NO. 3542 OSTRACODS — HOBBS AND WALTON S 



Types. — The holotypic male, the allotypic female, and a dissected 

 paratypic male are deposited in the U.S. National Museum (nos. 

 111251, 111252). Para types are in the collections of C. W. Hart, Jr., 

 and the joint collection of the authors. 



Host. — An undescribed species of the genus Camharus. 



Relationships. — Dadylocythere brachystrix is closely related to 

 D. daphnioides (Hobbs, 1955), D. runki (Hobbs, 1955), D. chalaza 

 (Hobbs and Walton, 1962), and D. pachysphrata, new species, but 

 differs from all of them in possessing an accessory groove on the pen- 

 iferum which extends dorsally only to the ventral extremity of the 

 loop of the spermatic duct. In the other species, the groove reaches 

 the dorsal extremity of the loop. 



Remakks. — The name brachystrix is derived from the Greek jSpax^s, 

 meaning short, and from crrpt^, meaning groove, referring to the short 

 accessory groove of the peniferum of the male. 



Dadylocythere pachysphyrata, new species 



Figures le-g 



Male. — Eye present. Shell (fig. Ig) highest posterior to midlength 

 and with dorsal and ventral margins more gently tapered anteriorly 

 than posteriorly; submarginal setae limited largely to anterior, 

 anterodorsal, posterior, and posterodorsal areas, nowhere abundant, 

 rare ventrally, and absent dorsally. Range of shell size of eight 

 specimens recorded in table I. 



Copulatory complex (figs. le,J) with posterior margin of peniferum 

 entire; antero ventral extremity directed ventrally and postero ventral 

 extremity directed anteriorly. Penis small, its length about one- 

 fourth of anterior-posterior dimension of distal portion of peniferum, 

 and situated at level of base of ventral two-fifths of peniferum. 

 Accessory groove extending dorsally to level of dorsalmost extremity 

 of loop of spermatic duct. Dorsal finger moderately stout with its 

 terminal seta extending to ventral margin of finger guard; ventral 

 finger slender, curved throughout its length, somewhat strongly so 

 at base of proximal two-fifths. Finger guard prominent with its 

 anterior margin straight and its ventral margin slightly emarginate 

 but without distinct prominences. Clasping apparatus with vertical 

 and horizontal rami indistinctly delimited by thickened "ankle"; 

 vertical ramus with a bend of about 30° at distal end of proximal two- 

 fifths; internal border of vertical ramus inclined antero ventrally at 

 approximately a 45° angle to main axis; internal border of horizontal 

 ramus with three teeth; apex of clasping apparatus with three denti- 

 cles; external borders of both rami entire, their posteroventral ex- 

 tensions forming a right angle. 



Female. — Unknown. 



