CRUSTACEANS. 225 



nevei- seen or heard of any specimen ; but, whether it may not be identi- 

 fied with the Cancer scorpioides of the late Mr Montague, who also 

 describes a mutilated specimen, I cannot presume to determine. 



This specimen occurred among the muddy residue from a quantity 

 of marine collections. 



The form bears a considerable resemblance to the general appear- 

 ance of a lobster ; yet I cannot pretend to define precisely the number 

 and structure of the organs of which it is composed : figs. 15 and 16 seem 

 to me sufficiently expressive, — the former, natural size, the latter, mag- 

 nified, of the animal. Total length six lines. Tlie body composed of 

 about six segments, the first infinitely the largest, and much resembling 

 a lobster shell ; the tail round, solid, and consisting of seven articulations, 

 the last with a small fork. The animal lay constantly on its side ; but, if 

 rising to stand, which was seldom, it carried the tail erect, at right angles 

 to the body, or sometimes recurved and folded in, as usual with the 

 lobster. 



When the creature was stimulated, it rose and sprung up among the 

 water, as if to reach the surface : otherwise it scarcely ever inclined 

 to move ; colour universally brownish or dingy white. — Plate LXII. 

 figs. 15, 16. 



I could discover nothing more from the original, hitherto the ex- 

 clusive subject of reference, than above described ; but, in about three 

 weeks, I was induced to conjecture the presence of an advancing ovarium 

 in the vicinity of the abdomen, though I could not discern it distinctly. 

 On the 26th of March, however, my conjecture was partly confii-med by 

 finding a number of the young. 



It is from these and the adult that we are to understand the real 

 structure of the animal, not forgetting that possibly it may undergo cer- 

 tain modifications from subsequent metamorphosis. 



The young were pure white to the naked eye, not extending half a 

 line. When subjected to the microscope, they exhibited what was defec- 

 tive or imperfect in the parent. Thus, the antennae were forked un- 

 equally, the smaller prong being an offset at a third of the whole length 

 above the root ; a forked offset also issued from each side of the penult 



2 F 



