414 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



aDd on the third trip, October 1 to 3, five hauls (stations 891 to 895) 

 ■were made, in 238 to about 500 fathoms. At station 872, 86 fathoms, 

 the bottom was covered with shells and sponges, but at all the other 

 stations it was composed of fine sand and mud, varying in proportions 

 and in compactness. The collections from the last trip have not yet 

 been fully examined, and only a few of the species are recorded in the 

 following pages. There was, however, a much smaller number of crus- 

 taceans obtained upon this last trip than upon the others. 



The wonderful richness of the fauna of the sea-bottom in this region, 

 in mollusks and echinoderms, has been shown in Professor Verrill's 

 papers just referred to, and it is not less remarkable as regards the crus- 

 taceans. The richness, in both species and individuals, of this crusta- 

 cean fauna would never have been suspected, and scarcely dreamed of, 

 by one accustomed only to the meager fauna of the shallower waters 

 of the south coast of Kew England. The larger part of the species 

 secured from the great masses of material brought up in the trawl and 

 dredge are Decapoda. There are comparatively few small species of 

 Schizopoda, Cumacea, and Amphipoda, and further dredging will un- 

 doubtedly increase very greatly the number of species in these groups. 

 The following enumeration is not complete even for the Decapoda, and 

 much less so for the other groups, as several of the species are repre- 

 sented by specimens insufficient for proper determination, while others 

 are omitted because not yet satisfactorily determined. 



The exact location, depth, character of bottom, and temperature for 

 each of the stations are given by Professor Yerrill in the papers above 

 referred to, and in the following pages I give only the serial numbers of 

 the stations at which the species occurred, and the range in depth from 

 the shallowest to the deepest of these stations. In occasionally refer- 

 ring to localities of dredgings carried on by the Fish Commission in 

 l^revious years, I give the serial numbers of the stations according to 

 the "Lists of the Dredging Stations of the United States Fish Commis- 

 sion from 1871 to 1879, inclusive, with Temperature and other Observa- 

 tions, arranged by Sanderson Smith and Eichard Eathbun", in the 

 Commissioner's Eeport for 1879. 



BEACHYUEA. 



Hyas coarctatus Leach. 



Several specimens from 86 fathoms, station 872, and 115 fathoms, 

 station 871. 



CoUodes depressus A. Milue-Ed-wards, Crust. E(5gion Mexicaine, p. 176, pi. 32, fig. 



I refer to this species a considerable number of specimens from stations 

 865, 871, 872, 873, 874, 875, 878 ; 65 to 142 fathoms. Most of these speci- 

 mens are much larger than those described by Milne-Edwards, and in 

 all the larger, and in some of the smaller, specimens examined the three 

 dorsal spines of the carapax and abdomen are almost wholly obsolete, 



