A. E. Yerrill — Decapod Crustacea of Bermuda. 377 



narrower; the posterior lateral tooth is stout, thickened, excavate on 

 the front edge; the other lateral teeth are regular, triangular, nearly 

 equilateral, not much inclined forward. 



The ratio of length to breadth of carapace, not inchiding latei'al 

 spines, is about 1: 1.60. 



The inner orbital tooth is usually simple, but in one case (4036^) 

 it was bilobed on one side, entire on the other. 



No. 1903a, with few eggs, was taken by the Biological Station party in July, 

 1900. The specimen (No. 40366), carrying eggs, was taken in July, 1883, by the 

 " Albatross." No. 11074^ was taken Sept. 21. 



This is one of the numerous species of invertebrates that have 

 acquired the habit of living normally among the masses of floating 

 "giilf-weed" or Sargassum, etc , in mid-ocean, and especially along 

 the course of the Gulf Stream. Like most of the other animals 

 associated with it, this crab has colors imitative of the gulf-weed 

 and the whitish patches of encrusting bryozoa {Bifiusta), so common 

 oh the gulf-weed. The whitish patches of bryozoa look much like 

 the pale patches on the back of the crab, while the olive-green and 

 brown mottled colors of the latter are like those of the plants. It 

 is, however, able to leave the gulf-weed and swim rapidly for some 

 distance. Perhaps it does not come ashore at the Bermudas except 

 when cast on the shores in masses of gulf-weed, etc. Most of those 

 collected, if not all, have thus occurred. It is usually associated, 

 in such cases, with Planes minutus, Leander tenuicornis, and other 

 species having the same mode of life. 



It was in the collection of Mr. Goode, 1876. We took it, in the 

 same way, in 1898 and 1901. Young specimens were contained in 

 the collections of the Bermuda Biological Station, obtained in the 

 summer of 1903, associated with Planes. 



It is often carried northward in the Gulf Stream to Cape Cod, St. 

 Georges Bank, and even off Nova Scotia. Prof. Smith took it in 



