, and carina, but not on the rostrum ; so that 
these valves follow the same law of development, as in the 
ordinary and hermaphrodite form of Scalpellum. The 
scuta {a, fig. 4, greatly enlarged), the terga {b), and carina 
(c) of the male, resemble the same valves in the herma- 
phrodite, much more closely than do these valves in the 
male and hermaphrodite S. Peronii. The rostrum has not 
its basal margin hollowed out, and is very much larger 
relatively to the carina, than in the hermaphrodite. The 
large relative size of the rostrum in the complemental male 
both of this species and of S. Peronii, is a remarkable 
character, which I can in no way account for. 

The peduncle is narrow and short, but in a different 
degree in the two specimens examined. It is naked. The 
prehensile antennae were not in a good state of preserva- 
tion : the disc is narrower than the basal segment, and 
only slightly pointed, in which important respect it differs 
from the same part in the foregoing species ; at its distal 
end, rather on the inner side, there are two or three 
spines, apparently in place of the excessively minute hairs, 
which are found at the same spot in some or in all the 
other species of Scalpellum, and in Ibla : similar strong- 
spines occur in Pollicipes. Unfortunately, for the sake of 
comparison, I was not able to find the prehensile antennae 
in the hermaphrodite S. vittosum. 

Mouth. — Labrum bullate, with teeth on the crest. 
Palpi blunt, spinose. 

Mandibles, with three teeth ; inferior point rather 
strongly pectinated. 

Maxillce, with a considerable notch under the upper pair 
of large spines ; inferior part of the edge not prominent. 



280 SCALPELLUM VILLOSUM. 

Outer MaxillcB, with the spines on the inner edge 
arranged into two groups. Olfactory orifices tubular and 
prominent, with some long bristles near their bases. In 
the mandibles having only three teeth, in the maxillae 
being notched and in the lower part not being prominent, 
and, lastly, in the bristles on the inner face of the outer 
maxillae being arranged in two groups, these several 
organs differ from those in the hermaphrodite. 

Cirri. — First pair short, with only three or four seg- 
ments in each ramus : second cirrus, with the basal 
segments not very thickly clothed with spines : sixth 
cirrus with seven segments, not protuberant in front, 
each bearing four pairs of spines, without intermediate 
tufts. 

Caudal dppendages, none. This is an interesting fact, 
considering that these organs are likewise absent in the 
hermaphrodite iS. villosum, — an absence highly remarkable, 
and confined to the genus Conchoderma and the one 
species of Anelasma. 

Penis thick, not tapering, rather exceeding in length 
the pedicel of the sixth cirrus, square at the end, and 
furnished with some spines. In one specimen, I believe 
I distinguished the vesiculae seminales : if so, they con- 
tained only pulpy matter, and not spermatozoa. There 
were no ovarian tubes within the peduncle, which was 
lined by the usual muscles ; I traced the two delicate 
cement- ducts, running from within the antennae close up 
to the animal's body. Hence in this case, as in that 
of S. Peronii, I dare positively affirm that ovarian tubes 
do not occur; for it is out of the question that I could have 
traced the cement-ducts, and, at the same time, overlooked 
the far larger and more conspicuous ovarian tubes, into 
which, moreover, the ducts, had they existed, would have 
run. Consequently, these parasites are not females; 
but judging from the probosciformed penis, and from 
the presence, as I believe, of vesiculae seminales, they are 
males. 

The complemental males of the present species, and of 
S. Peronii, so closelv resemble each other, that what I 



IBLA AND SCALPELLUM. 281 

have stated regarding the affinities of the latter, are here 
quite applicable. It is singular how much more alike 
the parts of the mouth and the cirri of these two com- 
plemental males are, than the corresponding parts in the 
two hermaphrodites : this no doubt is due to the two males 
having been arrested in their development, at a corre- 
sponding early period of growth. Several of the characters, 
by which the hermaphrodite S. vittomm so closely ap- 
proaches, and almost blends into the genus Pollicipes, — 
such as the thicker cirri, with the intermediate tufts of 
bristles, the small second tooth of the mandibles, and 
the little brush-like prominence on the maxillae, — are not 
in the least apparent in the complemental male. 

SUMMARY ON THE NATURE AND RELATIONS OF THE MALES 
AND COMPLEMENTAL MALES, IN IBLA AND SCALPELLUM. 

Had the question been, whether the parasites which I 
have now described, were simply the males of the Cirripedes 
to which they are attached, the present summary and dis- 
cussion would perhaps have been superfluous ; but it is 
so novel a fact, that there should exist in the animal king- 
dom hermaphrodites, aided in their sexual functions by 
independent and, as I have called them, Complemental 
males, that a brief consideration of the evidence already 
advanced, and of some fresh points, will not be useless. 
These parasites are confined to the allied genera Ibla and 
Scalpellum ; but they do not occur in Pollicipes, — a genus 
still more closely allied to Scalpellum ; and it deserves 
notice, that their presence is only occasional in those 
species of Scalpellum which come nearest to Pollicipes. In 
the genera Ibla and Scalpellum, the facts present a singular 
parellelism; in both we have the simpler case of a female, 
with one or more males of an abnormal structure attached 
to her ; and in both the far more extraordinary case of 
an hermaphrodite, with similarly attached Complemental 
males. In the two species of Ibla, the complemental and 
ordinary males resemble each other, as closely as do the 
.corresponding hermaphrodite and female forms ; so it is 



282 SEXUAL RELATIONS OF 

with two sets of the species of Scalpellum. But the males 
of Ibla and the males of Scalpellum certainly present no 
special relations to each other, as might have been expected, 
had they been distinct parasites independent of the animals 
to which they are attached, and considering that they 
are all Cirripedes having the same most unusual habits. 
On the contrary, it is certain that the animals which I 
consider to be the males and complemental males of the 
two species of Ibla, if classed by their own characters, 
would, from the reasons formerly assigned, form a new 
genus, nearer to Ibla than to the parasites of Scal- 
pellum : so, again, the assumed males of the three latter 
species of Scalpellum would form two new genera, both 
of which would be more closely allied to Scalpellum, 
than to the parasites of Ibla. With respect to the 
parasites of the first three species of Scalpellum, they are 
in such an extraordinarily modified and embryonic condi- 
tion, that they can hardly be compared with other Cirri- 
pedes ; but certainly they do not approach the parasites 
of Ibla, more closely than the parasites of Scalpellum ; and 
in the one important character of the antennae, they are 
identical both with the parasitic and ordinary forms of Scal- 
pellum. That two sets of parasites having closely similar 
habits, and belonging to the same sub-class, should be 
more closely related in their whole organisation to the 
animals to which they are respectively attached, than to 
each other, would, if the parasites were really distinct and 
independent creatures, be a most singular phenomenon ; 
but on the view that they differ only sexually from the 
Cirripedes on which they are parasitic, this relationship is 
obviously what might have been expected. 

The two species of Ibla differ extremely little from each 
other, and so, as above remarked, do the two males. In 
Scalpellum the species differ more from each other, and so 
do the males. In this latter genus the species may be 
divided into two groups, the first containing S. vulgare, 
S. ornatum and S. rutihim, characterised by not having a 
sub-carina, by the rostrum being small, by the constant 
presence of four pair of latera, and by the peculiar shape 



IBLA AND SCALPELLUM. 283 

of the carinal latera ; the second group is characterised by 
having a sub-carina and a large rostrum, and may be sub- 
divided into two little groups ; viz., S. rostratum having 
four pairs of latera, and S. Peronii and villosum having 
only three pairs of latera : now the males, if classed by 
themselves, would inevitably be divided in exactly the 
same manner, namely, into two main groups, — the one in- 
cluding the closely similar, sack-formed males of S. vulgare, 
ornatum, and rutilum, the other the pedunculated males of 
S. rostratum, Peronii, and villosum; but this latter group 
would have to be subdivided into two little sub-groups, 
the one containing the three-valved male of S. rostratum, 
and the other the six-valved males of S. Peronii and S. vil- 
losum. It should not, however, be overlooked, that the 
two main groups of parasites differ from each other, far 
more than do the two corresponding groups of species to 
which they are attached ; and, on the other hand, that 
the parasitic males of S. Pero?iii and S. villosum resemble 
each other more closely, than do the two hermaphrodite 
forms ; — but it is very difficult to weigh the value of the 
differences in the different parts of species. 

Besides these general, there are some closer relations 
between the parasites and the animals to which they are 
attached; thus the most conspicuous internal character by 
which Ibla quadrivalvis is distinguished from /. Cumingii, 
is the length of the caudal appendages and the greater 
size of the parts of the mouth ; in the parasites, we have 
exactly corresponding differences. Out of the six species 
of Scalpellum in their ordinary state, S. ornatum is alone 
quite destitute of spines on the membrane connecting the 
valves ; and had it not been for this circumstance, I should 
even have used the presence of spines as a generic 
character ; on the other hand, S. villosum, in accordance 
with its specific name, has larger and more conspicuous 
spines than any other species. In the parasites we have 
an exactly parallel case ; the parasite of S. ornatum being 
the only one without spines, and the spines on the parasite 
of S. villosum being much the largest ! This latter species 
is highly singular in having no caudal appendages, and 



284 SEXUAL RELATIONS OK 

the parasite is destitute of these same organs, though 
present in the parasites of S. rostratum and S, Peronii. 
Again, S. villosum approaches, in all its characters, very 
closely to the genus Pollicipes, and the parasite in having 
prehensile antennae, with the disc but little pointed, and 
with spines at the further end, departs from Scalpellum 
and approaches Pollicipes ! Will any one believe that 
these several parallel differences, between the Cirripedial 
parasites and the Cirripedes to which they are attached, are 
accidental, and without signification ? yet, this must be 
admitted, if my view of their male sex and nature be 
rejected. 

One more, and the most important special relation 
between the parasites and the cirripedes to which they are 
attached, remains to be noticed, namely that of their 
prehensile larval antennae. I observed the antennae more 
or less perfectly in the males of all, and except in S. vil- 
losum, in all the species, though so utterly different in 
general appearance and structure, I found the peculiar, 
pointed, hoof-like discs, which are confined, I believe, to 
the genera Ibla and Scalpellum. In the hermaphrodite 
forms of Scalpellum, I was enabled to examine the antennae 
only in two species, S. vulgare and S. Peronii, (belonging, 
fortunately, to the two most distinct sections of the genus,) 
and after the most careful measurements of every part, I 
can affirm that, in B. vulgare, the antennae of the male and 
of the hermaphrodite are identical ; but that they differ 
slightly in the proportional lengths of their segments, and 
in no other respect, from these same organs in S. Peronii, 
— in which again the antennae of the male and of the her- 
maphrodite are identical. The importance of this agree- 
ment will be more fully appreciated, if the reader will con- 
sider the following table, in which the generic and specific 
differences of the antennae in the Lepadidae, as far as 
known to me, are given. These organs are of high func- 
tional importance ; they serve the larva for crawling, and 
being furnished with long, sometimes plumose spines, they 
serve apparently as organs of touch • and lastly, they are 
indispensable as a means of permanent attachment, being 



IBLA AND SCALPELLUM. 235 

adapted to the different objects, to which the larva adheres. 
Hence the antennae might, a priori, have been deemed of 
high importance for classification. They are, moreover, em- 
bryonic in their nature ; and embryonic parts, as is well 
known, possess the highest classificatory value. From 
these considerations, and looking to the actual facts as 
exhibited in the following table, the improbability that 
the parasites of 8. vulgar e and 8. Pero?iii, so utterly dif- 
ferent in external structure and habits one from the other, 
and from the Cirripedes to which they are attached, should 
yet have absolutely similar prehensile antennae with these 
Cirripedes, appears to me, on the supposition of the para- 
sites being really independent creatures, and not, as I fully 
believe, merely in a different state of sexual development, 
insurmountably great. 

The parasites of 8. vulgare take advantage of a pre- 
existing fold on the edge of the scutum, where the chitine 
border is thicker; and in this respect there is nothing 
different from what would naturally happen with an in- 
dependent parasite ; but in 8. ornatum the case is very dif- 
ferent, for here the two scuta are specially modified, before 
the attachment of the parasites, in a manner which it is 
impossible to believe can be of any service to the species 
itself, irrespectively of the lodgment thus afforded for the 
males. So again in 8. rutilum, the shape of the scutum 
seems adapted for the reception of the male, in a manner 
which must be attributed to its own growth, and not to 
the pressure or attachment of a foreign body. Now there 
is a strong and manifest improbability in an animal being 
specially modified to favour the parasitism of another, 
though there are innumerable instances in which parasites 
take advantage of pre-existing structures in the animals 
to which they are attached. On the other hand, there 
is no greater improbability in the female being modified 
for the attachment of the male, in a class in which all the 
individuals are attached to some object, than in the mutual 
organs of copulation being adapted to each other through- 
out the animal kingdom. 



286 



SEXUAL RELATIONS OF 



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IBLA AND SCALPELLUM. 



287 




288 SEXUAL RELATIONS OF 

It should be observed that the evidence in this summary 
is of a cumulative nature. If we think it highly, or in 
some degree probable, — from the ordinary form of Ibla 
Cumin gii having been shown on good evidence to be ex- 
clusively female, — from the absence of ova and ovaria 
in the assumed males of both species of Ibla, at the period 
when their vesiculae seminales were gorged with sperma- 
tozoa, — from the close general resemblance between the 
parts of the mouth in the parasites and in the Iblas to which 
they are attached, — from the differences between the two 
parasites being strictly analogous to the differences be- 
tween the two species of Ibla, — from the generic character 
of their prehensile antennae, — and from other such points, 
— if from these several considerations, we admit that these 
parasites really are the males of the two species to which 
they adhere, then in some degree the occurrence of para- 
sitic males in the allied genus Scalpellum is rendered 
more probable. So the absolute similarity in the antennas 
of the males and hermaphrodites both in S. vulgare and 
S. Peronii; and such relations as that of the relative 
villosity of the several species in this same genus, all 
in return strengthen the case in Ibla. Again, the six- 
valved parasites of S. Peronii and S. villosum are so closely 
similar, that their nature, whatever it may be, must be the 
same ; hence we may add up the evidence derived from 
the identity of the antennae in the parasite and her- 
maphrodite 8. Peronii, with that from the antennae in 
the male S. villosum, approaching in character to Polli- 
cipes, to which genus the hermaphrodite is so closely 
allied ; and to this evidence, again, may be added the 
singular coincident absence of caudal appendages in the 
male and hermaphrodite S. villosum. If these two six- 
valved parasites be received as the complemental males 
of their respective species, no one, probably, will doubt 
regarding the nature of the parasite of S. rostratum, in 
which the direct evidence is the weakest ; but even in this 
case, the particular point of attachment, and the state of 
development of the valves, form a link connecting in some 



IBLA AND SCALPELLUM. 289 

degree, the parasites of the first three species with the last 
two species of Scalpellum, in accordance with the affinities 
of the hermaphrodites. 

When first examining the parasites of 8. rostratum, 
8. Peronii, and 8. villosum, before the weight of the 
cumulative evidence had struck me, and noting their 
apparent state of immaturity, it occurred to me that pos- 
sibly they were the young of their respective species, in 
their normal state of development, attached to old indivi- 
duals, as may often be seen in Lepas ; this, however, 
would be a surprising fact, considering that 8. rostratum 
and 8. Peronii are ordinarily attached, in a certain definite 
position, to horny corallines, and considering that the 
exact points of attachment in these three parasites, (of 
which I have seen no other instance amongst common 
Cirripedes,) namely, between the scuta, would inevitably 
cause their early destruction, either directly or indirectly, 
by their living supports being destroyed. Nevertheless, 
I carefully examined a young specimen of 8. rostratum 
only thrice as large as the parasite ; and not having very 
young specimens of 8. Peronii and villosum, I procured 
the young of closely-allied forms, namely, of 8. vulgare, 
(with a capitulum only T ^th of an inch in length,) and of 
Pollicipes polymeries, (with a capitulum of less size than 
that of one of the parasites,) and there was not the least 
sign of anything abnormal in the development of the 
valves. In 8. vulgar e, at a period when the calcified scuta 
could have been only ^th of an inch in length, (and 
therefore considerably less than the scuta in the parasites,) 
the upper latera must have been as much as ^ths of 
an inch in length, and the valves of the lower whorl cer- 
tainly distinguishable. 

To sum up the evidence on the sex of the parasites, I 
was not able to discover a vestige of ova or ovaria in the 
two male Iblas ; and I can venture to affirm positively, 
that the parasites of 8. Peronii and 8. villosum are not 
female. On the other hand, in the two male Iblas, I was 
enabled to demonstrate all the male organs, and I most 

19 



290 SEXUAL RELATIONS OF 

distinctly saw spermatozoa. In the parasitic comple- 
mental male of S. vulgare, I also most plainly saw sper- 
matozoa. In the parasites of S. rostratum, S. Peronii, and 
S. vittosum, the external male organs were present. I 
may here jnst allude to the facts given in detail under 
Ibla, showing that it was hardly possible that I could be 
mistaken regarding the exclusively female sex of the 
ordinary form of I. Cumingii, seeing how immediately 
I perceived all the male organs in the hermaphrodite 
I. quadrivalvis ; and as the parasite contained spermatozoa 
and no ova, the only possible way to escape from the 
conclusion that it was the male and L Gumingii the female 
of the same species, was to invent two hypothetical crea- 
tures, of opposite sexes to the Ibla and its parasite, and 
which, though Cirripedes, would have to be locomotive ! 
I insisted upon this alternative, because if the parasite of 
I. Cumingii be the male of that species, then unquestion- 
ably we have in I. quadrivalvis a male, complemental to 
an hermaphrodite, — a conclusion, as we have seen, hardly 
to be avoided in the genus Scalpellum, even if we trust 
exclusively to the facts therein exhibited. 

With respect to the positions of the parasitic males, in 
relation to the impregnation of the ova in the females and 
hermaphrodites, it may be observed that in the two male 
Iblas, the elongated moveable body seems perfectly adapted 
for this end ; in the males of the first three species of 
Scalpellum, the spermatozoa, owing to the manner in 
which the thorax is bent when protruded, would be easily 
discharged into the sack of the female or hermaphrodite; 
this would likewise probably happen with the comple- 
mental male of S. rostratum, considering its position within 
the orifice of the capitulum, between the mouth and the 
adductor scutorum muscle. The males of S. Peronii and 
villosum being fixed a little way beneath the orifice of the 
sack, below the adductor muscle, are less favorably situated, 
but the spermatozoa would probably be drawn into the 
sack by the ordinary action of the cirri of the hermaphro- 
dite, and therefore would at least have as good a chance of 



IBLA AND SCALPELLUM. 291 

fertilising some of the ova, as the pollen of many dioecious 
plants, trusted to the wind, has of reaching the stigmas of 
the female plants. Regarding the final cause, both of the 
simpler case of the separation of the sexes, notwithstanding 
that the two individuals, after the metamorphosis of the 
male, become indissolubly united together, and of the much 
more singular fact of the existence of Complemental males, 
I can throw no light ; I will only repeat the observation 
made more than once, that in some of the hermaphrodites, 
the vesiculae seminales were small, and that in others the 
probosciformed penis was unusually short and thin. 

Viewing the parasitic males, in relation to the structure 
and appearance of the species to which they belong, they 
present a singular series. In S. Peronii and S. vittomm, 
the internal organs have the appearance of immaturity; 
the shape of the capitulum is specially modified for its 
reception between the scuta of the hermaphrodite, and 
several of the valves have not been developed. This 
atrophy of the valves, is carried much further in S. ros- 
tratum. In Ibla, many of the parts are embryonic in 
character, but others mature and perfect ; some parts, 
as the capitulum, thorax, and cirri, are in a quite ex- 
traordinary state of atrophy ; in fact, the parasitic males 
of Ibla consist almost exclusively of a mouth, mounted on 
the summit of the three anterior segments of the 21 normal 
segments of the archetype crustacean. In the males of 
the first three species of Scalpellum, some of the cha- 
racters are embryonic, — as the absence of a mouth, the 
presence of the abdominal lobe, and the position of the 
few existing internal organs ; other characters, such as 
the general external form, the four bead-like valves, the 
narrow orifice, the peculiar thorax and limbs, are special 
developments. These three latter parasites, certainly, 
are wonderfully unlike the hermaphrodites or females to 
which they belong ; if classed as independent animals, they 
would assuredly be placed not in another family, but in 
another Order. When mature they may be said essentially 
to be mere bags of spermatozoa. 



292 IBLA AND SCALPELLUM. 

In looking for analogies to the facts here described, I 
have already referred to the minute male Lerneidas which 
cling to their females, — to the worm-like males of certain 
Cephalopoda, parasitic on the females, — and to certain 
Entozoons, in which the sexes cohere, or even are 
organically blended by one extremity of their bodies. The 
females in certain insects depart in structure, nearly or 
quite as widely from the Order to which they belong, 
as do these male parasitic Cirripedes ; some of these 
females, like the males of the first three species of Scal- 
pellum, do not feed, and some, I believe, have their 
mouths in a rudimentary condition ; but in this latter 
respect, we have, amongst the Rotifera, a closely analogous 
case in the male of the Asplanchna of Gosse, which was 
discovered by Mr. Bright well* to be entirely destitute of 
mouth and stomach, exactly as I find to be the case with 
the parasitic male of S. vulgare, and doubtless with its 
two close allies. For any analogy to the existence of males, 
complemental to hermaphrodites, we must look to the 
vegetable kingdom. 

Finally, the simple fact of the diversity in the sexual 
relations, displayed within the limits of the genera Ibla 
and Scalpellum, appears to me eminently curious; we 
have (1st) a female, with a male (or rarely two) perma- 
nently attached to her, protected by her, and nourished by 
any minute animals which may enter her sack ; (2d) a 
female, with successive pairs of short-lived males, destitute 
of mouth and stomach, inhabiting two pouches formed 
on the under sides of her valves ; (3d) an hermaphrodite, 
with from one or two, up to five or six similar short-lived 
males without mouth or stomach, attached to one par- 
ticular spot on each side of the orifice of the capitulum ; 
and (4th) hermaphrodites, with occasionally one, two, or 
three males, capable of seizing and devouring their prey 

* 'Annals of Natural History,' vol. ii, (2d series, 1848,) p. 153, PI. vi. 
Mr. Dalrymple has published a very interesting paper on the same subject 
in the 'Philosophical Transactions/ (p. 342,) 1849; and there is another 
Memoir by Mr. Gosse in the 'Annals of Natural History,' vol. vi, (1850,) p. 18. 



GENUS — POLLICIPES. 293 

in the ordinary Cirripedial method, attached to two diffe- 
rent parts of the capitulum, in both cases being pro- 
tected by the closing of the scuta. As I am summing up 
the singularity of the phenomena here presented, I will 
allude to the marvellous assemblage of beings seen by 
me within the sack of an Ibla quadrwalvis, — namely, an 
old and young male, both minute, worm- like, destitute of 
a capitulum, with a great mouth, and rudimentary thorax 
and limbs, attached to each other and to the hermaphro- 
dite, which latter is utterly different in appearance and 
structure ; secondly, the four or five, free, boat-shaped 
larvae, with their curious prehensile antennas, two great 
compound eyes, no mouth, and six natatory legs ; and 
lastly, several hundreds of the larvae in their first stage of 
development, globular, with horn-shaped projections on 
their carapaces, minute single eyes, fihformed antennae, 
probosciformed mouths, and only three pair of natatory 
legs; what diverse beings, with scarcely anything in 
common, and yet all belonging to the same species ! 



Genus — Pollicipes. PL VII. 

Pollicies. Leach. Journal de Physique, torn, lxxxv, Julius, 

1817* 
Lepas. Linn. Systema Naturae, 1767. 
Anatifa. Brugiere. Eucyclop. Method, (des Vers), 1789. 
Mitella. Oken. Lehrbuch der Naturgeschi elite, 1815. 
Ramphldiona. Schumacher. Essai d'un Nouveau Syst. &c., 1817 

(ante Julium). 
Polylepas. Be Blainville. Diet, des Sc. Nat., 1824. 
Capitulum (secundum Klein). /. E. Gray. Anuals of Philos., 

torn, x, new series, Aug. 1825. 



* This is one of the rare cases in which, after much deliberation, and with 
the advice of several distinguished naturalists, I have departed from the 
Rules of the British Association ; for it will be seen that Mitella of Oken, 
and Raii/phidioua of Schumacher, are both prior to Pollicipes of Leach ; yet, 



294 GENUS — POLLICIPES. 

Valvm ab\& usque ad 100 et amplius: later ibus verticitti 
inferioris multis; lineis incrementi deorsum ordinatis: sub- 
rostrum semper adest : pedunculus squamiferus. 

Valves from 18 to above 1 00 in number : latera of the 
lower whorl numerous, with their lines of growth directed 
downwards : subrostrum always present : peduncle squa- 
miferous. 

Hermaphrodite ; filamentary appendages either none, 
or numerous and seated on the prosoma and at the bases 
of the first pair of cirri ; labrum bullate ; trophi various ; 
olfactory orifices generally highly prominent; caudal ap- 
pendages uni-articulate and spinose, or multi-articulate. 

Attached to fixed, or less commonly to floating objects, in the warmer 
temperate, and tropical seas. 

It has been remarked, under Scalpellum, how im- 
perfectly that genus is separated from Pollicipes ; and we 
have seen under Scalpellum villosum that the addition of 
a few small valves to the lower whorl, would convert it 
into a Pollicipes, most closely allied to P. sertus and 
spinosus. It has also been shown, that the six recent 
species of Pollicipes might be divided into three genera, 
of which P. cornucopia, P. elegans, and P. polymerus y 
would form one thoroughly natural genus, as natural as 
Lepas and the earlier genera; P. mitella would form a 
second ; and P. sertus and P. spinosus a third ; but I have 
acted to the best of my judgment in at present retaining 
the six species together. As far as the valves of the capi- 
tulum are concerned, it would be very difficult to separate 
P. mitella from P. sertus and spinosus. 

as the latter name has been universally adopted throughout Europe and North 
America, and has been extensively used in geological works, it appears 
to me to be as useless as hopeless to attempt any change. It may be ob- 
served that the genus Pollicipes was originally proposed by Sir John Hill 
('History of Animals,' vol. iii, p. 170), in 1752, but as this was before the 
discovery of the binomial system, by the Rules it is absolutely excluded as 
of any authority. In my opinion, under all these circumstances, it would be 
mere pedantry to go back to Oken's 'Lehrbuch der Naturgeschichte' for the 
name Mitella, — a work little known, and displaying entire ignorance regard- 
ing the Cirripedia. 



