194 CCELOCION, CCELIAXIS. 



bilicus. Some specimens taper markedly, like the figures of. 

 C. exigua. These Warroo specimens seem to be nearer the 

 typical form than those from farther south at N. Pine River. 

 I have not seen specimens from Port Molle, the northern- 

 most point for the species, and also the type locality. 



The variety from North Pine Eiver (pi. 29, fig. 19; pi. 30, 

 figs. 27, 28, 29) is larger than the typical northern form, re- 

 tains more of the cuticle, has a more widely open, funnel- 

 shaped umbilicus, and weaker parietal ridge. It may event- 

 ually be separated from the northern form as a subspecies. 



The identity of C. exigua with P. australis, claimed by 

 Hedley, seems to admit of little question. C. exigua was de- 

 scribed as from the Solomon archipelago. One of the orig- 

 inal figures is copied in my pi. 30, fig. 25; and the original 

 description follows: " Shell narrowly and deeply umbilicate, 

 cj^indric-turrite, thin, obliquely rib-striate, pale fulvous; 

 spire decollate, tapering above; whorls remaining 11, sub- 

 planate, the last with a basal rib forming a groove in the in- 

 terior; aperture subvertical, rhomboidal, with a spiral pari- 

 etal fold in the middle ; peristome simple, continuous, solute, 

 the columellar margin expanded. Length 17, diam. 4 mill., 

 ap. 4 mill, long." (A. & A.) 



OTHER CYLINDEELLOID GENERA which should be mentioned 

 in this connection belong to a peculiar group of Stenogyroid 

 Achatinidce, characterized by the development of internal 

 lamellae on the axis, parietal wall and basal wall. The axis 

 is hollow in Cceliaxis, Pyrgina and Distcechia, solid and slen- 

 der in Thomea. 



CCELIAXIS Adams & Angas, P. Z. S., 1865, p. 54, type Subu- 

 lina (Cceliaxis] layardi Ad. & Ang. Bathyaxis ANCEY, Conch. 

 Exch., ii, p. 39 (Sept., 1887), same type. Sphalerostoma 

 GIRARD, Jornal de Sciencias Math., Phys. e Nat. Acad. Real 

 Sci. de Lisboa (2 ser.), ii, p. 247 (1892), same type. South 

 Africa. 



In this genus the parietal and basal lamellae are present in 

 young shells only, the columellar persisting in adults. The 



