689 



81) Diplodiscus temperatus. 



Rectum, Rana virescens Kalm. (Common Frog). Eana catesbiana 



Shaw (Bull. Frog). 



New species: temperatus, temperate. Reported by Leid y as long 

 ago as 1856 (Proc. Acad. Nat. So. Philad. 1856. p. 42), by myself in 

 1900, both referring it to the European Ampidstomum (:= Diplodiscus) 

 suhdavatmn. My specimens vary in length from 1,2 to 6. One of 

 medium size measured 3,62 in length, 1,23 greatest breadth of body, 

 and 1,49 breadth of acetabulum. The body narrows from the aceta- 

 bulum forwards, first slowly but at the anterior third more quickly, 

 to the mouth-sucker. Sections of the anterior end are circular but 

 farther back elliptical. The mouth-sucker opens forwards, the large 

 posterior sucker backwards and downwards. The cuticle is thick and 

 smooth. 



The mouth opens back into right and left pharyngeal-pockets, be- 

 tween and below which it also opens into a rather long tube resembling 

 an oesophagus. This bears posteriorly a pharynx-like swelling, beyond 

 which are broad right and left caeca extending almost to the poste- 

 rior sucker. 



There are two testes in the anterior half of the body, situated ven- 

 trally, a little distance apart, the antorior slightly to the right, the 

 posterior slightly to the left of the median plane. From each springs 

 a short vas deferens, the two uniting into a vesicula seminalis that 

 anteriorly coils on itself and passes into a short ductus with prostate 

 glands and a structure resembling a thin-walled penis-sac. A short 

 genital-sinus opens ventrally, just under or behind the forking of the 

 intestine. The ovary is smaller than the testes, is dorsally situated, 

 in the median plane, a little way behind the second testis. A Laurer's 

 canal runs upwards and slightly forwards to the surface. A shell- 

 gland lies behind the ovary and the broad uterus passes first back 

 and then forwards, making several transverse folds on its way to the 

 genital pore. The vitellaria extend from the level of the posterior 

 testis to near the ends of the coeca. The anterior follicles are below 

 but the posterior ones are above the coeca. From the centre of each 

 half, where it is passing round the inner side of the coecum, springs 

 the transverse duct. 



Between ovary and acetabulum is the bladder of the excretory 

 system, opening upwards in the median dorsal line. From it, below, 

 spring right and left lateral ducts, which pass below the ends of the 

 coeca and fold up and down along the outside of the latter on their 

 way forwards to the region of the pharyngeal-pockets. Two large 

 lymph-vessels lie along the inner, lower sides of the coeca and 



