301 ANIMAL PARASITES. 



Iceland, was established by Dubini, as a separate genus, Anchy- 

 lostomum, and exhibited by Von Siebold to the meeting of 

 naturalists at Gotha in 1852 as Strongylus quad ride at aim, but 

 this name has recently been retracted by him, as Dujardin had 

 already employed the name of Sclerostomum quadridentatum for 

 the Strongylus tetracanthus (Mehlis). 



With regard to Dubinins proceeding in establishing a new 

 genus, Ancylostomum, Von Siebold mentions that, from the horny 

 nature of the capsule of the mouth, this worm might certainly 

 have been arranged in the genus Sclerostomum, but that, never- 

 theless, the genus Ancylostomum, established by Dubini, may 

 very well be allowed to remain, as the parts of the mouth of 

 this worm are distinguished from all other Strongyli by the 

 asymmetrical arrangement of the dental apparatus. 



Of the genus Ancylostomum, we are at present only acquainted 

 with the single species — 



1. Ancylostomum duodenale. PI. VI b, fig. 16 — 29. 

 The synonyma of which have just been spoken of. 



The description of A. duodenale runs as follows, according to 

 Diesing's description as improved by Von Siebold. 



Caput apice rotundatum ; oris limbi papiilis conicis inccqualibus, 

 duabus minoribus, uncinis papiilis impositis apicibus convergentibus. 

 Corpus subrectum v. parum curvaium, anteriore parte transparens, 

 ventriculo globoso nigrescento, posteriore flavido-fuscum, maris 

 antrorsum attenuatum, exlremitate caudali inflexd; bursa cyathi- 

 formi bilobd W-radiatd, cujus radii ita sunt posili, ut triplicem 

 eorum ordinem conspicere possis, in utroque enim latere ordinem 

 quatuor, media in parte trium radiorurn (radiis lateralibus utriusque 

 5 simplicibus : Diesing) ; radio dorsali apice furcato ; femince 

 extremitate posticd acute conicd. Longit ; mar. 3 — 4'"; fern. 

 4 — 5"'; crassit. ad % 



l'" 



8 



As soon as the attention of Bilharz had been called by Von 

 Siebold's letters to this worm, which had already been found in 

 Egypt by Pruner, he found it in nearly every corpse, sometimes 

 in small numbers, sometimes in hundreds of specimens, less in 

 the duodenum than in the jejunum, between the transverse folds 

 of the mucous membrane. One male is found to three females. At 

 the oral end we observe a large, obliquely truncated, horny capsule, 



