PUPOIDES. 109 



appendix being simple, rather short, and the spermathecal 

 duct without a diverticulum. In End there is a very long 

 appendix, coiled and enlarged distally, and a long branch of 

 the spermathecal duct, with various other differences. This is 

 one of several points where the Bulimini and Pupae approach 

 very closely. The separation of the former group as a dis- 

 tinct family appears to be without sufficient foundation. 



A monograph has been published by Kobelt in his useful 

 volume on " Buliminid, " but the species were partly scat- 

 tered among those of other genera and no revision or new 

 information was attempted. 



The American and Australian species are now fairly well 

 understood. Many of those of Africa, Arabia and Mesopo- 

 tamia were described by authors who made no comparisons 

 with the older species ; they may be in large part referable to 

 P. canopictus as synonyms or local races. 



Though many descriptions call these shells " umbilicate, " 

 they are properly designated rimate; sometimes with also a 

 very minute perforation. The internal axis is quite slender, 

 as in pi. 17, fig. 1, representing Pupoides mtidulus. 



Pupoides is mainly a tropical and subtropical genus of arid 

 regions or of relatively dry stations in humid areas. The 

 American species harbor under stones or at the roots of grass ; 

 following rains they are sometimes found on trees a few feet 

 from the ground. The living shells are often coated with dirt 

 adhering by the slime of the animal. 



As in Pupilla, the sinistral species belong to decidedly arid 

 regions. They are found only in Central and West Australia. 



The distribution of Pupoides is remarkably discontinuous. 

 In Asia and Africa its range is about like that of Zootecus, 

 which prefers similar climates. The absence of the genus in 

 southeastern Asia and the East Indies leaves the Australian 

 herd profoundly isolated, as is also the American herd. Yet 

 the hypothesis of radiation from a northern, Asiatic or Asia- 

 tico-American center, as in the case of Gastrocopta, appears 

 not improbable. 



A species referable to Pupoides or perhaps Microstele has 

 been described as Pupoides pilsbryi Dall (Monograph of the 



