TBEMATODES FROM FISHES — LINTON 159 



Encysted trematodes from a fresh-water JSsli, the wall-eyed pike 

 {Stizostedion vitreu7)i), are here recorded. 



Cysts from fish from market, Washington, Pa. (U.S.N.M. No. 

 8397) , presumably from Lake Erie, collected March 7, 1891. A slide 

 in my collection contains sections of a cyst with enclosed larval 

 trematode, and of a trematode which had been removed from its cyst. 



The structure of cyst and larva, so far as shown in these sections, 

 agrees with the detailed description given by Hughes, but there is no 

 trace of spines, and the pharynx is not well shown. 



Measurements of cyst, 0.80 by 0.60 mm. ; of contained larva, length, 

 0.55 mm., breadth, 0.42 mm. ; ventral sucker, breadth, 0.17 mm., ver- 

 tical diameter, 0.17 mm.; oral sucker, length, 0.11 mm., breadth, 

 0.14 mm. 



Genus NEASCUS Hughes, 1927 



NEASCUS CUTICOLA (van Nordmann) 



Plate 24, Figures 320-323 



Diplostomum cuticola Diesing, Linton, Proc. U. S. Nat. Miis., vol. 20, p. 513, 



pi. 41, figs. 1-10, pi. 42, figs. 1-5, 1898. 

 Diplostomum cuticola (van Nordmann), Luhb, Bi"aner's Siisswasserfauna 



Deutschlands, Trematodes, pp. 166, 167, 1909. 

 Neascus outlcola (van Nordmann), Hughes, Trans. Amer. Micr. Soc, vol. 47, 



pp. 331, 332, figs. 3, 9-11, 1928. 



The encysted trematodes from four species of fresh-water fishes here 

 recorded, although differing somewhat in the relative proportions of 

 the suckers, so far as the anatomy is shown, agree with descriptions 

 of this species. 



Hosts. — Large-mouthed black bass {Euro iloridana), small- 

 mouthed black bass {Micropterus dolomieu)^ brook trout {Salveli- 

 nus fontin-alis)^ yellow perch ( Perca flavescens) . 



Record of collections. — Specimens of large-mouthed black bass 

 were received on July 8, 1915, from Dr. E. E. Smith. They were 

 collected by T. C. H. Richardson, who stated that the fish came from 

 a reserve pond where the fish were dying off. The location of the 

 pond was not given, but it is in New Jersey, not far from New York 

 City. Numerous cysts on fins and in the muscle tissue. The cysts 

 were surrounded by black pigment. A cyst in glycerin measured 

 0.40 by 0.23 mm.; estimated length of larval trematode in cyst, 

 0.54 mm. 



Ten large-mouthed black bass were received on July 31, 1919. 

 The fishes had been taken in June from Bass Lake, Wliite Earth 

 Reservation, Minn., and had been collected and sent at the instance 

 of Dr. Earl A. Danielson. The fishes had been sent on account of 

 heavy cestode infection. Cysts surrounded by black pigment were 

 found on each of the fish, from 2 to 35 on each, most of them on the 



