506 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



Generic diagnosis. Gorgorhynchidae of small to medium size with 

 body spination in an uninterrupted mantle restricted to the anterior part 

 of the body. Proboscis long, relatively few longitudinal rows of hooks. 

 The entire proboscis invested by a thick hyaline cuticular membrane or 

 the individual hooks ensheathed in prominent cuticular elevations of 

 the proboscis surface. Proboscis receptacle double walled. Brain near 

 anterior extremity of receptacle. Lemnisci at least as long as the recep- 

 tacle. Testes contiguous followed by four clavate cement glands. Para- 

 sitic as adults in intestine of marine fishes. 



Type species. Tegorhynchus brevis Van Cleave, 1921. 



In the parasitic worms collected by the Allan Hancock Pacific 

 Expedition of 1934, 2 specimens represent a previously unknown species 

 which is assigned to this genus and is named Tegorhynchus pectinarius. 



Tegorhynchus pectinarius, new species 

 (Plate 52, figs. 8, 9) 



Host: Medialuna (?) taken from stomach of Seriola sp., Puerto 

 Culebra, Costa Rica, February 24, 1934. 



Types. Description based on 2 females, one of which, designated as 

 holotype (VC 3124.2), is deposited in the Allan Hancock Foundation of 

 The University of Southern California and the other, as a paratype, is 

 deposited in the collection of H. J. Van Cleave, Urbana, Illinois. 



Specific diagnosis. Body slightly fusiform, anterior extremity clothed 

 with scattered spines about 30 to 48 p. long, not disposed in distinct zones 

 but extending backward as a continuous mantle along almost three 

 fourths the length of the body. Body proper 8.4 to 8.8 mm long. Pro- 

 boscis, fully extended, about 1.4 mm long; armed with 12 longitudinal 

 rows of about 28 to 30 hooks each (see figs. 8 and 9) , the hooks displaying 

 profound regional differentiation. A series of 6 or 7 hooks at the base of 

 each longitudinal row forms a closely set, comblike series of thorns (fig. 

 9). The thorns of these combs are arranged in check rows in both direc- 

 tions, not in the alternating quincunxial order characteristic of the hook 

 arrangement on the anterior region of the proboscis. Besides this regional 

 specialization involving the base of the proboscis there is a conspicuous 

 dorsoventral differentiation of the proboscis. Each of the 4 middorsal 

 rows of hooks has one very heavy, strongly recurved hook with an 

 exaggerated root standing immediately anterior to the basal comb. These 

 peculiarly modified heavy hooks have a length of about 27 /t, while the 

 large, recurrent root is almost twice the length of the hook proper. In 



