716 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.47. 



PROBRACHIELLA, new genus. 



Generic characters of female. — Cephalothorax nearly in line with 

 the trunk and arched; head covered with a dorsal carapace; trunk 

 subquadrilateral, a little narrowed anteriorly, separated from the 

 cephalothorax by a well-defined groove; four pairs of posterior proc- 

 esses, one pair at the ventral, another at the dorsal, posterior corners, 

 a third pair partly fused on the dorsal midline, and a fourth pair just 

 outside the third and fused with them at their base; no abdomen, anal 

 laminae, or genital process; egg strings short and spherical. First 

 antennae indistinctly three-jointed; second antennae a flattened 

 lamella, biramose at the tip but with the rami unsegmented and 

 unarmed. First maxillae tripartite, without a palp; second maxillae 

 very short and completely fused; maxillipeds with swollen basal 

 joints and weak terminal claws. 



Generic characters of male. — Cephalothorax at right angles to the 

 trunk axis and separated from the trunk by a shght constriction; no 

 dorsal carapace; trunk cone-shaped, somewhat flattened ventrally; 

 no anal laminae. First antennae three-jointed; second antennae 

 uniramose, indistinctly segmented, tipped with a claw and a corru- 

 gated knob. First maxillae like those of the female; second maxiUae 

 and maxillipeds about the same size and armed with powerful chelate 

 claws (see pi. 28, fig. R.). 



Type. — Prohrachiella anserina (Brachiella anserina Wilson), 



(Prohrachiella, the prefix IJpo and Brachiella.) 



Remarlcs .—The female is readily distinguished by the eight posterior 

 processes and the spherical egg strings, neither character being found 

 anywhere else in the entire family. In the male the turning of the 

 cephalothorax at right angles to the trunk axis, and the general squat 

 appearance of the body, the uniramose second antennae, and the 

 chelate second maxUlae and maxiUipeds are the chief character- 

 istics. This is an arctic species and may be far more common than 

 the single lot of specimens would indicate. The fish around Bering 

 Straits have hardly been examined at all for parasites; when they are, 

 it is possible that this species will be found more abundantly. 



When first described* this species was placed in the genus Brachiella, 

 but when the characters of that genus were definitely established this 

 species differed in so many particulars that it was necessary to estab- 

 lish a new genus for it. At present the generic and specific characters 

 are the same. 



EUBRACHIELLA, new genus. 



Generic characters of female. — Cephalothorax about the same length 

 as the trunk, inclined a little forward or nearly in the same line; no 

 dorsal carapace; trunk stout and short and separated from the 



1 Proc. U. S. Nat. Mus., vol. 35, p. 467. 



