340 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXXIII. 



and consists of a V-shaped string of small spots starting at the leases 

 of the first antennje on either side and extending obliquely backward 

 to meet behind the eyes. 



The two free segments hkve a few spots irregularly arranged, and 

 there are a few more at the posterior end of the abdomen and in the 

 anal laminse. These spots are all of a reddish purple color; the eyes 

 are a deep purple with bright red lenses. Total length, including the 

 second antennae, 2.1 mm. Length of carapace, 1 mm. Width of 

 same, 0.5 mm. Length of fused genital segment and abdomen, 

 0.51 mm. 



This metanauplius stage was obtained from the gill filaments of 



the sharp-nosed shark, Sco- 

 liodon terrae-novsc, at Beau- 

 fort, North Carolina, in 

 company with two adult 

 females and three males of 

 the same species. The pe- 

 culiar stag-horn antennae 

 give these larvae a more 

 secure hold upon their host 

 than in the Euryphorinse. 

 With such organs of pre- 

 hension it would also be 

 more difficult for the larva 

 to loosen its hold and move 

 about. There is thus per- 

 haps in this larval stage an 

 indication "of the greater 

 subsequent fixity of the 

 adult. 



THE CHALIMUS as seen in 

 the genus Perissopus. 



Only fully developed 

 male chahmi were found, 

 and they are described 

 under the species Perisso- 

 pus communis on page 357. 

 Single specimens of the 

 female chalimus in three 

 stages of development were obtained, measuring, respectively, 3, 4, 

 and 4.5 mm. in length. 



(1) In the chalimus 3 mm. long the carapace, includmg the pos- 

 terior lobes, is semielliptical, longer than wide, and has strongly 

 convex sides (fig. 11). The posterior lobes are long and wide, 

 reaching back to the fourth segment, and are bluntly rounded at the 

 tip. The frontal plates are narrow at the center and widened at the 



Fig. U. — A chalimus of Perissopus communis. 



