314 M. A. Milne-Edwards 07i the Caret nologi'cal 



fauna ; for the groups just enumerated it amounts to 214, of 

 which 153 are new to science. Forty of these species differed 

 too much from the forms previously known to take their place 

 in existing genera, and I have been compelled to regard them 

 as the types of new generic divisions. This variety of species 

 is the more remarkable when we consider that fifty years ago 

 the existence in these same regions of scarcely a score of 

 Crustacea had been indicated. 



Certain groups, supposed to be foreign to the American 

 seas, are, on the contrary, extraordinarily abundant at these 

 great depths. Such is the family Galatheidge, of which I 

 have recognized forty-one species of very varied forms, and 

 which I have had to distribute into eight different genera. 

 Some of these have representatives in nearly all seas, such as 

 Oalathea and Munida*. The others have never been met 

 with elsewhere. Among these I may indicate the Galacanthcp^ 

 the carapace of which is armed above and on the sides with 

 large sabre-shaped spines ; the Galathodes^ of which the eyes 

 are very small, with imperfect corneola ; the Orophorhynchi^ 

 in which the eye-peduncles are greatly reduced, spinous, and 

 capable of concealing themselves in part beneath the rostrum ; 

 the Elasmonoti, with a carapace destitute of teeth or spines ; 

 the DiptycMj in which the abdomen is twice folded upon 

 itself and concealed beneath the sternum ; and, lastly, the 

 Ptychogastres^ which greatly resemble the preceding, but have 

 the legs of unusual length. 



The true Crabs, or Brachyurous Decapods, do not inhabit 

 the very great depths of the Caribbean Sea. They abound 

 on the shores ; numerous species, but generally of small size, 

 are found down to 500 metres below the surface ; beyond this 

 they seem to disappear. Nevertheless at 800 metres a crab 

 with a square carapace, which I have described under the 

 name of Batliyplax ^ was captured, representing in these seas 

 the Gonoplax of our shores ; but its eyes are atrophied and 

 destitute of corneola, its orbits are rudimentary, and it is blind. 

 On the other hand, the Anomiirous and Macrurous Crustacea 

 swarm at great depths. Down to 3500 metres there have 

 been found representatives of the genus Willemoesia, those 

 singular Macrura which almost exactly reproduce the forms 

 of the Eryonidee of the Jurassic period, but are blind, while 

 the eyes of the above fossil Crustaceans appear to have 

 attained their ordinary development. From a bottom of more 

 than 4000 metres the dredge brought up some Galatheidge 

 of very remarkable forms, which I have placed in the new 

 genus Galathodes. 



* I have described two species nf GaJathea and eleven of Mimida. 



