A. E. Verrill — Species of Grapsoid Crustacean. 121 



white ;■ an irregular pale band, specked with dark gray, extends 

 from eye to eye. Legs above variegated with similar colors, 

 but paler, the dark brown color mostly in irregular transverse 

 bands. Chelae whitish or pale yellow ; legs bluish white 

 beneath. The colors are evidently imitative of the surround- 

 ings and probably protective. 



Measurements of Bermuda Specimens. 







Carapace 



Carapace 



Front 



Chelae 



Chel as 



umber 



Sex 



length 



breadth 



breadth 



length 



breadth 



3H8fl 



$ 



18-0 



20-0 



ll-o 



15 



8-5 



31486 



6 



16<» 



17-0 



9-0 



12 



7-0 



3148c 



? 



175 



18-5 



9-7 



10 



5 "5 



d 



$ 



17-0 



19-0 



11-0 



10 



5-5 



e 



$ 



13-5 



15-5 



8-0 



10 



7-0 



Although there are several distinctive characters, as shown 

 above, it agrees so well in most other respects with S. Ricordi, 

 that it does not seem to have become of actual specific rank. 

 We found no intermediate specimens, but it is possible that a 

 more extended search might reveal such. None were found 

 with eggs. It is probable that its breeding season is in mid- 

 summer. 



It is not improbable that it has the habit of eating different 

 food from its parent species, and also a somewhat different 

 breeding season, so that the two forms may no longer inter- 

 breed. This could not be determined at the season of the 

 year when we were in Bermuda. 



It is also possible that it has acquired a somewhat different 

 larval life, for in some other genera of grapsoid crabs (e. g. 

 Pinnixia) the species differ widely in their metamorphoses. 



JS T o doubt it goes into the sea at the breeding season, and 

 the young probably pass through zoea and megalops stages, as 

 in allied species, but these stages may be abbreviated. 



The young crabs, moulting from the megalops at the shore, 

 have evidently inherited the instinct to seek the higher and 

 drier localities, where they probably have fewer enemies. 

 The modifications that have taken place are in accordance with 

 the change in habitat. The increased hairiness of the carapace 

 and legs serves to retain the dirt that aids materially in their 

 concealment when exposed. Probably they feed mostly at 

 night. The larger gill capacity and longer legs have evident 

 advantages. 



That it is not a casual or transitory variation is evident from 

 the fact that there are, in the Museum of Yale University, 

 several good characteristic adult specimens sent to us before 