GENUS — POLLICIPES. 295 

Description. The number of valves in the capituluni 
has in this genus acquired its maximum. The number 
varies considerably in the same species, and even on 
opposite sides of the same individual, and generally in- 
creases with age. It is more important, that the number 
of the whorls in P. cornucopia, and in the two following 
closely-allied forms, also increases with age. In P. sertus 
and P. sjjinosus, even the number of the whorls varies in 
different individuals, independently of age. The valves are 
arranged alternately with those above and below; they 
are generally thick and strong, making the capituluni 
somewhat massive ; in some species they are subject to 
much disintegration ; but in others, the apices of the 
several valves, especially of the carina and rostrum, are 
well preserved, and project freely : they are covered with 
membrane, which, differently from in most species of Scal- 
pellum, either does not bear any spines, or only exceed- 
ingly minute points. In all the species there is a sub- 
rostrum and sub-carina, and often beneath these a second 
sub-rostrum and sub-carina. In medium-sized specimens 
there are at least 20 valves in the lowermost whorl. 
The carina is either straight or curved, but never rec- 
tangularly bent, and is always of considerable breadth. 
None of the valves are added to at their upper ends. 
The scuta have a deep pit for the adductor muscle. The 
valves lie either some little way apart, or more commonly 
close together. In P. mitella the scuta and terga are 
locked together by a fold, and the valves of the lower 
whorl overlap each other in a peculiar manner, resembling 
that in which the compartments in the shells of Sessile 
Cirripedes fold over each other. 

The Peduncle is of considerable length in some of 
the species, and rather short in others ; it is, in every 
case, clothed with calcified scales. The scales in the first 
four species are placed alternately and symmetrically; 
they are formed and added to in the same manner as 
in Scalpellum ; they differ in size according to the size 
of the individual, and consequently the lower scales 



296 GENUS — POLLICIPES. 

on the peduncle, formed when the specimen was young, 
are smaller than the upper scales ; the lower scales 
are separated from each other by wide interspaces of 
membrane, owing to the continued growth of the pe- 
duncle by the formation of new layers of membrane, 
and the disintegration of the old outer layers. Each 
scale is invested by tough membrane (or has been, 
for it is often abraded off), in the same manner as the 
valves ; each is furnished with one or more tubuli, 
in connection with the underlying corium. In P. sertus 
and P. spinosus, the scales are small, spindle-shaped, 
and not of equal sizes, and the rows are distant from 
each other, so that their alternate arrangement is not 
distinguishable; in these two species, new scales are formed 
round the summit of the peduncle, and the growth of 
each is completed whilst remaining in the uppermost 
row; but, besides these normal scales, such as exist in the 
other species of Pollicipes and in Scalpellum, new scales 
are formed in the lower part of the peduncle, which 
are generally of very irregular shapes, are often larger 
than the upper ones, are crowded together, and some- 
times do not reach the outer surface of the membrane. 
This formation of scales in the lower part of the peduncle, 
independently of the regular rows round the uppermost 
part, is perhaps a feeble representation of the calcareous 
cup at the bottom of the peduncle in the genus Lithotrya. 
The prehensile antennas will be described under P. cor- 
nucopia. 

Size. — Most of the species are large: and P. mitella 
is the most massive of the Pedunculated Cirripecles. 

The Mouth is not placed far from the adductor muscle. 
The labriun is highly bullate. The mandibles have either 
three or four main teeth (PL X, fig. 1), with often either 
one or two smaller teeth inserted between the first and 
second. The maxillae (PI. X, figs. 13, 14), have their edges 
either straight and square, or notched, or more commonly 
with two or three prominences bearing tufts of finer spines. 
The outer maxillae (fig. 17) generally have a deep notch 



GENUS — POLLICIPES. 297 

on their inner edges, but this is not invariable. The olfac- 
tory orifices in most of the species are highly prominent. 
Cirri. — The first pair is never placed far distant from 
the second. The posterior cirri have strong, somewhat 
protuberant segments ; and between each of the four or 
five pair of main spines (PL X, fig. 27), there is a rather 
large tuft of straight, fine, short bristles. The second and 
third pair have the basal segments, either of the anterior 
rami, or of both rami, so thickly clothed with spines 
(fig. 25), as to be brush-like : in P. mitella, however, the 
third pair is like the three posterior pair in the arrange- 
ment of its spines, in this respect resembling the sessile 
Chthamalinae. The caudal appendages are either uni- 
articulate and spinose, or multi-articulate : it is remark- 
able that there should be this difference in such closely 
allied species as P. cornucopia and P. poli/merus : the 
short, obtuse, obscurely-articulated caudal appendage of 
the former species (fig. 22) makes an excellent passage 
from the uni-articulate (fig. 19) to the multi-articulate 
form, as in P. mitella. 

The stomach, in those species which I opened, is desti- 
tute of caeca ; the hepatic glands are arranged in straight 
lines ; the rectum is unusually short. The prosoma is well 
developed. 

In P. cornucopia, P. elegans, and P. polymerus, there 
are numerous filamentary appendages both on the pro- 
soma, and at the bases of the first pair of cirri: these 
appendages are occupied by testes, and I suspect stand 
in relation to the length of the peduncle and consequent 
great development of the ovaria. In order to give space 
for the filamentary appendages, the sack (generally rough- 
ened by small inwardly-pointing papillae) penetrates more 
deeply than usual into the upper part of the peduncle. 
There are small ovigerous fraena in P. sertus, P. spinosus, 
and P. mitella ; in the three other species, the fraenum or 
fold occupies the usual position on each side, and is large ; 
but in one specimen carefully examined by me, I was 
unable to see any glands ; and in another specimen, the 



298 POLLICIPES CORNUCOPIA. 

ovigerous lamellae were not attached to the fraena ; hence 
I conclude that the fraena are functionless in these three 
species. 

Affinities. — T have already remarked on the close rela- 
tionship between this genus and Scalpellum ; there is 
also some affinity with Lithotrya. 

Distribution. — All over the world. The P. cornucopia ranges from Scot- 
land to Teneriffe : the P. polymerus is found in opposite hemispheres in the 
Pacific Ocean, extending from California to at least as far as 32° south of the 
Equator. 

Geological History. — Having so lately given, in the 
' Memoirs of the Palaeontographical Society/ a full ac- 
count of all the fossil species known, I will not repeat 
here the conclusions there arrived at. I will only state, 
that species of Pollicipes are found in all the formations, 
extending from the Lower Oolite to the Upper Tertiary 
beds. 



1. Pollicipes cornucopia. PI. VII, fig. 1. 

Pollicipes cornucopia. Leach. Encyclop. Brit. Supp., vol. iii, 

1824. 

— Smythii, var. Leach. Ibid. 

Lepas pollicipes. Gmelin. Systema Naturae, 1789. 

— gallorum. Spengler. Skrivter Naturhist. Selskabet, 

Bd. i, Tab. vi, fig. 9, 1790. 

P. capitulo, valvarum duobus aut pluribus sub-rostro 
verticillis instructo: valvis albis, aut ylaucis : _pedimculo, 
squamarum densis verticillis symmetrice dispositis. 

Capitulum with two or more whorls of valves under 
the rostrum ; valves white or gray ; scales on the peduncle 
symmetrically arranged in close whorls. 

Maxillae with three tufts of fine bristles, separated by 
larger spines : segments in the first cirrus less than half 
the number of those in the sixth cirrus : caudal appendages 
multi-articulate: filamentary appendages attached to the 
prosoma. 



POLLICIPES CORNUCOPIA. 299 

Coast of Portugal; mouth of the Tagus. England,* Ireland, and the 
Frith of Forth in Scotland. Mediterranean (according to Brugiere) : 
Teneriffe : Mogador, Africa. 

Capitulum, obtusely triangular, massive : valves close 
together, rather thick, with their exterior surfaces convex, 
naked, except in the lower parts, where united together 
by tough, greenish-brown membrane, destitute of spines. 
The edges of the orifice are widely bordered by mem- 
brane, coloured fine crimson red. The valves, in a spe- 
cimen with a capitulum above three quarters of an inch 
long, were 52 in number; in a specimen one fifth of an 
inch long, only between 20 and 30. Two whorls of 
valves are distinct beneath the carina and rostrum. In 
one specimen in Mr. Cuming's collection, with a capitulum 
1*4 of an inch long, there were three whorls beneath 
the rostrum, and four beneath the carina. The scuta, 
terga, and carina are much larger than the other valves. 

Scuta, oval, the basal and t ergo-lateral margins sweep- 
ing into each other, and the apex pointed ; internally 
(PI. VII, fig. ] a) the pit for the adductor muscle is deep. 

Terga, larger than the scuta, internally (fig. 1 a) slightly 
concave ; carinal margin much curved and protuberant ; 
basal angle blunt ; scutal margin either curved with the 
upper part straight, or formed of two almost distinct 
lines, corresponding with the tergal margin of the scutum, 
and with one of the sides of the upper latus. 

Carina, much curved, extending far up between the 
terga, internally deeply concave, widening much from the 
top to the bottom ; basal margin highly protuberant, with 
a central portion either truncated and very slightly hol- 
lowed out, or bluntly and rectangularly pointed, with the 
apex itself rounded. 

Rostrum, not one third of the length of the carina, 
concave, triangular, with the basal margin slightly pro- 

* This species is said by Montagu (' Test. Brit. Supplement ') to have 
been found attached to drift timber in the Frith of Forth, and to the bottom 
of a wrecked vessel towed into Dartmouth. According to Mr. W. Thompson 
('Annals of Nat. Hist.' vol. xiii, p. 436), it has been found attached to wood- 
work near Dublin. 



300 POLLICIPES CORNUCOPIA. 

tuberant. Of the other valves, including the sub-carina 
and sub-rostrum, the shape of their inner surfaces is sub- 
triangular, with the basal margin convex ; externally the 
umbones are pointed, and slightly curled inwards, so as 
to overlap each other like tiles : the smaller valves, how- 
ever, of the lower whorls (fig. 1 a) are more or less trans- 
versely elongated, so as to become almost elliptic instead 
of triangular. Of the latera, the upper pair, which cor- 
responds to the interspace between the scuta and terga, is 
the largest, but barely exceeds in size the pair answering 
to the carina! latera in Scalpellum, which lie between 
the terga and carina : the next largest pair is the rostral, 
or that between the scuta and rostrum. Some, however, 
of the lower latera are of nearly equal size. 

Peduncle, narrower, but generally longer than the 
capitulum ; upper part encased with small calcareous scales, 
with their apices curved inwards, and overlapping each 
other. The inner surface of each scale is triangular, with 
the basal margin protuberant. The scales continue to 
grow or be added to, only in about the ten upper whorls, 
which form but a small part of the whole peduncle ; in 
the lower part, the scales become further and further 
separated from each other. The surface of attachment, 
in full-grown specimens, is broad ; but in two very young 
specimens, which I removed with great care after the 
action of potash, I found the peduncle ending in a filiform 
prolongation, such as often occurs in Scalpelhwi vulgar e 
and in Lepas fascicularis. At the extremity of the pointed 
peduncle, there were seated the larval prehensile antenna^ 
of which the following measurements are given to show 
how minute they are. 

Inch. 
Length, from apex of disc, to the further edge of the basal articulation boos 
Breadth of basal segment, in broadest part .... ^ m 
Hooi'-like disc, length of ....... so %> 

Ultimate segment, entire length of m ^ 

breadth, in broadest part .... 5 oik> 



j> » 



The disc resembles a broad, rounded hoof, very little 
longer than broad, and narrowed in at the heel; the 



POLLICIPES CORiNUCOPlA. 301 

apex is not at all pointed, and bears some minute and 
thin spines. There is one large spine on the under side 
of the disc ; and another on the basal segment, on the 
outside, in the usual position. The ultimate segment is 
long and thin; it has a notch on the inner side (the 
segment supposed to be stretched forward), bearing two 
or three long flexuous spines ; and there are three or four 
other spines on the summit : altogether there is a close 
resemblance with the antennas in Scalpellum, excepting 
that the hoof-like disc is not here pointed. 

Colours. — Valves internally tinted, in parts, grey; 
peduncle, brown ; corium of sack, purplish-brown, of pe- 
duncle, rich coppery brown ; cirri, banded dorsally, and 
with the front surfaces of the segments, purplish-brown. 
Edge of the orifice of sack, fine crimson red. The speci- 
men here described had been dried for a few weeks, and 
was then moistened. 

Dimensions. — The largest specimen which I have seen, 
in Mr. Cuming's collection, had a capitulum 1 and T \ ths 
of an inch long ; a fine specimen, from TenerhTe, was t% ths 
in length. In a specimen with a capitulum Ath of an inch 
long, and about the same in breadth, there were eighteen 
valves ; so that, besides the principal valves, five pair of 
latera, the sub-carina, and sub-rostrum, were already de- 
veloped, and on the upper part of the peduncle, there 
were many calcareous scales. 

Filamentary dpjiendages. — The prosoma is well-de- 
veloped, with thirteen or fourteen pair of short, blunt 
filaments, placed close together in two longitudinal rows ; 
those nearest the thorax are the longest; outside this 
double row, on each side, there is a row of papillae, indi- 
cating a tendency to the formation of two other rows of 
filaments. There is a pair of longer filaments, one on each 
side of the mouth, pointing upwards, and thinly clothed 
with long spines ; at the bases of the first pair of cirri there 
is a second pair of filaments, shorter and bearing a few 
minute spines. The bottom of the sack is studded with 
small rounded papillae, with roughened summits. 



302 POLLICIPES CORNUCOPIA. 

Mouth, not placed very far from the adductor muscle. 

Labrum, highly bullate, equalling, in its longitudinal 
diameter, the rest of the mouth ; upper part square, not 
overhanging the lower part ; there are some small teeth 
on the crest. 

Palpi, oval, outer and inner margins nearly alike, 
thickly clothed with spines. 

Mandibles, with three very strong, yellow teeth ; inferior 
point broad, coarsely pectinated. In one specimen, on 
one side, the third tooth was represented by two smaller 
teeth. 

The Maxilla bear three conspicuous tufts of fine 
bristles, separated by larger spines ; the first tuft is placed 
close to the two, upper, large, but unequally-sized spines; 
the second tuft is placed in the middle, and the third at 
the inferior angle. The two latter tufts stand on pro- 
minences ; between the two upper tufts there are three 
pair, and between the two lower tufts four or more pair 
of rather strong spines : (see the figure, 13, PL X, in the 
allied P. poly merits .) 

Outer Maxilla, with the inner edge divided in the 
middle by a conspicuous notch, and with the bristles 
above and below short, making two equal combs. On 
the exterior surface, the bristles are longer and more 
spread out. Olfactory orifices prominent, protected by 
a punctured swelling between the bases of the first pair 
of cirri. 

Cirri, short and rather thick ; the first pair is not far 
removed from the second. The segments of the three 
posterior pair are somewhat protuberant, bearing six pair 
of short, strong spines, graduated in length, between 
which there is a very thick, longitudinal brush of short, 
fine, straight bristles, of which the lower ones are the 
longest ; some thick, minute spines arise from the upper 
lateral edges of the segments. The spines in the dorsal 
tufts are short, much crowded, and of nearly equal 
length; see figure, 27, PL X, in the allied P. polymerus. 
In a specimen in which the sixth cirrus had seventeen 



P0LLIC1PES CORNUCOPIA. 303 

segments, the first cirrus had, in the shorter ramus, eight 
segments, of which the lower four were thick and pro- 
tuberant, with the spines doubly serrated. In this same 
specimen, the anterior ramus of the second cirrus had 
twelve segments, of which the live basal ones were highly 
protuberant, and thickly clothed with non-serrated spines. 
In the third cirrus the basal segments of the anterior 
ramus are highly protuberant. The basal segments in 
the posterior rami of both these cirri, are slightly pro- 
tuberant, but otherwise resemble the segments in the 
three posterior pair. 

The Caudal Appendages (PI. X, fig. 22), in full-grown 
specimens, just exceed in length the lower segments of 
the pedicels of the sixth cirrus ; they are nearly cylindrical, 
bluntly pointed, with five oblique imperfect articulations ; 
the lower or basal articulations cannot be traced all round, 
being distinct only on the ventral surface. There is a 
row of short spines round the upper edge of each segment, 
with a little, short tuft on the point of the terminal 
segment. In a rather young specimen, however, with 
its capitulum one fifth of an inch long, each appendage 
certainly consisted of a single segment, with spines only 
on the summit. 

Penis purple, with excessively short and fine spines in 
tufts, chiefly near the extremity. In a specimen with a 
capitulum only one fifth of an inch long, the penis con- 
sisted of a mere pointed papilla, not so long as the caudal 
appendage, and therefore equalling in length only the 
lower segment of the pedicel of the sixth cirrus. 

Ovigerous frcena. — I could see none, though there were 
two large lamellae in the sack. The ova were flesh- 
coloured, but they had been dried and then placed in 
spirits. The ova were wonderfully numerous, oval, much 
elongated, and ^th of an inch in length. 



304 POIiLICIPES ELEGANS. 



2. POLLICIPES ELEGANS. 

Pollicipes elegans. Lesson. Voyage de la Coquille, torn, ii, 

p. 441, 1830, et Must. Zool, PL xxxix, 
1831. 
— rubeu. G. B. Sowerby. Zoolog. Proc, 1833, p. 74. 

P. capitulo, valvarum duobus aut pluribus sub-rostro 
verticillis instructo : valvis et pedunculi squamis rufo- 
aurantiacis : squamarum verticillis densis symmetrice dis- 
positis. 

Capitulum with two or more whorls of valves under the 
rostrum : valves and scales of peduncle reddish-orange ; 
the latter symmetrically arranged in close whorls. 

Maxillae with three tufts of fine bristles, separated by 
larger spines ; segments in the first cirrus more than half 
the number of those in the sixth cirrus ; caudal appen- 
dages multi-articulate; filamentary appendages attached 
to the prosoma. 

Coast of Peru, Payta, attached to wooden posts, according to Lesson : 
Lobos Island, Peru, Mus. Cuming : West Coast of Mexico, Tekuantepec, on 
an exposed rock, according to Hinds. 

The resemblance of this species is so close to P. cornu- 
copia, that it is quite useless to do more than point out 
the few points of difference. Valves of the capitulum 
and scales of the peduncle, coloured (after having been 
in spirits,) reddish-orange. In a specimen in which the 
capitulum was 1*3 of an inch in length, there were three 
whorls of valves below the carina ; in this large specimen 
altogether there were about eighty valves ; in medium- 
sized specimens, the number is about the same as in 
P. cornucopia. The upper latus, (viewed internally,) has 
an area about twice as large as that latus, which cor- 
responds to the interspace between the carina and terga; 
whereas in P. cornucopia the upper latus is only slightly 
larger than this same valve. The apex of the basal in- 



POLLICIPES ELEGANS. 305 

ternal margin of the carina is here rounded, instead of 
being square, as is generally the case with P. cornu- 
copia. The strong membranous margin of the orifice of 
the sack, in its upper part, is almost one third as wide as 
the widest part of the terga, whereas in P. cornucopia it 
is only one fourth of this same width. The peduncle 
apparently is rather longer, compared with P. cornucopia, 
and the calcareous scales on it perhaps a little larger 
in proportion. 

In a very young specimen, with the capitulum barely 
exceeding ^th of an inch in length, T could distinguish 
the sub-rostrum, sub-carina, the upper, and some of the 
lower latera. 

Filamentary Appendages. — These, in a medium-sized 
specimen, are arranged on the prosoma in four longi- 
tudinal approximate rows, there being twelve in each 
row ; those in the two outer rows are only half the length 
of those in the two inner rows ; those nearest the thorax 
are the longest ; there are some papillae outside the outer 
rows. In a very large specimen with its capitulum 13 in 
length, these filaments were very much more numerous, 
and some were placed on the first segment of the thorax, 
and at the bases of several of the posterior cirri. Some 
of the filaments are bifid, trificl, and even branched. In all 
the specimens, at the bases of the first pair of cirri, there 
are, on each side, a pair of filaments, (one below the 
other,) pointing upwards, less than half as long as those 
on the prosoma : also on each side of the mouth, there is a 
longer and thicker filament, pointing upwards, with a 
few very minute scattered spines on it ; the apices of these 
three pair of filaments, as w 7 ell as of some of the others, 
are roughened with very minute pectinated scales. All 
these filaments were gorged with the branching testes. 

Mouth. — The parts are closely similar to those in P. cor- 
nucopia; in the mandibles, the interspace between the 
third tooth and the inferior angle, is slightly pectinated : 
in the maxillae, there are six or eight pairs of spines 
between the tw r o upper tufts of fine spines. 

20 



306 POLLICIPES ELEGANS. 

Cirri. — These are in most respects similar, to those of 
P. cornucopia. In a specimen in which the sixth cirrus 
had eighteen segments, the shorter ramus of the first 
pair had ten segments, of which the five lower seg- 
ments were thick and clothed with doubly serrated spines. 
In the second cirrus the anterior ramus had fifteen seg- 
ments, of which the four basal ones were highly protu- 
berant, and thickly clothed with spines. These spines, 
and some on the third cirrus, and a few on the first cirrus, 
have peculiar bent teeth, presently to be described under 
P.polymerus. These singularly toothed spines are absent 
in P. cornucopia. From the above numbers, we see that 
the first and second pairs of cirri have more segments in 
proportion to the sixth pair, than in P. cornucopia; and in 
the second pair, a fewer proportional number of the basal 
segments are protuberant and thickly clothed with spines. 

Caudal Appendages, shorter than the lower segments of 
the pedicels of the sixth cirrus, with only four articulations; 
rather constricted near the base. 

The Ovigerous Frcena consist of very long and pro- 
minent folds, thinning out to nothing towards the bases of 
the scuta, but not furnished, as far as I could see, with 
glands, and therefore not normally functional. 

Diagnosis toith P. cornucopia. — The reddish-orange 
colour of the valves alone suffices. There is a very slight 
difference, in the larger proportional size of the upper 
latera, and in the outline of the basal margin of the 
carina. In the maxillae there is, in P. elegans, a greater 
width between the two upper tufts of fine spines. In the 
cirri, the segments in the first pair, are more than half as 
many as those in the sixth pair ; in the anterior ramus of 
the second pair, only tMIis of the segments are protuberant 
and brush-like, whereas in P. cornucopia -ftths are in this 
condition. 



POLLICIPES POLYMERUS. 307 



3. POLLICIPES POLYMERUS. PI. VII, fig. 2. 

Pollicipes polymektjs.(!) G. B. Sowerby. Proc. Zool. Soc, 1833, 

p. 74. 
— Mortoni (!) Conrad. Journal Acad. Nat. Sci. Phila- 
delphia, vol. vii, p. 261, PI. xx, 
fig. 12, 1837. 

P. capitulo, valvarum duobus, tribus, aut pluribus sub- 
rostro verticillis instructs : valvis sub-fuscis : lateribus a 
supremo ad infimum gradatim quoad magnitudinem positis : 
carina margine basalt (introrsunt spectanti) ad medium 
ewcavato: pedunculi sauamarum verticillis densis, sym- 
metrice dispositis. 

Capitulum with two, three, or more whorls of valves 
under the rostrum : valves brownish : latera regularly 
graduated in size from the uppermost to the lowest : 
carina with the basal margin, (viewed internally,) hollowed 
out in the middle : scales of the peduncle symmetrically 
arranged in close whorls. 

Maxillae with three tufts of fine bristles, separated by 
larger spines; caudal appendages uniarticulate; filamentary 
appendages attached to the prosoma. 

Upper California, St. Diego and Barbara, 32° to 35° N., according to 
Conrad ; Mus. Cuming : Low Archipelago, Pacific Ocean ; Mus. Coll. of 
Surgeons : Southern Pacific Ocean, collected during the Antarctic Expedi- 
tion, Mus. Brit. 

Capitulum, but little compressed, broad, with the scuta 
and terga placed in a more oblique direction, with respect 
to the peduncle, than is usual, so that the line of orifice 
forms an unusually small angle with the basal margin 
of the capitulum. The capitulum is composed of several 
whorls of valves, which gradually decrease in size from 
above downwards. In a medium-sized specimen there 
were four whorls under the rostrum ; in the lowest of these 
whorls, there were between eighty and ninety valves, and 
in the whole capitulum from one hundred and seventy, to 
one hundred and eighty. The valves in the lower whorls 



308 POLLICIPES POLYMEliUS. 

are not of equal sizes. Viewed externally, the valves 
seem to touch and overlap each other ; viewed internally 
(PL VII, fig. 2a) they are found to be just separated from 
each other by transparent membrane ; none of the valves 
are articulated together. The outer surfaces of nearly 
all the valves, except in the two last formed whorls, are 
much disintegrated, and seem to be composed of alternate 
white and brown layers of shell. The membrane con- 
necting the valves, as well as that of the peduncle, (in 
specimens long kept in spirits,) is brown ; but in some 
dried specimens, there are indications of its having been 
coloured crimson (as in P. cornucopia), round the orifice 
and between the valves. 

Scuta, irregularly oval, convex, narrow at the upper 
end ; basal margin may be almost said to be formed of 
three short, unequal margins, corresponding with the 
rostrum, the rostral and the adjoining latus. The edge 
corresponding with the latter, is the best marked, and is 
generally slightly hollowed out, as if a piece had been 
broken off'. The tergo-lateral margin is curved and pro- 
tuberant. The umbo projects a little over the scutal 
margin of the terga. 

Terga, projecting beyond the other valves to an un- 
usually small degree, broadly oval ; basal angle bluntly 
pointed, apex rounded, blunt ; scutal margin, hollowed 
out to receive the upper part of the tergal margin of the 
scuta ; carinal margin curved and protuberant ; occludent 
margin consists of two short sides at right angles to each 
other. The whole valve in length and area is about equal 
to the scuta ; internally, somewhat concave. 

Carina, triangular, rather narrow, internally deeply 
concave, very slightly curled inwards ; basal margin pro- 
tuberant, with a large central portion considerably 
hollowed out. 

Rostrum, triangular, of nearly the same shape as the 
carina, but only one third of its length, internally very 
slightly concave, and with the basal margin various, being 
either truncated or angularly prominent in the middle. 



POLLICIPES POLYMERUS. 309 

Later a, — The upper pair (corresponding to the interval 
between the scuta and terga) is only a trifle larger than the 
latera immediately beneath ; and these only a little larger 
than those lower down. In the lowest whorl, the valves 
are very minute, though still about twice as large as the 
scales on the peduncle, and of a different shape from them. 
The upper latera (viewed internally) are almost diamond- 
shaped, owing to the prominence of the basal margin, bnt 
this varies considerably in decree. The latera in the 
next whorl are triangular, with the basal margins pro- 
tuberant and arched, in a less and less degree in the lower 
whorls, until in the lowest, the valves are elongated trans- 
versely. 

Microscopical Structure. — A valve placed in acid leaves 
a thick opaque mass, formed of three different kinds of 
tissue, one having a finely shaded appearance ; a second 
with a largely hexagonal reticulated structure, and the 
third thin, transparent, and marked with arborescent 
lines, which I imagine to be tubes, as will be hereafter 
seen in Lithotrya. Near the exterior surface, there are 
many tubuli. It appears to me probable that the strong 
tendency which the valves in this species have to dis- 
integrate, is connected with the unusual quantity of ani- 
malized tissue contained by them. Externally the valves 
are covered by a strong membrane, either white or yellow, 
or white streaked with yellow, and marked by lines of 
growth, and by longitudinal, sinuous, little ridges. 

