Quarterly Journal of Conchology. 53 



not only by their smooth, polished surface, but by their purely arboreal 

 habits. L. Alaugeri (Wood), the commonest and best known species, 

 is exceedingly abundant in Jamaica on pimento trees. 



Another section will also, I think, have to be raised into a genus 

 — Casta (Albers). This consists of three Jamaica species — aquesiana 

 (Adams), elongata (Chem.) and gracilis (Wood), which differ from the 

 rest of the genus by their sinistral volution, pure white colour, and 

 more particularly by being viviparous. They all have similar habits, 

 being found sticking, like so many spikes, on rocks and stone walls, 

 on the lichens clothing which they feed. I have personally ascer- 

 tained both their viviparity and the nature of their food. 



The genus Lia^ it should be mentioned, contains ten species — 

 eight from Jamaica and two from Haiti. 



The genus Cylindrella, after the separation of all these new genera, 

 still remains very rich in species, numbering nearly 200. Its 

 distribution becomes still more largely West Indian. To this, however, 

 there is one curious exception, Gyl. Cumingiana (Pfeiffei"), from the 

 Philippines. As this species, however, is only known by its shell, 

 and even that differs from the rest of the genus in being umbilicated, 

 it is doubtful whether it really belongs to Cylindrella. The most 

 remarkable forms in the restricted genus are : — 



1. The rosea group. These are thick pupiform shells, of large 

 size for the genus, and varying in colour from light pink to dark 

 purple. The peristome is often more or less attached to the last 

 whorl. In external characters they are Eucalodia m. miniature. 

 They are chiefly Jamaican. 



2. The BrooTisiana group. These are remarkable for the inordi- 

 nately long detached tube into which the last whorl is pro- 

 longed. The extreme is found in C. Brooksiana (Gundlach), in 

 which the tube is more than half the length of the rest of the shell, 

 but the character exists in more moderate proportions in C. angustior 

 (Wright) and others. All these species are from Cuba. 



3. C. Ulliotti, (Poey), from Cuba, is covered with hollow spines or 

 tubes, in a manner that reminds one of ChoanojJOJiia echinus and 

 /tystrix, from the same island. 



This is one of the most peculiar of all known land-shells, and 

 good specimens, with the white spines brought into relief by the 

 chocolate ground-colour of the shell, are wonderfully beautiful. 



One peculiarity of the genus, to which there are but few excep- 

 tions, is the decollation of the spire. As the moUusk attains 

 maturity, the animal deserts the upper whorls of the shell, and these 

 almost invariably get broken off, and it is therefore necessary when 

 describing a Cylandrella to state whether the number of whorls is 

 that of an entire shell, or after decollation. This peculiarity is 

 shared by Costa, Lia, and Eucalodium, 



Several species of Cylindrella have peculiar revolving lamellae on 

 the columella. 



The true Cylindrellce are not arboreal. Many of them, especially 

 of the rosea group, are chiefly found on the ground amongst dead 



