114 U.S. NATIONAL MUSEUM BULLETIN 23 6 



produced to cover basal parts of oral appendages. Thoracic somites 

 2 and 3 have about same length; somite 4 is much shorter and less 

 wide, in dorsal aspect with laterocaudally produced, rounded epimeral 

 plates. 



5th thoracic somite small, in dorsal aspect drawn out laterally into 

 bluntly pointed projection, set with some spinules. Abdomen % 

 length of cephalo thorax; genital somite resulting from fusion between 

 abdominal somites 1 and 2; line of fusion distinctly visible along 

 whole of dorsal and greater part of lateral surfaces (figs. 37a, 38a). 

 Genital somite about as long as wide and as long as rest of abdomen, 

 furca included. There is a chitinized expansion on both sides of the 

 genital somite near the line of fusion, which is finely haired. 

 Abdominal somites 3 and 4 of nearly same length, with some fine 

 spinules on laterocaudal part of distal margin. Anal somite very 

 short, anal operculum broadly rounded, scarcely visible since it is 

 neatly telescoped under distal end of 4th somite. Furcal rami 

 slightly broader than long, with 5 marginal setae and 1 appendicular 

 seta on each ramus. In addition, there are some hairs along internal 

 and external furcal margins. Setae 1 and 4 short, with slightly 

 swollen base. Setae 2 and 3 much thicker than other setae, damaged 

 in this specimen, but in others greatly lengthened, especially 2nd. 

 Seta 5 small, inserting halfway along external margin. 



Ventral aspect of genital somite represented in figure 376. Fusion 

 between both composing somites complete on ventral side, no line of 

 fusion being visible. 



Antennules, antenna and mouth parts of this specimen were not 

 studied in detail. 



Leg 1 (fig. 39a) with both rami 3-segmented, though the terminal 

 exopodal and endopodal segments are very small. Basis big, with 

 strong spine at external and internal borders. 1st exopodal and 

 endopodal segments of about same length. 1st endopodal segment 

 with swollen internal margin, with short, thick seta halfway along 

 that margin. 2nd endopodal segment styliform, internal seta halfway 

 along internal margin. 3rd endopodal segment small, carrying 2 

 curved, apical spines, of which terminal portion is set with character- 

 istic pectiniform row of hairs. 1st exopodal segment with small 

 external seta nearly at end of external margin. 2nd exopodal seg- 

 ment about as long as broad, with seta or setiform process at end of 

 internal margin. 3rd exopodal segment small, with 5 curiously 

 shaped setae, apices of which have pectiniform row of hairs; in addition 

 there is a short internal seta. 



The particulars of legs 2 to 4 appear in figures 39b-d and the setal 

 formula. Unfortunately, legs 3 and 4 fragmentated during dissection, 

 but they were reconstructed. Setal formula: 



