BY H. LEIGHTON KESTEVEN. 475 



specific nomenclature. I have thought it would be useful to 

 collect these together. 



LOTORIUM WATERHOUSEI, Ad. (t Ang. 



This species, rightly treated as distinct by Tryon, has been 

 relegated to the synonymy of L. spengleri, Chemnitz, by Pritchard 

 and Gatliff (29, 264). The revolving ribs of spengleri are broader 

 than their interstices; those of luaterhousei are only half as broad, 

 and duplicate. The transverse lirse of the former are very much 

 coarser than those of the latter. The varices of L. waterhousei 

 are filled up inside, whereas in L. sj^engleri the porcellanous 

 interior may be seen in every varix. The epidermis of L. 

 spengleri is quite smooth; that of ivaterhousei is, as its authors 

 say, "squamato-pilose." In Port Jackson, where L. spengleri is 

 to be found on most of the rocks, L. waterhousei never occurs. 



LoTORiUM GRACiLE, Reeve. 



Both Watson (39, 394) and Dall (7, 227) disagree with Tryon 

 that this is a synonym of L. vespaceum. 



LoTORiuM PARKiNSONiANUM, Perry. 



I have said of this species that it is not related to the ^Hritonis '' 

 group. In arriving at this conclusion I have been influenced by 

 the evolution of the species as evidenced by its stages of growth. 

 It is one of the few species in which a neanic stage is plainly 

 definable. I regard it as being a very recent species evolved 

 from L. to7'tirostris, Tate. My reasons for so regarding it are — 

 (1) it has the contour of this species; (2) had it existed in Tertiary 

 times it is reasonable to suppose it would have been found in 

 these beds^ especially as (3) it is common on the coasts of South- 

 Eastern Australia; (4) in the neanic stage it is ornamented with 

 the complex sculpture of this form (vide 19, pi. 36, ff. 3, 4); (5) 

 some specimens of L. tortirostris show a tendency to lose their 

 complex sculpture on the ultimate whorls. On the other hand, 

 there is undoubtedly an underlying, but indefinable, resemblance 

 to the " tritonis "-group. This, it seems, is to be attributed to a 



