HEXATHYEIDIUM PINGUIOOLA. 205 



caudal extremity. The reproductive orifices are situated near the 

 mouth. 



The Tetrastoma is stated to infest the tubes of the kidney, but 

 the evidence on which this statement rests is not altogether satis- 

 factory. According to the original account given by Lucarelli, the 

 patient in whom this parasite occurred was a woman upwards of 

 sixty years of age, and resident at Oapodimonte. She had symp- 

 toms of calculus, with highly-coloured urine, in which latter there 

 were deposited some small yellowish bodies. They exhibited a 

 definite form, and were apparently organized. Altogether five 

 specimens were collected for examination, when they showed signs 

 of life. Lucarelli also adds : — " After minute investigation, I 

 thought that these creatures were tetrastomes, to which I applied 

 the epithet renal, in accordance with their presumed habita- 

 tion." At the expiration of two months the patient died, and on a 

 post-mortem examination being made, no more tetrastomes were 

 found either in the kidney, or in the urinary bladder. The renal 

 organ was slightly enlarged. 



8. Hexathyeidium pinguioola. 



H. pinguicola, Treutler ; Jordens ; Brer a ; etc. 



Hexastoma pinguicola, Cuvier. 



Linguatula pinguicola, Lamarck. 



Poly stoma pinguicola, Tieder ; Rudolphi; Bremser ; etc. 



This species was once found by Treutler in a tumour about the 

 size of a nut, which was connected with the left ovary, and no 

 second instance of its occurrence, either in Germany or elsewhere, 

 has since been recorded. The original figure and description given 

 by Treutler have been copied in various works ; and from these 

 records we gather that this trematode attains a length of eight 

 lines, the body being flat, somewhat hourglass-shaped in outline, 



