96 TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS. 
Realia scitula, Gray, Cat. Phan., p. 220. Pfeiffer, Mon. Pneum., iv, p. 220. 
Hydrocena scitula, Pfeiffer, Mon. Pneum., ii, p. 162. 
Atropis scitula, Pease, Proc. Zool. Soc., 1871, p. 476. Schmeltz, Cat. Mus. Godeff., v, p. 102. 
This protean species is very common and widely diffused throughout all the valleys 
on the northwest part of Tahiti, and is equally as plentiful in the various valleys on 
Moorea. On the ground in forests. 
Though usually cited as Gould’s scitula, I have serious doubts of the correctness 
of the identification. His diagnosis is as follows :— 
“'T. parva, elongato-conica, tenuis, rufo-cornea, striis incrementi tenuibus solum 
insculpta, arcte umbilicata ; spira elevata, anfr. 6-7 rotundatis, supernis subangulatus ; 
sutura profunda; apertura rotundato-ovata, parva, trientum longitudinis adequans ; 
perist. simplex, pallidum. Long. 1-5, lat. 1-10 poll.” (Gould). 
In his remarks he says: “Almost exactly like Amnivola Suyana, Anth. It is 
larger and more ventricose than C. vallatum, and is distinguished from C. terebrale by 
its less slender form and unexpanded lip.” 
The above short diagnosis does not agree very closely with the numerous specimens 
now before me. His dimensions are too small to accord with our shells. Neither do 
they resemble Binney’s figure of Amnicola Sayana. ‘The only Tahiti shell that 
resembles Binney’s figure is Atrop/s Bythinel @formis, which is the same size as Gould’s 
species, but the whorls are not * supernis subangulatus,” 
The species under consideration is 6 mill. long and 3 mill. in diameter. The spire 
is oblong-conical with slightly convex outlines ; whorls six, convex, smooth, the penul- 
timate frequently projecting over the suture as in ferebralis, and sometimes filocari- 
nated at the angle. The last whorl is more or less distinctly angulated, rarely with 
a thread-like keel; sometimes rounded. The axis is rimate or minutely perforated 
and the margin slightly compressed, rarely filocarinated, sometimes simple, as in 
Atropis. The nearly vertical aperture is ovately rounded, with a slight posterior angle 
and about one-third the length of the shell. 
O. optonaa, Pfeiffer. Plate IIT, fig. 59. 
Hydrocena oblonga, Pfeiffer, Proc. Zool. Soc., 1854, p. 305; Mon. Pneum.,ii, p. 159. H. and 
A. Adams, Gen. Moll., ii, p. 299. 
Omphalotropis oblonga, Pease, Jour. de Conch., 1869, p. 154. 
Atropis oblonga, Pease, Proc. Zool. Soc., 1871, p. 476. 
Realia oblonga, Pfeiffer, Mon. Pneum., iv, p. 213. 
Abundant on the ground in forests, on the north side of Moorea. 
I think Pfeiffer is wrong in assigning this species to the Marquesas Islands. The 
Moorea shells coincide so nearly with his description, that I do not in the least hesitate 
in referring them to his species. I am also inclined to believe it only a form of seitwla. 
My largest examples are 7 mill. long by 3} in diameter, being a little larger than 
