ART. 22 TWO SPECIES OF TREMATODE WORMS— PRICE 3 



uterus runs anteriorly from the shell gland in more or less regular 

 coils extending beyond the lateral limits of the ceca, and terminates 

 in a well-developed metraterm which is about two-thirds as long as 

 the cirrus pouch. The eggs are oval, 30/. long by 18/x wide, provided 

 with a slender filament at each pole. 



Hosts.— Angelichthys ciliaris, A. isabelita, Poviacanthus arcuatus, 

 and P. paru. 



Location. — Intestine. 



Dlstrihiition.—\JmiQ({ States (New York Aquarium). 



In 1917 a peculiar species of trematode was described by Mac- 

 Callum from the oviducts of Trionyx aspidonectes ferox to which 

 the name Paramphistomum aspidonectes was given. Poche (1926) 

 in discussing his supersuperfamily Paramphistomida writes that 

 " in no case does this species belong to the genus Paramphistomum 

 or to any of the other genera of Paramphistomida which are difi'er- 



Figure 1. — Pledrogonius pomacanthi (MacCallum, 1916). Ventral view 



entiatecl at present." Fukui (1929) states: " The general anatomy is 

 apparently that of an amphistome, as the author pointed out. But 

 the situation of the genital pore is entirely different from that of 

 all the other amphistomes, the arrangement of the vitellaria is pe- 

 culiar and the position of the excretory pore is also remarkable. In 

 general appearance this worm is somewhat like a distome stood on 

 its head." Because of these characters which are so outstandingly 

 different from all other amphistomes, he proposed a new genus, 

 Opisthoporus.1 and family, Opisthoporidae, for this species, assuming, 

 as he says : " that there are no mistakes in the original description." 

 The spechnens of this species which are available for .study consist 

 of five specimens representing two different lots. The first consists 

 of four specimens stained with carmine and mounted on a single slide 

 (U.S.N.M. No. 8092) labeled ''''Paramphistomum aspidonectes., ovi- 

 duct, Aspidonectes ferox. Soft-shelled turtle. Aq. May 10, '16," 