Peduncle, in the upper part, of rather less diameter 
than the capitulum; twice or thrice as long as it; tapering 
a little downwards ; surface of attachment wide and flat. 
Calcareous scales, minute, symmetrically and closely 
packed together : each scale is much flattened, and its 
shape, including the imbedded portion, is that of a spear 
with its point broken off. The basal end of each scale 
is conically hollow, and from the layers of growth con- 
forming to this hollow, there is a false appearance of an 
open tube running through the scale. 

attachment. — The surface of attachment is wide : the 



310 POLLICIPES POLYMEPvUS. 

two cement- ducts, after running down the sides of the 
peduncle in a sinuous course, within the longitudinal 
muscles and close outside the ovarian tubes, pass through 
the corium, and then separately form the most abrupt 
loops or folds. These are represented in PL IX, fig. 2, 
in which a space about T Vth of an inch square is given, 
as seen from the outside. At each of the bends, an 
aperture has been formed through the membrane of the 
peduncle, and cement poured forth. The manner in 
which the discs of cement (b) come out of the two ducts 
(a a), and reach the external surface, is shown in the 
section, figure 2 d . The two tubes are firmly attached to 
the older layers of membrane, and are covered by the last- 
formed layers. In a young specimen, the cement-ducts 
were a little above ^ths of an inch in diameter, which 
had increased, in a medium-sized specimen, to ^. The 
cement-glands are retort-shaped, seated near each other, 
high up in the peduncle. 

Size. — The largest specimen which I have seen, was 
three inches in length including the peduncle ; the capi- 
tulum was T%ths of an inch long, and one in width. 

Young Specimen. — 1 examined one with a capitulum 
Troths of an inch long, measured from the lowest whorl 
to the tips of the terga ; the width was only Tilths of 
an inch ; in old specimens the width of the capitulum is 
greater than the length. The length of one of the scuta 
was tAo oths of an inch, therefore, greater than the width 
of the entire capitulum, which is not the case with mature 
specimens. Besides the scuta and terga, the carina and 
rostrum, and three pair of large latera, there was a lower 
whorl formed of ten or twelve valves, giving altogether to 
the capitulum of this very small specimen, either twenty- 
two or twenty-four valves. 

Shape of Body, Sack, Colours, <^e.-^From the posi- 
tion of the orifice of the capitulum, the animal's body is 
suspended to the scuta in a more transverse direction 
than is usual. The prosoma is well-developed, and is 
distinctly separated from the three posterior thoracic seg- 



POLLICIPES POLYMERUS. 311 

ments, by a band of thin membrane. The tunic of the 
basal part of the sack, where it enters the peduncle in a 
blunt point, is thickened and covered with roughened 
rounded papillae. The corium of the sack under the 
valves, is coloured (after spirits) so dark a brown as to 
be nearly black ; the cirri and tropin are similar, but 
with a tinge of greenish-purple. 

Filamentary Appendages. — Of these there were, on the 
prosoma of one specimen, twelve pairs, and in another 
specimen fourteen pairs, seated in two approximate rows ; 
the middle filaments are the longest, equalling about half 
the diameter of the thorax : each is flattened, and tapers 
but little towards its summit, which is roughened with 
microscopical crests serrated on both sides ; on the summit, 
also, there are a few bristles and some very short, thick, 
minute spines. These appendages are directed rather 
towards each other, and towards the thorax. 1 do not 
doubt that their numbers vary according to the size of 
the specimen. I believe that they are occupied by testes. 
Outside these filaments, on each side of the prosoma, there 
are two very irregular rows of papillae, intermediate in 
length between the filaments and the rounded swellings 
at the bottom of the sack. Beneath the basal articulation 
of the first cirrus, there is on each side, a short appendage, 
with a few bristles on its summit. Lastly, on each side of 
the middle of the mouth, on the prosoma, there is a longer 
appendage, dark-coloured, furnished with a few scattered 
bristles on its sides and apex, and directed upwards and 
a little towards the adductor scutorum muscle. 

Mouth. — Labrum highly bullate, but with the upper- 
most part not more bullate than the lower part, and there- 
fore not overhanging it ; basal margin much produced ; 
crest with some small blunt teeth and some bristles. 
The inner fold of the labrum is much thickened, yellow, 
punctured, and with a tuft of fine bristles on each side. 

Palpi, approaching each other but not touching, club- 
shaped, or with broad and square extremities, thickly 
fringed with serrated bristles. 



312 POLLICIPES POLYMERUS. 

Mandibles with three unusually strong teeth, slightly 
graduated in size, with the inferior angle very coarsely 
pectinated ; the lower edges of the main teeth are rough- 
ened. 

Maxillce, (PL X. fig. 13). Spinose edge about half the 
length of the mandibles ; the two upper spines are un- 
usually strong ; close under, and almost hidden by them, 
there is a tuft of fine spines ; in the middle there is a 
second similar tuft mounted on a prominence; and at 
the inferior angle there is a third tuft, also mounted on a 
rather wider prominence, not quite accurately figured. 
In the interspaces between these tufts there are three or 
four pairs of spines of the usual appearance and projecting 
just beyond the fine tufts ; the upper of the two interspaces 
is rather narrower, but rather deeper, than the lower in- 
terspace. Apodeme very long, irregularly shaped, like 
an S, with a remarkable elbow near its attachment ; apex 
slightly enlarged, thin and rounded. 

Outer Maxilla. — On the inner margin there is a deep 
and conspicuous notch, above and beneath which, there is 
a compact row of serrated bristles ; exteriorly the bristles 
are rather longer. 

Olfactory Orifices very prominent, pointing obliquely 
towards each other. 

Cirri. — Posterior cirri moderately long, much curled, 
with the segments (PI. X, fig. 27) flattened and wide; the 
anterior surface hemispherically protuberant, supporting 
six pairs of spines, of which the lower ones approach each 
other ; between these spines there is a large tuft of very 
fine spines, of which the central ones are the longest ; there 
is an upper lateral group of very short strong spines; dorsal 
tufts composed of short, fine numerous spines. First 
pair seated close to the second pair, short, having in both 
rami eight segments, whereas in the same individual the 
second pair, which is nearly twice as long, had thirteen, 
and the sixth pair eighteen segments. Rami of the first 
pair nearly equal in length, with their segments, excepting 
the two upper ones, thickly paved with bristles, in the 



POLLICIPES POLYMERUS. 313 

midst of which a tuft of fine spines, as in the posterior 
cirri, may be distinguished; the dorsal tufts encircle the 
whole of each segment ; the spine-bearing anterior surfaces 
are protuberant chiefly in the upper part, so that they are 
oblique. The posterior (?) ramus has its segments much 
wider than those on the other ramus ; and amongst the 
common spines, in the third and fourth segments, (counting 
from the bottom,) there are some very strong spines 
with their upper ends coarsely and doubly pectinated, 
each tooth being upwardly bent into a rectangular elbow. 
In the fifth segment, some of the spines are doubly 
pectinated with simple teeth ; and most of the spines are 
doubly serrated. The Second (PL X, fig, 25) and Third 
cirri have the five basal segments (-rVths of the whole 
number in the second cirrus, and Tiths in the third cirrus) 
of their anterior rami, extremely broad, protuberant, and 
paved with serrated bristles, amongst which, (except on 
the actual lowest segment,) there are some simply pecti- 
nated spines, and others with their teeth elbowed, exactly 
as in the first cirrus. The basal segments of the posterior 
rami of the second and third cirri, differ from the three 
posterior cirri only in the spines being slightly more 
numerous ; but none of them are pectinated. 

Pedicels, rather short ; the upper segment resembles, in 
the arrangement of its spines, the segments of the pos- 
terior cirri ; the lower segment is longer than the upper, 
and has two tufts of fine spines, between the two rows 
of long spines. In the second and third cirri, these two 
intermediate tufts on the lower segment of the pedicel, 
are not so distinctly separated from each other. 

Caudal Appendages, very small, uniarticulate, blunt 
and rounded ; tips bearing a few, very short, thick spines. 

Alimentary Canal. — (Esophagus, somewhat curved at 
the lower end, where it enters the stomach, which has no 
caeca ; rectum, unusually short, extending from the anus 
only to the base of the fifth pair of cirri. Within the 
stomach, from top to bottom, there were thousands of 
a bivalve entomostracous crustacean. 



314 POLLICIPES POLYMERUS. 

Generative System. — Both ovaria and testes are largely 
developed ; the former fill the long peduncle ; the testes 
enter both the pedicels of the cirri, and the filamentary 
appendages on the prosoma; vesiculse seminales very large, 
reflected at their ends, extending across each side of the 
stomach. Penis rather small, coloured purplish, with nu- 
merous little tufts of bristles. 

Variation. — In some specimens in the British Museum, 
collected by Sir J. Ross, in the Southern ocean, and in 
another older set from an unknown source, several parts 
of the outer tunic of the animal's body presented the 
remarkable fact of being calcified, but to a variable 
degree ; whereas in several specimens from California, 
there was no vestige of this encasement. Considering 
it most improbable that the calcification of the integu- 
ments should be a variable character, I most carefully 
compared the above-mentioned sets of specimens, valve 
by valve, tropin by trophi, and cirri by cirri, and found no 
other difference of any kind ; therefore I cannot hesitate to 
consider both to be the same species. The first Southern 
specimen which I examined presented the following cha- 
racters : on the prosoma there was a central longitudinal 
band, formed of a thin, brittle, brown-coloured calcified 
layer, which became irregularly rather narrow towards the 
thorax; on each side it sent out six or seven irregular 
rectangular plates, which surrounded and supported the 
bases of the two rows of filamentary appendages; and out- 
side these, some of the papilliform projections also had their 
bases surrounded by small, calcified, separate rings. The 
thoracic segments corresponding with the second, fourth, 
fifth, and sixth cirri had, on each side, an elongated cal- 
cified plate ; on the ventral surface of the thorax, between 
the first and second cirri, there were two minute plates. 
In all the cirri, excepting the first pair, the segments of 
the rami, and in the three posterior pairs, the segments 
of the pedicels, had their dorsal surfaces strengthened 
by oblong, quadrilateral, calcified shields, the upper mar- 
gins of which are notched for the dorsal tufts of spine, 



POLLICIPES POLYMERUS. 315 

and the two lateral margins are also slightly hollowed out ; 
these are represented in figure 27. The lower segments 
of the pedicels of some of the cirri, had an additional 
calcified plate on the anterolateral face. 

These plates are of a faint-brown or yellowish colour, 
and are conspicuous : the degree of calcification differs 
considerably; some are quite brittle and very thin, others 
half horny, and effervesce only slightly in acids. After 
having been placed in acid, there is no apparent difference 
between the parts before occupied by the calcified plates 
and the surrounding membrane; these plates, however, 
are not superficial, but consist of several of the laminae, 
which together compose the ordinary integument, in a 
calcified condition. Like the integuments of the body, 
and unlike the valves of the capitulum, these calcified 
plates are thrown off at each exuviation. Neither the 
exact shape nor number of the plates corresponded in 
different individuals, nor even on opposite sides of the 
same individual. The margins of the plates often have 
a sinuous corroded appearance ; they are, moreover, often 
penetrated by minute rounded holes, that is, by minute, 
rounded, non-calcified portions. In one specimen from 
the Antarctic expedition, there were only here and there 
a single shield on the segments of the posterior rami, and 
no plate on the prosoma. Of two specimens in another 
and older set in the British Museum, from an unknown 
locality, both had shields on the segments of the cirri, 
but only one had the large plate on the prosoma. I may 
here mention that in one specimen, in which the calcified 
plates were most developed, and which was nearly ready 
to moult, there were, within the filamentary appendages 
on the prosoma, small irregular balls of calcareous matter, 
appearing to me as if calcareous matter had been morbidly 
excreted, and not like a provision for the future. 

Range. — This species, in the present state of our 
knowledge, seems to range further than any other of the 
genus, extending from Upper California, (lat. 32° to 
35° N.,) across the Pacific, to at least 32° S., perhaps 



316 , POLLICIPES M [TELL A. 

much farther south, for it was collected during the 
Antarctic expedition, and 32° was the highest latitude 
traversed by that expedition. 

Affinities. — This species is closely related to P. cor- 
nucopia and P. elegans, but differs rather more from them, 
than these two do from each other. In the capitulum the 
chief distinctive characters are — the more perfect gradua- 
tion in size, and the greater number, (taking equal-sized 
specimens,) of the whorls of latera — the darker colours 
— the central part of the basal margin of the carina in 
this species, being considerably excised — the peculiar form 
of the basal margin of the scuta — and lastly, the scutal 
margin of the terga being more hollowed out. In the 
animal's body, the most obvious distinctive character is 
the uniarticulate caudal appendage. This species agrees 
with P. elegans, in the presence of the singular elbowed 
teeth, on some of the spines in the first three pairs of cirri. 



4. POLLICIPES MITELLA. PL VII, fig. 3. 

Lepas mitella. Linn. Systema Naturse, 1767. 

Pollicipes mitella. G. B. Sowerby. Genera of Shells, fig. 2. 

Polylepas mitella. De Blainville. Diet. Sc. Nat. (1824) Plate, 

fig. 5. 
Capitulum Mitella. /. K Gray. Annals of Philosoph., new 

series, vol. x, 1825. 

P. capitido valvarum unico sub-rostro verticillo instructo: 
laterum pari superiore {introrsum spectanti) inferiorum 
magnitudinem ter aut quater super ante: later ibus inferiors 
bus utrinque obtegentibus ; pedunculi squamarum verticillis 
densis, symmetrice dispositis. 

Capitulum with only one whorl of valves under the 
rostrum : the upper pair of latera, viewed internally, are 
three or four times as large as the lower latera, which 
overlap each other laterally : scales of the peduncle sym- 
metrically arranged in close whorls. 



POLLICIPES MITELLA. 317 

Maxillae, deeply notched : caudal appendages, multi- 
articulated : filamentary appendages, none. 

Philippine Archipelago, Mus. Cuming : China Sea, Mus. Brit. : Amboyna 
and East Indian Archipelago, according to Rumphius and other authors : 
Madagascar, according to J. E. Gray. 

Capitulum, compressed, consisting of the scuta, terga, 
carina, rostrum, and a large pair of upper latera, with a 
single lower whorl of smaller valves ; these latter vary 
from 22 in very small specimens, to 26 in large speci- 
mens. The capitulum, therefore, is formed of at most 
34 valves ; but in the largest specimen seen by me, the 
capitulum being 2*3 of an inch in width, there were only 
32 valves. In the smallest, namely, with a capitulum 
"15 of an inch in width, there were 30 valves. The valves 
are remarkably strong, and formed of white shelly matter ; 
they are closely approximate, and overlap each other : the 
scuta and terga are articulated together by a fold ; the 
apices of the valves are either worn and disintegrated, or 
they project freely like horns beyond the sack, to a much 
greater extent than in any other recent species of the 
genus : even a considerable portion of the scuta projects 
obliquely upwards. The exterior surfaces of the valves 
(when not worn) are covered by a strong yellow mem- 
brane, and the upper free parts are generally attached 
together for some little length by this same membrane. 
The valves are plainly marked by the zones of successive 
growth ; and most of them are ribbed and furrowed 
slightly, from their umbones to their basal margins. The 
yellow external membrane, examined microscopically, is 
marked by, or rather formed of, numerous growth-lines, 
crossed by longitudinal beaded ridges. The tubuli are not 
numerous, and of small diameter. 

Scuta (PI. VII, fig. 3 a , a) triangular, with the apex 
more or less produced, according to the state of its pre- 
servation, and a little curved towards the terga ; basal 
margin, and in some degree the tergo-lateral margin, 
arched, and slightly protuberant; occludent margin thick- 



318 POLLICIPES MITELLA. 

ened, slightly prominent, with the inner edge covered 
by the yellow membrane, like the exterior surface of the 
valve. The upper part of the tergo-lateral margin over- 
laps a little the edge of the tergum, and receives it in a 
furrow, — the two valves being thus locked together. 
This furrow lies in the freely-projecting, membrane- 
covered portion, and extends up to the apex ; it is of 
variable depth. Internally the scuta are concave, and in 
some old specimens to a high degree. In these latter, the 
basal margin, towards the tergo-lateral side, is strongly 
sinuous ; the prominences are formed by the terminations 
of the external longitudinal ridges, and correspond to 
the interspaces between the valves of the lower whorl. 

J. 

These ridges, which are interesting, from throwing light 
on similar ridges in some fossil species, are present, both 
on old and young specimens, and run from the apex of 
the valve, in a slightly curved line, to the tergo-lateral 
half of the basal margin, where, as we have just seen, they 
sometimes form prominences. They consist of three or 
even four obscure, almost confluent, ridges, of which the 
middle one is generally (but not always) the smallest : 
together they cover the whole of that part of the scutum, 
which is not overlapped along the basal margin by the 
rostrum and large upper latus ; and they seem evidently 
clue to the growth of the shell in this interspace having 
been freer. So, again, the three or four small, confluent, 
component ridges have the same relation to the interspaces 
between the small latera of the lower whorl. 

Terga large, four-sided, with the internal growing 
surface (fig. 3 ad), almost diamond-shaped; basal angle 
blunt, rounded; exteriorly, from the apex to the basal 
angle there is a rather broad, very slight prominence, 
which bears the same relation to the carina and upper 
latus, as do the compound ridges on the scuta to the 
rostrum and upper latus. The upper part of the scutal 
margin forms a slightly-projecting, rounded shoulder, 
though variable in its degree of prominence, in relation 
to the variable depth of the recipient furrow in the scuta. 



POLLICIPES MITELLA. 319 

Externally, parallel to the occludent margin, and close 
below the prominent shoulder, just mentioned, there is 
a slight and variable depression, extending up to the apex 
of the valve. This depression is clue to the prominence, 
variable in degree, of the tergal edge of the recipient 
furrow in the scuta. 

Carina, triangular, strong, inwardly bowed, generally 
with a large upper portion freely projecting ; exteriorly 
with a narrow, sharp, central ridge or keel, which is solid, 
the interior concavity not reaching so deep ; inner growing 
surface (fig. 3 b\ b) deeply concave, triangular. Basal 
margin square — that is, transverse to the longer axis of the 
carina, or it even rises (as is best seen in the growth- 
ridges) a little towards the exterior keel. On each side 
of the central exterior keel, there is a narrow longitudinal 
ridge, corresponding with the interspace between the 
sub-carina and the next-but-one latus of the lower whorl ; 
the latus next to the sub-carina is very small, and over- 
lies the ridge itself. In a very large specimen, these 
lateral longitudinal ridges formed (as they likewise did on 
the rostrum) slight prominences on the basal margin. In 
one specimen the carina was straight. 

Rostrum closely similar, in almost every respect, to the 
carina, even to the exterior, lateral, longitudinal ridges, 
and in their relation to the interspaces in the lower whorl. 
The valve is generally not so long, but rather wider, more 
inwardly bowed, and with the exterior solid keel less 
prominent than in the carina. The inner growing surface 
(fig. 3 b' d) is less acuminated at its upper end. 

Upper pair of Later a. — These are much larger than 
the remaining valves of the lower whorl ; they are straight, 
triangular, and much acuminated, with their apices, when 
well preserved, extending far up, for fully three fourths of 
the height of the scuta. They nearly equal in length the 
carina. The growing surface (fig. 3 b\ a) is flat, triangular, 
in well-preserved specimens forming only a third or a 
quarter of the entire length of the valve. In the middle 
of the basal margin there is a very slight prominence, 



320 POLLICIPES MITELLA. 

corresponding with a slight external central ridge, formed 
as heretofore by the overlapping of two of the valves of 
the lower whorl. Basal margin nearly on a level with that 
of the scnta and with the basal points of the terga. 
The foregoing eight larger valves form the main cavity, 
in which the body of the animal is lodged. 

Valves of the Lower Whorl. — These, seen externally, 
seem to belong to more than one whorl, but inter- 
nally their basal margins stand on a level. They vary in 
number, as already stated, from 22 to 26. I have seen 
an individual with a valve more on one side than on the 
other. They are of unequal sizes, but they are rather 
variable in this respect : the largest are not above half the 
size of the upper latera : three or four pairs, together with 
the sub-rostrum (e) and sub-carina (c), are always larger 
than the others : these two latter valves differ from the 
others only in being more concave. Seen externally, all 
these valves project considerably, and curl a little inwards, 
with their apices generally worn and truncated. Viewed 
internally (fig. 3 b'), whilst the valves are in their proper 
places, the inner and growing surfaces of the smallest are 
seen to be triangular, — of the larger, some are rhomboidal, 
and others quadrilateral with the upper side much longer 
than the lower. These latter valves overlap the upper 
parts of the little valves on both sides of them ; the rhom- 
boidal valves overlap a valve on one side, and are over- 
lapped on the other ; the triangular valves are overlapped 
on both sides. 

The corium lining the capitulum is produced into 
narrow purple crests, which enter the interstices between 
the valves, more especially along the line separating the 
upper and lower whorls. There is, also, a distinct flattened, 
tapering, free projection of corium, which enters between 
the carina and sub-carina ; and another between the ros- 
trum and sub-rostrum. 

Peduncle, much compressed, short, rarely as long as 
the capitulum ; in one very large specimen it was ex- 
tremely short, barely one fifth of the length of the capi- 



P0LLIC1PRS MITELLA. 321 

tulum. The attached portion, which is moderately pointed 
in young specimens, becomes extremely broad in old spe- 
cimens. The calcified scales sometimes differ a little in 
size, in specimens of the same age : they are always com- 
pactly and symmetrically arranged : in old specimens they 
are much larger than in young ones : each scale has, 
at first, a transversely elliptic growing base, which ulti- 
mately becomes nearly circular. Exteriorly the tips of 
the scales are always disintegrated ; they are sometimes 
club-shaped, owing to the scales having been re-added to 
after a period of reduced growth. The scales are fringed 
with brown disintegrating membrane. 

Attachment, — At the base of the peduncle, the two 
cement-ducts running together, twist about in a singular 
manner, and at their bends pour forth cement. According 
to the age of the specimen, the ducts vary in diameter from 
5~th to Keiths of an inch. The two cement glands are 
small and difficult to find ; they are retort-shaped, with two 
ovarian tubes entering each. They lie close together, in 
nearly the centre of the peduncle, and less than half-way 
down it. This proximity of the two cement-glands, and 
their position low down the peduncle, are of interest in 
relation to the position of these same glands in the sessile 
Cirripedes. 

Size and Colours. — This is the largest and most massive 
species in the family. I have seen one specimen in the 
British Museum, from the Coast of China, 2*3 inches 
across the capitulum, and 1*5 in length, with the valves 
surprisingly thick. The relative width and length of the 
capitulum varies. The sack (in specimens long kept in 
spirits) is dirty purple, and exteriorly between the scuta, 
dark purple. The cirri, tropin, penis, caudal appendages, 
three posterior segments of the thorax, and the abdominal 
surface are dark-brownish purple. 

Body. — Thorax remarkably compressed and carinated ; 
prosoma pretty well developed. Extending from the base 
of the second cirrus, to nearly a central line on the thorax, 
there is on each side a rounded ridge : there is a second 

21 



322 POLLICIPES MITELLA. 

transverse ridge, running from the base of the first cirrus 
to near the adductor scutorum muscle : these ridges seem 
formed merely to allow of the larger development of the 
testes. 

Mouth. — Labrum highly bullate; crest without any 
teeth, but with a few minute hairs. The inner fold of the 
labrum forming the supra-cesophageal cavity, is thickened, 
and shows a trace of a central line of junction, as in Sessile 
Cirripedes. 

Palpi (PL X, fig. 7), small ; of a singular club-like 
shape, owing to the convexity of the outer margin ; exterior 
spines long, all doubly serrated. 

Mandibles (PL X, fig. 1), with five teeth, of which the 
second is very small ; inferior angle coarsely pectinated. 

Maxilla (fig. 14), with a deep narrow notch (bearing 
some fine spines) beneath the two upper great spines, 
which stand on a prominence; edge straight, bearing 
fourteen or fifteen pairs of spines : on the inferior angle 
there is an obscure tuft of shorter and finer spines : apo- 
deme long, sinuous, and slender. 

Outer Maxillce (fig. 17), with the inner margin divided 
by a deep notch into two lobes, of which the upper one 
is rather short ; both are clothed with a compact row of 
short bristles ; exterior margin with longer bristles. 

Olfactory Orifices, large and prominent to an unusual 
degree. 

Cirri, moderately long and curled j the four posterior 
pair are alike j each segment has its anterior face some- 
what protuberant, and bears six pairs of long spines, with 
a rather large, narrow tuft of intermediate spines, some 
of which are finely and doubly serrated. The dorsal tufts 
consist of short, thick spines, with some fine longer ones. 
The first cirrus is seated near the second; its rami are 
slightly unequal in length; lower segments paved with 
bristles ; one ramus is thicker than the other, and some 
of its segments have coarsely pectinated spines. Second 
cirrus has the five basal segments of its anterior ramus 
highly protuberant, and paved with bristles, of which 



POLLICIPES MITELLA. 823 

some are coarsely pectinated j the basal segments of the 
posterior ramus are rather more thickly clothed with 
bristles than are the posterior cirri, but otherwise resemble 
them. The third cirrus, as already stated, is exactly like 
the three posterior pairs ; and this is a very unusual cir- 
cumstance. On the dorsal surfaces and sides of the 
pedicels of the posterior cirri, there are some scattered, 
short, thick, minute spines. 

Caudal djjpendages, multi-articulate : in a medium- 
sized specimen, each contained eight segments, which 
reached half-way up the upper segment of the pedicel of 
the sixth cirrus. Lower segments flattened; the upper, 
tapering, and cylindrical; all have their upper margins 
furnished with stiff, little spines. In a young specimen 
(only '3 of an inch in length, including the peduncle), 
the caudal appendage contained only four segments, and 
the tip did not reach to the upper edge of the lower 
segment of the pedicel of the sixth cirrus. 

Stomach, without caeca. 

Generative System. — Vesiculae seminales not reflexed 
at their broad ends ; white, spotted with black. Testes, 
pear-shaped, borne on long footstalks : penis covered with 
minute bristles, in little tufts arranged in straight lines. 
The ovarian tubes fill up the peduncle to its base, but do 
not surround the sack ; they are of small diameter, and 
simply branched. There is a very narrow ovigerous frae- 
num, with a straight edge, lying on each side under the 
line of junction between the scutum and upper latus. 

