PCECILOPODA. 4;7 



filumcnts at the extremity of the body as o\aries. I have sometimes found the eggs beneath the posterior branchial 

 ief^s, but never in these tubes. In other eases, the external ovaries, thus elongated, are only found in those females 

 which lay their eggs in holes or deep burrows ; whereas this is not the case with the Cahgi. Wiiller and other 

 zoologists have observed that these Crustacea trim and agitate these appendages. We believe, together with both 

 the Jurincs, that they serve for respiration, in the same manner els the anal fjiaments of Apus.* 



Tlie species of the restricted subgenus Caligxis (including Rincuhin, Leach) have all the legs free, and attached, 

 ^vith the exception of the two last, to the anterior part of the body [cephalothoraXi Latr.), covered by the shield ; 

 and some, at least, of the feet are furnished with numerous filaments. The siphon is not distinct. The abdomen 

 is naked above, and terminated by two long filaments or two styles. Catiyus piscintM, Latr. ; C. curtus, RliiU. ; 

 ^Jonoculu.^ pischiits'f Linn. The Oniacus lutosus, Slabber, ought perhaps to form a distinct subgenus, on account 

 of the fin-like appendages. The Bhiocle a queue en plumct of Geoffroy may be introduced into this subgenus. 



[:\Iessrs. Pickering and Dana have published an extremely elaborate description of a species of Caligus (C. ameri- 

 ciuiHs) found upon the Cod, as many as forty or more individuals occasionally occurring on a single fish; but they 

 are never found within the gill covers. Tlie figures illustrating this memoir have never been surpassed.] 



[M. JNL Edwards has published a memoir upon this genus in the Aimales des Sciences Nalurellcs, especially with 

 reference to the structure of the mouth]. 



In all the other subgenera of Caligus, the upper side of the aljdomeu is imbricated, or this part of the body is as 

 though it were inclosed in a kind of case, formed by the terminal feet, which resemble membranes, and are turned 

 upwards. 



Pferygopoda, L.atr. {i^ogaus? Leach), has the posterior extremity of the body terminated by two fin-like ap- 

 pendages. It has digitated feet on the under-side of the post-abdomen, or second division of the body, not covered 

 by the shield, and a distinct beak. Founded upon a single species, found on the shark. 



Pandarus, Leach, has two filaments at the posterior extremity of the body. The legs, of the first and fifth pairs, 

 are unguiculated, and the others digitated. The siphon is not distinct. Pandarus hicolor, Leach ; P. lioscii, 

 Leach, &c. [Two other species of this genus have been described and figured by Ur. Johnston, in the Magazine 

 of Natural Jlislori/, vol. viii.] 



Sinemoura, Latr., has two long filaments at the anus, but m which the siphon is distinct. The two fore-legs 

 arc unguiculated; the two following are terminated by two long fingers; the others are in the form of membranous 

 leaflets. C. productus, Miiller ; M. salmoneiis, I'abr. • 



Anthosoma, Leach, approaches the preceding, as regards the existence of the siphon and the two anal filaments; 

 but it recedes from it, as well as the two preceding, in its antenna-, of which two are directed fonvards, in the 

 shape of small monodactyle claws, and in the six hind-legs, which are membranous, folded upwards, at the sides, 

 ujion the post-abdomen, which they envelope. The first and third pairs of legs are unguiculated ; and the second 

 tei-minated by two short, obtuse fingers. Ant/iosoma Smithii, Leach. 



[Nemesis, Risso, is a curious genus, of a narrow form, with the anal filaments many times longer than the entire 

 body.— See Pol. Roitx, Crust. Meditcr., pi. 20.] 



In the second subtribe of the Caligides, the liody is oval, without exserted aual appendages, in the 

 form of filaments or fiu-like scales. A portion of the superior integuments composes in front of the 

 bodv a shield, which does not cover tlie anterior half, harrov\'cr than it, rounded, and notched anteriorly, 

 dilated and bilohed at the other end, succeeded by tln-ee other pieces, or rounded scales, posteriorly 

 notched, the second of wdiich is the smallest, being in the shape of a reversed heart; the last is the largest. 

 Tiie four posterior legs are in the form of plates, united in pairs ; those of the first and third pairs are 

 iiU'^uiCLilated; the second are bifid at the tip. The siphon is apparent. The eggs are covered by two 

 lar're, oval, contiguous, coriaceous pieces, placed beneatli the abdomen, and surpassing it in length. 



Such are the characters of the genus 



Cecrops, Leach, of which a single species is only known, which has been found fixed to the branchia; of the 

 tu:iny and turbot. C. Latreiltei, Leach. 



The second of the tribes of the Siphonostoma—Vas>.t of the Lern/Eiformes, Lat.,— is composed of 

 Eiitoniostraca still nearer allied than the preceding to the Lernajue. The number of the legs does not 

 clearly exceed ten, (l)ut there is perhaps another pair still more minute), and these organs are, for the 

 most part, very short, and unfitted for swimming. Sometimes the body is nearly vermiform, cylindrie, 

 with the anterior segment simply a little wider, and furnished with two didactyle advanced claws, and 

 sometimes, in consequence of two lateral expansions in the shape of lobes or wings, directed behind 

 tlie thorax, and of the two ovaries, which are posterior, it forms a small quadi-ilobed mass. This tribe 

 comprises two genera. 



th.a, li 



hird v.ilume of Uic .Innal. Gnrr. del Sci. Ph),ij.. p. 3«, I closing; a HvinE telus, Tcry lUfffrent Irom its parent, and of ^vbich lie 



( u.ssels there is an extract front the observations of Dr. gives a description, from these observations, these filaments tvoalrt 



oTThef'cetu, of a species of CaliB,is(C.rl«»i-a(«.?) which I seem to be esterior oviducts; bat is there not some error in this 



„„n upon the operculum of S.o,.' SWone. This naturalist statement? I have sttidied, tvith greu care, these oteans in many 



rrushcd tlie anal filaments of the animal, he oh- specimens— preservetl, it is true, in spirits of wine— but I have never 



,. membranous and transparent cei-s discharsed, each in- 1 yet discovered any body inclosed in them. 



