2 PROCEEDINGS OF THE NATIOI^AL MUSEUM vol. 72 



hraBiliense deserved serious consideration. Lane concluded, how- 

 ever, that : " The doubt can only be cleared up by the reexamination 

 of Alessandrini's original material, if this be still in existence." 

 Darling (1923) appears to accept the view that A. pluridentatwn 

 is probably identical with A. hrasiliense, basing this view on Ales- 

 sandrini's statement that the inner pair of teeth is almost rudi- 

 mentary, a feature noted by Darling as well as by other investigators 

 with reference to the corresponding teeth of A. hrasiliense. Darling 

 states further that there is a possibility that the three dorsal teeth 

 on each side of the mouth capsule as noted by Alessandrini may have 

 been the result of some pathological condition. 



In view of the doubt expressed by Lane and Darling concerning 

 the present status of Ancylostoma pluridentatuin the writer exam- 

 ined the specimens collected by Chapin from Felis tigHna as well 

 as specimens of this species from two other lots present in the 

 Helminthological collections of the United States National Museum. 

 One lot was collected about a year ago from the intestine of a 

 South American carnivore {Felis eyra) that had died in the IsTa- 

 tional Zoological Park, the specimens having been determined by 

 Chapin and the writer. The second lot was discovered by the 

 writer in the course of examinations of various specimens of 

 hookworms from carnivores present in the helminthological col- 

 lections of the United States National Museum. The lot in ques- 

 tion was collected in January, 1905, from Felis species by Dr. 

 Albert Hassall in the course of a post-mortem examination of the 

 animal which had died in the National Zoological Park. These 

 specimens were later examined by Dr. C. W. Stiles, of the hygienic 

 laboratory of the United States Public Health Service, who labeled 

 them '''' Ancylostorma^ new species." It should be noted in this con- 

 nection that Doctor Stiles's determination was made before Ales- 

 sandrini's description of A. fluridentoAum was published. 



The observations recorded in this paper not only confirm the 

 specific validity of A. fluridentatvmh^ based on a study of specimens 

 from the type locality, but also clear up certain points in the 

 morphology of these worms that led Darling to the view that 

 Ancylostovia 'pluridenta^jmh and Ancylostom.a hraziliense are prob- 

 ably identical. 



DESCRIPTION OF ANOYLOSTOMA PLURIDBNTATUM 



The features of the mouth capsule that differentiate AncylostoTiia 

 pluridentatuTTh from all other species of the genus Ancylostoma are 

 the structure of the two pairs of teeth in the anterior and ventral 

 portion of the mouth capsule, coupled with the presence of three 

 small teeth on each side of the dorsal wall of the mouth. (Fig. 1.) 

 As has already been said these features were noted and emphasized by 



