518 GROTESQUE CRUSTACEANS. 



be known before a perfect monograph of the Phyttostoma- 

 tidte can be formed. 



Notwithstanding that Crustaceology abounds in forms 

 sufficiently bizarre, those very singular paradoxes, the 

 Zoea, exceed them all in curious and fantastic shapes. 

 One form, which I have provisionally christened Zoea- 

 boops, would serve as an excellent model for a gro- 

 tesque monster in a pantomime : in fact, they all more 

 resemble phantasms than the ordinary organizations we 

 are in the habit of contemplating. I have noticed and 

 figured several varieties, and from the constant recurrence 

 of regular types among them, I should be inclined to 

 doubt the accuracy of Dr. Thompson's opinion, that these 

 whimsical-looking beings are merely the larvae of different 

 kinds of Crabs ; and this more particularly, as the Zoea3 

 are generally found in the high seas, where few of the 

 larger Crustacea are ever discovered, were it not for the 

 investigations of Rathke on the development of the Astacus 

 jluviatilis, and the additional testimony of Capt. Du Cane 

 and M. Joly, who have obtained similar results. I can 

 with certainty affirm that Megalopa is no true genus, as 

 1 have observed specimens in every stage of growth be- 

 tween the common type of Megalopa and that of ordinary 

 Brachyarous Crustacea. Among Entomostracous Crus- 

 taceans, small animals with natatory feet terminating in 

 two branches, and belonging to that division named 

 Cyproides, the bodies of which are enclosed in a conchi- 

 fonn carapace, which causes them occasionally to be mis- 

 taken for bivalve Mollusca, were several individuals of the 

 genus Cypridina, distinguished by having two elongated 

 eyes situated in the median line, about the middle of their 