Affinities. — This species differs from all the others of 
the genus, in the third cirrus resembling exactly the three 
posterior pairs. In most of its characters — namely, in the 
symmetrical arrangement of the scales on the peduncle, 
in the considerable size of the valves of the lower whorl, 
in the general approximation of the valves, in the multi- 
articulated caudal appendages, in the form of the outer 
maxillae, in the prominent olfactory orifices, in the basal 
segments of the anterior ramus alone of the second cirrus 
being paved with bristles, there is more affinity to P. cor- 



324 POLLICIPES SPINOSUS. 

nucopia, P. elegahs, and P . polymeries than to P. sertus 
and P. spinosus. 

In the scuta and terga being articulated together, in 
the union of all the valves by stiff membrane, in the 
peculiar manner in which the valves of the lower whorl 
overlap each other, in the corium entering between some 
of the valves in filiformed appendages, in the near equality 
of size of the rostrum and carina, in the shortness of the 
peduncle in old specimens, in the position of the cement- 
glands, and lastly in the characters of the third pair of 
cirri, this species presents a closer affinity to the sessile 
Cirripedes, more especially to the Chthamalinae, than does 
any other species of any other genus amongst the Lepa- 
didse. The movements, however, of the four opercular 
valves are not at all more independent of the other valves, 
than in the other Pedunculated Cirripedes ; and the pe- 
duncle is furnished with all its characteristic muscles. 



5. Pollicipes spinosus. PL VII, fig. 4. 

Anatifa spinosa. Quoy et Gaimarch Voyage de 1' Astrolabe. PI. 
xciii, fig. 17. 

P. capitulo valvarum uno aut pluribus sub-rostro verti- 
cittis instructo : laterum pari superiore vice inferioribus 
longiore : membrand vahas tegente {post desiccationem) 
subfuscd flavescente : peduncidi squamis inceaualibus, non 
spnmetricis : verticittis longiuscule distantibus. 

Capitulum with one or more whorls of valves under 
the rostrum : upper pair of latera only slightly larger than 
the lower latera : membrane covering the valves (when 
dried) light yellowish-brown : scales of the peduncle of 
unequal sizes, unsymmetrical, arranged in rather distant 
whorls. 

Maxillae, with the edge square and straight: caudal 
appendages uniarticulate : filamentary appendages, none. 

New Zealand. Mus. Jardhi des Plautes, Paris : Mus. Cuming 



POLLICIPES SPINOSUS. 325 

Capitulum, flattened, triangular, broad, with the valves 
varying in number, in full-grown specimens of the same 
size, from 30 to above 60 ; the scuta, terga, and carina 
are very much larger than the other valves ; the rostrum, 
however, is nearly half the size of the carina ; the remaining 
valves are exceedingly small. In some specimens there is 
only one whorl under the carina ; in other specimens there 
are distinctly two whorls. The scuta, terga, and carina 
stand pretty close together ; they are moderately thick, 
and are covered, in chief part, by yellowish-brown mem- 
brane, which is destitute of spines. 

Scuta, triangular, broad, basal margin slightly pro- 
tuberant. 

Terga, as large as the scuta, flat, regularly oval, basal 
point blunt and rounded. 

Carina very slightly curved, triangular, internally 
rather deeply concave, basal margin straight. The inner 
and growing surface is four fifths of the entire length of 
the valve. In half-grown specimens the apex projects a 
little outwards. 

Nostrum, small, much curled inwards ; the basal margin 
is much hollowed out ; the inner surface is broadly tri- 
angular, more than twice as wide as high, and about 
one fourth of the entire length of the valve. The re- 
maining valves, about 26 in number, do not correspond 
on the opposite sides of the same individual, they are 
exceedingly small, with the sub-carina, sub-rostrum, and 
three pairs of latera a trifle larger than the lower latera, 
which are generally arranged in two whorls. In shape 
all the latera are nearly alike ; they consist of flattened 
styles, with their inner surfaces transversely oval, and more 
or less elongated, the larger ones being most elongated. 

Peduncle, broad, barely as long as the capitulum. The 
calcareous scales are irregularly shaped, minute, elongated 
and pointed, placed in separate transverse rows, and 
crowded together in each row. Only the scales in the 
uppermost row grow regularly; but some of the lower 
scales continue to be added to irregularly, and hence are 



326 POLLICIPES SPINOSUS. 

the largest. On the other hand, the lower part of the 
peduncle, from the first formed scales having been worn 
away, is often quite naked. From this cause, and from 
the continued and irregular growth of some of the lower 
scales, the rows in this part of the peduncle, generally 
become irregular. The surface of attachment is broad. 

In a half-grown specimen, with a capitulum only ^ths 
of an inch long, all the lower valves were considerably 
larger in proportion to the scuta, terga, and carina, than 
in full-grown individuals. 

Size and Colours. — Length of capitulum in the largest 
specimen, ^ths of an inch; breadth, slightly exceeding 
the length. Colours after having been long in spirits — 
upper part of sack, thorax, pedicels of cirri, and penis, 
clouded with fine purple ; cirri banded with the same ; 
exterior convex surface of the outer and inner maxillae 
and palpi dark purple ; prosoma yellow. The membrane 
of the peduncle and of the capitulum is dirty yellow, with 
bands of purple between some of the valves. 

Filamentary Appendages, none. Ovigerous fraena placed 
near the middle of the basal margin of the scuta ; small, 
semi-oval, with an elliptical ring of bead-like glands ; 
glands seated on long footstalks. 

Mouth. — Labrum far produced towards the adductor 
muscle ; upper part highly bullate, nearly equalling the 
longitudinal diameter of the rest of the mouth, and very 
slightly overhanging the lower part ; crest with very 
minute bead-like teeth. 

Palpi, with their inner margins considerably excised, 
most thickly clothed with spines. 

Mandibles, with three strong teeth, two unequal-sized 
small teeth being placed between the first and second, 
thus making five altogether; inferior angle broad, pec- 
tinated. 

Maxillce, with its edge broad, straight, bearing about 
twenty pairs of spines, shorter than the large upper spines. 

Outer Maxilla, with the bristles in front, continuous, 
and without any notch ; exterior surface with a promi- 



POLLICIPES SERTUS. 327 

nence clothed with long spines. Olfactory orifices slightly 
prominent. 

Cirri. — First cirrus placed near to the second ; poste- 
rior cirri not much elongated, with their segments slightly 
protuberant, bearing four pairs of spines, of which the 
lower pair is small ; spines slightly serrated. In the lower 
segments, these spines are exceedingly unequal in length, 
the inner spines on both rami, not being above one fourth 
of the length of the outer corresponding spine in each 
pair. The tufts intermediate between these pairs, are not 
very large : on the lateral upper rims there are some strong, 
short spines : dorsal tufts with short, thick spines. First 
cirrus about three fourths as long as the second cirrus, with 
numerous tapering segments, three or four of the lower 
ones being thick and protuberant : in the first cirrus there 
are eleven segments, and in the sixth cirrus, seventeen. 
Second cirrus, with the anterior ramus slightly thicker 
than the posterior ramus : a few of the basal segments of 
both rami are protuberant, and thickly clothed with spines. 
In the third cirrus, the two rami are nearly equally thick, 
with some of the basal segments in both clothed, like a 
brush, with spines. In these brushes on the first, second, 
and third cirri, most of the spines are doubly toothed, 
each tooth being simply conical. 

Caudal Appendages, small, much flattened, straight on 
the exterior side, and curved on the inner side, with a 
row of short, rather thick spines on the crest, and a few 
on the exterior margin. 

The Affinities of this species will be given under the 
head of the following, P. sertus. 



6. POLLICIPES SERTUS. PL VII, fig. 5. 

P. capitido valvarum uno aid pluribus sub-rostro ver- 
ticillis instructo : laterum pari superiore vix inferioribus 
longiore: membrand valvas tegente (post desiccationem)fusco 
rufescente obscuro: rostro dimidiam carince longitudinem 



3.28 POLLICIPES SERTUS. 

cequante, superficiei interna altitudine latitudinem plus 
duplo superante: pedunculi squamis inaqualibus, non sym- 
metritis: verticillis longiuscule distantibus. 

Capitulum with one or more whorls of valves under the 
rostrum : upper pair of latera only slightly larger than the 
lower latera : membrane covering the valves (when dried) 
dark reddish-brown : rostrum half as long as the carina, 
with its inner surface more than twice as high as broad : 
scales of peduncle of unequal sizes, unsymmetrically 
arranged in rather distant whorls. 

Maxillse with two tufts of fine bristles, separated by 
larger spines : caudal appendages uniarticulate : fila- 
mentary appendages none. 

New Zealand; Mus. Cuming. 

Capitulum, much flattened, broad, sub-triangular. 
Valves exceedingly various in number; in the largest 
specimen with a capitulum foths of an inch high, and 
Toths of an inch wide, there were only thirty-one valves, 
and these formed only a single whorl under the carina 
and rostrum; whereas, in another specimen, which was 
barely Toths of an inch in length, there were fifty-two 
valves, and these formed two or three distinct whorls under 
the carina. Scuta, terga, carina, and rostrum, much 
larger than the other valves. All are moderately thick, 
placed rather distant from each other, covered with thick 
membrane which abounds with tubuli, arranged in rows ; 
surface apparently smooth, but with a very high power, 
extremely minute spines can be seen at the extremities of 
almost all the tubuli. Little bunches of reddish fibrous 
matter are imbedded in the membrane, like tufts of sea- 
weed floating in water. 

Scuta, triangular, basal margin curved, protuberant; 
the upper part of the tergo-lateral margin is, also, slightly 
protuberant. 

Terga, large, oval, basal angle broad, square; lower 
part of carina! margin straight, upper part narrowed in; 
the apex is covered with membrane and projects freely. 



POLLICIPES SERTUS. 329 

Carina, triangular, internally deeply concave, either 
straight, and with the apex free, or inwardly and con- 
siderably curved ; basal margin nearly straight. 

Rostrum, about half the length of the carina; either 
straight or inwardly curved ; it projects freely for full half 
its length ; inner growing surface triangular, more than 
twice as high as wide ; basal margin very slightly hollowed 
out. The sitb-carina and sub-rostrum are larger than 
the largest of the latera ; their inner surfaces are trans- 
versely elongated, rounded at both ends, and slightly 
concave j externally they are pointed, and project out- 
wards ; sometimes the sub-carina, and sometimes the 
sub-rostrum is the largest. 

Latera, small, with their inner surfaces transversely 
elongated, the larger being the most elongated. Externally 
they are acuminated, and directed upwards ; they project 
but very little beyond the thick membrane in which they 
are imbedded. Neither the number, size, nor shape of 
the latera agree on opposite sides of the same individual ; 
and it would appear that, occasionally, some of them cease 
to grow, and disappear. In the large specimen with only 
thirty-one valves, the three pairs of latera, corresponding to 
the upper, rostral, and carina! latera in Scalpellum, were 
larger in a marked manner than the others ; but in the 
specimen with fifty-four valves, this could hardly be said 
to be the case. In this latter specimen, some of the valves 
in the lowermost whorl were exceedingly minute. 

Peduncle, broad, about as long as the capitulum ; 
surface of attachment wide ; calcareous scales minute, 
placed in transverse rows, which become less and less 
regular in the lower part. The scales do not stand very 
close together ; they are of unequal sizes and irregular 
outline ; generally spindle-shaped ; calcareous matter is 
added regularly only to the scales in the uppermost row, 
and irregularly to some of the lower scales. The latter, con- 
sequently, are the largest, and often much elongated ; they 
are sometimes of singular and irregular shapes. 

Colour. — The membrane covering the valves and 



330 POLLICIPES SERTUS. 

forming the peduncle, (after having been long kept dry, 
and not having been in spirits,) is dark reddish chocolate- 
brown; corium of sack dark purple; cirri banded with 
dark purplish-brown, with the lower parts of the trophi 
similarly coloured. 

Filamentary Appendages, none, but on the prosoma 
there are scattered some small papillae, which are rough- 
ened by finely spinose scales, like combs ; these papillae 
certainly seem to represent the filaments in Follicipes 
cornucopia and its two allies. 

Ovigerous Frcena, seated in the same position as in 
F. spinosus, but rather longer, with an elliptical tuft of 
glands on the crest. 

Mouthy not placed far from the adductor muscle. 

Zabrum, moderately bullate, with the upper part not over- 
hanging; no teeth on the crest. Palpi, short, broad, blunt. 

Mandibles, with three main teeth, with either one or 
two smaller teeth inserted between the first and second, 
making four or five altogether ; inferior angle rather 
narrow, pectinated with long and fine spines. 

Maxillae, rather broad, with two long upper spines ; 
beneath which there is a very small prominence bearing a 
minute tuft of fine bristles ; beneath this, there are eleven 
pairs of rather long and strong spines ; and the inferior 
angle is formed by a rather broad, upraised, and obliquely 
rounded prominence, bearing a broad tuft of fine spines. 

Outer Maxillce, with the inner surface continuously 
clothed with short spines ; exteriorly there is a slight 
prominence with long hirsute spines. 

Olfactory Orifices barely prominent. 

Cirri. — First pair placed near the second; the seg- 
ments of the three posterior pairs are slightly protuberant, 
and bear three or four pairs of finely serrated spines; 
intermediate tufts long, the middle spines being the 
longest ; spines on the upper lateral edges long and strong; 
dorsal tufts rather short. First cirrus, long, multiarticu- 
late, having fourteen or fifteen segments, whilst the sixth 
cirrus had nineteen segments; rami unequal in length by 



POLLICIPES SERTUS. 331 

about two segments; basal segments protuberant/ brush- 
like. Second and third cirri with live basal segments of 
both rami protuberant and brush-like ; but the anterior 
rami in both cirri are broader than the posterior rami- 
Spines on the protuberant segments of both rami of both 
cirri, coarsely and doubly pectinated. 

Caudal Appendages (PI. X, fig. 19), minute, uniarticu- 
late, club-shaped, with the enlarged ends directed inwards, 
or towards each other ; summits sparingly clothed with 
very short spines. 

Penis, small. 

Affinities. — This species makes a very close approach 
in the general form and relative sizes of all the valves, 
and in the variability of the number of the whorls, to 
P. spinosus; there is a still closer and more important 
resemblance, in the inequality and manner of growth of 
the calcareous scales on the peduncle. These species 
differ, in the colour of the membrane covering the valves, 
and in the greater development of both rostrum and sub- 
rostrum in P. sertus. The rostrum of the latter is longer 
than half the length of the carina, and its inner surface 
is more than twice as high as wide ; and the sub-rostrum 
is twice as large as any of the latera, — all points of dif- 
ference from P. spinosus. 

In the characters of the mandibles, and more especially 
of the outer maxillae ; in the length of the first pair of 
cirri ; in both rami of the second and third cirri having 
their basal segments brush-like, with pectinated spines ; 
and in the shape of the caudal appendages, there is a 
close relationship to P. spinosus, and through this species 
to Scalpellum villosum. In the little prominence of the 
olfactory orifices, P. sertas differs from most of the allied 
forms, excepting P. spinosus. In the maxillae having two 
prominences bearing fine tufts of bristles, in the rough- 
ened knobs on the prosoma, and in the presence, in some 
individuals, of two or three whorls of valves under the 
carina and rostrum, there is a marked tendency in P. sertus 
to approach P. cornucopia, P. elegans, and P. polymerus. 



332 GENUS LITHOTRYA. 



Genus — Lithotrya. PL VIII, IX. 

Lithotrya. G. B. Sowerby. Genera of Shells, April 1822. 
Litholepas. Be Blainville. Diet, des Scienc. Nat., 1824. 
Absia.* Leach. Zoological Journal, vol. ii, July 1825. 
BmsNiEUS et conchotrya. /. E. Gray. Annals of Philosophy, 

vol. x, (new series,) August 1825. 
Lepas. Gmelin. Systema Naturae, 1789. 
Anatifa. Qaoy et Gaimard. Voyage de 1' Astrolabe, 1832, 

Valvce 8, si inter eas parvum (satpe rudimentale) rostrum 
et duo par v a later a numerentur ; incrementi lineis concinne 
crenatis : pedunculus squamis calcareis parvis vestitus, in 
verticillis superioribus crenatis ; aut calyci basali calcareo 
aut discorum ordini affixus. 

Valves 8, including a small, often rudimentary rostrum 
and a pair of small latera : lines of growth finely crenated. 
Peduncle covered with small calcareous scales, those of 
the upper whorls crenated; attached either to a basal 
calcareous cup, or to a row of discs. 

Body lodged within the peduncle : mandibles with 
three teeth, the interspaces being pectinated; maxillae 
various : olfactory orifices slightly prominent : caudal 
appendages multiarticulate. 

Lodged in cavities, bored in calcareous rocks, or shells, or corals ; generally 
within the Tropics. 

Description. — The capitulum is not much compressed, 
a horizontal section giving an oval figure ; it is placed 
obliquely on the peduncle, the scuta descending lower 
than the terga and carina. There are eight valves, of 
which the scuta, terga, and carina are large ; the rostrum 
and a pair of latera are very small and often rudimentary. 
These three latter valves are essentially distinguished from 
the scales of the peduncle, the upper ones of which they 

* The description of Absia is so inaccurate, that I should not have recog- 
nised it, had not the Lithotrya Nicobarica, in a bottle in the British Museum, 
borne this name. 



GENUS LITHOTRYA. 333 

sometimes hardly exceed in size, by not being moulted at 
each period of exuviation. The latera overlie the carinal 
half of the terga ; I presume that they are homologous 
with the carinal latera in Scalpellum. Each successive 
layer of shell forming the valves is thick, and extends 
over nearly the whole inner surface ; hence the carina and 
terga, and to a certain extent the scuta, either actually do 
project freely much beyond the sack, or would have done 
so, had not their upper ends been removed; for the upper 
and old layers of shell, in most of the species, either scale 
off or disintegrate and wear away. A rectangularly pro- 
jecting rim, serrated by small teeth, is formed at the 
bottom of each fresh layer of growth, along the external 
surfaces of each valve (see upper part of fig. 1 V PL VIII.) 
This structure, as well as that of the crenated scales on 
the peduncle, is important, for by this means the animal, 
as we shall presently see, forms and enlarges the cavity 
in the rock or shell in which it is imbedded. 

The scutum overlaps either about one third or even one 
half of the entire width of the tergum, and abuts against a 
prominent longitudinal ridge on its exterior surface. In 
L. truncata and L. Valentiana, this ridge on the tergum 
being folded over towards the scutum, forms a conspicuous 
furrow, receiving the tergal margin of the latter. In 
L. Valentiana, there is a second furrow on the carinal 
side of the tergum, receiving the upper end of the corium- 
covered or growing surface of the carina. Besides these 
provisions for holding together the valves, there are, appa- 
rently, others for a similar purpose ; thus in each scutum, 
under the rostral angle, there is a roughened knob-like 
tooth, which touches the under side of the little rostrum, 
and no doubt serves to give attachment to the mem- 
brane uniting the three valves together. In some species, 
the adjoining basal margins of the scuta and terga, where 
touching each other, are inflected and roughened ; again 
in L. Rhodiopits, the carinal angles of the terga are pro- 
duced into points, and in L. truncata and L. Valentiana 
into prominent roughened knobs, which touch two cor- 



334 GENUS — LITHOTRYA. 

responding small knobs, on the upper part of the growing 
surface of the carina. Moreover, considerable portions 
of the inner surfaces of the scuta and terga, are rough- 
ened with minute sharp, imbricated points, apparently for 
the firmer attachment of the corium. The roughened 
knobs at the rostral angles of the scuta, no doubt are 
homologous with the teeth in a similar position on one or 
both scuta in Lepas, and in some fossil species of Pollicipes, 
as in P. validus. The other projections and roughened 
surfaces are peculiar to Lithotrya. The growth of all the 
valves is, as in Pollicipes, simply downwards. 

The Scuta are triangular, with their umbones or centres 
of growth at the apex ; the tergal margin, as seen from 
within, is either nearly straight or much hollowed out, 
accordingly as the scuta simply overlap the terga, or are 
received in a furrow. In some of the species there is a 
distinct pit for the adductor muscle, and in others this 
cannot be distinguished. 

Terga. — These present great differences in shape ; but 
all appear to be modifications, (as seen internally,) of a 
rhomboidal figure, which seems to be the normal form of 
the terga in the Lepadidse. Of the lower part of the 
valve, the whole exterior surface, with the exception of 
a narrow ridge running from the apex down to the basal 
angle, is hidden by the overlapping of the scuta, latera, 
and carina. 

The Carina, in outline is triangular, with the basal 
margin in some species extremely protuberant. In the 
first four species, the internal surface is concave, in 
L. truncata and L. Valentiana it is convex, with a central 
raised ridge, and consequently the upper freely-projecting 
portion of the valve, has a prominent central crest or ridge ; 
in L. Nicobarica and L. RJiodiopus there is only a trace 
of this ridge. The rostrum, as before stated, is always 
very small ; it, as well as the latera, are most developed 
in L. Nicobarica, and least in L. truncata and L. Valen- 
tiana ; generally only a few zones of growth are preserved, 
and from their being enlarged at their basal serrated rims, 



GENUS LITHOTRYA. 335 

the rostrum sometimes appears like a few beads of a neck- 
lace strung together. 

The Latera are remarkable from being placed over the 
carinal half of the terga, in an oblique position, parallel 
to the lower carina! margin of the terga. A section, 
parallel to the growth layers, varies in the different 
species from elliptic to broadly oval, and in Z. Nicobarica 
it is triangular. Only a few layers of growth are ever 
preserved. In Z. tru/icata, where the latera are repre- 
sented by mere stiles, (like strings of beads), and are even 
less in width than the rostrum, they are imperfectly cal- 
cified. 

Microscopical Structure of the Valves. — The shelly 
layers are white, and generally separate easily, so that in 
Z. dorsalis it is rare to find a specimen with the upper part 
of the valves perfect. The valves are so translucent, that 
in the thin margins, even the tubuli could be sometimes 
distinguished. The valves are coated by strong yellow 
membrane, which, after the shelly matter in Z. dorsalis 
had been dissolved in acid, separated into broad slips, 
answering to each zone of growth. On the lower margin 
of each slip, there is a row of closely approximate spines, 
generally slightly hooked, pointed, ^th of an inch in 
length, and i^th of an inch in diameter ; they arise out of 
a little fold; all are furnished with tubuli of the same 
diameter with themselves, running through the whole 
thickness of the shelly layers, and attached, apparently, by 
their apices, to the underlying corium. As the spines are 
very numerous, so are the parallel rows of tubuli. After the 
shelly layers had been dissolved, there was left in Z. dor- 
salis (well seen in the latera), an extraordinary, conferva- 
like mass of branching, jointed, excessively thin tubes, 
sometimes slightly enlarged at the articulations, and ap- 
pearing to contain brown granular matter : other portions 
of the valves, instead of this appearance, exhibited mem- 
branes or films with similar, branching, articulated tubes 
or vessels attached to them : I have not seen this appear- 
ance in any other cirripede. The yellow exterior en- 



336 GENUS — LITHOTRYA. 

veloping membrane, with its spines, is present in all the 
species of the genus ; in L. Rhodiopus these spines are 
much larger than in L. dorsal is, and on the inner sides 
of the carina they are trifid and quadrifid, and large 
enough to be conspicuous with a lens of weak power. 

Pedimcle. — The most remarkable fact concerning this 
part, is that the outer tunic, together with the calcareous 
scales with which it is covered, is moulted at each 
successive period of exuviation and growth. I demon- 
strated this fact in L. dor sails and L. trimcata, by removing 
the old tunic and finding a new membrane with perfect 
calcified scales beneath ; and as these two species, (I ob- 
tained, also, pretty good evidence in L. Nicobarica,) are 
at the opposite extremes of the genus, no doubt this fact 
is common to the whole genus. I know of no other 
instance, amongst Cirripedia, in which calcified valves or 
scales are moulted. I am not certain that the whole skin 
of the peduncle is thrown off in a single piece ; though 
this almost certainly is the case with the uppermost and 
lowest portions. The animal's body is partly lodged 
within the peduncle, which is generally from one to three 
times as long as the capitulum, and in the upper part is 
fully as broad as it. The scales with which it is clothed, 
extend up in the triangular interspaces between the basal 
margins of the valves. The scales of the upper whorl, or 
of the two or three upper whorls (PL VIII, figs. 1 b' 
and 3d) are larger than those below; and these latter 
rapidly decrease in size, so as to become low down on the 
peduncle, almost or quite invisible to the naked eye. The 
scales in each whorl, are placed alternately with those in 
the whorls, above and below. All the upper scales are 
packed rather closely together; those in the uppermost 
row are generally nearly quadrilateral ; those in the few 
next succeeding whorls, are triangular, with their basal 
margins protuberant and arched ; the scales, low down 
on the peduncle, stand some way apart from each other, 
and generally consist of simple rounded calcareous beads, 
of which some of the smallest in L. dorsalis were only 



POWERS OF BURROWING. 337 

^th of an inch in diameter. In the lowest part of the 
peduncle these scales, after each fresh exuviation, are ap- 
parently soon worn entirely away by the friction against 
the sides of the cavity ; hence in most specimens this part 
of the peduncle is quite naked. This same part, how- 
ever, is furnished with nail- or rather star-headed little 
projections of hard, yellow, horny chitine (fig. 3 e). The 
star on the summit seems generally to have about five 
irregular points ; one star which I measured was ^th of 
an inch in total width, the foot- stalk being only ^th of 
an inch in diameter ; the whole projected gj^ths of an inch 
above the surface of the peduncle ; from the footstalk a 
fine tubulus runs through the membrane to the under- 
lying corium. These star-headed little points are often 
much worn down; in one specimen which was on the 
point of exuviation, there remained, in the lower part, 
close above the basal calcareous cup, only some hard, 
smooth, yellow, little discs, on a level with the general 
surface of the membrane, — these being the intersected or 
worn down footstalks, with every trace of the calcareous 
beads gone. But in this same specimen, under the old 
peduncular membrane, there was a new one, studded with 
the usual circular calcareous beads, slightly unequal in 
size, generally about ^th of an inch in diameter, and 
each furnished with a tubulus ; but as yet none of the 
star-headed points of chitine had been formed. I believe 
that these latter are developed from the tubuli leading to 
the calcified beads, and, therefore, are formed directly 
under them. In Z. cauta the lowest scales on the peduncle 
are a little larger than in L. dorsalis, giving a frosted 
appearance to it, and all of them are serrated (fig. 3 d) 
round their entire margins. Generally only the scales in 
the uppermost, or in the three or four upper rows are 
serrated, and this only on their arched and protuberant 
lower margins. The state of the serrated edge varies 
extremely in the same species, from elongated conical 
teeth to mere notches, according to the amount of wear 
and tear the individual has suffered since the last period 

22 



338 GENUS LITHOTRYA. 

of exuviation ; so also do the teeth or serrated margins 
on the valves of the capitulum. Each scale has a fine 
tubulus passing from the corium through the membrane 
of the peduncle to its bluntly-pointed imbedded fang or 
base. The membrane is transparent, thin, and tender, 
to a degree I have not seen equalled in the other Lepa- 
didae, except, perhaps, in Ibla. It is much wrinkled 
transversely. 

