610 



PROCEEDINGS OF THE NA TTONAL MUSEUM. 



VOL. XXVIII. 



strong, the terminal claw three-fourths as long as the swollen basal 

 joint, with a large tooth on its inner margin near the base. Furca 

 small, the base about the same length as the branches. The latter are 

 slender, well separated, and nearly parallel. This furca is reenforced 

 on either side by a stout curved spine, situated about halfway between 

 the furca and the bases of the first legs and a little distance from the 

 mid line. 



First legs short and stout, the last joint bearing a single short termi- 

 nal spine, not curved, and the usual three plumose setae on its posterior 

 border. There are no terminal claws. 



The second legs are like those of Caligus in segmentation and append- 

 ages, with the spines on the three joints of the exopod the same size 

 and rather small. Rami of the third legs close together, each two- 

 jointed and furnished with the usual setae and fringe of hairs. Fourth 

 legs two-jointed, the joints the same size and length, the second one 

 terminating in a single spine of medium size. Fifth legs entirely 

 lacking. 



Total length, 6.1 mm. Length of carapace, 1.25 mm.; width of 

 same, 1.1 mm.; length of genital segment, 2 mm. (4 mm. including 

 the posterior processes); length of abdomen, 2.2 mm.; length of free 

 segment, 0.7 mm. 



Color a dark yellowish brown, abdomen and egg strings darker than 

 the rest of the body. 



(?negacephalus, ptiyag large and KS(J)a\rj head.) 



There is but a single female of this species in the National Museum 

 collection, numbered 6103 which was taken from the underside of 

 the mouth of a silver gar (Lepisosteus osseus) at Woods Hole. It has 

 apparently shrunk somewhat in the preservative, but as the shrinkage 

 has been uniform it has not affected the proportions of the different 

 parts. 



This is of importance, because the details of the appendages in the 

 two species of this genus already described are meager, especially for 

 the species laciniatus, the type. Hence the distinction of species 

 must be based upon the relation of the different parts. This will 

 appear to better advantage in tabular form. 



Measurements. 



Total length 



Length of carapace 



Length of free segment . . . 

 Length of genital segment 



Width of carapace 



Width of genital segment. 



Laciniatus. Carangis. Me %?™ ph ~ 



mm. 



mm. 



mm. 



5-5.5 



11- 



-12 



6.1 



.75 





1.6 



1.25 



1.3 





.2 



.7 



2.9 





6.3 



4 



.8 





1.7 



1.1 



1.7 





1.5 



1.5 



