450 W. N. F. WOODLAND 



C. laticeps, W. acuminata, and W. mi nut a the 

 borders of the two apertures are contiguous, as is also usually 

 the case in W. virilis. In all other respects the genitalia 

 of C. filiformis appear to conform to the plan charac- 

 teristic of Caryophyllaeus. 



The two main nerve-trunks (PI. 25, figs. 25, 27, 28, n) are 

 visible anteriorly, and I have seen them (with difficulty) in my 

 transverse sections. 



The excretory channels (PI. 25, figs. 27, 28, 29) are mostly 

 situated between the inner and outer zones of longitudinal 

 muscles, but a few also occur in the medulla. The vessels 

 cut across in transverse sections form a part of a complicated 

 network, and there appear to • be no definite longitudinal 

 vessels ; posteriorly, however, some eight or ten longitudinal 

 excretory channels open into the excretory bladder. 



The eggs are of the usual ovoid smooth-shelled type and 

 measure, when mounted in balsam, 62-2-69-5 microns in 

 length and 29-2-32-9 microns in ])readth, thus being excep- 

 tionally long. 



The definition of this species, C. filiformis, will be 

 supplied below. 



The Genera and Species of the Caryophyllaeidab. 



Skrjabin (23) has, with his description of Caryophyllaeus 

 syrdarjensis, included a summary of the small differences 

 which distinguish C. laticeps, C. tuba, C. fennicus, 

 and C. syrdarjensis (all from Cyprinoid fishes) from each 

 other, and C. armeniacus (Cholodkowsky, 2) only differs 

 from these principally in its large size (55 mm. in length), 

 truncated head, and large eggs (80 x45 microns). Linton 

 (10, 11) has described two other species (also collected from 

 Cyprinidae), which, on account of the form of the head, he 

 refers to Diesing's (6) genus j\I o n o b o t h r i u m ,i but, excepting 



1 The " Monobothriiim serpentum n. sp." of v, Liiistow (' Arch, 

 f. Mikr. Anat.', Bd. Ixii, 1903, p. 108), 1-4 mm. long, from a cyst in the 

 mesentery of a snake, Patalung, cannot of course be referred to the 

 Caryophyllaeidae. It is almost certainly a Dithyridium larva, 

 S3veral kinds of which have been described from snakes. 



