Decapod Crustacea of Bermuda, Part II. 87 



1899; Proc. U. S. Nat. Mus., vol. xxxvi, pp. 1-93, 1909. M. J. 

 Rathbun, Macrura Porto Rico, p. 109, 1901. Stebbing, South African 

 Crustacea, part viii, Annals S. African Mus., vol. 15, p. 85, 1915. 

 DeMan, Siboga Expecl., vol. 390-, p. 185, 1911. 



This genus was separated from AlpJieus on account of important 

 structural differences. The most important character is the 

 absence of epipodites on the thoracic legs, which are present in 

 Alplicus. The large chela is always simple, without notches or 

 grooves, and is usually more swollen or more nearly ellipsoidal 

 than in the latter, and the dactyl is usually more simple and 

 relatively smaller ; it has the plunger-like lobe within, but lacks 

 the disk at the articulation. 



The front is usually tridentate ; the three teeth may be subequal 

 or unequal; the rostrum is usually small and simple, triangular, 

 but often styliform ; sometimes almost or quite lacking. The eyes 

 are covered by a lobe or hood, usually bearing a triangular or 

 pointed tooth, rarely rounded. The basal segment of the anten- 

 nules is the longest ; the basal spine is usually elongated ; the 

 external flagellum usually has a short secondary branch. Basi- 

 cerite is spiniform, acute; often with a smaller spine at its base. 



The legs of the second pair have the carpus 5- jointed (rarely 

 4- jointed in young) ; the second, third, and fourth segments are 

 short and often about equal, sometimes moniliform. The dactyls 

 of the ambulatory legs are usually biunguiculate, sometimes tri- 

 unguiculate. The males lack the two extra retinules on the second 

 pleopods, present in Alphcus. 



The species have habits more or less similar to those of Alphcus. 

 Many are found in holes in rotten limestone and dead corals, others 

 under stones, oysters, etc., but many species are only found living 

 as commensals in the oscular cavities of various large sponges, 

 where they are often gregarious, forming large colonies. 



Specimens of 5*. harfordi (Kingsley), now in the Yale Museum, 

 were labelled as taken by Mr. Harford from under the mantle of 

 the abalone shell (Haliotis rufcsccns) at Catalina Island, 

 California. 



Some species live clinging in the interstices of branched corals. 

 Several oriental species cling to crinoids (comatulids) in deep 

 water, and have their claws so modified as to adapt them to this 



* The holotype of this genus was 5". falcatus=S. comatulanim Haswell, 

 according to Coutiere. See below. 



