306 U.S. NATIONAL MUSEUM BULLETIN 236 



triangular plate with rounded apex and broad base, bordered by 

 hyaline membrane and at apex with 2 hairs placed each in a pit (fig. 

 I22d). Base distinctly visible in dorsal aspect as rounded tubercle 

 in front of head, separated from cephalic somite by shallow groove. 

 Thoracic somites 2 to 4 of equal length, epimeral plates well produced, 

 rounded, slightly backwardly produced. 



Abdomen of nearly same length as cephalothorax. 5th thoracic 

 somite prominent in both lateral and dorsal aspects. Genital somite 

 resulting from fusion of abdominal somites 1 and 2, line of fusion 

 very distinct on lateral and dorsal surfaces of genital somite. 3rd 

 and 4th abdominal somites of about same length, each % length of 

 genital somite. Patches of spinules occur on ventrolateral surfaces 

 of 2nd, 3rd, and 4th abdominal somites. Anal somite slightly longer 

 than 3rd or 4th somite, slightly tapering, with big, almost straight, 

 hyaline anal flap, sunken into dorsal surface of anal somite and 

 bordered by two walls (fig. 1206). Lateral parts of anal somite 

 haired. Furcal rami conical, about IK times as long as wide, parallel. 

 Each ramus has 5 marginal setae and 1 appendicular seta; setae 1, 3, 

 4, 5, and appendicular seta apparently fine, but damaged in my 

 specimen; seta 2 on each side greatly lengthened and thickened, 

 apical part missing on both sides. 



Antennules short, half length of cephalic somite, 7-segmented. 1st 

 segment big, with small internal spine. 4th segment small, with 

 short conical process bearing aesthetasc and seta. Setation repre- 

 sented m figure 122c?. 



Antenna (fig. 122e) short and powerful. Coxa short, with single 

 external seta. Allobasis short, with internal seta. Exopodite small, 

 represented by conical process, carrying 2 setae. Endopodite com- 

 posed of single short segment, with 6 strong spines. 



Mandible (fig. 122/) with narrow praecoxa, cutting edge with 2 

 rounded teeth. Palp well developed, basipodite cylindrical. Exopo- 

 dite not sharply separated, unsegmented, with 3 setae. Endopodite 

 coalescent with basipodite, with 2 setae. 



Maxillule (fig. 122g) smaU; arthrite well developed, with 5 curiously 

 modelled, flattened teeth. Basopodite, endopodite, and exopodite 

 coalescent, forming small lobe with 4 setae, almost obscured by big 

 endite, which carries 4 setae. 



Maxilla (fig. I22h) with small praecoxal and small coxal endite, 

 each with 3 setae. Basal endite bigger, with strong, curved spine, 

 coalescent with endite, bearing one additional seta. 



Maxillipede strongly reduced, completely fused to chitinized ridges 

 of oral field, and nonarticulating. It is more or less triangular and 

 carries 2 small apical setae. 



