PEOCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 78 



and the second, one specimen, also a toto mount stained with carmine 

 (U.S.N.M. No. 8093), labeled '"'' Paramyhistomwii aspidonectes n. sp., 

 int., Trionyx sjrbiifer, soft-shelled turtle. First found May 10, '16. 

 W. H., Aug. 16, '23." As in the case of Pleurogonius pomacanthi^ 

 the specimens have been flattened and are somewhat distorted, and 

 some characters can not be made out with certainty. 



OPISTHOPORUS ASPIDONECTES (MacCallum, 1917) Fukui, 1929 i 



Synonym. — Parmn/phisfoniutn aspidonectes MacCallum, 1917. 



Specific description. — -Oplsthoporus: Body spindlelike in outline, 

 more attenuated posteriorly than anteriorly, 2.4 to 3.2 mm. long by 

 620/A to 930/A wide at the equator. Cuticle smooth and without spines. 

 Oral sucker subterminal, 310/x to 403/a in diameter. There is a low 

 ridge or collar immediately posterior to the oral sucker which resem- 

 bles that in the genus Eucotyle. This collar is indistinct in the speci- 



//n/n. 

 Figure 2. — Opisthopords aspidonectes (MacCallum, 1917). Ventral view 



mens from Aspidonectes ferox but is quite evident in the specimen 

 from Trionyx spinifer. There is no acetabulum. The esophagus is 

 from 230/A to 310/* long; intestinal ceca simple and without diver- 

 ticula, and terminating near the posterior edge of the anterior testis. 

 The excretory pore is simple and terminal, but the details of the 

 remainder of the excretory system can not be made out. The genital 

 pore is situated in the median line at the bifurcation of the intestine. 

 It is impossible to determine Avhether the male and female genital 

 openings are separate or whether they open into a common sinus. 

 The cirrus pouch is pestle-shaped, 685/* to 774/* long, strongly mus- 

 cular, containing a w^ell-developed prostate and a long cirrus armed 

 with needlelike spines. The seminal vesicle is a convoluted dilation 

 of the vas deferens and lies free in the parenchyma. The testes are 



^ While this paper was in course of publication a paper has appeared by Stunkard 

 (Trans. Amer. Microsc. Soc, vol. 48, no. 3, 1930), in which a description of this species 

 is given. Stunkard had access to an abundance of well-preserved material and his de- 

 scription of this form is, therefore, more complete than that given in this paper. 



