366 U.S. NATIONAL MUSEUM BULLETIN 236 



ciated by reference to figures 1446,c. Lateral parts of cephalic somite 

 distinctly swollen; more elevated part of sides marked by presence 

 of pair of lateral spines, preceded by stiff hair; spines directed caudally. 

 Cephalic somite produced laterofrontally at sides of antennular 

 insertions to form pair of "cheeks." Sides of cephalic somite not 

 greatly produced with the result that oral parts and conical oral 

 field are free for observation (fig. 144c). Distinct, backwardly 

 directed median spine almost at distal end of cephalic somite. Spine 

 smaller than in preceding species and with only its tip overlapping 

 2nd thoracic somite. From socle of this spine radiate four chitinized 

 ridges, two laterocaudally, two laterofrontally. In middorsal 

 line, two depressions: shallow depression in front of cephalic spine, 

 and much deeper and larger depression haKway between spine and 

 rostrum; latter depression surrounded by ridge. 



Rostrum thin plate with broad base and truncate apex, placed 

 between insertion of antennules, reaching length of 1st antennular 

 segment. Base and sides of rostral plate chitinized, central part thin ; 

 two fme hairs indicate presence of frontal organ. 



Thoracic somites 2 to 5 of equal length, distally provided with 

 thickened ridge, bearing some spines. Distribution of these spines as 

 follows: thoracic somite 2, four small chitinized knobs; somite 3, 

 6 small chitinized knobs; somite 4, 2 big lateral spines flanking a small 

 median spine; segment 5, small median spine flanked on each side by 

 small spine and big spine. 



Genital somite composed of partly fused abdominal somites 1 and 2, 

 showing distinct line of fusion dorsally. Epimeral plates of both 

 somites expanded laterally, lateral walls haired; laterocaudal angle 

 of 1st somite with a strong hair, of somite 2 with some spinules. 

 Distal wall of somite 1 with 3 spines (1 median, 2 lateral), somite 2 

 with median elevated part, slightly overlapping abdominal somite 3, 

 and provided on each side with 2 spines. Abdominal somites 3 and 4 

 of equal length; sides of somite 3 caudally with 3 hairs on each side; 

 distal dorsal wall on each side with group of 3 spines. Dorsal part of 

 distal wall of somite 4 strongly armed with bifid teeth, covering part 

 of anal somite and obscuring anal plate. 



Anal somite half as long as somite 4; anal plate, just visible between 

 spines of somite 4, smooth, broadly rounded. 



Furcal rami Iji times as long as broad, parallel, slightly tapering 

 caudally. Internal and external margins smooth. 5 marginal setae 

 and 1 appendicular seta. All setae, with exception of seta 2, short; 

 seta 2 greatly lengthened and thickened, % body length. 



Whole body strongly haired; hairs generally short, but better de- 

 veloped on cephalic somite, where placed in small pores, which give 

 integument of cephalic somite a pitted structure. 



