456 MR HARPER PEASE ON POLYNESIAN LAND SHELLS. [May 2, 



latter proved to be a synonym of Theba, Leach. He cites four 

 species as types : the first, H. come, I do not find mentioned by 

 any other author, and has not been published ; the three remaining 

 are from Polynesia and agree in their characters, leaving no doubt 

 as to the genus intended; they are brunnea, Anton, =glandula, 

 Beck, subtilis, Antcm, = vitrineUa, Beck, and orbis, Beck. 



The animal of the species I have had an opportunity of examining 

 is rather slender and elongate, tapering gradually posteriorly to a 

 point, and provided with a glandular opening, slightly raised, at 

 about an equal distance between the extremity of the foot and the 

 shell ; the mantle wholly included within the shell. They should 

 therefore be arranged in the family Stenopidce, under the genus 

 Ariophanta, rather than Nanina. 



The species enumerated in the following catalogue vary consider- 

 ably from the type ; their generic relations cannot be determined 

 until the animals have been examined. The columella of the typical 

 species is simple, occasionally slightly everted ; in others it is more 

 or less callous, sometimes deutately so, or the callosity is transverse 

 to the columella. 



The type is a depressed form, orbicular in shape, either rounded 

 at the periphery or slightly angulate ; other species are acutely an- 

 gulate, assuming a trochiform shape, one form of which M. Mousson 

 has lately separated under the generic name of Trochonanina. Other 

 species assume a conical shape, such as 77. cultrata, Gld., and conula, 

 Pse., which would, by some authors, be ranked under the European 

 genus Conuhts. 



Genus Trochomorpha, Alb. 



Trochomorpha trochiformis, Pfr. 



The above is one of several Ferussacian species which appear by 

 name in his ' Prodrome,' of which the types are probably lost, as 

 they are not described in his great work on land-shells, nor recorded 

 by M. Deshayes. The first description of the above is that by Dr. 

 Pfeiffer, from a Tahitian species, which is generally accepted as the 

 type, although the locality given by Ferussac is the island of Mau- 

 ritius. 



As there is at least a doubt as to the species originally named 

 by Ferussac, I think proper to attach the name of Dr. Pfeiffer to 

 the above as author. 



I have received several distinct species from collectors under the 

 name trochiformis, Fer. 



Dr. Pfeiffer' s type inhabits the island of Baiatea. It occurs of 

 larger size, and occasionally wholly dark brown or wholly pale yellow ; 

 a variety is rarely met with more depressed than the type, of a 

 whitish or pale yellow colour encircled by a single narrow dark 

 brown line or band ; base ornamented the same. On the island of 

 Moovea, where the species also occurs, this variety prevails and 

 assumes the size and shape of the type. 



On Tahaa, adjoining Baiatea, the type occurs of smaller size and 

 more conical in shape. 



