72 ZONITIDAE 



Genus HAWAII A Gude 



Only one species of the genus Hawaiia is found in Illinois. 

 The small size, peculiar umbilicus and silky appearance of the 

 shell distinguish this genus. 



HAWAIIA MINUSCULA (Binney) 



A little snail, Hawaiia m'tnuscula has a shell less than one- 

 eighth inch (2.5 mm.) in diameter. Each of the 4 tightly coiled 



whorls is separated from the next 

 by a distinct suture. The spire is 

 depressed and the base flattened. 

 The whitish, hyaline surface is 

 marked by many closely set lines 

 of growth that give the shell a 

 silky appearance. A large, round 

 umbilicus at the base shows all of the whorls clear to the apex. 

 The small size and the peculiar umbilicus separate this shell 

 from all others found in Illinois, except that of Helicodiscus 

 single y anus inermis, the surface of which is not silky, but smooth 

 like paraffin, and the umbilicus of which, although resembling 

 that of Hawaiia minuscula, is not so deep. 



Long known as Zonitoides minusculus, Hawaiia minuscula 

 is abundantly though sporadically distributed throughout Illinois. 

 It has doubtless been overlooked by many collectors on account 

 of its small size. Its most common habitat is in woodlands of 

 oak, hickory and sycamore. 



The name Hawaiia kawaiensis was first given to a small 

 zonitoid snail living in the Island of Kauai of the Hawaiian 

 group, by the English conchologist, G. K. Gude, in 1911. This 

 snail previously had been named Helix kawaiensis by the Ger- 

 man conchologist, L. Pfeiffer, in 1854. Suspecting that the 

 Hawaiian snail might be an American form. Dr. H. B. Baker 

 dissected the animal and found its anatomy to agree essentially 

 with that of Michigan specimens of Helix minuscula. 



It appears, therefore, that the Hawaiian snail kawaiensis 

 was described from specimens of the American minuscula which 

 had been introduced into the Island of Kauai. Thus, the generic 

 name Hawaiia, first bestowed upon a snail in far off Hawaii, 

 becomes the name of a common snail of Illinois. 