Muscles of the Peduncle. — These consist of the usual 
interior and longitudinal, — exterior and transverse — 
and oblique fasciae ; the former are unusually strong ; 
downwards they are attached to the basal calcareous cup 
or disc, and upwards they extend all round to the lower 
curved margins of the valves. They are, as usual, without 
transverse striae. Besides these, there are, (at least in 
L. dorsalis and L. Nicobarica,) two little fans of striae-less 
muscles, which occur in no other pedunculated cirripede ; 
they are attached on each side of the central line of the 
carina, near its base; they extend transversely and a 
little upwards, and each fan converges to a point where 
the lower margins of the carina and terga touch ; of these 
muscles, the upper fasciae are the longest. Their action, 
I conceive, must be either to draw slightly together the 
basal points of the terga, and so serve to open their 
occluclent margins, or to draw inwards the base of the 
carina : these muscles apparently first shadow forth the 
posterior or carinal, transversely-striated, opercular muscles 
of sessile cirripecles. 

Basal Calcareous dip or Discs. — I have seen this part 
in all the species, except L. Valentiana, and in this it 
probably occurs, considering its very close alliance with 
L. truncata. The size, form, and conditions of the cup 
or disc varies infinitely according to the age, size, and 
position of the individual specimen. We will commence 
with a full- sized animal, which has ceased to burrow 
downwards into the rock, in which case the discs usually 
grow into a cup, and become largely developed. In 
L. dorsalis alone, I have seen many specimens, so that 



POWERS OF BURROWING. 339 

the following description and remarks, though applicable 
I believe to all the species, are drawn up from that alone. 
The cup (PL VIII, fig. 1 a', 1 c) is hardly ever regular 
in outline, and is either slightly or very deeply concave ; 
I have seen one, half an inch in diameter ; it is formed of 
several thick layers of dirty white, translucent, calcareous 
matter, with sinuous margins ; externally the surface is 
very irregular, and is coated by yellow membrane presently 
to be described. The innermost and last-formed layer 
sometimes covers the whole inside of the cup, and ex- 
tends a little beyond its margin all round ; but more 
generally it projects beyond only one side, leaving the 
other sides deserted. I have seen a single new layer 
extending beyond the underlying old layers, as much as 
one sixth of an inch ; and again I have seen a part of the 
cup, as much as a quarter of an inch in width, deserted 
and covered with serpulae. So irregular, however, is the 
growth, that after a period an old deserted portion will 
occasionally be again covered by a new layer, though of 
course without organic adhesion. Again it sometimes 
happens that the last-formed layer, remaining central, is 
very much less than the older layers ; in one such instance 
the innermost and last-formed layer (fig. 1 a) had a dia- 
meter of only a quarter of that of the whole cup, in the 
middle of which it was placed ; the cup thus tends to 
become filled up in the middle. The cup, in its fully de- 
veloped condition, is seated at the very bottom of the 
cavity in the rock. From the aggregate thickness of the 
several component layers forming the cup, the old and 
mature animal rises a little in its burrow ; for instance, 
the bottom of the cup in one specimen which I measured, 
was -^ths of an inch in thickness. 

In a younger condition, before the animal has bored 
down to the full depth, and whilst the cavity is only of 
moderate diameter, the lower part of the peduncle, instead 
of being attached to the inside of a cup, adheres to small, 
irregular, nearly flat, calcareous discs, overlapping each 
other like tiles (figs. 1, 2 a). They are placed one 



340 GENUS LITKOTKYA. 

below the other, generally in a straight line, and are 
attached firmly to one side of the burrow. The discs are 
oval, or rounded, or irregular, and are commonly from 
2*0 th to -roth of an inch across : they usually form a quite 
straight ribbon, widening a little downwards : each little 
disc overlaps and extends beyond the one last formed, 
fully half its own diameter. I have seen one row of discs 
an inch in length, but the upper discs are always worn 
away by the friction of the calcified serrated scales on the 
peduncle. It is very important to observe that the lowest 
disc is not fixed, (as was the case with the cup,) at the very 
bottom of the burrow, but on one side, just above the 
bottom, which latter part is occupied by the blunt basal 
end of the peduncle. 

In a valuable paper on L. Nicobarica, by Reinhardt, 
presently to be referred to, the disc is said to be attached 
on the carinal side (see fig. 2) of the peduncle ; and this, 
I believe, is general. I have seen one instance in which, 
during the excavation of a new burrow, an old burrow 
was met with, and the row of discs turned down it, 
making, with their previous course, nearly a right-angle. 
In another similar instance, the discs, instead of turning 
down, became very large and broad, and so fairly formed 
a bridge across the old burrow (fig. 1), — becoming narrow 
again as soon as the animal recommenced burrowing into 
the solid rock. Sometimes, as it appears, the animal, 
whilst still small, from some unknown cause, stops bur- 
rowing downwards, and then a cup is formed at the bottom 
of the hole. As soon as the animal has got to its full 
depth, the burrow increases only in diameter, and during 
this process the linear row of discs is ground away and 
lost ; a cup is then formed. The little discs can be de- 
posited or formed only at each fresh exuviation ; and as 
some of the burrows are above two inches in depth, and 
as on an average each disc does not extend beyond the 
underlying disc more than Tsth of an inch, an animal 
which has bored two inches in depth, must have moulted 
at least thirty times. I may here remark that I have 



POWERS OF BURROWING. 341 

reason to believe, from some interesting observations made 
by Mr. W. Thompson, of Belfast, that some sessile cirri- 
pedes moult about every fortnight. 

Internal Structure of the Cup. — When the cup is dis- 
solved in acid, each shelly layer is represented by a rather 
tough, pale-brown membrane, itself composed of numer- 
ous fine laminae, which, under a one-eighth of an inch 
object glass, exhibit generally only the appearance of a 
mezzotinto drawing; but there often were layers of branch- 
ing vessels, (like moss-agate,) less than the T^cboth of an 
inch in diameter, and of a darkish colour ; these vessels 
are not articulated, but otherwise resemble the same 
peculiar structure in the valves of the capitulum. The 
exterior yellow membrane is marked, or rather composed 
of successive narrow rims, which, in fact, are the lines of 
termination of the laminae of membrane, which in a cal- 
cified state form the cup itself. In most parts, both on 
the borders and under the centre of the cup, but not 
everywhere, there are imbedded in the yellow membrane, 
elongated, irregular, top-shaped masses of bright yellow 
chitine, each furnished with a tubulus, which penetrating 
the calcareous laminae leads to the corium ; the little aper- 
tures thus formed, are clearly visible in the layers of mem- 
brane, left after exposure to acid. In L. Nicobarica, the 
innermost shelly layer of the cup was punctured, like the 
surface of the shell in Chthamalus and many other sessile 
Cirripedes, by the internal orifices of these tubuli. The 
top-shaped masses often have star-shaped summits ; and 
they differ in no essential respects from those on the lower 
part of the peduncle, excepting that they are quite im- 
bedded in the membrane covering the under surface of the 
cup, whereas those on the peduncle project freely. I 
found these top-shaped bodies in the outer membrane of 
the cups in L. dorsalis, L. cauta, and L. Rhodiopus, which 
alone I was enabled to dissolve in acid ; and [ mention 
this fact, as indicating the probable presence of the more 
important star-headed projections on the lower parts of 
the peduncle in these same species. The basal calcareous 



342 GENUS — LITHOTRYA. 

cup resembles, in essential structure, the valves of the 
capitulum ; the chief difference being that in the former 
there is a larger proportion of animal matter or mem- 
branous lavers. 

After the dissolution of the cups, in L. dorsalis and L. 
H/wdiojMS, I most distinctly traced the two cement-ducts ; 
they included the usual darker chord of cellular matter ; 
they were of rather small diameter, namely, ^oth of an 
inch. The two (in L. dorsalis) ran in a very irregular 
course, not parallel to each other, making the most abrupt 
bends. They passed through the membranous layers, (as 
seen after dissolution,) and running for short spaces pa- 
rallel to the component laminae, were attached to them. 
In their irregular course, these cement-ducts resemble 
those of Pollicipes mitella, but I could not perceive that 
any cement had been poured out at the abrupt bends. 
In one specimen of a basal cup, which I was enabled 
to examine whilst still attached to the rock, I found 
under the very centre, (and of course outside the yellow 
membrane,) a very small area of dark brown cement of 
the usual appearance. In several specimens of full-sized 
cups, I was not able to perceive any cement on the external 
surfaces of the upper and later-formed layers ; hence I 
believe that the cup is cemented to the bottom of the hole 
only during the early stages of its formation ; and this, 
considering its protected situation, would no doubt be 
sufficient to affix the animal. This probably accounts for 
the small size of the cement-ducts, and for the facility with 
which, as it appears, the cups can be removed in an un- 
broken condition from the rock. In the case, however, 
of the small, flat, calcareous discs, which are formed whilst 
the animal is burrowing into the rock, these are attached 
firmly to the sides of the holes, in the usual manner, by 
cement. In this cirripede it would be useless to look for 
the prehensile antennse of the larva under the cup, for the 
animal, during the formation of the successive discs, must 
have travelled some distance from the spot on which the 
larva first attached itself. 



POWERS OF BURROWING. 343 

The membrane of the peduncle is continuous with the 
yellow membrane coating the external surface of the cup ; 
and this latter membrane is continuous with those delicate 
laminae which, in a calcified condition, form the layers of 
the cap itself. In an exactly similar manner, in this and 
other cirripedes, the membrane of the peduncle, at the 
top, is continuous with that coating the valves, and is 
attached to the lower exterior edge of the last-formed 
layer of shell. When a new shelly layer is formed, both 
under the valves of the capitulum and inside the basal 
calcareous cup, it projects beyond the old layer, and is 
included within the old, as yet not moulted, membrane of 
the peduncle. Within the cup of L. Nicobarica I found 
a lately-formed layer of shell, projecting ^th of an inch on 
one side of the cup, and by its protuberance distinguish- 
able even through the old coat of the peduncle, which was 
nearly ready to be moulted. In an analogous manner, 
in the capitulum of L. dorsalis and L. truncata, I have 
found a new peduncular membrane bearing the usual, 
but then sharp, calcified scales, attached to the lower pro- 
jecting edge of the last-formed shelly layer, lying under 
the old peduncular membrane, which was attached to the 
penultimate layer of shell, and with its worn scales was 
just ready to be moulted. 

The final cause of the moulting of the calcified scales, 
together with the membrane of the peduncle to which they 
are attached, — a case confined to Lithotrya, — I have 
scarcely any doubt is the reproduction of a succession of 
scales, sharply serrated for the purpose of enlarging the 
cavity in which the animal is lodged. The extreme thinness 
of the membrane of the peduncle has been noticed ; this 
may be partly related to its protected condition, but partly, 
I think, to the necessity of its being formed in a very 
extensible condition ; for the new coat, owing to the pro- 
jection of the new shelly layers under the valves, and 
within the basal cup, is by so much shorter than the old 
peduncle, yet after exuviation it has to stretch to a greater 
length than the old membrane, to allow of the growth of 



344 GENUS LITHOTRYA. 

the Cirripecle. Owing to the thinness and fragility of 
this membrane, the basal attachment of the Cirripede is, 
no doubt, chiefly effected by the unusually strong lon- 
gitudinal muscles ; and the necessity of a surface of attach- 
ment for these muscles, stronger than the external mem- 
brane of the peduncle, probably is one of the final causes 
of the basal calcareous disc and cup, and likewise for the 
unusual manner in which the valves of the capitulum are 
locked together by folds and small roughened projections. 
The basal discs and cup, however, apparently serve for 
several other purposes, namely, for raising the animal a 
little in its burrow, (which is narrow and pointed at the 
bottom,) at that period of growth when it has ceased to 
burrow downwards, but still increases in diameter ; also 
for carrying the animal, as over a bridge, across any pre- 
existing cavity in the rock; and lastly, perhaps, for removing 
lower down, in the intervals of exuviation, the point of 
attachment for the longitudinal peduncular muscles. 

Position of the animal in the rock, and its power of ex- 
cavation. — A specimen of rock, two or three inches square, 
in Mr. Cuming's possession, is full of Lithotryas ; the 
cavities extend in every possible direction, and several 
were parallel, but with the animals in reversed positions ; 
the same thing is apparent in some specimens of Mr. 
Stutchbury's, and it was evident that the positions 
occupied by the animals w 7 ere entirely due to chance. 
In Mr. Cuming's specimen of rock, aconsielerable portion 
of the external surface is preserved, and here it can be 
seen that many of the specimens have their capituluins 
directed from the external surface directly inwards. These 
individuals, which were of full size, must have preyed on 
infusoria inhabiting the cavities of the porous, calcareous 
rock. On the other hand, I have seen some young 
specimens of L. dorsalis with their valves not at all rubbed, 
and others of full size with uninjured Balani and corallines 
on the tips of the valves, and again a specimen of L. trim- 
cala with minute pale-green seaweed on the summit of 
the capitulum, — all which appearances induce me to 



POWERS OF BURROWING. 845 

believe that in these cases, the valves had projected freely 
beyond the cavity in which their peel ancles were lodged. 
I may here also mention that in Mr. Cuming's specimen, 
above alluded to, the basal cups of five specimens touched 
and adhered to each other ; I was not able to make out 
whether there had originally existed separate burrows, as 
I think is most probable, and that the walls had been 
wholly worn away, or whether the five specimens had fixed 
themselves on one side of a large pre-existing, common 
cavity. Young specimens seem to burrow to the full 
depth, before nearly acquiring the diameter which they 
ultimately attain. I measured one burrow, 1*2 of an 
inch in depth, which, at its mouth or widest part, was 
only *17 in diameter. 

The several species occur imbedded in soft calcareous 
rocks, in massive corals, and in the shells of mollusca and 
of cirripedes. It has been doubted by several naturalists, 
whether the basal calcareous cup at all belongs to the 
Lithotrya, but after the foregoing microscopical observa- 
tions on its structure, it is useless to discuss this point. 
So again it has been doubted whether the cavity is formed 
by the cirripecle itself; but there is so obvious a relation 
between the diameters of specimens of various sizes, and 
the holes occupied by them, that I can entertain no doubt 
on this head. The holes, moreover, are not quite cylin- 
drical, but broadly oval, like the section of the animal. 
The simple fact, that in this genus alone each fresh shelly 
layer round the bases of the valves, and therefore at the 
widest part of the capitulum, are sharply toothed ; and 
secondly, that in this genus alone a succession of sharply 
serrated scales, on the upper and widest part of the pe- 
duncle, are periodically formed at each exuviation ; and 
that consequently the teeth on the valves and scales are 
sharp, and fit for wearing soft stone, at that very period 
when the animal has to increase in size, would alone 
render the view probable that the Lithotrya makes or at 
least enlarges the cavities in which it is imbedded. 

Although it may be admitted that Lithotrya has the 



346 GENUS — LITHOTRYA. 

power of enlarging its cavity, how does it first bore down 
into the rock ? It is quite certain that the basal cup is 
absolutely fixed, and that neither in form nor state of 
surface it is at all fitted for boring.* I was quite unable 
to answer the foregoing question, until seeing the ad- 
mirable figures by Reinhardt f, (PL VIII, figs. 2 and 2 a) 
of L. Nicobarica, still attached in its cavity. Subsequently 
I obtained from Mr. Stutchbury several pieces of rock 
completely drilled with holes, many of small diameter, by 
L. dorsalis, and in these I found numerous instances of 
the linear rows of little discs, like those of L. Nicoharica, 
showing in the plainest manner, that each time a new disc 
is formed, that is, at each exuviation, the animal moves a 
short step downwards; and as the lowest of these little discs 
in none of the burrows was placed at the very bottom, we 
see that the lowest point of the peduncle must be the 

* Mr. Hancock, in bis admirable account of bis burrowing Cirripede, 
Alcippe lampas, ('Annals of Nat. Hist./ Nov. 1849, p. 313,) came to this 
conclusion regarding the cup of Lithotrya, and hence was led to think that 
this genus did not form its own burrows, but inhabited pre-existing cavities. 
I am much indebted to this gentleman, who has been so eminently successful 
in his researches on the boring powers of marine animals, for giving me his 
opinion on several points connected with the present discussion. 

f I owe to the great kindness of Prof. Steenstrup the sight of this Plate, 
published in the ' Scientific Communications from the Union of Natural 
History,' Copenhagen, January 30, 1850, No. I. Since this sheet has been 
set up in type, I have received from Prof. Steenstrup the memoir, in Danish, 
belonging to the figures in question ; and the greater part of this has been 
translated to me by the kindness of a friend. My account of the means of 
burrowing is essentially the same as that published by Reinhardt ; but the 
moulting of the scales" on the peduncle, the presence of scales and of points 
of a different nature, the method of attachment by cement, the conversion of 
the discs into a cup, &c, seem not to have been known to this naturalist. 
Reinhardt states that the points on the peduncle will scratch Iceland spar, 
and that, apparently, they are formed of phosphate of lime : in the case of 
the closely-allied L. dorsalis, I must believe that the scales or beads on the 
peduncle are formed of carbonate of lime, for they were quickly dissolved 
with effervescence in acetic acid; and the star-headed points, which are 
subsequently developed under the calcareous scales, appeared to me, under 
the compound microscope, to be formed of a horny or chitine substance. 
Reinhardt states that the basal point of the peduncle is arched a little under 
the lowest disc, and there forms for itself a slight furrow (as represented in 
the lateral view, PL VIII, fig. 2) ; but in the burrows examined by me, this 
furrow or depression did not really exist, the appearance resulting from the 
basal margin of the lowest disc, projecting beyond the wall of the cavity by 
the amount of its own slight thickness. 



POWERS OF BURROWING. 347 

wearing agent. In the peduncle of an individual of 
L. dorsalis, nearly ready to moult, I found, it may be re- 
membered, beneath and round the basal disc, under the 
old membrane of the peduncle, a new membrane studded 
with calcified beads, but with the horny star-headed spines 
not yet developed, whilst on the old outer coat these latter 
had been worn down quite smooth, and the calcified beads 
worn entirely away. Here, then, we have an excellent 
rasping surface. With respect to the power of movement 
necessary for the boring action, the peduncle is amply 
furnished with transverse, oblique, and longitudinal striae- 
less muscles, — the latter attached to the basal disc. In 
all the pedunculata, I have reason to believe that these 
muscles are in constant slight involuntary action. This 
being the case, I conceive that the small, blunt, spur-like 
portion of the peduncle, descending beneath the basal rim 
of the lowest disc, would inevitably partake slightly of the 
movements of the whole distended animal. As soon as 
the Lithotrya has reached that depth, which its instinct 
points out as most suitable to its habits, the discs are 
converted into an irregularly growing cup, and the animal 
then only increases in diameter, enlarging its cavity by 
the action of the serrated scales on the peduncle, and of 
the serrated lower edges of the valves of the capitulum. 
With respect to those reversed individuals attached with 
their capitulums downwards, I suppose that the larvae 
had crept into some deep cavity, perhaps made originally 
by a Lithotrya, of which the rock in the specimen in ques- 
tion was quite full, and had there attached themselves. 
Finally, it appears that in Lithotrya the burrowing is 
simply a mechanical action ; it is effected by each layer 
of shell in the basal attached discs over-lapping, in a 
straight line, the last-formed layer, — by the membrane 
of the peduncle and the valves of the capitulum having 
excellent and often renewed rasping surfaces, — and, 
lastly, by the end of the peduncle (that is homologically 
the front of the head) thus roughened, extending beyond 



348 GKNUS — L1TH0TRYA. 

the surface of attachment, and possessing the power of 
slight movement. 

We will now proceed with our generic description. — 

Animal's Body. — This, as already stated, is partially 
lodged within the peduncle. The prosoma is rather largely 
developed. 

The Mouth is placed at a moderate distance from the 
adductor muscle. 

The Labrum is moderately bullate, with a row of blunt 
bead-like teeth, mingled with fine bristles, on the crest, 
which in the middle part is generally somewhat flattened. 

The Palpi are blunt, and even squarely truncated at 
their ends; they are of large size, so that, if they had been 
half as large again, or even less, their tips would have met. 

Mandibles (PL X, fig. 2), with three nearly equal large 
teeth, and the inferior angle produced, broad, and strongly 
pectinated : in the interspaces between these teeth there 
are, in all the species, some very fine teeth or pectinations, 
which are seated a little on one side of the medial line. 
The mandibles are somewhat singular from the size of 
the transparent flexible apoclemes (a a) to which the 
muscles are attached; these are oval and constricted at 
their origins : in L. dorsalis they are roughened with little 
points ; in L. cauta and L. truncata they are large, of the 
same shape, but smooth. 

MaxillcB. — These are larger, compared to the mandibles, 
than is usual with pedunculated Cirripedes ; they differ in 
shape in the different species, being either nearly straight 
on their edge, and notched or not (fig. 10), or notched with 
the inferior part forming a double prominence (fig. 12); 
the spines on the inferior angle, which is sometimes 
slightly produced, are always crowded together into a 
brush, and are finer than those on the upper parts. The 
apoclemes are less straight than is usual, and at their 
origin take, in all the species, a rather abrupt bend ; 
their extremity is enlarged into a little disc, which in 



VJ 



ENUS LITHOTRYA. 349 



L. dorsalis is covered with strong points, but in the 
other species is, as usual, smooth. 

Outer Maxilla. — The inner margin is slightly concave, 
and in L. truncata alone, the bristles are hardly continu- 
ous, being interrupted in the middle part. The olfactory 
orifices are only very slightly prominent. The spines on 
all the tropin are more or less doubly serrated. 

Cirri. — The three posterior pair are elongated, with 
their anterior surfaces not at all protuberant. The seg- 
ments bear from three to five pair of spines, with a row 
of three or four small intermediate spines ; there are, 
as usual, some little lateral upper rim spines ; the dorsal 
tufts contain some thick and thin spines mingled. First 
cirrus is short, and placed not quite close to the second 
pair; the basal segments are broad and thickly paved 
with bristles. The second pair is rather short compared 
with the third pair ; a varying number of the basal seg- 
ments in both rami of both these cirri are protuberant, 
and are thickly paved with bristles ; such segments are 
more numerous and are broader on the anterior rami than 
on the posterior rami. In L. cauta alone, none of the 
basal segments in the posterior rami of the second and 
third cirri are thickly paved with bristles. The pedicels 
of the first three pair are irregularly covered with spines ; 
those of the three posterior pair have the spines arranged 
in a regular double line. Most of the spines are doubly 
serrated. 

Caudal Appendages (PI. X, fig. 23 and 24), multiarti- 
culate, with thin elongated segments fringed with short 
spines; in length generally exceeding the pedicel of the 
sixth cirrus, and in L. Nicobarica equalling half the entire 
length of this cirrus. 

Stomach, destitute of caeca; oesophagus somewhat curled. 

Filamentary Appendages, none. 

Ovaria filling up the peduncle and surrounding the 
sack, but not extending up to the bases of the scuta and 
terga ; I saw the ova only in L. truncata; they were here 
oval and large, being nearly ^ths of an inch in length. 



350 GENUS LITHOTRYA. 

Penis, elongated; vesiculse seminales extending into the 
prosoma. I noticed the ovigerous frsena only in L. trun- 
cata; here they were large, with an almost bilobed out- 
line ; the margin and whole lateral surface being covered 
with elongated cylinders, finely pointed, but not enlarged 
at their extremities, as are the glands observed in most 
of the other genera. 

Colours. — The posterior thoracic segments, the pedicels, 
the anterior and dorsal surfaces of the segments of the 
cirri, the caudal appendages, and the outer sides of the 
trophi are, in most of the species, more or less mottled 
with dark purple ; parts of the interior surfaces of the 
valves in some of the species are coloured fine purple. 

Geographical Distribution. — The species are found all 
round the world in the tropical seas ; this fact may have 
some connection with the presence of soft coral-reef lime- 
stone and of massive corals in these seas. The presence, 
however, of L. cauta on the shores of New South Wales, 
shows that the genus is not strictly tropical. 

Affinities. — Lithotrya is a well-pronounced distinct 
genus ; although there is a considerable difference in the 
shape of the valves between L. dorsalis and L. Valentiana, 
at the opposite extremes of the genus, the strict uniformity 
of the internal characters shows that there are no grounds 
whatever for any generic separation ; moreover, L. fflio- 
diopus neatly blends together these extreme forms. Indeed 
it is not easy to imagine a better marked series of transi- 
tional forms, than those presented by the terga, in passing 
from L. dorsalis through L. Nicobarica, L. Rhodiopus, 
and L. truncata, to L. Valentiana. Lithotrya has most 
affinity to Scalpettum villosum or to Pollicipes spinosus and 
_P. sertus; though the affinity is far from close. In these 
two species of Pollicipes, we have seen that large irregular 
calcified spines are formed at the base of the peduncle, 
whereas in the other Pedunculata the scales or spines 
are formed exclusively round the upper margin of the 
peduncle. Lithotrya, as has been remarked by Sowerby 
and other authors, exhibits some affinity to the sessile 



LITHOTRYA DORSALIS. 351 

Cirripedes, as shown by the calcareous basis, — by the 
manner in which the scuta and terga are locked together, 
— by the two little fans of muscle attached to near the 
basal points of the terga, — and perhaps by some of the 
characters of the tropin ; nevertheless, this affinity is far 
from being well-marked, and I think is hardly so plain as 
in Pollicipes mi tell a. 



I. LlTHOTRYA DORSALIS. PL VIII, fig. 1 CI ' . 

Lithotrya dorsalis. G.B.Sowerby. Genera of Shells, April, 1822. 
Lepas dorsalis. Ellis. Nat. Hist. Zoophytes, Tab. xv, fig. 5, 

1786. 
Litholepas de Mont Serrat. De Blamville. Diet, des Sc. Nat., 

Plate, fig. 5, 1824. 

L. scutis terga anguste obtegentibus: carina intus con- 
cavd : rostro, duorum aut trium squamarum subjacentium 
latitudinem cequante : lateribus, squamarum quinque sub- 
jacentium longitudinem cequantibus, superficie interna an- 
guste ellipticd : pedunculi squamis superioribus verticittum 
secundum minus duplo superanlibus. 

Scuta, narrowly overlapping the terga : carina inter- 
nally concave : rostrum as wide as two or three of the 
subjacent scales : latera with their internal surfaces nar- 
rowly elliptical, as long as five of the subjacent scales : 
upper scales of the peduncle less than twice as large as 
those in the second whorl. 

Mandibles, with twice as many pectinations between 
the first and second main teeth, as between the second 
and third teeth. Maxillae without a notch, edge nearly 
straight, and spines very numerous : caudal appendages 
exceeding, by half, the length of the pedicel of the sixth 
cirrus. 

Barbadoes, West Indies ; Venezuela ; Honduras ; imbedded in limestone ; 
Mus. Brit. Cuming and Stutchbury. 

