no.1653. PACIFIC COAST C0PEP0D8 -WILSON. 437 



ally. The head is partially covered with a carapace, ovate in shape, 

 much narrowed anteriorly, and with a deep groove along the mid 

 line for two-thirds of its length. There is hut a single free thorax 

 segment behind the head: this is nearly as wide a> the head and 

 carries a single pair of rudimentary legs. 



The genital portion of the body is elliptical, slightly narrowed 

 posteriorly, one-third wider than the head, and entirely covered with 

 small triangular flattened spines. It shows no traces of segmenta 

 tion. not even in the form of indentations along the lateral margins. 

 At its posterior corners it is produced into broad conical processes, 

 short and bluntly rounded at their tips. Egg-tubes one-third the 

 diameter of the genital portion and as long as the entire body; eggs 

 quite large and arranged in five <>r six longitudinal row-. Abdomen 

 small, about as long as the posterior processes, and either conical, 

 with a triangular outline similar to that of the processes, or some- 

 times in the shape of a trefoil, the base swollen on either side. 



First antenna' -mall, with a swollen base and a much narrower 

 terminal portion, tipped with two setce. Second antenna 1 in the form 

 of sickle-shaped claws, very sharp and having their bases articu 

 lated directly with the ventral surface of the head. 



Mouth and mouth parts at the posterior margin of the head as 

 in Ohond Iracanthus^ but in the present genus the sides of the head 

 opposite the mouth (the cheek-) are swollen out into a hemisphere 

 on either side, as though suffering from a had attack of the mumps. 

 This swelling is ^\\\^ to the enlargement of the basal joints of the 

 maxillipeds. Mouth opening narrow and covered with a semicircular 

 upper lip. very ditl'erent from the long and ribbon-like one usually 

 found in Ckondracanthu8. To increase the difference, the upper 

 lip of the present genus is armed with a row of short hairs around 

 its margin. 



The mandibles are curved rather strongly, especially at the tip-. 

 and are furnished with a row id' -harp teeth along either margin, 

 as in Chondracanthu8. The maxilla? are similarly curved and are 

 armed with a row of large, blunt teeth on either margin and a long 

 spur or palp at the base on the dorsal surface, shaped like a knife 

 blade and directed diagonally backward and inward. The maxilli- 

 peds are very different from those in Chondr acanthus; instead of 

 being -lender, but little larger than the maxilla?, and attached to 

 the front of the face close to the mid-line, they are so much en- 

 larged that they cover the ha-es of the other mouth parts and 

 occupy the whole side of the face. Their swollen basal joint- are 

 filled with powerful muscles, a- can he seen in fig. L5, which must 

 render them useful organs of prehension. Their terminal joint is 

 bilobed, each lobe forming a knob; the dorsal one i- covered with 

 short spines and is much larger than the ventral, which i- armed 



