298 BULLiETIN 15 8, UNITED STATES NATIONAL MUSEUM 



bathing beach at Woods Hole, July, 1927. The male holotype is 

 U.S.N.M. No. 63435. 



Color. — Body transparent and whitish, with a streak of carmine- 

 red down the dorsal midline, beginning at the center of the cephalic 

 segment and extending to the anus; contents of the digestive tube 

 often yellow ; eye deep carmine-red ; eggs bluish, deepening in color 

 with development. 



Fenmle. — Body somewhat fusiform, without a sharp distinction 

 between the two divisions; cephalic segment widest across the pos- 

 terior margin, much narrowed anteriorly. Rostrum narrow, quad- 

 rangular in outline, well defined at its base, and horizontal but turned 

 downward at its tip. Second and third segments wider than the 

 head, their width a little more than one-fifth of the body length. 

 Epimeral plates well developed and projecting at the posterior 

 corners of the metasome segments; fifth segment longer than the 

 fourth and projecting ventrally. The four free segments are one- 

 fourth longer than the cephalic segment plus the rostrum. The 

 length of the urosome in comparison with the length of the metasome 

 is in the proportion of 7 to 16. The two halves of the genital seg- 

 ment and the two basal abdominal segments have short rows of 

 lateral spinules. The anal segment is shorter than the penultimate 

 segment; the anal operculum and the posterior margin of the seg- 

 ment between the caudal rami are fringed with cilia. The caudal 

 rami are almost three times as wide as long; each is produced at its 

 inner distal corner into a conical process, armed with one long and 

 two short setae, and there is a row of spinules across the tip of the 

 ramus above the bases of the apical setae, of which the inner one is 

 about half the body length. 



First antennae 6-segmented, the basal segment fairly long, the 

 second segment with two large doubly pectinated spines on its dorsal 

 surface, the third segment with one at each distal corner, and the 

 fourth segment with one at the anterior distal corner. The third and 

 fourth segments are lobed on the anterior margin, and the former 

 bears an elongated slender aesthetask and two very long filiform 

 setae. The exopod of the second antenna is 3-segmented, the middle 

 segment very short, with an inner seta, the other two segments much 

 longer and equal; the basal segment bears two inner setae, the end 

 segment four apical setae and a minute outer spine. The endopod is 

 also 3-segmented, the basal segment very short, the end segment with 

 five apical setae, the three inner ones geniculate, an inner apical spine, 

 and a row of spinules along the inner margin, increasing in length 

 distally. The exopod is attached to the side of the second endopod 

 segment near its distal end. 



The mandible has a chewing blade set with one large outer tooth 

 and a row of 9 or 10 much smaller ones; the palp is made up of a 



