Mr. H. J. Carter on a Bisexual Nematoid Worm. 29 



the lower part of the last whorl, the shoulder of that whorl 

 is also distinctly angulate, almost giving the appearance of a 

 new species ; but the other characters of the shell prove it to be 

 merely a variety. It was found at the Farm Caves by Capt. 

 Haughton. 



In a former paper, the discovery of Cyclophorus [Turbo) folia- 

 ceus, Chemn., in the Andamans was announced. I am indebted 

 to Capt. Haughton for larger specimens of the shell, containing 

 the operculum in situ ; so that no doubt remains of the propriety 

 of referring the species to Cyclophorus. The younger specimens 

 are depressed, angulate at the periphery, and wider in the umbi- 

 licus. The adult shell is more lengthened, the last whorl is 

 rounded, and the umbilicus narrow. In some specimens, vestiges 

 of a br»wn scabrous epidermis, which hiad concealed the white 

 and rose-colour of the surface, are visible. The largest specimen 

 is 22 mill, in length by 19 in breadth. 



In the paper on Opisthostoma lately published by the Messrs. 

 Blanford, a shell named Cijclotus malabaricus, BL, allied to C. 

 filocinctus, Bens., and likewise found in the Nilgherries, is de- 

 scribed. Mr. W. T. Blanford informs me that he intended to 

 separate these shells under the generic name of Cyathopoma, Bl.^ 

 with reference to the singular construction of the operculum, 

 which fully bears out his opinion on the subject. 



An interesting shell from Assam, partaking of the characters 

 of Rhiostoma and Opisthoporus, has lately been communicated 

 to me by Mr. W. T. Blanford, who proposes to describe it iu a 

 future number of the Calcutta Journal. 



Cheltenham, Nov. 30, 1860. 



VI. — On a Bisexual Nematoid Worm which infests the common 

 House-Fly (Musca domestica) in Bombay. By H. J. Carter, 

 Esq., F.ll.S. 



[Plate I. A. figs. 1-4.] 



In November last (1859), while examining the head of the 

 common House-fly {Musca domestica), I noticed that two Nema- 

 toid worms came out of it ; but not having time to look after 

 them then, I deferred the subject for a future opportunity, 

 thinking that the occurrence would be found to be frequent, 

 and if so, that the form and origin of these worms would be 

 worth investigating for the light it might throw on the origin 

 of the Guinea-worm [Filaria Medinensis) in the human subject. 

 Accordingly during the past month (July 1860) I have returned 

 to the inquiiy, and have observed that, on an average, about 



