72 Papers from the Marine Biological Laboratory at Tortugas. 



pouch. The folds are so disposed as to incline from their marginal limits 

 postero-mediad to the median line. The muscular metraterm lies parallel 

 with the proximal portion of the cirrus-pouch and on its posterior side. 

 The ova are oblong elliptical with a long filament at each pole. The 

 characteristic musculature of the preceding species (Barisomum erubes- 

 cens) is seen in this species, though neither the fascicles nor the fibers 

 are so strongly developed as they are in that species. The excretory 

 vessels unite near the head above the esophagus. They pass laterad of 

 the intestines until a short distance in front of the ovary, where they 

 pass under the intestinal rami, then mediad to unite just behind the 

 shell-gland. The single excretory vessel now passes between the testes 

 and the posterior extremities of the intestines to the terminal excretory 

 pore. Further anatomical details are given in the figures. 



Host, Angelichthys isabelita: July 3, 1908, 1 fish, 1 trematode. 



Host, Pomacanihus arcuaius: 



1906, July 18, 1 fish, 5 trematodes. 



1907, July 3, 1 fish, 4 trematodes; July 11, 1 fish, 48 trematodes; 

 July 15, 1 fish, 7 trematodes. 



1908, June 29, 1 fish, 7 trematodes; July 1, 1 fish, 4 trematodes; 

 July 3, 2 fish, 18 trematodes; July 4, 2 fish, 4 trematodes; 

 July 7, 2 fish, 4 trematodes. 



Dimensions in glycerin: Length 2.46; breadth, anterior 0.08, 

 middle 0.33, posterior 0.28; breadth 0.12 from anterior end 0.26; geni- 

 tal aperture 0.7 from anterior end; diameter of oral sucker 0.08; ova, 

 exclusive of filaments, 0.034 by 0.017. 



Length in most cases from 3 to 4.5 mm. 



Dimensions of one of larger specimens, life, flattened and the pos- 

 terior end unrolled: Length 4.69; breadth, anterior 0.36, middle 0.36, 

 posterior 0.78; ova, exclusive of filaments, 0.033 by 0.017; length of 

 filaments 0.42 ±. 



PARAMPHISTOMIDjE. 

 Cleptodiscus reticulatus gen. et sp. nov. (Figs. 198-204.) 

 Etymology: k.II-to>, to conceal; SitrKos, a quoit. 



Outline of body somewhat variable but usually fusiform or long 

 oval, tapering moderately to the rounded anterior end and narrowing 

 very slightly towards the posterior end, which bears a round sucker 

 ventrally placed. Body smooth, crossed by fine transverse lines which 

 give to the surface a somewhat crinkly appearance; color white, some- 

 times tinged with red or pink, especially in the vicinity of the posterior 

 sucker. Mouth terminal, provided with a muscular, pharynx-like sucker, 

 which is glandular in its peripheral portion, at least supplied with numer- 

 ous, deeply staining nuclei (fig. 200 a'). There are 2 small, rudimentary 

 suckers at the postero-lateral border of the mouth-pharynx, which, 

 however, can be seen only by deep focussing (figs. 201 r and 202 r). The 

 esophagus is slender and surrounded by deeply staining nuclei (figs. 200 

 and 202 w), which are more abundant around its anterior portion. Rami 

 of the intestine simple, extending to the posterior end, often inflated, 



