512 



BULLETIN OF THE BUREAU OF FISHERIES. 



of two or three joints, of which the first is much the longest; lower margins of both pairs of antenna} 

 clothed with longsete; first gnathopods in both sexes with hand ovate, broader in female than in male; 

 palm very oblique, with a row of three spines around its upper end; second gnathopods with hand 

 enormously developed and produced at upper end of palm into a long, narrow process; a triangular 

 tooth near lower end of palm; second gnathopods in the female much smaller than in the male, the 

 hand stout, oval in general outline, anterior margin very convex; palm concave, with a huge triangular 

 tooth near the lower end; two short, stout spines just above upper end of palm; merus of first and 

 second perseopods much dilated and produced downward in front; peduncle of first uropods with a 



Jassa mamwrata. Three different forms of the second gnathopods of the male are shown. Narragansett Bay. 



large spine on lower apex which is nearly half the length of the rami; third uropods with peduncle 

 twice the length of rami; telson broader than long, rounded or subacute behind, with a minute spine 

 and one or more set;e on either side. 



This species is conspicuously mottled. The ground color is reddish, which is interrupted with 

 large light-colored spots. There is a light spot or band on the head behind the eye; first thoracic 

 segment mostly colored, but the second light, except in the mid-dorsal line and occasionally on the 

 sides; third and fourth segments mostly colored, and the fifth with a broad median blotch; a median 

 dorsal band extending through the following segments, with a lighter band on either side; both antenna' 

 crossed by rather wide bars of color. 



Length of a large male, 10 mm. 



I have compared this species with specimens of Jassa pulehella, from North Devon, England, 

 which were received through the kindness of the Rev. T. R. R. Stebbing. There is a striking simi- 

 larity in the general appearance and color-marking of the two species. Both pairs of antenna' are, 

 however, much stouter in marmorata; the flagellum of the first pair is not so elongate and is com- 

 posed of fewer and very much stouter joints and has the first joint much longer. The second antennae 

 differ considerably in their fiagella. which are composed of six joints in the specimens oipulchella that 



