1851.] 207 



5. DisTOMUM RETVSVM.D iij. Hist. Nat. des Helm. p. 405 ; Dicsiiig, Syst. 

 Helm. p. 



Body whitish, with yellowish brown from the ova: oblong, sublinear, slightly 

 narrowed anteriorly ; posteriorly truncated, slightly sinuous. Oral acetabulum 

 larger than the ventral. Posterior respiratory sinus very large. 



Length 3 to li lines; breadth i line. 



Hab. Small intestine of Rana halecina. 



6. DisTOMTJM cYGNOiDES. Zecler, Nachtrag. p. 175; JDiijardin, Hist. Nat. des 

 Helm. p. 396; Diesirig, Syst. Helm. p. 342. 



Body yellowish white, posterior to ventral acetabulum sublinear, or com- 

 pressed fusiform, subacute ; neck cylindrical, translucent. Ventral acetabulum 

 two to three times larger than the oral, cup-shaped. 



Length li to 4 lines; breadth l-5th to ^ line. 



Hab. Urinary bladder of Rana pipiens, Salamandra maculata, and Salamandra 

 (Ambystoma) rubra. 



7. DisTOMDM VARiEGATTJM. RudolfJu, Syn. Ent.p. 90 ; Dvjardin, Hist. Nat. 

 des Helm. p. 416; Diesiug, Syst. Helm. p. 354; Monostomum ellipticum, Riid. 

 Entoz. Syn. p. 84; Bremser, Icon. Helm. pi. 8, fig. 12 14; Diesing, Syst. 

 Helm. p. 322. 



Body soft, oblong oval, slightly antero-posteriorly compressed; integument 

 translucent, with the black oviduct, white ovary, and brownish or yellowish 

 intestine visible ; convex upon the under surface ; posteriorly dilated, obtuse. 

 Mouth small, round, with a thick trenated lip, subterminal. Male generative 

 aperture immediately behind the mouth. Ventral acetabulum very small, round, 

 li lines from the mouth. 



Length 1 to 4 lines; breadth of largest anteriorly 1 line, posteriorly li lines ; 

 thickness | of a line. 



Hab. Found frequently, in numbers from 1 to 6 in the lungs of Rana pipiens. 

 Remarks. I was on the point of considering this entozoon as a Monostomum, 

 when I was led to examine it more carefully by the observation of Dujardin,* 

 that it had been described by authors under the name of M. ellipticum, because 

 the ventral acetabulum is very small and difficult to perceive. The latter 1 found 

 without difficulty in the position stated in the description. 



EcHINOKHyNCHUS, Miiller. 



8. EcHiNORHYNCHUs EMYDis, n. s. Body v.nite, cylindrical, slightly narrowed 

 posteriorly, recurved, broadly annulaled, smooth ; posterior extremity dilated 

 into a small globular portion terminating abruptly or in a short, conical, obtuse 

 point. Proboscis sub-globular, or oval, with a single transverse row of six 

 strong booklets and a row in a rudimentary condition ; neck very short. 



Length 2 to 8 lines; breadth i- to i of a line. 



Hab. Seventeen individuals were obtained from the commencement of the 

 small intestine of Emys geographica. Received from Prof. S. F. Baird. 



Remark. This is, so far as I can ascertain, the first Echinorhynchus whicli 

 has been detected in the Emydae. 



9. EcHiNOKHYNCHUs LATERALIS, n.s. Body cylindroid, Or subfusiform ; poste- 

 riorly narrowed, with an obtusely rounded extremity. Proboscis cylindrical, | of 



*Hist. Nat. des Hem. p. 416. 



