18 



PROCEEDINGS OF THE NATIONAL MUSEUM 



segment elongate, broader proximally than distally, posterior and me- 

 dial sm^aces rugose. Distalmost segment short, subspherical, fused 

 with clawlike terminal process, with very fine, hairlike accessory 

 process (not shown in figiu-e). Distinct flaplike projection present on 

 heavily sclerotized cephalothoracic depression associated with an- 

 tenna base (figs. Qd, e). Mandible (fig. 6/) appearing 3-parted although 

 divisions indistinct; appendage rodlil^e, curved inward distally, distal 

 surface composed of 3 small denticulations. Maxillule? platelike, 

 projecting posteriorly and slightly ventrally from just lateral and 

 posterior to mouth cone base, nregularly pointed distally, with single 

 setule from distal surface. 



MaxHliped (figs. 6^,^) 3- or 4-segmented, basalmost portion appear- 

 ing as segment-like projection of cephalothorax. Projection concave 

 distally, forming articulation surface for first distinct segment ; segment 

 slightly wider proxunally than distally although proximal end tapered 

 sharply to narrow proximal surface. Penultimate segment slender, 

 proximal end with knob-shaped articulation surfaces, distal end with 

 hairlike process. Distalmost segment short, heavily sclerotized, with 

 bifurcate terminal process. Terminal process with both tines sharply 

 pointed, mnermost slightly less than twice the length of outermost. 



First thoracic legs with 2-segmented exopodite, 1-segmented 

 endopodite; second thoracic legs with 2-segmented exopodite and 

 endopodite. Interpodal plates heavily sclerotized. For natm'e and 

 armature of legs see figiu"es 7a, b, and table 4. 



0.03 mm 



003mm. 



Figure 7. — Hatsckekia breviramus, new species, female, thoracic legs: a, first; b, second. 



Discussion. — Hatsckekia breviramus has characteristics which can 

 be compared most closely to 5 other members of the genus: 



1. H. diodontis Yamaguti, 1953: Similar in general body shape, 



