MOLLUSCA FROM JUAN FERNANDEZ AND EASTER ISLAND 235 
new genus Pacificella {see below|, which, however, may perhaps be made the 
type of a distinct family) may be given as follows: — 
Radula (fig. 14) achatinelloid but its front part reflected and ring-like 
closed’, genital organs (fig. 15) situated above the retractor oculi?; penis with 
a well developed appendix and a bifid retractor inserting with the one part the 
penis proper, with the other the appendix; spermatheca with a very long 
stalk; albuminiparous gland well developed. Viviparous; oviduct with many 
embryoes. 
The most important conchological character of Tornatellinidae is, according 
to PILSBRY, the presence of a parietal lamella in the aperture. This is a feature 
constant in Zornatellina proper, but is wanting in Fernandezia, which proves, 
however, to be very closely related to Zornatellina. There exists, indeed, two 
species, which are variable in this respect inasmuch as they lack a parietal 
lamella in adult stage but possess it as young. This fact proves that the 
anatomical characters alone are available for constituting natural groups and 
judging affinities of the Pacific land mollusca in question. 
Tornatellina (Beck) Pfeiffer 1842. 
PILSBRY, in his excellent Monograph of Tornatellinidae, (1915), states that 
»the type of TZornatellina is a little-known species from a peripheral locality 
(Juan Fernandez)». This type is 7. dcz/amellata Anton, and to the same genus 
a great many species have been allotted, scattered over the whole Pacific, 
though the interrelations of them, as PILSBRY holds forth, have been totally 
undetermined on account of the entire lack of anatomical data. I am inclined 
to the opinion that they must be further divided, the Pacific forms probably 
being, to a great extent, congeneric with the Easter Island Paczficella variabilis, 
described below, and the Juan Fernandez forms solely constituting the genus 
Tornatellina. The anatomical characters of this genus are deduced from an 
examination of the typical species 7. dc/amellata and prove to coincide with 
those of ernandezia, though there is a much longer appendix of the vestigial 
penis, and that is simply cylindrical and destitute of the accessory sac, charac- 
teristic of the other genus. 
Tornatellina bilamellata Anton. Pl. 9, fig. 36 (a variety). — The 
specimens before me agree in size as well as in habitus and dentition with the 
figure given by KUSTER (Conchyl. Cab. I: 15, Pupa, pl. 18, figs. 35), the identity 
stated by PFEIFFER and SMITH, who also record it from Juan Fernandez, thus 
being verified. ANTON’s locality of the typical specimen, »Opana:», is certainly 
a mistake (cf. PILSBRY I915, p. 139). 
Localities. Masatierra, Aug. 1917: Pangal, on ferns and under leaves, 
many shs., max. h. 7, br. 3,2, and h. 6,5, br. 3,2, and h. 6,2, br. 3,3; all with 8 
1 In Achatinellide the radula is open throughout. 
2 In Achatinellide the eye retractor (the right in dextral, the left in sinistral animals) is 
situated above the penis according to an examination of Achatinella livida Swainson from 
Honolulu, Eugenie Exp. 1852 (Riksmus.). 
