452 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



exopod of the last three pairs of legs in Perissopus. The rami of 

 the first three pairs of legs are two-jointed, of the fourth pair one- 

 jointed. All the rami are short and rudimentary, but are much more 

 like those of Nesippus than of Perissopus. They are armed only with 

 spines, however, and have no plumose seta\ The fifth legs appear as 

 large papilla 1 upon the ventral surface of the posterior lobes of the 

 genital segment, each tipped with a single spine. 



The cement glands are similar to those of Perissopus, but are 

 larger, curved like parentheses marks, and considerably enlarged 

 at the base. The semen receptacles are in the shape of inverted com- 

 mas, one on either side near the base of the abdomen and between the 

 bases of the cement glands. 



Total length, 8.5 mm. Length of carapace, 4.25 mm.; of dorsal 

 thorax plates, 2.25 mm.; of genital segment, 3 mm.; of abdomen, 

 1 mm. Width of carapace, 3.5 mm. ; of genital segment, 2.6 mm. 



Color (preserved material). — A clear cream color without pig- 

 ment of any sort. 



Chalimus. — Carapace acorn-shaped, a little longer than wide; 

 frontal plates indistinctly separated from the carapace by grooves, 

 their outer ends projecting considerably over the bases of the first 

 antenna^. Gland at the base of the attachment filaments rather small 

 and pushed forward to the very margin of the carapace. Attach- 

 ment filaments two in number, narrow and ribbon-like. Posterior 

 margin of the carapace nearly straight; posterior lobes narrow and 

 pointed, and projecting far behind the central margin. 



Second and third thorax segments not yet fused; the second seg- 

 ment much the shorter and sending out a lateral lobe on either side 

 which is curved backward and downward closely over the anterior 

 margin of the third segment. Third and fourth segments each with 

 a pair of rudimentary dorsal plates; genital segment the same shape 1 

 as in the adult, but relatively smaller. At the posterior corners it is 

 prolonged into broad and rounded lobes which reach back nearly to 

 the tip of the abdomen. The latter is entirely visible in dorsal view 

 and is of the same shape as in the adult, but the anal laminae are fur- 

 nished with much longer seta?, which are also plumose. Appendages 

 the same as in the adult. 



Total length, 3.8 mm. Length of carapace, 2 mm.; of free seg- 

 ments, 1 mm. ; of genital segment, 1 mm. ; of abdomen, 0.4 mm. 

 Width of carapace, 1.75 mm.; of genital segment, 0.9 mm. 



(oblongus, oblong, referring to the general shape of the body.) 



ECHTHROGALEUS COLEOPTRATUS Guerin. 



Echthrogah us coleoptratus Wilson, 1907, p. 367, pi. xix. 

 Host and record of specimens. — Both sexes were obtained from a 

 shark captured near Unalaska, Alaska, and are Cat. No. 1205G. 

 U.S.N. M. 



