STOMAPODA. 123 



pendaLre at the base, the fourtli pair beinir the longest. I only know one speci. - >M. LenutorUi, collected in the 

 seas of North America. Olivier found, in tli>- Penna nun-inn, a crostaceona animul rerj timilai al the !ir-t 



si^lit ; but the specimens were so much injured tli.it 1 was not able to study its characters. 



The Nebalice, which I had at first placed in this section, not having any natatory appendages under 

 the terminal Begments of the body, and their legs being very similar to those of Cyclops, I have intro- 

 duced, together with Condylura, at the head of the order Branobiopoda, Xibalia, in its exposed eyes, 

 which appear to be pedunculated, and in some other characters, seems, in conjunction with Zoea, to 

 unite the Schizopoda with the Branchiopoda. 



THE SECOND ORDER OE CRUSTACEA — 



STOMAPODA (commonly called Sea-Mantes), - 



Have the branchiae naked, and adhering to the five pairs of appendages attached beneath the 

 abdomen or tail, which this part of the body also presents to us in the Decapods, which 

 appendages here, as m the majority of the Macroura, are used in swimming, or are fin-feet. 

 The carapax is divided into two parts, of which the anterior bears the eves and intermediate 



antenna-, or more properly composes the head without supporting the foot-jaws. The latter 

 organs, as well as the four fore-legs, often closely approach the mouth in two lines, converging 

 inferiorly : whence arises the name Stomapoda, given to this order. 



Tin heart — to judge at least from the Squillep, the most remarkable genus in the order, 

 and the only one in which it has been studied — is elongated, and resembles a large vessel ex- 

 tending the whole length of the back, and terminating posteriorly near the anus, in u point. 

 The teguments of the Stomapoda are slender; and, in some species, almost membranous 

 and diaphanous. The carapax, OT shell, is sometimes formed of two shields, of which the 

 anterior represents the head, and the other the thorax, Bometimea of a single piece, but free 

 behind, leaving generally uncovered the thoracic segments, which bear the three hind pairs of 

 legs, and having in front an articulation serving as a base for the eyes and intermediate an- 

 tenna' : the latter organs are always terminated by two or three filaments. The eyes are 

 always close together. The composition of the mouth is essentially the same as in the 

 Decapods; but the palpi of the mandibles, instead of being adpressed to them, are always 

 raised. The foot-jaws are not furnished with the whip-like appendage {/(met) which exists m 

 the Decapods. They have the form of claw-legs, or small feet ; and, in many at least Squilla . 

 the base externally exhibits, as well as that of the two fore-legs, properly so called, a vesicular 

 body. The second pair of foot-jaws, in the same Stomapoda, is much larger than the others, 

 and even than the legs themselves: hence the] have been generally considered legs, and the 



number of these organs lias been stated to be fourteen. 4 The tour anterior [true] legs have 

 aNo the form of claw-feet; but are terminated, like the foot-jaws, by a book which folds 

 Upon the inferior and anterior edge of the preceding joint. Bui in some others, such as the 



Vhyllo8onuf\, all these organs are filiform, and without an] didactyle claw. Some of these, 



however, as well as the six hind-legs of the Squilla, are furnished with B lateral appendage or 

 branch. The seven terminal segments of the body — inclosing a considerable portion of the 

 heart, and to which the respirators organs are attached — cannot, moreover, in this respect, 



be considered analogous (assimtfe*) to that portion of the body which ia called the tail in the 



Decapods, being an abdomen, properU so called. Its penultimate segment lias, on each side, 



■ iwimmerel formed in the same manner as thai of the tail of the Macroura, but often armed, 



as well as the terminal segment or intermediate piece, with Spines Or teeth. 



All the Stomapoda are marine, pr e fe rr in g tropical climates, and not going beyond the tem- 



.-. n.l pair <.f tmr anffia of thr Squill* I... not llit ■ •n.r | c»l«r. »nd *<TT much notrtai-u. 



bra • > i" -. Ma| <•( u ttttaguad, tttugalw form, dh | t la ill ihoM which i>»>rtnr ton »mcri..r bM tlra-Uht, e , 



Moad Into Sna* joiat* by iiumium Imr,. t>. ■ ■tnrtthln «rr i.iiur- I ■pwliilw ti» awafl Cm ■■lain » 



