MOLLUSCA FROM JUAN FERNANDEZ AND EASTER ISLAND 24Q 



The terrestrial mollusca collected belong to the following species: 

 Limax arboruiii BouchardChantereaux, many sps., max. 1. 33 mm, ^/t. 

 *Milax gagates Draparnaud, many sps., max. 1. 23 mm, ^li. 

 *Melanipus philippii Kiister, i sp., h. 9,5 mm. 



Melampus pascus n. sp. PI. 8, fig. 5. — Shell small, short and broad, 

 without trace of umbilicus, smooth, except very fine lines of growth; colour 

 light yellowish brown, paler (almost grayish-white) on the shoulder and the base 

 of the body-whorl; middle of this whorl with 3 narrow, almost obsolete, lines 

 of yellow. Aperture with 3—4 lamellae on the columellar wall, the uppermost 

 (or second) under the middle of the aperture height, and very strong, the 3rd 

 very indistinct and separated from the 4th by a deep sinus; the undermost 

 fold strongly twisted, crossing the lip and joining its outer margin. Outer lip 

 with simple margin having 8 long plicae deep on its inside but no callus at its 

 margin. Spire much depressed, with a small acute apex. Whorls 8. Dimen- 

 sions of the shell: height 5, a, h. of aperture 4,5, breadth of the shell 3,6 mm. 



The small size and the short and broad habitus of this shell, of which 

 only two dead specimens were collected on the beach, separate it from the 

 preceding species and approach it to M. brevis Gassies, from N. Caledonia, or 

 to M. parvulus (Nuttall) Pfeiffer, from the Sandwich Islands. From both it is, 

 however, distinct in the kind of armature of the aperture. 



Pacificella n. gen. [^romatelUna Pilsbry, 191 5, partim, non [Beck] Pfeif- 

 fer, 1842). 



Shell small, imperforate, uniformly brown or corneous, aperture with a 

 parietal lamella (sometimes lacking in adult specimens), and a sinuous, often 

 lamellate, colurnella; palatal wall smooth or variously toothed. 



Genital organs with a well developed penis, situated above the eye retractor 

 and having a bifid retractor, inserted with its one part on the penis proper, 

 and with the other on a short flagellum; spermatheca with long stalk; albu- 

 miniparous gland well developed; no, or vestigial, vesicula seminalis. 



It becomes necessary to separate generically the species described below 

 from the genus Tornatellina in its original sense, restricted to the Juan Fernandez 

 forms, on account of important anatomical differences. These characters, it is 

 true, are found hitherto in one single species only, and thus the limitation of 

 the new genus cannot yet be stated, but it seems likely that a large number of 

 the species referred to Tornatellina in the sense of PiLSBRY, will show congenity 

 with the present new form in their anatomy quite as well as they do in their 

 shells. Previously, until further knowledge has been gained, the genus Pacifi- 

 cella may be retained within the same family as the typical Tornatellinas; to 

 this family the name Tornatellinidae is to be attributed on the grounds exhibited 

 above by treating the Juan Fernandez fauna. 



Pacificella variabilis n. sp. PI. 8, figs. 15 — 17. — Shell elongate, imper- 

 forate, horn-brown, often with pale-brown narrow spiral lines on the last whorl; 



