CONTRIBUTIONS TO AMERICAN HELMINTHOLOGY. 73 



Bitterns above referred to, along witli a single male of Ascaris 

 inicrocepliala, Rud. (?) in one of these; and although closely related to 

 two species (F. laticeps, R., and F. tridentata, V. Linstow^^) whicli 

 have been described from Falco lagopus on the one hand, and from 

 Colymbus arcticus and Larus ridibundus on the other, it does not 

 appear to resemble any of the numerous Filarise described from 

 Ciconise, except perhaps F. alata. 



I hope I may shortly have an opportunity of examining the dis- 

 position of the prse- and post- anal papillae in the male, a character 

 of essential systematic value in this genus ; in the meantime, however, 

 I record the following points which seem to distinguish it from the 

 above mentioned forms : 



Densely striated. Length 10 mm. ; greatest breadth, 0.43 mm. A 

 cervical fascia or frill, the tops of the lateral loops of which are 

 0.18 mm. from the anterior end, and which extends 0.405 mm. back- 

 wards on the neck. The root of the cervical papilla (or trifurcate 

 spine) is 0.06 mm. from the end of the frill. The trident measures 

 from the root to the end of the median fork 0.06 mm. The eggs 

 measure 0.027 mm. x 0.018 mm. The tail is terminated by a short 

 rounded conical projection. 



A comparison of Fig. 1 6 with the figures of Schneider ^ and V. 

 Linstow, will show how it difiers from the similar structures repre- 

 sented there, the teeth of the trident being much longer and narrower 

 in proportion to the body. The uterus was packed full of eggs, so 

 that its walls were extended in every direction, occupying almost the 

 whole of the body cavity. 



Ancybacanthus cystidicola (Schn.) B. 



I find this worm very commonly present in considerable numbers 

 in the swim-bladder of Salmo siscowet, Ag. The males are, how- 

 ever, usually about twice (19-22 mm.) the length recorded by 

 Schneider, while the females measure 30-33 mm. The two teeth 

 (Fig. 17) which are doubtfully ascribed to the head by Schneider are 

 quite evident in my specimens, and are continuous with two longi- 

 tudinal ridges in the oesophagus. It is somewhat difiicult, on account 

 of the coiled up taU, to get a satisfactory view of the papillfe in the 

 male, but there seemed to be five pairs of these behind the anus. 

 The eggs measure 0.04 x 0.02 mm. 



38 Trosch. Archiv., 1877, pp. 10 and 175. 

 S7 Loc. ci±., Taf. VI., Fig. 3. 



