482 



BULLETIN OF THE BUREAU OF FISHERIES. 



mainly. I believe, with the latter genus. The form of the mandibular palp is like that of the type 

 species of Byblis, but the broad second joint of this appendage, which is said to characterize A mpelisca, 

 is not .1 generic character of much importance. In Ampelisca spinipes, for example, this joint is only 



Ampelisca ayassisi. A, dorsal margin of the 3d, 4th, and 5th segments of the abdomen. Drawings made from one of Mr. 



Judd's type specimens. 



slightly widened, although it is broader than in Byblis. .1. nt/nssi:, agrees with Ampelisca and differs 

 from Byblis in that the telson is much longer than broad and cleft nearly to the base, in the form ■■( the 



last pair of perseopods, and in the fart that the terminal uro- 

 pods project much beyond the preceding ones and have no 

 serrations on the opposing margins of the rami. 



Byblis serrata Smith. 



Body and appendages furnished with scattered pigment 



cells; first antenna? much longer than peduncle of second: 

 second antennae shorter than body in the female, but longei 

 than body in the male, last joint of peduncle a little shorter 

 than preceding one; lower margins of anterior pairs of coxa! 

 plates serrated, tin- si nations prominent ami acute in the 

 female but blunt in the male; dactyls of first two perseopods 

 about as long as the propodi; posterior lobe of basal joint of 

 last pair of perseopods reaching about to tip of carpus; postern- 

 lateral angle of third abdominal segment rounded; fourth 

 abdominal segment in male with a dorsal depression, behind 

 which is a prominent, rounded carina; these features much 

 less pronounced in the female; first and third uropods ex- 

 tending backward to about the same distance, second pair 

 not reaching so far; telson pointed, cleft to the middle. 



Length, 1 1 niiii. 



\\'ni»\< I b.le; Newport. 



A description of the sexual differences in this species is given by Judd (Proc. U. S. Nat. Mus., 

 Vol. Will. p. 596, 1896). 



Steg-ocephalus inflatus Kroyer. 



A largi -. easily recognizable from its tumid form and enormous coxal plates. Head partly 



c tealed and pointing downward, with a flattened, triangular rostrum and a prominent, subacute 



process between bases of antennae; antennae short, of nearly equal length; first pair very stout, with 



llijblvs serrate, \\ Is Bole, Mass. 6, Lower 



margin of lirst coxa] plate in the male. 



