1862.] DR. T. S. COBBOLD ON HUMAN ENTOZOA. 293 



Schistosoma in favour of Bilharzia, which he admits has the priority. 

 Though it is of httle consecjuence which name be retained, the genus 

 itself is one of remarkable interest, not merely in a structural point 

 of view, but also from its prevalence on the borders of the Nile. 

 The first specimens were discovered by Dr. Bilharz, of Cairo, in the 

 portal system of blood-vessels ; and others were subsequently ob- 

 served by him, Griesenger, Reinhard, and Lautner in the veins of 

 the mesentery, bladder, and other parts, giving rise to a formidable 

 and very prevalent disease. The anatomy of Bilharzia has been 

 fully described by the original discoverer and by Kiichenmeister ; 

 but I would observe, in passing, that it is rather singular that Moquin- 

 Tandon should express his belief that the sexes have been mistaken 

 by such competent authorities. The circumstance of the smaller 

 form being carefully described by them as furnished with uterine 

 ducts containing eggs ought to leave no doubt in our minds as to the 

 correctness of the generally received opinion, unless we have distinct 

 evidence to the contrary. In connexion with this subject I would 

 also again call attention to the circumstance of my having discovered 

 the second species of Bilharzia (B. maffna) in the portal system of an 

 African M.onkey (Cercopithecus /uliffinosus). Those who pay regard 

 to the distribution or limitation of particular forms will see in this 

 fact a curious illustration of the affinities of habit ; for there can be 

 little doubt that the Sooty Monkey procures the larvse of its Bil- 

 harzia from a source similar to that from which our Egyptian bre- 

 thren procure the larvse of B. hcematobia, and it is not a little sig- 

 nificant that the genus in question should only at present be known 

 to infest men and monkeys. For further particulars in regard to 

 this parasite I must refer to my previous papers in the ' Linnean 

 Transactions' (vol. xxii. p. 364), 'Linnean Proceedings' (vol. v. 

 Zool. Div. p. 30), 'Zoological Society Proceedings' (1861, p. 118), 

 and in the 'Intellectual Observer ' (vol. i. p. 352). 



7. Tetrastoma renale, Delle Chiaje. 



T. renale, Delle Chiaje, Diesing, Dubini, Leidy, "Weinland. 



The occurrence of this entozoon as a human parasite appears 

 hitherto to have escaped the notice of English zoologists, although 

 discovered by Lucarelli and Delle Chiaje in 1833. All that we now 

 know of it is due to the original description of Chiaje, from whose 

 ' Elmiutografia Umana ' we learn that it attains a length of 5 lines, 

 has an oval flattened body, and is furnished with four suckers disposed 

 in a quadrate manner at the caudal extremity. The reproductive 

 orifices are situated near the mouth. It infests the tubes of the 

 kidney. 



8. Hexathyridium pinguicola, Treutler. 



H. pinguicola, Treutler, Jordens, Brera, Leidy, Weinland. 

 Hexastoma pinguicola, Cuvier. 

 Linguatula pinguicola, Lamarck. 



Polystoma pinguicola, Zeder, Rudolphi, Bremser, Delle Chiaje, 

 Owen, Dujardin, Dubini. 



