r.UAXcinoroDA. 



437 



Tig. 16.— Zoca. 



Zoea, Bosc, having the eyes large, globular, and entirely uncovered, with the thorax conrate L Z Petagua, 



Hose, found in the Atlantic ( ><van ; Monocuhu Taurus of Slabber ; and probably 

 the Cancer Qermamu Of Linnaeus. [These curious creatures, of which Latnille 

 observed that they had not been sufficiently studied, and at the lame time re- 

 gretted that be had never been able to obtain a specimen, have recently at 1 1 

 a great deal of attention, from having been asserted to be merely the lai 

 Decapod Brachyurous Crustacea, such as the common edible <*rab, &c, by Dr. 

 J. v. Thompson, who, in his Zoological Retearchet, and other memoirs published 

 in the different scientific periodicals, has given figures of many new species, with- 

 out, however, gaining a knowledge of the perfect analogy which 1 \ i-t s between 

 the organs of these animals and the Macroura. Having fortunately been en 

 to dissect a very large species of this singular group, 1 have ascertained that 

 the supposed legs are merely the two outer pairs of foot-jaws immensely de- 

 veloped; the five pairs of true thoracic legs existing beneath the carapax. (See 

 my memoir, published in the Philosophical Tratuactiont.) If. Milne Edwards 

 treats of them as Crustace'i douteux, and thinks it possible that they may be the 

 young of some of his Anomourous order. In this state of the question (the change 

 from a Zoea to a Crab never having been observed, although the genera ; . 

 lopui and Macropa of Latreille are affirmed to be the intermedial II that 



can with certainty be arrived at is, that Zoea is a Malacostraeous animal, be- 

 longing to the order Decapoda, and that it must consequently be removed from 

 the Entomostraca.] 



Nebalia, Leach, has the eyes flattened, and in part covered by a triangular channelled scale. The legs are 

 furcate; and the appendages at the extremity of the body setaceous. N. Herbstii, Leach and Ucsmarest ; and 

 A'. >;. offroyi, Edwards. The latter is described, in a very detailed manner, by M. Milne Edwards, in the Annate* 

 des •Science/ Xaturelles, [vol. xiii. pi. 15]. The rostrum in front of the shell is articulated at its base. The eyes 

 are pedunded : the superior antenna' are inserted beneath them, with the BeCOnd joint furnished with an Oval 



ciliated plate. [The terminal part is Q-annulated: these organs are elbowed, and bent down in front. The in- 

 ferior antennae are longer, more slender, and equally directed downwards: they consist of four strong basal joints, 



and nine long terminal annuli. The shell is ovaL and the animal considerably resembles a small short Shrimp, 

 only tin- Iclcs are very Bhort, bifid, and inserted tar behind. Between them ami the mouth, there are, hOWl 

 live pain of minute, lamellose appendages, which probably represent the hinder foot-jaws and the fore-legs. The 

 abdomen is Ion::, slender, nine-jointed, and terminated by two bifid appendages.] 



The Nebalie vent rue of Kisso (Joum. Phyt., < tot. 1822) probably constitutes a distinct genus in the section of the 

 Schizopoda. In the Cyclops exilieits Of Viviani, the thorax is divided into several segments, which excludes it 

 from Nebalia. It also forms a subgenus intermediate between the preceding and following. 



Cuma, Edwards, is allied to Condylwa, but the superior antennas are rudimental, and consist of a single joint. 

 The head is distinct from the thorax, which is divided into four segments, of which the first supports the four 

 fore-legs, and each of the three following another pair. All the legs are natatory, directed forwards, and without 

 hooks at the tip. The two first pairs are alone bifid. [M. Edwards placed it amongst the amphipoda. The 

 ■ r tcorpioidet of Montague, overlooked by all Crustaceologists, appears to be congenerous. Type, Cuma 

 And nut nii, J '.d wards.] 



Condylwa, I.atr. The inferior antennas are longer. The anterior sides of thefirsl segment are prolonged and 

 pointed, forming two scales close together like a beak. Some of the middle feel are furnished, like the Schixo- 

 pods, with an outer appendage close to the base. The tail is narrow, 7-jointed, the last being long, conical, 

 and extends between the two slender, styliform, 2-jointed lateral ap >. C.DorbianU, Latr. From the 



coast of La Rochelle.* 



The other Lophyropa of the first division, and in which the thorax is divided into several segments, 

 the first being by far the largest, are only furnished with a single eye, situated in the middle of the 

 forehead between the upper antennae, constituting the genus 



Cyrl, ,/,.<;, Mflll., studied by the elder Jill'iue and EUmdohr, 'I le OOdj is umiv or leSS OVBl, soft. 01 gelatiUOUS, 



divided Into two portions; the anterior, composed ol the bead and thorax, and the other posterior, or the tail. 



Thefirsl segment of the latter, in the female, bears two minuti feet, and is not always easflj distinguishable 

 from the thorax. The tail is 6-jointed : the terminal joint forked, and more or less furnished with leather-like 

 filaments. The anterior part of the body is divided into four segments. The first, being the largest, com| 

 the head and part of the thorax : it hears the eye, four antenna , two palpigerous mandibles, two m a x il l a * , and 

 legs, each divided into two cylindrical stems. Bach of the three following segments is furnished with a pair of 

 feet. The two upper antenna are long and multiarticulate, assisting in locomotion, having nearl] the action ol 

 1 t. lie- mf. nor antenna are much shorter, filiform, and generally four-J ted. H\ their rapid mi ■ 



• X . XT, -\ud. mn. I I ,| fur- I" " »ulciili». • i Mt4 



in, h«- 1 Lblct »ni imuUIk ; bat m it U • panalte, 1 



think I ii lv ■ . rackcr, 1 1. o a pi 



in tin* order I 



bawl 1, diallncl Iron the trunk, Ami terminated by * 

 raetnun, which is ruber tcat«,Md 1 1 I: •_■.. 



- 



mlt>| leg*. Tin ■ 



■p.tule 



'• 



