TOn LARVAL CESTODE PARASITES OF FISHES— LINTON. 



10. Cysts from peritoneum of Phycis chuss. Woods Holl, Massachu- 

 setts, August 2!), 18S7 (Xo. 47(>2, U.S.X.M.). 



Blastocyst with ver^^ coarse retractile bodies iii the pareuchyiua. 



Dimensions of alcoholic specimens: Length of head and neck, about 

 2 mm.; length of bothrium, 0.37; breadth, 0.32; diameter of neck, 

 0.24; lengtli of contractile bulbs, 0.47; length of largest broad hooks, 

 0.044; lengtli of long slender hooks, 0.035. 



11. Cysts from .Uacnini.s hairdii (Xo. 4773. U.S.X.M.). Collected by 

 United States Fish Commission, station 894. 



Dimensions: Length of blastocyst, 18 mm.; diameter of anterior 

 end, 3; of posterior end, 2; length of embryo, 3,7; diameter of neck, 

 0.7; length of bothria, 0.7."»; length of longest hooks, at base of probos- 

 cis, about O.O.J ; length of contractile bulbs, 1.7; longest diameters of 

 calcareous bodies observed, 0.03 (Plate III, tigs. 7, 8). 



The proboscides are about three times as long as the bothria, sheaths 

 spiral. The arrangement of hooks could not be nuule out. Hooks of 

 various sizes. Xot shaped like those of A', imparispine. 



III. 



The species in this section are distinct for each host. 



12. Two lots of cysts from the scup {Stenotomns chrysops) were col- 

 lected at Woods IIoll, Massachusetts, August, 1884, and July 23, 1887. 

 On the latter date about a dozen fish were examined and only a few 

 cysts found. 



In the first lot the cysts arc smaller than they are in the second, but 

 they are evidently the same species. 



Dimensions: Length of cyst, 1.1 mm.; breadth of cyst, 0.8; length 

 of embryo, 0.84; breadth, 0.78. Proboscides retracted. Hooks of two 

 kinds (Plate III, fig. 9). Length of longest, slender hooks, 0.023 mm., 

 (Xos. 4775, 47(J5, U.S.X.M.). 



Along with the cyst in the first lot were several slender cysts, with 

 slender blastocyst, whose identity I was unable to determine. One of 

 these measured G.5 mm. in length, and from 0,18 to 0.4G in diameter. 

 Xo traces of embryo could be found. Xunierous calcareous bodies 

 were present in the interior, some of them showing a concentric struc- 

 ture, others yellowish opaque without distinct structure, average size 

 about 0.05 mm. 



An embryo taken from a cyst in the second lot yielded the following 

 measurements, alcoholic specimen: Length of bothrium, 0.7G mm.; 

 breadth of bothrium, 0.4; breadth of head, 1.05; diameter of proboscis 

 at base, including hooks, 0.00; diameter of proboscis in front of tumid 

 base, 0.05; length of shortest hooks, 0.005; length of longest hooks, 

 0.024. 



The bothria have a deej) central depression and thick edges, are 

 widely divergent at base so as to ai)i)ear almost terminal. The approxi- 

 mate length of a proboscis was 2 mm. 



