6 PEOCEEDINGS OF THE NATIONAL MUSEUM vol.72 



DISCUSSION 



It will be noted from the description that there are certain slight 

 differences in the morphology of the worms from Felis tigrina and 

 Felis eyra, the most important differences being in the position of the 

 cephalic papillae and in what appear to be malformations of the 

 teeth. In specimens from Felis tigrina the cephalic papillae are 

 located anterior to the middle of the esophagus and but slightly 

 posterior to the nerve ring, whereas in specimens from Felis eyra 

 the cephalic papillae are located posterior to the middle of the 

 esophagus and considerably posterior to the nerve ring. Other 

 minor differences in specimens from the two hosts were noted but 

 these were rather variable, and possibly due to the fact that the 

 worms from F. tigrina are not fully grown. 



So far as concerns Lane's suggestion that Ancylostoma flwriden- 

 tatum represents a new genus, the writer is of the opinion 

 that Lane's judgment was sound in not actually proposing a new 

 generic name, that the special differentiating characters of this worm 

 should be regarded at this time as of specific rank, and that for the 

 present, at least, these parasites may be left in the genus Ancylostoma 

 since they possess all of the essential characters of this genus. If 

 for no other reason than that of convenience, the creation of a new 

 genus for A. plv/ridentatum is avoided in this paper as not 

 justified at the present time owing to the comparatively small number 

 of easily differentiated species now assigned to the genus Ancylos- 

 toma. In general we feel that dividing a comparatively small and 

 coherent genus to form from one of its species a new genus containing 

 only that species frequently adds unwarrantably to the already bur- 

 densome nomenclature with which the taxonomist must cope. Should 

 other forms be found to share with A. pluridentatum characters not 

 shared by other species assignable to Ancylostom^a, it will then be 

 time to consider the proposal of a genus for this group, 



SPECIES OF THE GENUS ANCYLOSTOMA 



Yorke and Maplestone (1926) list the following species as belong- 

 ing to the genus Ancylostoma: A. duodenale (Dubini, 1843) Crep- 

 lin, 1845, type species of the genus; A. braziliense de Faria, 1910; 

 A. caninum (Ercolani, 1859) ; A. conefati (Solanet, 1911) ; A. gil- 

 soni Gedoelst, 1917; A. malayanum (Alessandrini, 1905); A. mdni- 

 TYium (Linstow, 1906) ; A. mucronatum (Molin, 1861) ; A. mycetes^ 

 new name, Yorke and Maplestone, 1926 { = DiploodonquadTidentatuon 

 Molin, 1861); A. pluridentatum (Alessandrini, 1905). Molin's two 

 species are inadequately described, but his figures indicate quite 

 clearly that they belong to the genus Ancylostoma. His figure of 

 A. mucronatum shows two equal spicules nearly one- fourth as long 

 as the total length of the male. In this connection it is interesting 



