12 BULLETIISr 54, UNITED STATES NATIONAL MUSEUM. 



""The antennae lie close beneath the antennulte, by which they are 

 slightly exceeded in length in both male and female. They are five- 

 jointed, the fourth joint being the longest, slightly exceeding the 

 second; the fifth, third, and first following in the order named, the 

 last mentioned being very short. Each antenna is terminated b}^ a 

 densely setiferoas rudimentary tiagellum considerabh^ longer than 

 that of the antennules and sometimes imperfectly articulated. 



''The mandibles are of the usual form, curved inward at the tip, 

 where each bears a pair of horny teeth, shaped like the limbs of the 

 letter U. Proximad of the middle a stout transverse column passes 

 mediad bearing at its end an oval plate transversed by a series of par- 

 allel ridges with deep grooves between. Under a high power each 

 ridge appears to be broken up bj^ shallow indentations into a series of 

 rounded teeth. 



"The first maxilhe consist of a stout forwardly directed column 

 and a posteriorly directed palpus, bearing at its end a brush of seven 

 or eight long sette. The anterior ramus is stout and curved toward 

 the median line, bearing at its tip a group of about eight stout, curved 

 spines, each with two series of fine, apically directed denticuli. A brush 

 of stiff setjB lies near the base, and laterad of, the spines. A smaller 

 group of spines lie on one face near the tip; these are not denticulate 

 and lack the brown color of those in the apical group. 



""The maxillipeds are adherent basally by means of short, stout 

 hooks. The basal joints are prolonged on their anterior or oral 

 aspects into plate-like processes, which are coupled together in the 

 median line. Each basal joint bears a flattened palpus, consisting of 

 four joints, the terminal three being furnished with long setpe. The 

 distal joint is strongly flexed on the penultimate. A somewhat falci- 

 form branchial epipod is attached to the maxilliped at its base by 

 means of a slender stalk. 



"The first gnathopods are strongly chelate in both sexes, but 

 especially so in the males. The 'thumb' of the propodite is termi- 

 nated by a horny tooth, and external to and just within this is a sharp- 

 edged tubercle; the tooth of the dact3dopodite bites between the two. 

 Fig. 15, y and ^, on page 13, show the gnathopods of male and female 

 side by side, and give a better idea of their appearance than can be 

 gained from a description. 



"The limbs of the first free segment of the perseon are long and 

 slender, their terminal claws being but slightly curved. The two 

 succeeding pairs are stouter, with the dactylopodite and claw shorter 

 than in the first pair. The last three pairs are still stouter; the 

 dactylopodite bears a strongly hooked claw with a comb-like series of 

 minute, curved teeth on each side, and the distal end of the propodite 

 bears a row of stout setse. All the limbs except those of the first 

 free segment have the distal end of the carpopodite crowned with a 



