254 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 21 



on the outer margin of the basal antennal [article] behind the one at the 

 anterior angle. Preorbital spine acute. Pterygostomian regions with sev- 

 eral rounded teeth. 



Chelipeds of the male large, the merus subcylindrical, somewhat flat- 

 tened below, and strongly pustulate, especially at the angles ; the carpus 

 pustulate and with several ridges on the outer side ; hand long, narrow, 

 compressed, the palm below the wide carina often inflated ; fingers de- 

 flexed and, in old males, gaping at the base and generally with a large 

 tooth near the base of the dactyl. 



Legs subcylindrical, more or less pubescent, the propodi sulcate on 

 either side ; dactyls considerably shorter than the propodi and furnished 

 with sharp, corneous tips. 



The third, fourth, fifth, and sixth abdominal segments in the male of 

 nearly equal length ; the seventh longer than broad and rounded at the 

 tip. (Holmes, modified) 



Two distinct types are present in the Hancock series. One, which 

 follows Dana's original description, has a raised carapace with gastric 

 region deeply separated from cardiac and branchial regions. The latter 

 are as prominent as in Microphrys branchialis and impart a triangular 

 appearance to the carapace. This form is characterized by a broad ros- 

 trum, properly designated as ovate-lanceolate, a flat hepatic region con- 

 tinuous with the postocular cup and devoid of a tooth, and massive chelae, 

 cristate, and having a dactylar tooth. 



The second type, which Rathbun (1925) refers to as occurring in 

 females of 13 and 14 mm, occurs in both sexes and in individuals of 17 

 mm which are adult in all respects. The carapace is rounded but not 

 elevated, the regions separated by shallow sulci and covered with dense 

 pile. The narrow rostrum fails to conceal the antennal flagellum from 

 dorsal view and the hepatic swelling is tipped with a sharp spine. The 

 males have an uncrested chela and no tooth or gape between the fingers. 

 California specimens collected ashore or in shallow bays like Monterey 

 were of the latter type, whereas specimens dredged off Redondo Beach, 

 where a submarine canyon permits upwelling from a considerable depth, 

 were of the lumpy type. This would lead one to believe that typical Scyra 

 acutifrons is a northern form recurring wherever cold water conditions 

 prevail. 



Material examined: A total of 284 specimens from 96 stations, divided 

 as follows: (See Table 50) 



Hancock expeditions and related material: 243 specimens from 86 

 stations. 



