BRANCHIOPODA. 
437 
Fig. 16. — Zoea. 
Zoea, Bose, Laving the eyes large, globular, and entirely uncovered, with the thorax cornuted. Z. Pelagica, 
Bose, found in the Atlantic Ocean ; Monoculus Taurus of Slabber ; .and probably 
the Cancer Germanus of Linnaeus. [These curious creatures, of which Latreille 
observed that they had not been sufficiently studied, and at the same time re- 
gretted that he had never been able to obtain a specimen, have recently attracted 
a great deal of attention, from having been asserted to be merely the larvae of 
Decapod Brachyurous Crustacea, such as the common edible Crab, &c., by Dr. 
J, V. Thompson, who, in his Zoological Researches, and other memoirs published 
in the ditferent scientific periodicals, has given figures of many new species, with- 
out, however, gaining a knowledge of the perfect analogy which exists between 
the organs of these animals and the Macroura. Having fortunately been enabled 
to dissect a very large species of this singular group, I 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 Transactions.) M. Milne Edwards 
treats of them as Crustaces 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 Mega- 
lopus and Macropa of Latreille are affirmed to be the intermediate stage), all that 
can with certainty be arrived at is, that Zoea is a Malacostracous 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 Desmarest ; and 
N. Geoffroyi, Edwards. The latter is described, in a very detailed manner, by M, Milne Edwards, in the Annales 
des Sciences NatureJles, [vol. xiii. pi. 15]. The rostrum in front of the shell is articulated at its base. The eyes 
are peduncled : the superior antennae are inserted beneath them, vrith the second joint furnished with an oval 
ciliated plate. [The terminal part is 9-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 the legs are very short, bifid, and inserted far behind. Between them and the mouth, there are, however, 
five pairs of minute, lamellose appendages, which probably represent the hinder foot-jaws and the fore-legs. The 
abdomen is long, slender, nine-jointed, and terminated by two bifid appendages.] 
The Nebalie ventrue of Risso (Journ. Phys., Oct. 1822) probably constitutes a distinct genus in the section of the 
Schizopoda. In the Cyclops exiliens of Nnixm, i\\e thorax is divided into several segments, which excludes it 
from Nebalia. It also forms a subgenus intermediate between the preceding and following. 
Cunia, Edwards, is allied to Condylura, but the superior antennae 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 
Cancer scorpioides of Montague, overlooked by all Crustaceologists, appears to be congenerous. Type, Cima 
Audouinii, Edwards.] 
Condylura, Latr. The inferior antennae are longer. The anterior sides of the first segment are prolonged and 
pointed, forming two scales close together like a beak. Some of the middle feet are furnished, like the Schizo- 
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 appendages. C. Borbignii, 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 antennse, constituting the genus 
Cyclops, Miill., studied by the elder Jurine and Ramdohr. The body is more or less oval, soft, or gelatinous, 
divided into two portions ; the one anterior, composed of the head and thorax, and the other posterior, or the tail. 
The first segment of the latter, in the female, bears two minute feet, and is not always easily distinguishable 
from the thorax. The tail is 6-jointed : the terminal joint forked, and more or less furnished with feather-like 
filaments. The anterior part of the body is divided into four segments. The first, being the largest, composes 
the head and part of the thorax : it bears the eye, four antennse, two palpigerous mandibles, two maxillae, and four 
legs, each divided into two cylindrical stems. Each of the three following segments is furnished with a pair of 
feet. The two upper antennae are long and multiarticulate, assisting in locomotion, having nearly the action of 
feet. The inferior antennae are much shorter, filiform, and generally four-jointed. By their rapid movements. 
Nicothoe, Aud. and Kdw., would belonar to this section if fur- 
nished with mandibles and maxillae ; but as it is a parasite, and as I 
think I have observed in it the vestiges of a sucker, I have placed it 
in the order Poecilopoda. Its legs, and the mode in which it carries its 
cgifs, agrees with Cyclops. Pontia, Edwards, appears to be allied to 
Cyclops. The head is distinct from the trunk, and terminated by a 
rostrum, which is rather acute, and apparently two-jointed. It has 
two sessile eyes ; four antennte, the superior [long], setaceous, and 
multiarticulate, the inferior leg-like, and two-branched. The thorax 
is composed of five segments, and supports five pairs of bifid swim- 
ming legs. The abdomen is two-jointed, and terminated by two 
spalulated appendages. [Type, P. Savignii, Edw.ards. The .Ano 
pherttra minutissinia, Templeton {Trans. Ent. Soc., vol. i. pi. 20), is 
probably allied to the above.] 