The state of preservation of the valves in different 
specimens varies greatly ; generally only two or three, or 



352 L1TH0TRYA DORSALIS. 

even only the last-formed shelly layer, is preserved, the 
upper ones having scaled off; in a few young specimens, 
however, all the layers were perfect. The carina is 
generally better preserved than the other valves, and 
hence the upper part usually projects freely ; in one spe- 
cimen no less than ten zones of growth were preserved in 
the carina, whilst the other valves consisted of only three : 
the terga generally project rather more than the scuta. 
As each growth-layer is thick, if the scaling process had 
not taken place, all the valves would have projected greatly. 
The little teeth lie close together on the prominent ser- 
rated rims, on each zone of growth. The internal surfaces 
of the valves are roughened with small imbricated points. 
Exteriorly the valves are covered with yellow membrane, 
with rows, corresponding with each zone of growth, of very 
minute, yellow, horny spines, generally having their tips 
bent over, and so made hook-shaped. These spines are 
less than ^th of an inch in length. 

Scuta, triangular ; internally concave, with a large de- 
pression for the adductor muscle ; there is the usual small 
roughened internal knob, or tooth, at the rostral angle of 
both the right and left hand valves. Tergal margin 
straight, overlapping about one third of the entire width 
of the terga. 

Terga, irregularly oval, with the scutal margin straight ; 
basal point blunt, with the two sides placed at about an 
angle of 45° to each other; the lower part of the carinal 
margin, immediately over the latera, (as seen internally,) 
is slightly hollowed out. Exteriorly, towards the bottom 
of the valve, from the overlapping of the scuta, of the 
latera, and of the carina, only a narrow rounded ridge is 
exposed, which runs down to the basal angle at about 
one third of the entire width of the valve, from the scutal 
margin. Internally the valve is slightly concave. 

The Carina slightly overlaps the terga ; internally con- 
cave ; generally with a large upper portion freely pro- 
jecting; inwardly curved, without any central crest or 
ridge ; valve nearly as wide as the middle part of the 



LITHOTRYA DORSALIS. 353 

terga ; inner growing or corium-covered surface, with its 
basal margin, protuberant and arched. 

Rostrum (PL VIII, fig. 1 a, a, and greatly magnified 
1 b') very narrow ; rarely more than two or three layers 
of growth are preserved ; the sides are deeply sinuous, 
owing to each zone widening downwards ; basal margin 
rounded ; in width equalling about two and a half of the 
uppermost scales of the peduncle, and about half as wide 
as the latera. 

Later a t small, placed obliquely, and parallel to the lower 
carina! margin of the terga ; longer axis equal to five of 
the uppermost scales of the peduncle, and to nearly half 
the width of the base of the carina ; growing surface (or 
a section made parallel to the growth-layers,) is narrow, 
elliptic, pointed at both ends, but the carinal half rather 
thicker than the scutal half. 

The Peduncle varies in length, generally about twice as 
long as the capitulum, in one specimen above thrice as 
long. The upper part as wide as the capitulum, the lower 
part sometimes much attenuated. The calcified scales in 
the uppermost whorl (PL VIII, fig. 1 b') are only slightly 
larger than those in the second whorl ; the scales in the 
succeeding three or four whorls, are considerably larger 
than those below, which latter very gradually decrease in 
size, till, low down on the peduncle, they are barely visible 
to the naked eye. In this lower part, they may be called 
calcareous beads ; they stand some way apart from each 
other ; they are nearly hemispherical, smooth, translucent, 
and furnished with a conical fang ; some of the smallest 
were ^th and ^th of an inch in diameter. The upper 
scales vary somewhat in the outline, the most usual shape 
being sub-triangular, with the lower margin arched and 
protuberant ; and this margin, in the two or three upper 
whorls, is crenated with teeth, which are conical and 
sharp, after exuviation, but soon become reduced to mere 
notches. The scales in the uppermost whorl are usually 
nearly quadrilateral ; the imbedded portion, or fang of 
each scale, is, in all, produced into a blunt rounded point. 

23 



354 LITHOTRYA DORSALIS. 

The basal calcareous cup (fig. 1 d and 1 c) is well de- 
veloped, and is sometimes even half an inch in diameter. 
Before the cup is formed, there is a row of small, flat 
discs (fig. 1, and like those in fig. 2 a) attached to the 
sides of the burrow ■ but a full account of these parts of 
the peduncle, and of the burrowing habits of this species, 
has been given under the generic description. 

Size and Colour. — Full average-sized specimens have a 
capitulum half an inch in width and height ; the entire 
length, with the contracted peduncle, being about an 
inch and a half. Valves coloured dirty white, with the 
enveloping membrane, when preserved, yellow. The 
outer maxillae, palpi, pedicels of the cirri, anterior faces 
of the segments, dorsal tufts, caudal appendages, and 
penis, dark purple. Thoracic segments brown. There 
is a purple spot between the bases of the first pair of 
cirri. 

Mouth. — Labrum considerably bullate, equalling about 
half the longitudinal diameter of the mouth ; inferior part 
produced so as to separate the mouth some way from the 
adductor muscle ; crest with a row of blunt teeth and 
hairs ; central part depressed and flattened. 

Palpi, rather large, separated from each other by only 
half their own length; bluntly pointed, thickly clothed 
with spines. 

Mandibles (PI. X, fig. 2), with twice as many pectina- 
tions, namely 15, between the first and second main teeth, 
as between the second and third teeth, namely about 7 ; 
inferior angle strongly and coarsely pectinated ; distance 
between the tips of the first and second main teeth, con- 
siderably less than between the tips of the second tooth 
and of the inferior angle ; sides hirsute. 

Maxilla (fig. 1 0), with the edge not quite straight, with 
the whole inferior part slightly projecting; spines very 
numerous, thirty or forty pairs ; those close beneath the 
two upper great unequal spines, form a tuft and are rather 
thinner than the others, as are also those near the inferior 
angle; sides hirsute. 



LITHOTRYA DORSALIS. 355 

Outer Maxillce, rather pointed, with the inner edge 
slightly concave, continuously and thickly clothed with 
short spines ; spines on the outer edge long ; there are 
also some minute, short, thinly scattered spines or points 
on the sides. Bristles on all the trophi doubly serrated. 

Cirri. — The first pair is placed at a small distance 
from the second. The segments in the three posterior 
pairs, support five pairs of very long spines, with a row of 
(I believe) four small intermediate spines ; on the lateral 
upper edges, there are some short blunt spines; anterior 
faces of the segments not protuberant ; the dorsal tufts 
consist of thick serrated, and of thin spines. The whole 
integument is hirsute with minute pectinated scales. Two 
or three of the basal segments in the sixth cirrus are 
confluent. First cirrus, anterior ramus rather shorter and 
thicker than the posterior ramus ; basal segments thickly 
paved with serrated spines ; in the posterior ramus, the 
six terminal segments are not paved with bristles. Second 
cirrus has the seven basal segments of the anterior ramus 
very broad, and paved with bristles ; the eight terminal 
segments having the usual structure; in the posterior 
ramus the three or four basal segments are similarly 
paved, but to a very much less degree, and the remaining 
thirteen have the usual structure. Third cirrus has the 
six basal segments of the anterior ramus very broad and 
paved, and the fourteen terminal ones of the usual struc- 
ture ; in the posterior ramus, the three or four basal seg- 
ments are similarly paved, but to a very much less degree, 
and the seventeen terminal ones have the usual structure. 
The pedicel of the first cirrus has very few spines ; those 
of the second and third cirrus are thickly and irregularly 
clothed with spines ; and those of the three posterior pair 
have a double row with intermediate small spines. On the 
antero-lateral faces of the pedicels of the second, third, 
and fourth pairs of cirri, there is an elongated white 
swelling or shield. Moreover, on the posterior thoracic 
segments, there are similar white-coloured swellings, with 
the membrane more plainly marked with scales than in 



356 LITHOTRYA CAUTA. 

other parts. The spines on the first three pairs of cirri 
are coarsely serrated. 

Caudal Appendages (PI. X, fig. 23), with numerous 
tapering segments, almost equalling one and a half times 
the length of the pedicel of the sixth cirrus. Each seg- 
ment is elongated and somewhat constricted in the middle, 
with its upper edge (fig. 24) crowned with short spines ; 
in a full-sized specimen there were seventeen segments. 



2. LlTHOTRYA CAUTA. PI. VIII, fig. 3. 

L. scutis terga ample obtegentibus : carina intus concavd: 
rostro squamarum subjacentium latitudinem vise cequante : 
lateribus, squamas subjacentes sesquitertio super antibus; 
superficie interna late ellipticd: pedunculi squamis supe- 
rioribus verticillum secundum pcene quadruplo superantibus. 

Scuta largely overlapping the terga : carina internally 
concave : rostrum hardly as wide as one of the subjacent 
scales : latera with their internal surfaces broadly ellip- 
tical, as long as two and a half of the subjacent scales : 
upper scales of the peduncle nearly four times as large 
as those in the second whorl. 

Mandibles with an equal number of pectinations 
between the first, second, and third main teeth : maxillae 
notched, edge nearly straight : posterior rami of the 
second and third cirri, with their basal segments not 
paved with bristles : caudal appendages slightly exceeding 
in length the pedicels of the sixth cirrus. 

New South Wales, Australia, imbedded iu a Conia, (uuique specimen,) 
Mus. Stutchbury. 

. Valves thin, white, translucent; upper layers of growth 
well preserved, excepting on the terga. A large portion 
of the carina projected freely. The teeth on the projecting 
margins of the growth-layers are broad, blunt, and often 
stand rather distant from each other. 

Scuta (PI. VIII, fig. 3 a) } triangular, internally concave, 



LITHOTRYA CAUTA. 357 

with no distinct pit for the adductor muscle. The scuta 
largely overlap the terga. 

Terga (fig. 3 b) approaching to rhomboidal ; basal angle 
rectangular, almost central, and consequently the exterior 
longitudinal ridge, winch is rounded, is likewise nearly 
central. 

Carina, internally concave, with no trace of a central 
internal ridge in the upper free portion ; the growing 
or corium-covered surface is transversely oval, and is as 
wide as the widest part of the terga. 

Rostrum, exceedingly minute, enlarged at each zone of 
growth, not so wide as the immediately subjacent scale 
on the peduncle. 

Latera (fig. 3 c), in width equalling two and a half of 
the upper peduncular scales, or about one fourth or one 
fifth of the width of the carina ; growing surface, (or a 
section parallel to the layers of growth,) broadly elliptic, 
pointed at both ends. 

Peduncle, about twice as long as the capitulum; the scales 
of the uppermost whorl are quadrilateral (fig. 3 d), and 
nearly four times as large as those in the second whorl ; 
these latter are about twice as large as those in the third 
whorl, which are very little larger than the small, almost 
equal-sized, equally distant, round beads scattered over 
the rest of the peduncle, down to the basal cup. All 
these scales are dentated, the upper rows most plainly 
and only on their basal margins ; the lower little beads 
are very slightly crenated round their entire margins ; 
they are mingled with star-headed spines (fig. 3 e) of yellow 
chitine. Basal calcareous discs thin, plainly marked ex- 
teriorly by concentric lines of growth, and covered by the 
usual yellow membrane, including the horny, spindle- 
shaped bodies. 

Size and Colours. — The whole specimen, including the 
peduncle, was only one fifth of an inch in length ; the 
capitulum being ^ths of an inch in width. I do not know 
whether the specimen had attained its full size, but think 
this is probable, as a large-sized species would not have 



358 LITHOTRYA CAUTA. 

made its habitation in one of the valves of so small a shell 
as a Conia. Shell white, exterior membrane, where pre- 
served, yellow, and bearing small spines. Thoracic seg- 
ments, the lower segments of the second, third, and fourth 
cirri, all the segments of the first cirrus and the trophi, 
slightly mottled with darkish purple. 

Mouth. — The teeth or beads on the crest of the labrum 
are blunt, few, not very small, and equidistant. 

Palpi, bluntly pointed. 

Mandibles, with the three main teeth nearly equal in 
size ; the pectinations are equal in number, namely, only 
three between the first and second, and the second and 
third main teeth • the inferior angle is coarsely pectinated, 
with one central spine much longer than the others ; the 
distance between the tips of the first and second main 
teeth, equals that between the second tooth and the in- 
ferior angle. 

Maxillce, with the tw T o upper spines very large ; beneath 
them there are two small spines, and a considerable notch ; 
the inferior part of the edge is nearly straight, bearing 
about thirteen pairs of spines, obscurely divided into two 
groups, the lower spines being smaller than the upper 
ones. The upper convex margin is hirsute with long hairs. 

Outer Maxillce, blunt, with the inner margin slightly 
concave ; continuously, but thinly clothed with spines. 

Cirri, — The segments of the three posterior pairs bear 
four pairs of spines, with the usual intermediate fine spines; 
dorsal spines thin and thick mingled together. First 
cirrus, short, with the anterior ramus rather the thickest 
and shortest \ all the segments thickly paved with bristles, 
except the two terminal segments, of which the ultimate 
one bears some serrated spines of most unusual length, 
namely, equalling within one segment the entire length 
of the ramus. I presume that these spines serve as feelers. 
Second cirrus; anterior ramus much thicker and con- 
siderably shorter than the posterior ramus; six basal 
segments paved with bristles, the two terminal segments 
having the usual structure; posterior ramus with all its nine 



LITHOTRYA N1COBARICA. 359 

segments on the usual structure. Third cirrus, longer, to 
a remarkable degree, than the second cirrus, with its an- 
terior ramus having the four basal segments paved, and 
the seven terminal ones on the usual structure ; posterior 
ramus with twelve segments, of which none are paved. 
The pedicels of the second and third cirri thickly and 
irregularly clothed with spines. The upper segments of 
the pedicels of all the cirri are unusually long. 

Caudal dppendages, longer than the pedicels of the sixth 
cirrus, by barely one third of their own length. Segments 
much elongated, seven in number ; I may add for com- 
parison that each ramus of the sixth cirrus contained, in 
this specimen, sixteen or seventeen segments. 

General Remarks. — It is difficult to give obvious cha- 
racters, (excepting the smallness of the rostrum compared 
with the scales on the peduncle,) by which this species can 
be externally discriminated from L.dorsalis, L. Nicobarica, 
and L. Rhodiopus; yet almost all the valves differ slightly 
in shape. In this species alone, (the peduncle of L. Rho- 
diojpus is not known,) the lower, microscopically minute, 
bead-like scales of the peduncle are crenated, though ob- 
scurely, all round. In the animal's body, the diagnostic 
characters are strongly marked ; — the long spines on the 
terminal segment of the first cirrus, — none of the seg- 
ments in the posterior rami of the second and third cirri 
being thickened and paved with bristles, — the pectina- 
tions being equal in number between the main teeth of 
the mandibles, — are all characters exclusively confined to 
this species. 



3. LlTHOTRYA NICOBARICA. PI. VIII, fig. 2. 

L. nicobaiiica. Reinhardt, Naturhist; Selskabet, 

Copenhagen. No. I. 1850. 
Tab. I, fig. 1—3* 



* I am not at all sure that the proper title of the periodical in which this 
species has been described, is here given. I am greatly indebted to Prof. 



360 LITHOTRYA NICOBARICA. 

L. scutis terga anguste obtegentibus : carina crista in- 
terna tenui in parte superior e positd: rostro conspicuo, 
squamarum sex subjacentium latitudinem aquante : lateri- 
bus, superficie interna trianguld, squamarum septem sub- 
jacentium latitudinem cequantibus. 

Scuta narrowly overlapping the terga : carina with a 
slight central internal ridge in the upper part : rostrum 
conspicuous, as wide as six of the subjacent scales : latera, 
with their internal surfaces triangular, as wide as seven 
of the subjacent scales. 

. Palpi square at their ends : mandibles with twice as 
many pectinations between the first and second main 
teeth, as between the second and third : maxillae slightly 
notched, with the inferior angle slightly prominent : 
caudal appendages more than twice as long as the 
pedicels of the sixth cirrus. 

Timor ; Brit. Mus., (given by Cuvier to Leach) ; Nicobar Islands, accord- 
ing to Keinhardt. 

Capitulum as in L. dorsalis. The teeth on the promi- 
nent rims of the valves are small and approximate ; but 
the specimen was much worn. 

Scuta, triangular, slightly overlapping the terga ; the 
line of junction between these valves slightly sinuous, the 
upper part of the tergal margin of the scuta being slightly 
hollowed out, and the corresponding upper portion of the 
margin of the terga being slightly protuberant. Inter- 
nally, there is a considerable depression for the adductor 
muscle ; and besides the usual knob at the rostral angle, 
there is a trace of a knob at the baso-tergal angle. 

Terga, as seen internally, irregularly rhomboidal, end- 
ing downwards in a blunt point, of which the two sides, 
(neither being sensibly hollowed out,) stand at about an 
angle of 45° to each other. Scutal margin, with the 
upper part, (as above remarked,) slightly protuberant : 

Steenstrup for sending me a separate copy of the paper in question, written 
in Danish. I believe I am right in identifying the specimen here described, 
from Timor, with the species from the Nicobar Islands, named by Keinhardt, 
L. Nicobar ica. 



UTHOTRYA NICOBARICA. 361 

near the bottom of tins margin, there is a very slight pro- 
jection, answering to the small knob at the baso-tergal 
angle of the scutum. Externally, towards the basal angle, 
the narrow strip not concealed by the overlapping of 
the latera and carina is square-edged, with the zones of 
growth on it straight. 

. Carina, internally concave in the upper free part, with 
a slight, central, internal crest, caused by the projection 
of each successive zone of growth. The inner growing 
surface is almost pentagonal in outline ; with the basal 
margin square and truncated in the middle. 

Bostrum (fig. 2 a), rather conspicuous, many zones of 
growth being preserved. It equals in width six of the 
subjacent scales of the peduncle, but as these are rather 
smaller than elsewhere, the width equals about five of the 
ordinary uppermost scales ; compared with the latera, it 
is nearly fths of their width. 

Latera, unusually large ; as seen on their interior sur- 
faces, (or in a section parallel to the zones of growth,) 
they are triangular, elongated transversely, with the 
carinal angle a rectangle. In width they equal the seven 
subjacent scales of the peduncle, and are more than half 
as long as the basal margin of the carina. 
, Peduncle, with the upper scales varying from circular 
to quadrilateral, thrice as large as those in the second 
whorl ; beneath which, in the next three or four whorls, 
the scales rapidly decrease in size ; and beneath these the 
whole peduncle is studded with equal-sized, rounded, cal 
careous beads, so minute as to be quite invisible to the 
naked eye. This specimen was, nearly ready to moult, 
and perhaps in consequence of this, even the upper scales 
were most obscurely serrated on their lower margins, and 
all the others quite smooth : there were some much worn 
horny spines c close to the bottom of the peduncle. Basal 
calcareous cup slightly concave, of moderate size ; its dia- 
meter, in the one specimen examined, was ^ths of an 
inch ; it was composed of several layers. In the specimen 
figured (2 a') by Reinhardt, instead of a cup, there is a 



362 LITHOTRYA NICOBAR1CA. 

straight row of small discs, which are attached to the walls 
of the cavity, as explained in the generic description. 

Mouth. — Palpi with their ends square and truncated ; 
thickly clothed with long spines. 

Mandibles, with fully twice as many pectinations, (viz. 
from 16 to 20,) between the first and second main teeth, 
as between (viz. 8 to 10) the second and third main teeth. 
Inferior angle, coarsely pectinated. The distance between 
the tips of the first and second teeth, is considerably less 
than between the tip of the second tooth and the inferior 
angle. 

Maxilla, with the edge very slightly irregular ; beneath 
the two great upper spines there is a slight notch, with 
some small spines : inferior angle slightly prominent, with 
a brush of moderately fine spines; besides these, there 
are about seventeen pairs of large spines ; sides very hairy. 

Outer Maxilla, with the inner margin slightly concave, 
and with the spines continuous. 

Cirri. — The segments in the three posterior pairs sup- 
port three or four pairs of long spines, with a single row 
of moderately long intermediate spines ; the dorsal tufts 
consist of a few rather thick, and some long and thin 
spines. The front of the segments is not protuberant ; 
the whole surface is hirsute with minute comb-like scales. 
Second cirrus, with the anterior ramus having its eight 
basal segments highly protuberant and thickly clothed 
with spines, the upper nine having the usual structure ; 
the posterior ramus has four or five basal segments 
thickly clothed with spines, and the twelve upper ones 
with the usual structure. Third cirrus, with the anterior 
ramus having six segments highly protuberant and thickly 
clothed with bristles, and the fifteen upper ones on the 
usual structure ; in the posterior ramus, only three or four 
of the basal segments are paved with bristles. The spines 
on the first three pairs of cirri, are coarsely and doubly 
serrated. 

The Caudal Appendages are more than twice as long 
as the pedicels of the sixth cirrus, and equal half the 



LITHOTRYA RHODIOPUS. 363 

length of the whole cirrus. In a specimen in which the 
sixth cirrus contained twenty- two segments, the caudal 
appendages actually contained twenty. The segments 
are thin, with their upper edges clothed with serrated 
spines. The slip of membrane on each side, whence this 
organ springs is united, for a little space, to the lower 
segment of the pedicel of the sixth cirrus. 

Size and Colour. — Width of the capitulum rather above 
^ths of an inch ; length, including the peduncle, (con- 
tracted by spirits,) nearly one inch. Valves, as usual, 
dirty white, partly invested by yellow membrane, fur- 
nished with a few minute yellow horny spines. Pedicels 
of the first four cirri, caudal appendages, penis, the two 
posterior thoracic segments, the segments of the cirri, and 
the trophi, clouded, banded, or spotted, with blackish 
purple. 

Affinities. — This species, in the characters derived from 
the valves, comes perhaps nearest to L. Bhodiopus ; in the 
characters derived from the animal's body, it is nearest to 
L. dorsalis. 



4. LlTHOTRYA RHODIOPUS. PI. VIII, fig. 4. 

Brisx^us rhodiopus. J. E. Gray. Annals of Philosophy vol. x, 

(new series,) 1825. 

— — J. E. Gray. Spicilegia Zoolog., Tab. xvi, 

fig. 17, 1830. 

L. scutis terga ample obtegentibus : carince crista in" 
ternd tenui, in parte superior e positd : lateribus, superjicie 
interna symmetrice et late ovatd, carince latitudinis plus 
quam tertiam partem cequantibus: tergorum basali apice 
tenui, et angulo carinali producto : rostro et pedunculo 
ignotis. 

Scuta largely overlapping the terga. Carina with a 
slight central internal ridge in the upper part. Latera 
with their internal surfaces symmetrically and broadly 
oval, more than one third of the width of the carina. 



364 LITHOTRYA RHODIOPTJS. 

Terga with the basal points narrow, and the carinal angle 
produced. Rostrum and peduncle unknown. 

Mandibles, with four times as many pectinations 
between the first and second main teeth, as between the 
second and third ; distance greater between the tips of 
the first and second teeth, than between the tip of the 
second tooth and the inferior angle. Maxillae widely 
notched, with the inferior part forming two obscure 
prominences. 

Hab. unknown. Imbedded in a massive coral. Brit. Mus. 

The specimens are in a rather bad condition, and have 
been disarticulated. They are of rather small size; the 
rostrum and peduncle are lost, and animal's body much 
injured. < 

Valves white, thin, translucent ; teeth on the projecting 
rims small, narrow, standing further apart than their own 
width. The upper layers have undergone but little dis- 
integration or scaling off, and consequently the carina and 
terga project freely. The valves, where not rubbed, are 
covered by bright yellow membrane, which is thickly 
clothed with rows of spines ; these are small on the 
exterior surfaces, but are very large and hooked in certain 
parts, as near the tergal margins of the scuta, and on the 
carinal margins of the terga, and especially on the inner 
face of the upper free part of the carina. Here the 
hooked spines (fig. 4 d) are trifid or quadrifid, and are 
very conspicuous. 

Scuta, as seen externally, triangular ; they overlap half 
the width of the terga; on their internal faces (fig. 4#), 
in the upper projecting part, there is a strong ridge, 
against which the scutal margin of the terga abuts. There 
is a deep and conspicuous pit for the adductor muscle. 

Terga, as seen externally, nearly triangular. The ridge 
which leads from the apex to the basal angle, is rounded, 
central, and extremely prominent ; but does not form a 
furrow, or include the overlapping margin of the scuta. 
The basal angle is narrow, spur-like, and slightly hollowed 



LITHOTRYA RHODIOPUS. 365 

out on both margins. The growing corium-covered sur- 
face (fig. 4 b) is transversely elongated, with the occludent 
margin rounded, and the carinal angle much produced, 
but not forming a roughened knob. 

Carina (fig. 4 d), concave within, with a slight central 
ridge in the upper free portion. The inner growing sur- 
face is concave, almost pentagonal, with a just perceptibly 
raised central rim in the upper part, and with two minute 
prominences on each side, against which the produced 
carinal angles of the terga abut. 

Mostrum t lost. 

Latera (fig. 4 c), growing surface (or a section parallel 
to the growth-layers,) symmetrically oval, more than one 
third as wide as the basal margin of the carina. Several 
zones of growth preserved. 

Peduncle, lost, but a few scales accidentally adhering 
to one of the valves, show that they are crenated in the 
three or four upper whorls. No basal calcareous cup was 
preserved, but by clearing out the base of one of the holes 
in the coral, in which a specimen had been imbedded, I 
found a little fiat disc about the size of a pin's head ; it 
was composed of two or three layers, and was externally 
coated by yellow membrane, including the usual spindle- 
shaped bodies and tubuli. The cement-ducts were also 
discovered after dissolution in acid. So that there could 
be no doubt regarding the nature of the little disc. 

Mouth. — Labrum with a row of little blunt teeth. 

Palpi, blunt, rather expanded at their ends, with the 
extreme margin much arched and furnished with two 
rows of long spines ; there is a fringe of short spines on 
the straight inner side. 

Mandibles. — There are nine pectinations between the 
first and second main teeth, and only two between the 
second and third teeth; the inferior angle is coarsely 
pectinated, with one central spine twice as long as the 
others. The distance between the tips of the first and 
second main teeth, is greater than between the tip of the 
second tooth and the inferior angle. 



366 LITHOTRYA TRUNCATA. 

Maxilla (PI. X, fig. 12). — These may be described as 
having their edge formed into three prominences ; or, as 
having a very wide notch under the two upper great spines, 
and with the whole inferior part forming two prominences. 
There are, altogether, about twelve pairs of spines, of 
which two stand singly on the inferior side of the wide 
notch under the two upper great spines. The spines on 
the inferior angle are rather smaller than those above; 
sides hirsute. 

Outer Maxilla, with the inner margin slightly concave, 
and sparingly covered with bristles. 

