140 PEOCEEDINGS OF THE NATIONAL MUSEUM vol. S3 



GLOSSOCERCUS CYPRINODONTIS, new species 



Plate 10, Figures 1-5 



Specific diagnosis. — Length of head and neck about 4 to 7 mm, ac- 

 cording to state of contraction ; of body 0.5 to 12.5 mm. Maximum 

 diameter of scolex (pi. 10, fig. 4) about 630/x, of neck (when relaxed) 

 about 280/M to 300fi, and of tail about 0.8 to 1.2 mm. Suckers oval, 

 about 175/A long and 155ju, wide. Rostellum very muscular, when re- 

 tracted shaped like cone with rounded sides, about 175/* wide and 

 about the same in depth. Hooks (pi. 10, fig. 5) in two rows of 10 

 hooks each, the larger ones 180/a long, with blade lOOji* long; guard 

 (or ventral root) 55/a measured from dorsal contour of hook to base, 

 and with breadth of about 25ju, across base; root shorter than blade 

 with expanded proximal end about 20/x broad. Smaller hooks 130^ 

 long, with more curvature than long hooks; guard 42/u, from dorsal 

 contour of hook to base, and with transverse breadth of about 30/j, 

 across base; root expanded at proximal end to transverse width of 

 about 20;u,. Oval cavity in i)osterior ])art of neck (pi. 10, fig. 3, A) 

 about 500/x long and 200/x wide. Longitudinal muscles in well-defined 

 bundles (pi. 10, fig. 3, B). Tail shaped like an elongated willow leaf, 

 its broadest point shortly behind junction with neck, thence tapering 

 to a rounded point at posterior end (pi. 10, fig. 1). Excretory tubes 

 in tail are very conspicuous and may bo over 100,ti broad. 



Type host. — Cyprlnodon varlegatus. 



Location. — Body cavity. 



Locality. — Galveston Bay, Tex. 



Type specimen. — U.S.N.M. Helm. Coll. no. 39527; paratypes, no. 

 39528. 



Remarks. — These worms, up to two or three in a host, were found 

 in about 30 percent of a dense swarm of top minnows {^Cyprlnodon 

 varlegatus') in a pool on Galveston Island. No specimens were 

 found in individuals of the same species taken in the upper part of 

 Galveston Bay, but one young specimen was found in a Fundulus 

 lieteroclltus in the upper bay. The worms were found free in the 

 body cavity of the fish, although in a few instances they were seen 

 coiled up in a delicate membranous (!.yst, which burst as soon as 

 touched. The worms are extremely active, and capable of contract- 

 ing and stretching to a remarkable extent. So far as I have been 

 able to find, no larvae in any way resembling this one have hitherto 

 been described, although the Gryporhynchus larvae come nearest to 

 them. The nature of the scolex suggests the probability of the adult 

 belonging to a member of the Dilepididae, but no form with a scolex 

 conforming with that of this species in details of structure has so 

 far been described in fish-eating birds. The nearest approach is 



