70 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.5:'. 



soft, and thin-walled; dorsal carapace and two or three anterior 

 terga and sterna often fully preserved; neck constricted just behind 

 the horns, then enlarged and constricted again into a narrow chitin 

 stalk where it joins the trunk and usually flexed; trunk claviform 

 with a minute abdomen on the dorsal surface; egg strings long, 

 straight, and uniseriate. 



Two pairs of antennae, second pair chelate; mandibles spine-like 

 and without teeth; two pairs of maxillae; three pairs of swimming 

 legs, first two pairs birnmose, third pair uniramose, all the rami two- 

 jointed and armed with setae. 



Internal generic characters of female. — Esophagus in line with 

 body axis and nearlj'' straight; anterior stomach neither lobed nor 

 convoluted; intestine enlarged in the anterior neck, then constricted 

 through the narrow stalk, enlarged again and flattened dorso-ven- 

 trally in the trunk, and abruptly constricted at the posterior end 

 into a short rectum. 



Ovaries paired and dorsal to the intestine at the anterior end of 

 the trunk, only a little flattened ; oviducts nearly straight and much 

 wider than the ovaries or intestine; cement glands not reaching the 

 anterior ends of the oviducts, glandular portion shorter than the 

 ducts and not segmented. Chitinogen layer of the skin especially 

 well developed at the anterior and posterior ends of the genital seg- 

 ment; a longitudinal row of skin glands along either side of the 

 ventral surface, some distance from the midline. 



Genus habitat. — This genus burrows into the cephalic or cephalo- 

 thoracic muscles of its host and brings its head in contact with the 

 apophj^sis of the vertebral column. The head and enlarged portion 

 of the neck are surrounded by a cyst formed in the tissues of the fish. 



External generic characters of Copepodid male (genus Sarco- 

 tretes). — Head and first thorax segment fused into a cylindrical 

 cephalothorax, three times as long as wide ; second, third, and fourth 

 thorax segments free; fifth and genital segments and abdomen indis- 

 tinguishably fused and without lobes; anal laminae short and wide, 

 each armed with four or five minute, nonplumose setae. First an- 

 tennae with indistinct joints; second antennae two- jointed and 

 chelate; mouth tube conical, at right angles to the axis of the head; 

 mandible a single slender spine; first maxilla a fingerlike process, 

 without joints; second maxilla uncinate; maxilliped reduced to a 

 mere knob; three pairs of swimming legs, first and second pairs 

 biramose, rami indistinctly two-jointed, third pair uniramose, with- 

 out joints. 



Type of the genus. — Sarcotretes scopeli Jungersen, monotypic. 



(Sarcptreies, 2dp^, flesh, and Tp-qriis, a borer or piercer.) 