Cirri, imperfectly preserved ; the three posterior pairs 
have segments of the usual character, bearing five pairs of 
very long spines, with the usual little intermediate, the 
minute lateral, and the dorsal spines. First cirrus lost ; 
second and third with only their few basal segments pre- 
served, sufficient, however, to show that at least two or 
three segments, in both the anterior and posterior rami 
of both cirri, were paved with bristles. 

Pedicels, as in the other species. 

Caudal Appendages, lost. 

This species comes very close, as far as the characters 
derived from the trophi serve, to the L. truncata, though 
readily distinguished from that species by the shape of the 
valves. On the other hand, the capitulum of this species 
is distinguished with difficulty from that of L. Nicobarica 
and L. cauta ; no doubt this difficulty is much enhanced 
by the rostrum and peduncle having been lost. 



5. LlTHOTRYA TRUNCATA. PL IX, fig. 1. 

Anatifa truncata. Quoy et Gaimard. Voyage de l'Astrolabe, 
PI. xciii, figs. 12 to 15, 1834. 

L. scutis in profundam tergorum plicam insertis : carina 
crista centrali prominente et rotundatd in parte superiore : 
rostro et lateribus rudimentalibus, carina latitudinis 
quindecimam fere partem aquantibus. 



LITHOTRYA TRUNCATA. 367 

Scuta locked into a deep fold in the terga: carina 
with a prominent central rounded ridge in the upper part : 
rostrum and latera rudimentary, about ^th of the width of 
the carina. 

Mandibles, with nearly three times as many pectina- 
tions between the first and second teeth, as between the 
second and third teeth ; distauce between the tips of the 
first and second teeth equal to that between the tip of 
the second tooth and inferior angle. Maxillae widely 
notched, with the inferior part forming two prominences. 
Caudal appendages shorter than, or barely exceeding in 
length, the pedicels of the sixth cirrus. 

Friendly Archipelago, Mus. Paris ; Philippine Archipelago, Mus. Cuming ; 
imbedded in coral rock. 

Capitulum rather thick, with the five main valves 
having their free apices, diverging and truncated. The 
upper and old layers of shell do not here scale off so 
readily as in many of the foregoing species ; and hence an 
unusually large proportional length of each valve pro- 
jects freely above the sack ; and the valves are of unusual 
thickness. The capitulum is very nearly as wide at its 
summit as at its base, owing to the divergence of the 
apices of the valves. The scuta and terga are articulated 
together by a conspicuous fold, which, when seen from 
vertically above, (PL IX, fig. 1 a',) appears like a deep 
wedge-formed notch in the terga. On the exterior sur- 
faces of the valves, the teeth on the successive rims are 
approximate ; on the inner surfaces, the rims are covered 
by strong yellow membrane, which is generally fringed 
with small horny spines. 

Scuta, exterior surface convex, sub-triangular, with the 
apex truncated : seen vertically from above, there is a 
small rectangular indentation or fold which receives the 
projecting scutal margin of the terga. The inner growing 
or corium-covered surface (fig. 1 5, b') is triangular, with its 
tergal margin largely hollowed out. Along the occludent 
margin there is a slight ridge, which terminates at the 



368 LITHOTRYA TRUNCATA. 

rostral angle, in both the right and left-hand valves, in a 
rounded, knob-like, roughened tooth. The lower part 
of the tergal margin is slightly inflected and roughened, 
where it meets the corresponding lower part of the scutal 
margin of the terga. There is a deep pit for the adductor 
muscle. The interior surface of the valve above this pit 
is faintly-coloured purple. The inner surfaces of both 
scuta and terga, are roughened with little points. 

Terga, seen externally, are almost quadrilateral (owing 
to the apex being truncated), with the free margin facing 
the scutum, arched. Seen vertically from above, each 
shows a deep fold, which receives the lower part of the 
tergal margin of the scutum. In the foregoing species, a 
prominent ridge runs down the exterior surface of the 
terga from the apex to the basal angle, against which 
ridge, the margin of the overlapping scuta abuts : here 
this ridge, instead of projecting straight out, is oblique 
or folded over, and thus forms a furrow, receiving the 
margin of the scuta. The interior growing surface of the 
tergum (fig. 1 b\ c), presents so irregular a figure, that 
it can hardly be described; in area it quite equals the 
scuta ; it is slightly concave j at the upper point of the 
carinal margin, there is a large, rounded, protuberant, 
roughened knob, which corresponds with a small knob on 
each side of the inner face of the carina ; these knobs seem 
firmly united together by membrane. The scutal margin 
of the terga, in the upper part, forms a shoulder, largely 
projecting over the scuta; on its lower part, there is a 
small roughened projection. The occludent margin is 
arched and protuberant, with a slight fold above the knob 
on the carinal margin, just mentioned : this fold is caused 
by the protuberance of the central internal ridge of the 
carina, but is so small, that when the capitulum is seen 
from vertically above, it can hardly be distinguished. 
Tin ally, the basal half of the carinal margin, runs in the 
same line with the basal margin of the scuta. 

Carina, moderately large ; seen externally, the surface 
presents an elongated triangle, with the apex truncated; 



LITHOTRYA TltUNCATA. 369 

on the internal face (fig. 1 6', d) of the free part, there is 
(instead of being concave as is usual) a great central 
ridge, which projects between the diverging apices of the 
terga, as may be seen from vertically above ; hence the 
thickness of the upper part of the carina, in a longitudinal 
plane, almost equals its breadth. The edge of this ridge 
is rounded. The inner or growing surface of the carina 
is tinted purple, and lies in a plane, oblique to the longer 
axis of the valve j it is triangular, with the apex cut off, 
and the basal margin rounded and protuberant ; it is not 
concave. There is a central raised line or slight ridge on 
this inner surface, and on each side in the upper part 
there is a small, white, roughened knob, corresponding 
with the similar knobs on the carinal margins of the 
terga. 

Rostrum (fig. 1 b', a), rudimentary ; in one specimen it 
was about ^th of an inch in width ; it is either as wide, 
or only half as wide, as the subjacent scale on the 
peduncle. 

Latera, rudimentary, placed between the edges of the 
carina and the terga; rather smaller than the rostrum ; 
almost cylindrical, slightly flattened, enlarged at each 
zone of growth, with one or two sharp teeth or spines on 
both faces ; imperfectly calcified ; in width barely -^th 
part of the carina. 

Peduncle, short ; the scales alone in the uppermost 
whorl are plainly toothed; they are transversely elon- 
gated, and almost quadrangular, and are nearly twice as 
large as those in the second whorl. Beneath this second 
whorl, there are two or three whorls, with scales, gradu- 
ated in size ; and the rest of the peduncle is covered by 
rather distantly scattered, minute, rounded or acutely 
pointed scales : the pointed scales are directed upwards, 
and are best developed under the carina. The basal cal- 
careous cup, judging from two specimens, is thin, and 
not much developed. 

Size and Colour. — The largest specimen was nearly 
-ths of an inch across its capitulum. The calcareous 

24 



370 L1THOTRYA TRUNCATA. 

valves are dirty white. The sack is (after having been 
long kept in spirits) pale coloured, excepting a small 
purple space, between the scuta and another over the 
carina. The three posterior segments of the thorax and 
portions under the second and third cirri, the tropin, the 
pedicels and the anterior faces of the segments (especially 
of the basal segments in the second and third cirri), and a 
spot on their dorsal surfaces, and the penis are all coloured 
dark purplish- black. The prosoina is pale coloured. 

Mouth. — Crest of labrum with a row of bead-like teeth 
and hairs. Palpi bluntly pointed, with neither margin 
hollowed out. 

Mandibles, with eight pectinations between the first 
and second main teeth, and three between the second 
and third teeth ; inferior angle coarsely pectinated, with 
a central spine much longer than the others ; the distance 
between the tips of the first and second main teeth, is 
about equal to that between the tip of the second tooth 
and of the inferior angle. 

Maxilla.— Under the two upper long spines (associated 
with some smaller ones), there is a slight and wide hollow ; 
and the whole inferior edge obscurely forms two blunt 
points, with the spines on the lower projection smaller 
than the upper spines. 

Outer Maxilla, considerably concave in front, with the 
spines almost discontinuous in the middle part. 

Cirri. — First pair rather far separated from the second 
pair. The segments of the three posterior cirri bear three 
or four pairs of main spines, and are otherwise charac- 
terised like the foregoing species. First cirrus, with its 
anterior ramus much thicker than the posterior ramus, 
and of nearly equal length ; all the segments, except the 
two terminal ones, thickly clothed with serrated spines. 
Second cirrus considerably shorter than the third cirrus : 
anterior ramus with the seven basal segments very pro- 
tuberant, and paved with bristles, and the four terminal 
ones on the usual structure ; posterior ramus, w T ith the five 
basal segments paved (but much less thickly than in the 



LITHOTRYA VALENTIANA. 371 

anterior ramus), and the nine terminal ones on the usual 
structure. Third cirrus, the anterior ramus, with the 
five basal segments, thick and paved, and eleven terminal 
segments on the usual structure : posterior ramus, with 
one basal segment paved, and sixteen other segments on 
the usual structure. In the posterior rami, however, of 
both the second and third cirri, it is difficult to draw any 
distinct line between the paved segments and the others. 
Caudal Appendages, short, either just exceeding in 
length the pedicels of the sixth cirrus, or equalling only 
the lower segment : segments flattened, cylindrical, six in 
number, there being, in the same individual, twenty- one 
segments in both rami of the sixth cirrus. 



6. LlTHOTRYA VALENTIANA. PI. VIII, fig. 5. 

Conchotrya Valentiana. /. E. Gray. Annals of Philosoph., 
vol. x (new series), 1825. 

L. scutis in profundam tergorum plicam insertis : tergo- 
rum opposito superior e margine, plica altera deque prof undd 
instructo : carina crista prominente centrali, marginibus 
quadratis, in parte superior e : rostro rudimentali : late- 
rib us et pedunculo ignotis. 

Scuta locked into a deep fold in the terga ; the latter 
having a second equally deep fold on the opposite upper 
margin. Carina with a prominent, central, square-edged 
ridge in the upper part : rostrum rudimentary. Latera 
and peduncle unknown. 

Animal unknown. 

"Red Sea, imbedded in an oyster-shell. British Museum. 

General Bemarh. — The two specimens in the British 
Museum are small, and in an imperfect condition, without 
the peduncle or the latera, and without the body of the 
animal. The capitulum so closely resembles that of 
L truncata, that it is quite superfluous to do more than 



372 LITHOTYRA VALENTIANA. 

point out the few differences. It is just possible, though 
not probable, that this form may prove to be merely a 
variety or younger state of L. truncata, in which case this 
latter name would have to be sunk. The difference, 
though one only of degree, in the form of the terga of the 
two species is conspicuous, and there is a slight difference 
in the carina, and again some dissimilarity in habits. 

Description. — The valves, as just stated, generally 
resemble those of L. truncata ; scarcely any appreciable 
difference can be detected in the scuta ; the apex, how- 
ever, of the inner surface seems coloured a darker purple. 
The terga, as seen from vertically above (PI. VIII, fig. 5 b), 
have a fold or indentation on the upper or occludent 
margin, as large and as conspicuous as that receiving the 
margin of the scuta : this fold, as seen on the inner 
corium- covered surface (fig. 5 a), descends below the 
roughened knob at the upper angle of the carinal margin, 
which is not the case with the slight fold in the same 
place in L. truncata; its presence seems caused by the 
edge of the central internal crest, in the upper part of the 
carina, being square (instead of round, as in L. truncata), 
and thus more deeply affecting the outline of the terga, 
between which it is inserted. The upper part of the scutal 
margin of the terga, as seen internally (fig. 5 a), overlaps 
the scuta in a large rectangular projection. From the 
depth of the two opposite folds, namely, that caused by 
the tergal edge of the scuta and that by the crest of the 
carina, the inner face of the tergum is divided into two 
almost equal areas. The carina has its central crest square 
(fig. 5 c, d,) instead of being rounded as in L. truncata. 
The inner growing or corium-covered face is nearly at right 
angles to the longitudinal axis of the whole valve, instead 
of being oblique to it ; it is convex or protuberant, with 
a central raised line, and two little knobs on each side 
of the upper part ; the two lateral margins are slightly 
hollowed out, and the basal margin is not highly pro- 
tuberant. The rostrum is excessively minute, barely above 
^th of an inch in width ; it is a little enlarged at each 



SPECIES DUBIiE. 373 

zone of growth. Latera lost ; no doubt they were rudi- 
mentary. 

A fragment of a posterior cirrus, which adhered to one 
of the valves, shows that each segment supported four 
pairs of spines. 

Width of the capitulum before disarticulation, probably 
was about -^th of an inch. 



Species mihi non satis notce, aid dubice. 

Anatifa villosa. Bmgiere. Eucyclop. Meth. Des. Vers., torn, i, 
1789, p. 62, PL clxvi. 

On ships : Mediterranean. 

Anatifa hirsuta.* Conrad. Journal of the Acad, of Nat. Sc., 
Philadelphia, vol. vii, 1837, p. 262. 

On fuci, Payal, Azores. 

The specimens, to which these names have been given 
by the above two authors, are described as small, and the 
A. villosa was suspected by Brugiere to be young. The 
A. hirsuta is said by Conrad to have the valves minutely 
striated, granulated, and covered by a strong hirsute 
epidermis ; the scuta, compared with the other valves, 
are very large ; the entire length of this specimen was a 
quarter of an inch. The A. villosa is described as having 
smooth valves, and apparently the peduncle alone is 
hirsute. Now, in young individuals of Lepas australis, 
the peduncle is hairy, whilst in full-grown specimens it 
is quite smooth. Again, in some varieties of L.fascicu- 
laris, the thorax, prosoma, and cirri are hirsute, whereas 
they are generally quite smooth ; hence I am inclined to 
suspect that A. villosa is the young, in a state of variation, 

* The Anatifa hirsuta of Quoy and Gaimard is the Ibla quadrivahis of 
this work. 



374 



SPECIES DUBIiE. 



of L. anatifera; and that A. hirsiita bears a similar re- 
lation to L. anserifera. In Lamarck's ' Animaux sans 
Vertebres/ Pollicipes villosus of Sowerby is quite incor- 
rectly given as a synonym to the above A. vittosa. 



Anatifa elongata. Quoy et Gaimard. Voyage de 1' Astrolabe, 
PL xciii, fig. 0. 

This, I think, is certainly a distinct and new species, 
but I am unable to decide whether to place it in Lepas or 
Paecilasma. It is briefly described and pretty well figured 
in the above work. It was procured at New Zealand, 
but it is not stated to what object it was attached. The 
capitulum is much elongated, and one inch in length; 
the peduncle is from six to eight lines long. The carina 
is said to be very narrow ; it is not stated whether it 
terminates downwards in a fork or disc ; judging from 
the figure, it extends some way up between the terga, 
the basal ends of which are bluntly pointed. The scuta 
are almost quadrilateral. The peduncle is short, yellow, 
and tuberculated. The general appearance of the drawing 
makes me suspect that it is a Paecilasma. 



Clyptra. Leach. Zoological Journal, vol. ii, p. 208, July, 1825. 

Leach has most briefly characterised a specimen in 
Savigny's Museum, from the Red Sea, under the above 
name of Clyptra. It has only four valves, and its peduncle 
is smooth; by the latter character it is distinguished from 
lbla. Apparently this is a distinct and new genus. 

Mr. J. E. Gray, in 'Proc. Zoolog. Soc./ 1848, p. 44, 
quotes a description by Stroem (' Nym. Saml. Danske,' 
1788, 295, n. hi, f. 20), namely, " Lepas testa compressd 
1-valvis, stipite lamellosd." It is found attached to 



SPECIES DUBLE. 375 

Gorgonia placomus, in the North Sea. I suspect that 
this is the common Scalpellum vulgare, and that Stroem 
counted the valves only on one side, overlooking the 
rudimentary and concealed rostrum ; and this would 
give seven for the number of the valves. Had it not 
been for the expression "stipite lamellosa," I should 
have thought this might have been an unknown species 
of Dichelaspis. 

Scalpellum ljevis. Risso. Hist Nat. cles Product, de l'Europe 

Mead., 1826, Tom. iv, p. 385. 

The chief characteristic of this species appears to be 
indicated by its specific name. It is found in the Me- 
diterranean, attached to Cidarites. I am inclined to 
believe that it is distinct from S. vulgare. 



Scalpellum papillosum. King. Zoolog. Journal, vol. v, p. 334. 

Captain King has described this species, taken from 
the depth of 48 fathoms, on the coast of Patagonia, in 
Lat. 44° 30' S. It is probably distinct, but is so im- 
perfectly described, that not even the number of the 
valves is given. 



Polylepas (Pollicipes), Sinensis. Chenu. Must. Conchy liolog., 

PI. U, fig. 7. 

This species is said to come from China ; it is nearest 
to P. sjjinosus, but is, I think, distinct. 



EXPLANATION OF THE PLATES. 



TAB. I. 



Eig. 

1. Zepas anatifera, (nat. size.) Far., with a row of 

square, dark-coloured marks on 

the scuta and terga. 
la. „ „ external view of carina, magnified 

thrice. 
\b. „ „ lateral view of carina, magnified 

thrice; var. dentata. 
\c. ,, ,, internal view of right-hand scutum, 

to show the tooth at the umbo. 

2. Zepas Ilillii, (nat. size.) 

3. Zepas pectinata, (magnified thrice.) 

3a. „ „ var. (spirilla), tergum, magnified 

thrice. 

4. Zepas anserifera, (nat. size.) 

5. Zepas australis, (nat. size.) 

5#. „ „ carina, external view of, magnified 

twice. 

6. Zepas fascicularis, (nat. size,) with its peduncle, 

together with those of three 
other specimens, imbedded in 
a vesicular ball of their own 
formation, of which a slice 
has been cut off to show the 
internal structure. The spe- 
cimen is in the College of 
Surgeons. 



37S EXPLANATION OF THE PLATES. 

6a. Zepas fascicidaris, carina of, nat. size. 

6$. „ „ var. villosa. 

6c. „ „ ,, carina of. 

6d. Part of the membrane from one side of the pe- 
duncle of Ze]jasfasciciilaris,with the ball removed, 
showing one of the cement-ducts, and the orifices 
through which the vesicular membrane forming the 
ball has been secreted ; greatly magnified ; viewed 
from the outside. 



TAB. II. 

1 . Pcecilasma Kamp/eri, (magnified two and a half times.) 
la. „ „ carina of. 

2. Pcecilasma aurantia, (magnified two and a half times.) 

3. Pcecilasma crassa, (magnified twice.) 
3a. „ „ carina of. 

4. Poecilasmajissa, (magnified five times.) 

5. Pcecilasma ebumea, (magnified five times.) 

ba. „ „ carina of, external view of. 
be. „ „ „ lateral view of. 

bb. „ „ scutum, internal view of. 

6. Zickelaspis Warwickii, (magnified five times.) 

6a. „ „ transverse section of the top 

of the peduncle, showing 
the deeply-notched end of 
the inwardly bent carina ; 
magnified five times. 

6b. „ „ var., scutum and tergum. 

7. Dichelaspis pellucida, (magnified five times.) 

7a. ,, „ basal end of carina of, much 

magnified. 

8. Dichelaspis Lowci, (magnified nearly ten times.) 
8a. „ „ fork of carina of, viewed inter- 
nally. 



EXPLANATION OF THE PLATES. 379 

Kg. 

9. Dichelasjris Grai/ii, (magnified eight or nine times.) 

10. Dichelaspis orthogonia, (magnified six times.) 
10#. „ „ carina, lateral view of. 

103. „ „ basal end of carina, viewed 

internally, much magnified. 



TAB. III. 

1. OxgnasjAs celata, (magnified three times.) 

la. „ „ with the skin of the encrusting 

horny zoophyte removed, (a), 
scutum; \b), tergum; and {c), 
carina. 

2. Conchoderma virgata, (magnified twice.) 

2a. ,, „ carina, viewed externally. 

25. „ „ summit of capitulum, showing 

the terga from vertically 

above. 
2c. „ ,, var. chelonophila, (magnified 

four times). 
2d. „ „ var. Olfersii, (scutum.) 

3. Conchoderma Hunteri, (magnified five times.) 

4. Conchoderma aurita, (nat. size,) with the rudimentary 

carina exhibited on the right 
hand. 

4a. „ „ summit of capitulum, viewed 

from vertically above, show- 
ing the ear-like appendages 
and rudimentary terga. 

43. „ „ section near the bases of the 

ear-like appendages, showing 
their folds. 

4c. „ „ (var.), scutum. 

5. Alepas minuta, (magnified five times.) 

6. Alepas cornuta, (magnified five times.) 



380 EXPLANATION OF THE PLATES. 

TAB. IV. 

1. Anelasma squalicola, (copied from Loven.) The 

ovigerous lamellae are seen 
within the edges of the aperture 
of the capitulum. Enlarged 
about one and a half times. 

2. „ „ (from Loven), with the mem- 

branes removed from one side 
of the capitulum and of the 
peduncle, exhibiting the body. 

(a.) External membrane of 
the capitulum. 

(a, a.) Inner membrane of 
ditto, lining the sack, and 
separated from the exter- 
nal membrane by a double 
fold of corium. 

ib.) The ovigerous lamellae, 
the edge projecting beyond 
the orifice of the capitulum. 

(c.) Penis, succeeded by six 
pairs of rudimentary cirri. 

(d.) Probosciformed mouth. 

{e.) Orifice of the acoustic (?) 
sack. 

(/.) Ovigerous frgenum. 

(c/.) Ovarian branching tubes 
filling up the peduncle. 

(k.) Outer integument of pe- 
duncle, lined by corium 
and muscles, continuous 
with the outer membrane 
(a) of the capitulum. 

3. ,, „ Small portion of the outer integu- 

ment of the peduncle, greatly 
magnified, exhibiting the natural 
lines of splitting, and showing 



EXPLANATION OF THE PLATES. 381 

Fif 



1 S- 



that it is composed of several 
distinct portions or layers, which 
are displayed by the corners 
having been turned over. Three 
of the branching filaments, filled 
with pulpy corium, are given ; 
the others have been cut off. 
The membrane {a) extends under 
(5), but not under the circular 
patches of membrane, (c, c.) 

4. Anelasma squalicola. Mandibles, seen from the side 

towards the maxillae. 

5. „ „ Mandibles, seen from the side to- 

wards the labrum. 
0. „ „ The right-hand, rudimentary cir- 

rus, the third from the mouth. 

7. „ „ Maxillae. The thin horny apo- 

deme, (a). 

8. Ibla Cumingii, female, (magnified four times.) 

8a. „ „ „ (magnified about five times), with 

the right hand valves and right 
side of the peduncle removed. The 
Male (A) is seen attached in the 
sack. The peculiar form of the 
body, caused by the small de- 
velopment of the prosoma, by the 
distance of the first and second 
pairs of cirri, and by the distance 
of the mouth from the adductor 
muscle, (a dark clotted circle op- 
posite i,) and lastly, the remark- 
able course of the oesophagus over 
the adductor muscle, together with 
the outline of the stomach, are 
here all exhibited. 
{a.) Scutum; the end of the large 
rounded adductor muscle, which 



382 EXPLANATION OF THE PLATES. 

Fig. 

was attached to the valve now re- 
moved, near its apex, is plainly seen. 

(b.) Tergum. 

(c.) On a line with this letter, is seen 
the largely bullate labrum, forming 
a blunt overhanging projection. 

(d.) Palpus, close to the upper seg- 
ment of the pedicel of first cirrus. 

(e.) Orifice of the acoustic (?) sack, 
between the bases of the first and 
second cirrus. 

(/.) Caudal appendages. 

(p.) Branching ovarian tubes within 
the peduncle. 

(Ji.) Male, on the same scale, lying in 
its natural position within the sack, 
with the lower part of its peduncle 
bent upwards, and imbedded in the 
corium and muscles of the female. 

(i.) Adductor scutorum muscle. 
86'. Ibla Cumingii, Internal view of the scutum and ter- 
gum, and of the upper part of the 
outer integument of the peduncle, 
with its horny spines magnified 
about three times. 
8c. „ ,, A small portion of the outer integu- 

ment of the peduncle, greatly 
magnified, showing the horny per- 
sistent spines ; two of the spines 
have been torn out. 

9. Ibla quadrivalvis; internal view of scutum and ter- 
gum, and of the upper part of 
the outer integument of the 
peduncle ; magnified four times. 

9a. ,, „ Penis, supported on a long un- 

articulated projection ; greatly 
magnified. 



EXPLANATION OF THE PLATES, 383 

TAB. V. 



Fig. 



1. Male of Ibla Cumingii, magnified thirty-two times. 

(«.) Mouth. 

(b.) A slight double fold, formed by the basal edge 
of the labrum, and by a lower fold, which at (//) 
becomes well developed ; the latter is a rudi- 
mentary representation of the double membrane 
and valves forming the capitulum. 

(c.) Eye. 

(d, d.) Torn membrane from the sack of the 
female, constricted round the body of the male. 

(e.) Terminal or basal point, with the prehensile 
larval antennae, represented on rather too large 
a scale. 

(/.) The imbedded portion of the male. 

(</.) Two pairs of cirri. 

(h.) The fold above alluded to, concealing a small 
portion of the slightly retracted thorax. 

2. The male of Ibla Cumingii, viewed from vertically 

above; magnified about sixty times. The 
dotted lower portion, represents the outline of 
the thorax and the positions of the cirri, which, 
from standing below the mouth, could not be 
well seen, when the summit of the mouth was 
in the proper focus. 

(a.) Labium, largely bullate. 

(b.) Palpi. 

(c.) Mandibles. 

(d.) Maxillae. 

(e.) Outer maxillae ; between which and the crest 
of the labrum, the orifice of the oesophagus can 
be obscurely seen. 

(/.) Anus. 

(g.) Rudimentary caudal appendages, under which 
is the pore leading from the vesiculae seminales- 

(//.) Posterior cirrus, (i.) Anterior cirrus. 



384 EXPLANATION OF THE PLATES. 



Pig. 



3. Male of Ibla Cumingii ; labrum and palpi, as seen 

with the eye on a level with 
the summit of the mouth. 

4. „ „ „ Posterior cirrus (h in fig. 2) 

much magnified. 

5. „ „ „ Larval antennae; from the 

terminal point of the body 
(e in fig. 1), as seen with 
a ^th of an inch object glass. 

6. „ „ „ Outer maxillae. 

7. „ „ „ Mandibles, with the underly- 

ing articulated membrane, 
forming the side of the 
mouth. 

8. „ „ „ Maxillae, with the apodeme. 

9. Complemental Male of Scalpellum vulgar e 9 attached 

over the fold in the occludent margin of the 
scutum of the hermaphrodite. 

(a.) Orifice of the sack of the male. 

(5.) Spinose projections above the rudimental 
valves ; at the bottom of the figure are repre- 
sented, as seen through the wdiole thickness of 
the animal, the prehensile larval antennae. 

