28o FAUNA HAWAIIENSIS 



( I ) Microcystis chamissoi Pfeiffer. 



Helix chamissoi Pfeiffer, P. Zool. Soc. London, 1855, p. 91 ; Bland and Binney, 

 Ann. Lye. New York, x. p. 338, pi. .\v. fig. 3 (jaw and radula ; copied 

 in Ann. New York Ac. iii. pi. xvii. fig. O). 

 Hab. Kauai, Waioli and Haena (Baldwin) ; Makawele and Mountains above 

 Waimea (Perkins). 



Bland and Binney give " W. Maui " on the authority of Newcomb, but this 

 seems very dubious ; Mons. Ancey gives Oahu, but I think this must be an error. The 

 figures in the Manual of Conchology (Vol. 11. pi. xxxviii. figs. 74 — 6) are not good. 



Philo\esi.\, gen. nov. 



Recently', I discussed the genus Microcystis Beck, and expressed the opinion that 

 these small Zonitoid forms so characteristic of the Hawaiian Islands, and scattered over 

 the Islands of the Central Pacific, could not be placed in that genus. I, further, 

 referred them to Macrochlamys, stating that " whether our small forms are in accord 

 with the typical group of this genus anatomically, remains to be proved-; but, concho- 

 logically, they only appear to differ in size." 



Specimens of a form which I refer to the unfigured Microcystis baldzvini Ancey, 

 and which were collected by Mr Perkins, contained the animal, and Lt.-Col. Godwin- 

 Austen has most kindly made an examination of it. His full report will be found on 

 p. 281, but I may here summarize it by saying that this species does not belong to 

 Maci'ochlamys at all, and the query I suggested has been answered. He points out its 

 affinity to Sitala and Kaliella and here it is interesting to note that Mr Perkins found 

 a species in the Hawaiian Islands that I have referred to the latter genus. 



Under these circumstances, and as the shells are distinct by the conchological 

 characters of the columella from both Microcystina and Laiiiprocystis — anatomically, 

 also, from the former — I have ventured to create a new genus and propose to take 

 Microcystis baldzvini Ancey, as the type. Probably the bulk of the Hawaiian Zonitoid 

 forms belong to this group. 



(i) Philonesia abeillei Ancey. 



Microcystis abeillei hncG.y, Bull. Soc. Malac. France, vi. (1889), p. 199. 

 Hau. Molokai (Ancey) ; Mapulehu (Baldwin) ; wet forest above Pelekunu 

 (Perkins). — Oahu, Waianae Mts. (Perkins). — Lanai (Perkins). 



All the specimens are young, but I cannot sever them from this species. 



' P. Malac. Soc. London, n. p. 130. 



