1862.] DR. T. S. COBBOLD ON HUMAN ENTOZOA. 303 



which (in nematodes generally) is denied by Dr. Williams of 

 Swansea. 



18. SCLEROSTOMA DUODENALE, Cobbold. 



St7-ongylus quadridentatus, Siebold. 

 Anchylostoma duodenale, Dubini, Siebold, Pruner. 

 Ancylostomum duodenale, Diesing, Leidy, Kiichenmeister, Moquin- 

 Tandon, Creplin, Weinland. 



This interesting worm was first discovered by Dubini at Milan, 

 and, though at first thought rare, is now known to be tolerably com- 

 mon throughout Northern Italy. According to Pruner, Bilharz, 

 and Griesinger, it is remarkably abundant in Egypt, the latter autho- 

 rity calculating that about one-fourth of the people are constantly 

 sufi'ering from a severe anaemic chlorosis, occasioned solely by its 

 presence in the small intestines. 



From the accurate descriptions of Siebold it becomes quite evident 

 that this worm is closely allied to his genus Syngamus ; and, as he 

 has himself remarked, it might have been placed in the genus Scle- 

 rostoma. In this genus I have arranged it because the asymmetrical 

 disposition of the so-called dental organs is not of itself sufficient for 

 the establishment or retention of Dubini' s genus Anchylostoma ; 

 otherwise, out of respect for the discoverer, I would prefer his nomen- 

 clature. Sclerostoma duodenale closely resembles the little worm 

 (^Syngamus trachealis of Siebold, Sclerostoma syngamus of Diesing) 

 which gives rise to the " gapes " in birds ; but the male of the latter 

 species is comparatively small, whilst the vaginal outlet of the female 

 is placed much further forward. Kiichenmeister' s ' Manual ' fur- 

 nishes an excellent account of the " ^Egyptian chlorosis " produced 

 by Sclerostoma duodenale ; and those who are interested in checking 

 the "gape disease" of fowls I maybe permitted to refer to my re- 

 cent memoir on ' Sclerostoma syngamus^ in the 5th volume of the 

 * Journ. of the Proceed, of the Linn. Soc.,' Zool. Div., p. 304. 



19. Spiroptera hominis, Rudolphi. 



S. hominis, Rudolphi, Dujardin, Diesing, Owen, Leidy, Moquin- 

 Tandon, Weinland, Molin. 



? S. hominis (var. major), Brighton. 

 ? S. gigas pullus, Bremser. 

 S. rudolphii, Delle Chiaje. 



Fresh instances of the presence of this worm in the human body 

 are necessary to satisfy many as to its being a good species ; but the 

 occasional occurrence of nematodes within the vesica urinaria is a 

 fact placed beyond dispute. The original six specimens of Spiro- 

 ptera, discovered by Barnett in England, were transmitted to Rudolphi 

 for description ; and there do not seem to be fair grounds for dispu- 

 ting his accuracy. It may be well doubted, however, if Brighton's 

 nematode, though found under similar circumstances in America, can 

 be referred to the same species. 