(d.) The depression for the attachment of the ad- 
ductor scutorum muscle of the hermaphrodite ; 
see fig. 15#'. 

(e, e.) A transparent layer of chitine, which forms 
a border to the occludent margin of the scutum 
of the hermaphrodite. This border supports 
long spines, which are connected with the un- 
derlying corium by sinuous tubuli. 

10. The basal (normally anterior) portion of the above 

complemental Male, greatly magnified, viewed 
dor sally from above, exhibiting the larval pre- 
hensile antennae, attached to the antero-sternal 
surface of the animal. 



EXPLANATION OF THE PLATES. 385 

Fig. 

11. One of the antennae of ditto, viewed laterally and on 

the outside. 

12. Ditto, ultimate segment of. 

13. Body of the above complemental male, consisting of 

the thorax supporting the four pairs of limbs, 
and of the terminal abdominal lobe, 

14. Small portion of the outer integument of the com- 

plemental male, as seen with a ^th of an inch 
object glass. 

15. /Scalpellum vulgare (hermaphrodite), magnified three 

times. 
(a, a.) Complemental males. 
{b.) Rostrum, of which a separate enlarged figure 

(b') is given. 

15 a. Scutum of the hermaphrodite Scalpellum vulgare, 
internal view of. 
(a.) Fold on the occludent margin. 
(d.) Pit for the adductor muscle. 

TAB. VI. 

1. Scalpellum ornatum, (female, magnified seven times.) 
Id. „ „ Upper latus, viewed internally. 

\b\ ,, „ Scutum of full-grown specimen, 

viewed internally, much mag- 
nified. 
{a.) Depression for the adductor 

muscle. 
{b.) Depression for the reception 
of the male. 

\c. ,, ,, Scutum of half-grown specimen, 

viewed internally, much magni- 
fied, on same scale with fig. lb '. 
The depression (b) for the re- 
ception of the male is here seen, 
in almost the first staaesSTtf, 
formation. ,'•' ' . 







386 EXPLANATION OF THE PLATES. 

Fi S; 

\d\ Scalpellmn omatum. An imaginary section through the 

cavity {x) in which the male is 

lodged. 
(a.) Section of the shell of the 

scutum of the female. 
(b.) A layer of chitine homologous 

with the shell, and partially 

lining the scutum. 
(c.) The inner lining (of chitine) 

of the sack of the female. 
(d.) A double fold of corium. 

2. Scaljjellum rutilum, (magnified two and a half times). 
2d. ,, „ Internal view of scutum, enlarged. 

(a.) Depression for the adductor 

muscle. 
(3.) Cavity for the reception of the 
male. 
2b' . ,, „ External view of carina. 

2c '. „ „ Section across middle of carina. 

3. Complement al Male of Scalpellum Peronii, greatly 

magnified. 

4. Complemental Male of Scalvellum villosum, greatly 

magnified. 
(d.) Natural size. 
4,#, b, c. Ditto, valves separated. 
(a.) Scutum. 
(b.) Tergum. 
(c.) Carina. 

5. Complemental Male of Scalpellum rostratum, a re- 

stored figure, greatly magnified. Scutum and 
rudimentary carina correct. 

0. JScalpellum Peronii, one and a half the natural 
size. 
(a.) Rostrum a little more enlarged, front view of. 

7, Scalpellum rostratum, magnified six times. 
(a.) Rostrum, front view of. 



EXPLANATION OF THE PLATES. 387 



Fig. 



8. Scalpellum villosiim, magnified one and a half the 

natural size. 
8a, b. „ „ (a.) Internal view of rostrum. 

(b.) ,, „ sub-rostrum. 



TAB. VII. 

1. Pollicipes cornucopia, (one and a half nat. size.) 
la. „ ,, internal view of valves. 



2. Pollicipes polj/merus, (one and a half nat. size.) 
2a. ,, ,. internal view of valves. 



3. Pollicipes mitella, nat. size. 

3# '. „ „ nat. size, internal views of 

(a.) Scutum, and of 
(6.) Tergum, showing articular fold. 
ZU . „ ,, Internal view of other valves, in a 

small specimen, showing the manner in which 
the valves of the lower whorl overlap each other. 
(a.) Upper latera. 
(b.) Carina, 

(c.) Sub-carina, both viewed a little obliquely. 
(d.) Rostrum, 
(e.) Sub-rostrum, both viewed a little obliquely. 

4. Pollicipes spinosus, one and a half nat. size. 

5. Pollicipes sertus, one and a half nat size. 



TAB. VIII. 

1. A piece of rock bored in two directions by Litho- 
trya dorsalis, with the calcareous basal discs in 
the upper cavity, serving as a bridge for crossing 
an old cavity. About twice natural size. 



388 EXPLANATION OF THE PLATES. 

Fig. 

[a. Litliotrya dorsalis, (nearly twice nat. size), with the 

basal calcareous cup adherent; 
(#), rostrum on same scale, 
seen externally. 

1 ;/ ,, rostrum and the rostral corners 

of the two scuta, together 
with a small portion of the 
subjacent membrane of the 
peduncle, with its calcareous 
scales ; viewed externally, 
greatly magnified, showing 
the inferior crenated edges 
of the scales. 

\ c \ 5 , „ basal calcareous cup, one and a 

half the natural size ; this is 
the largest specimen which I 
have seen. 

2. Litliotrya Nicobarica, (magnified nearly twice ;) at- 

tached to the rock, copied 
from Reinhardt; (#), rostrum 
on the same scale, with the 
other valves, seen externally ; 
(b), section of the row of discs; 
(c), extreme point of the pe- 
duncle, extending beneath 
the row of discs. 
2d. Rock bored by Litliotrya Nicobarica, showing the 
row of calcareous discs, copied from Reinhardt. 

3. Litliotrya cauta } magnified between seven and eight 

times ; (a), scutum ; {b) 9 tergum. 

3c. „ „ latus, greatly magnified. 

2>d. „ „ uppermost scales of the peduncle, 

greatly magnified. 

Se. „ „ star-shaped discs of hard chitine, 

supported on a peduncle of the 
same substance, taken from the 
lower exterior surface of the pe- 
duncle, very greatly magnified. 



EXPLANATION OF THE PLATES. 389 

4. Lithotrya Rhodiopus, (magnified five times,) internal 

views of; («), scutum; {5), 
tergum ; (c), latus ; id), 
carina. 

5. Lithotrya Valentiana, (magnified between three and 

four times ;) (a), internal 
view of scutum and tergum, 
locked together ; {5), capi- 
tulum seen from vertically 
above ; (c), internal view of 
carina; {d), section across 
the middle of the carina. 

TAB. IX. 

1. Lithotrya truncata, (magnified four times.) 

Id. „ „ capitulum seen from vertically 

above, not so distinctly repre- 
sented as in fig. hb, PL VIII. 

16'. „ „ internal views of valves; (a), 

rostrum, with a few subjacent 
scales of the peduncle ; {5) f 
scutum ; (c), tergum ; (d), 
carina. 

2. A portion (about ^th of an inch square) of the sur- 

face of attachment of the peduncle of Pollicipes 
polymerus, seen from the outside, greatly magni- 
fied, showing the small circular {55) patches of 
cement, poured out from the cement-ducts {ad) 
which lie within the peduncle. 

2d. „ „ a section, still more magnified, 

through the basal membrane 
of the peduncle, through one 
of the loops of the cement- 
ducts {ad), and through one 
of the circular patches {5) of 
cement. 



390 EXPLANATION OF THE PLATES. 

Fig. 

3. Cement gland, duct, and ovarian tubes of Concho- 

derma aurita; {act), ovarian tubes, with ova in 
process of formation; (#), cement-gland; (c), 
cement- duct. 

4 . Conchoderma virgata, enlarged, with one side of the ca- 

pitulum and of the peduncle 
removed, to show the form 
and position of the body. 
(a.) tergum, edge of. 
(b.) mouth, with one of the palpi 

seen on the inner, upper 

corner. 
(c.) adductor scutorum muscle. 
(d.) orifice of acoustic (?) sack. 
(e. ) scutum, occludent margin of. 
(/.) branching ovarian tubes 

within the peduncle. 
((/.) filamentary appendage on 

the prosoma. 
(It), ditto, close to basal articu- 
lation of the first cirrus. 
(i.) ditto, on the pedicel of the 

first cirrus. 
(j.) ditto, on the pedicel of the 

third cirrus. 
(k.) ditto, on the pedicel of the 

fourth cirrus. 
(/.) ditto, on the pedicel of the 

fifth cirrus. 
(m.) edge of the carina. 
(n.) prosoma. 

5. Apex of one of the filamentary appendages of Con- 

choderma aurita, greatly magnified, exhibiting the 
included branching testes. 

6. Acoustic (?) sack of Conchoderma virgata, taken out 

of the acoustic meatus, with the diaphragm from 
the summit removed ; greatly magnified. 



EXPLANATION OF THE PLATES. 391 
Fi &' 

7. Terminal part (magnified seven times), of the pe- 
duncle of an elongated specimen of Scalpellum ml- 
gare, slit open, with the corium removed, showing 
the two cement-ducts {a a), and a row of circular 
patches (bb) of cement, by which the peduncle, 
along its rostral edge, is attached to the thin horny 
branches of the coralline. The larval antennae 
are seen at the terminal point, and the two 
cement-ducts can be traced into them. 



TAB. X. 

Figures all greatly 'magnified. 

1 . Mandibles of Follicipes mitella : exhibiting the upper 

(a) and lower (b) articulations, and 
the three principal muscles; the 
short upper cut off muscle runs to 
its attachment at the base of the 
palpus. 

2. ,, Lithotrya dorsalis, exhibiting four {act) 

roughened, thin, ligamentous apo- 
demes for the attachment of the 
muscles. 

3. ,, Scalpellum Fero?iii. 

4. ,, Ibla Cumingii. 

5. ,, Lepas anatifera. 

6. Palpus of Lepas anatifera. 

7. ,, Pollicipes mitella. 

8. ., Alepas cornuta. 

9. Maxilla of Lepas anatifera. 

10. „ Litliotrya dor sails, exhibiting the horny, 

rigid apodeme {a) buried in muscles, 
together with the two other principal 
bundles of muscles. 

11. ,, Ibla Cumingii. 



392 EXPLANATION OF THE PLATES. 
Fig- 

12. Maxilla of Lithotrya Phodiopus. 

13. ,, Pollicipes polymer us. 

14. „ „ mitella. 

15. „ Pcecilasma eburnea. 

16. Outer maxilla of Conchoderma virgata ; {a), orifice 

of the olfactory cavity, the inner 
delicate chitine membrane of 
which is seen within, the spe- 
cimen having been treated with 
caustic potash. 

17. „ „ Pollicipes mitetta, showing the 

two principal muscles, and the 
prominent, tubular, (6) olfactory 
orifices. 

18. Caudal appendages, and basal segments of the sixth 

pair of cirri, of Lepas anatifera ; (a), anus; (b), 
caudal appendages ; (c), lower segment of pedicel 
of sixth cirrus ; (d), upper segment of ditto ; {e), 
basal segments of the two rami. 

19. Caudal appendage (right-hand side) of Pollicipes sertus. 

20. „ „ ?J Scalp ellum Pero?iii. 

21. ,. „ „ Scalpellum vulgare. 

22. ,, „ „ Pollicipes cornucopia. 

23. „ „ (left-hand) Lithotrya dorsalis; (a), 

caudal appendage; (c), lower 
segment of pedicel of sixth 
cirrus ; (d)> upper segment of 
ditto ; {e), segments of one of 
the rami. 

24. Portion of caudal appendage of Lithotrya dorsalis, 

highly magnified. 

25. Pollicipes polymer us ; anterior ramus of the second 

cirrus. 

26. Lepas anatifera; a segment of the sixth cirrus, showing 

the arrangement of the spines ; (a), main anterior 



EXPLANATION OF THE PLATES. 393 

Kg. 

spines, of which there is a corresponding row on 
the opposite side ; (c), dorsal tnft. 

27. Pollicipes polymeria; a segment of the sixth cirrus, 

showing the arrangement of the spines ; (a), main 
anterior spines, of which there is a corresponding 
row on the opposite side ; (6 b) y calcareous shields 
on the dorsal surfaces, with tufts of fine spines 
near their upper edges. 

28. Alepas comuta ; sixth cirrus of; (a) basal portion of 

one ramus, consisting of numerous segments ; 
(&), the other and almost rudimentary ramus. 

29. Pcecilasmafssa; segments of the sixth cirrus, showing 

the arrangement of the spines; (a), anterior spines ; 
(<?), dorsal tufts. 



INDEX. 



Synonyms and doubtful species are printed in italics. 



Abortion, extreme, in the male of 

Ibla, 202. 
Absia, 332. 

Acari, development of, 18. 
Acoustic (?) organs, general descrip- 
tion of, 53. 
Adductor scutorum muscle, 39. 
Affinities of the Lepadidae, 64. 
Alepas, Genus, 156. 

cornuta, 165. 

miuuta, 160. 

parasita, 163. 

squalicola, 170. 

tubulosa, 169. 
Allman, Professor, on Cyclops, 38. 
Anatifa vel Aaatifera, Genus, 67, 
99, 215. 

crassa, 107. 

dentata, 73. 

elongata, 374. 

engonata, 73. 

hirsuta, 203. 

Itevis, 73, 77. 

oceanica, 92. 

obliqua, 264. 

parasita, 163. 

quadrivakis, 203. 

sessilis, 81. 

spinosa, 324. 

striata, 81, 86. 

substriata, 77. 

sulcata, 86. 

tricolor, 77. 

truiicata, 361. 

univalvis, 163. 

v ill os a, 367. 

vitrea, 92. 



Anelasma, Genus, 169. 
Antennae, larval, 33. 

in the Lepadidas, 
table of measure- 
ments, 286. 
of Ibla Cumingii, 

191. 
of Lepas australis, 

15. 
of Scalpellum vul- 
gare, 237. 
Appendages, caudal, 43. 

in larva, 19. 
filamentary, 38. 
Asplanchna, male of, 292. 
Attachment of Cirripedes, 33. 

of Scalpellum vulgare, 

226. _ _ 
of Pollicipes polymerus, 
310. 

Balanidae, affinities of, 64. 

Bate, Mr. C. S., on the metamor- 
phoses of Cirripedes, 9-16. 

Bopyrus, parasite allied to, 55. 

Branta, 137. 

aurita, 141. 
virgatum, 146. 

Brightwell, Mr., on the Asplanchna, 
292. 

Br is nans, 332. 

Rhodiopus, 363. 

Brugiere, date of work of, 67. 

Buoyancy, means of, in Lepas fasci- 
cularis, 95. 

Burmeister, Professor, on the meta- 
morphoses of Cirripedes, 9, 13. 



396 



INDEX. 



Burrowing powers of, in Lithotrya, 
337. 

Calentica, 215. 

Homii, 274. 
Capitulum, general description of, 28. 
Capitulmn, Genus, 293. 

mi t el la, 316. 
Carapace of the larva, 15. 
Caudal appendages, 43. 

in larva, 19. 
Cement-discs, in a straight row, 
in Scalpellum vulgare, 

226. 
in Pollicipes polyme- 
rus, 310. 
Cement-ducts, 34. 

in the larva, 20. 
Cement-glands, incipient in larva, 24, 

34. 
Cement, nature of, 36. 
Cement-tissue, modified as a float in 

Lepas fascicularis, 95. 
Chitine, chemical nature of, 30. 
Chthamaliuse, 2, 65. 
Cineras, Genus, 137, 156. 
bicolor, 146. 
Cranchii, 146. 
chelonophilus, 146, 151. 
megalepas, 146. 
membranacea, 146. 
Montagui, 146. 
Olfersii, 146, 152. 
Rissoanus, 146. 
vittatus, 146. 
Circulation, 46. 
Cirri, general description of, 42. 

of young Cirripede, 22. 
Cirripede, immature whilst within 

the larva, 20. 
Cirripedes, sessile, affinities of, 64. 
sub-families of, 2. 
useful as food, 66. 
Clyptra, 374. 
Coates, Dr., on Lepas fascicularis, 

96. 
Conchoderma, Genus, 136. 
aurita, 141. 
Hunteri, 153. 
leporinum, 141. 
virgata, 146. 
Concholrya, 332. 

Valaitiana, 371. 



Cuming, Mr., obligations to, 181, 
189. 
on the Cirripedes of 
the Philippine Ar- 
chipelago, 65. 
on Balanus psittacus, 
66. 
Cup. basal calcareous, in Lithotrya, 
338. 

Dana, Mr. J. D., on the ovaria in cer- 
tain Crustacea, 26. 
on the antennas of 
larval Cirripedes, 
15, 26. 
Dichelaspis, Genus, 115. 
Grayii, 123. 
Lowei, 128. 
orthogonia, 130. 
pellucida, 125. 
Warwickii, 120. 
Distribution, geographical, 65. 
Dosima, 67. 

fascicularis, 92. 
Dujardin, on the larvse of Acari, 18. 

Encyclopedic Method., date of, 67- 
Entozoons, sexes of, 201. 
Epidermis of valves, 31. 
Exuviation, 61, 63. 

of the larval eyes, 24. 
of the larval integu- 
ments, 20. 
of the membrane of pe- 
duncle in Lithotrya, 
336. 
Eyes, in the Lepadidse, 49. 

of the larva, first stage, 10. 

last stage, 16, 24. 

Eamilies of Cirripedes, 2. 

Earre, Dr., on the acoustic organs 

in Crustacea, 54. 
Eemale organs of generation in the 

Lepadidae, 56. 
Eilaments, 38. 
Eorbes, Prof. E., on the homology 

of the peduncle, 26. 
Erama, ovigerous, 59. 

Ganglia, ophthalmic, 49. 



INDEX. 



397 



Generation, organs of, in the Lepa- 

didae, 55. 
Glands, supposed salivary, 57. 

on the ovigerous lamellae, 60. 
Goodsir, Mr., on the metamorphosis 
of Cirripedes, 9, 16. 
on the supposed male 
of Balanus, 55. 
Gray, Mr. J. E. , on the genus Dosima, 
99. 
on the metamorpho- 
sis of Cirripedes, 9. 
on the inequality of 
the valves in Paeci- 
lasma, 101, 103. 
on an unknown 7- 
valved Lepas, 374. 
on the genus Scal- 
pellum, 216. 
Growth, rate of, 63. 
Gymnolepas, 137. 

Cranchii, 146. 
Cuvierii, 141. 

Habitats, 65. 

Hancock, Mr., on the burrowing of 
Cirripedes, 346. 
on the larva of Lepas, 
11. 
Hectocotyle, 200. 
Heptalasmis, 115. 
Hermaphroditism, peculiar kind of, 

201. 
Heteroura androphora, 201. 
Homologies of the Cirripedia, 25-28. 
Ibla, Genus, 180. 

Cumingii (female), 183. 

(male), 189. 
Cuvieriana, 203. 
quadrivalvis (hermaphrodite), 
203. 
(complemental 
male), 207- 
general summary on its sexual 
relations, 28]. 
Impregnation of the females and 
hermaphrodites in Ibla and Scal- 
pellum, 290. 

King, Captain, on a new Scalpellum, 
375. 

Kolliker, on the males of Cephalo- 
poda, 200. 



Labrum, general description of, 40. 
Lamellae, ovigerous, 58. 
Larvae, general description of, 8. 
Larva of Ibla quadrivalvis, 210. 
Leidy, Professor, on the eyes of 

Cirripedes, 2, 49. 
Lepas, Genus, 67- 

anatifera, 73. 
anserifera, 81, 86. 
australis, 89. 

„ metamorphosis of, 14. 
coriacea, 146. 
cornuta, 141. 
cygnea, 92. 
dilata, 92. 
dor sails, 351. 
fascicularis, 92. 

„ peduncle, remark- 
able structure 
of, 95. 
Gallorum, 298. 
Hillii, 77. 
leporina, 141. 
vnembrancea, 146. 
mitella, 316. 
muricata, 85. 
nauta, 81. 
pectinata, 85. 
pollicipes, 298. 
scalpellum, 222. 
sulcata, 86. 
virgata, 146. 
Lerneidae, males of, 200. 
Leucifer, 28. 
Litholepas, 332. 

de Mont Serrat, 351. 
Lithotrya, Genus, 332. 
cauta, 356. 
dorsalis, 351. 
Nicobarica, 354. 
Rhodiopus, 363. 
truncata, 366. 
Yalentiana, 371. 
powers of burrowing, 337. 
Loven, Dr., on the habits of the 
Alepas squalicola, 178. 
on the homologies of 
Cirripedes, 26. 
Lowe, Rev. It. T., on the fishes of 

Madeira and 
Japan, 106. 
on the Cirripedes 
of Madeira, 65. 



398 



INDEX. 



Macgillivray, Prof., on Conchoderma, 

140. 
on Lepas anseri- 
fera, 81. 
Malacotta, 137. 

bivalvis, 141. 
Male Cirripedes, discussion on, 281. 
of Ibla Cumingii, 189. 

„ quadrivalvis, 207. 
of Scalpellura ornatum, 248. 
Peronii, 270. 
rostratum, 262. 
villosum, 278. 
vulgare, 231. 
organs of generation in the 
Lepadidae, 55. 
Mandibles, general description of, 41. 
Martin St. Ange, on the affinities of 

Cirripedes, 1. 
on a closed tube 
within the sto- 
mach, 45. 
on the generative 
organs, 55. 
Maxillae, general description of, 41. 
Membrane, covering valves, 30. 
Metamorphoses, first stage, 9. 

second stage, 13. 
last stage, 14. 
Mitella, Genus, 293. 
Mouth, general description of, 39. 
of young Cirripede, 22. 
of the larva, first stage, 11. 
last stage, 17. 
Muscles, 39. 

without striae in Ane- 
lasma, and in embryonic 
Cirripedes, 172. 

Nerves, general system of, 46. 
of Ibla Cumingii, 188. 
Nomenclature of the parts of Cirri- 
pedes, 3. 
Rules of, 293. 

Octolasmis, 11.5. 

Warwickii, 120. 
(Esophagus, general description of, 

44. 
Orders of Cirripedes, 2. 
Organs acoustic (?) general descrip- 
tion of, 53. 



Organs acoustic, of the larva of 
Lepas, 15. 
female, of generation, in the 

Lepadidae, 56. 
male, of generation, in the 
Lepadidae, 55. 
olfactory, general descrip- 
tion of, 52. 
Otion, 137. 

aurifm, 141. 
Bellianus, 141. 
Blainvillianus, 141. 
Cuvieranus, 141. 
depressa, 141. 
DumeriUianus, 141. 
Rissoanus, 141. 
saccutifera, 141. 
Ova, 58. 
Ovaria, incipient in the larva, 20, 24. 

in the Lepadidae, 57. 
Oviducts (supposed), 59. 
Owen, Professor, on certain Entozoic 
Worms, 201. 
• on the Concho - 
derma Hunteri, 
154. 
Oxynaspis, Genus, 133. 
celata, 134. 

Pamina, 137. 

trilineata, 146. 
Peach, Mr., obligations to, 240. 

on the movements of pe- 
dunculated Cirripedes, 
33. 
Peduncle, general description of, 31. 
origin and homologies of, 
21. 
Penis, general description of, 56. 
of Ibla quadrivalvis, 206. 
Pentalasmis, vel PenfalejMS, 67. 
anseriferus, 81. 
dentatus, 73. 
dilatata, 81. 
Donovani, 92. 
fascicular is, 92. 
Hillii, 77. 
inversus, 86. 
Icevis, 73, 77. 
radula, 86. 
spirula, 86. 
spirulicola, 92. 
sulcata, 86. 



INDEX. 



399 



Pentalepas vitrea, 92. 
Pcecilasma, Genus, 99. 

aurantia, 105. 

crassa, 107. 

eburnea, 112. 

fissa, 109. 

Kaempferi, 102. 
Pollicipes, 293. 

cornucopia, 298. 

elegans, 304. 

mitella, 316. 

Mortoni, 307. 

obliqua, 264. 

polymerus, 307. 

ruber, 304. 

scalpellum, 222. 

sertus, 327. 

sinensis, 375. 

Smythii, 298. 

spinosus, 324. 

tomentosus, 274. 

villosus, 274:. 
Polylepas, 215, 293. 

mitella, 316. 

sinensis, 375. 

vulgare, 222. 
Primordial valves, 22. 
Prosoma, shape of, 39. 
Proteolepas, 3, 26. 
Pupa, locomotive or last larval state, 
in Cirripedes, 18. 



RampJddiona, 293. 

Range, geographical, 65. 

Kate of growth, 63. 

Reinhardt on the burrowing of 

Lithotrya, 346. 
Reproduction, organs of, in the 

Lepadidse, 55. 
Rotifera, sexes of, 292. 
Rules of nomenclature, 293. 



Sack, description of, 31. 

origin of, 15, 23. 
Scalpellum, genus, 215. 
Icevis, 375. 
lave, 222. 
Sicilice, 222. 
ornatum, (female,) 244. 

(male,) 248. 
papillosum, 375. 



Scalpellum Peronii, 264. 

(male,) 270. 
rostratum, 259. 

(male,) 262. 
rutilum, 253. 

(male,) 258. 
villosum, 274. 

(male,) 278. 
vulgare, 222. 

larva of, 9. 
(complemental male,) 
231. 
general summary on sexual 
relations, 281. 
Schmidt, Dr., on chitine, 30. 

on the muscles in young 
Crustacea, 172. 
Senoclita, 137. 

fasciata, 146. 
Sexes, discussion on, in Ibla and 

Scalpellum, 281, 
Siebold, Dr. C. Von, 201. 
Smilium, 215. 

Peronii, 264. 
Spermatozoa in Scalpellum vulgare, 

236. 
Sprengel, Ch. K., on compositous 

flowers, 203. 
Steenstrup, Prof., on the homology 
of the peduncle, 26. 
on the non-hermaphroditism 
of Cirripedes, 55. 
Stomach of larva, 19. 

general description of, 44. 
Stroem on a seven-valved Lepas, 374. 
Syngamus trachealis, 201. 

Testes in the Lepadidse, 55. 
Tetralasmis, ISO. 

hirsutus, 203. 
Thaliella, 215. 

ornata, 244. 
Thompson, Mr. W., on Lepas an- 

atifera, (var.) 
74. 
on the exuvia- 
tions of sessile 
Cirripedes, 63. 
obligations to, 
240. 
Mr. Vaughan, on the 
metamorphoses of 
Cirripedes, 9, 10. 



400 INDEX. 

Trilasmis, genus, 99. 
ebumea, 112. 
Triton, genus, 156. 

fasciculatus, 163. 



Upopi, or young acari, 18. 

Vesiculae seminales, 56. 

Valves, general description of, 28. 



Valves, chemical nature of, 30. 

horny, colour changed by 

pressure, 184. 
primordial, 22. 



Wagner, R., on the male organs of 
generation, 55. 

Xiphidium, 215. 



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