604 Transactions. 
It is apparent that the shells now under consideration must be grouped 
with Chemnitzia s.l.—that is, with the family of Loxonematidae—since the 
growth-striae are far from straight, and since they show costae at one 
stage of growth. This conclusion is further supported by the obliquity of 
the columella, and by the tendency of the later whorls to mould themselves 
on the preceding whorls, a frequent feature of the Loxonematidae. 
"The genera of this family have been summarized by Dr. A. E. M. 
Cossmann (1) Miss McDonald and the writer consider that some of the 
genera are artificial, and, provisionally, are inclined to use the following for 
Mesozoic gasteropods (2) :— 
ygopleura : Whorls convex, sinuous axials, no spirals. 
atosira : As above, but with spirals. 
Hypsipleura : Whorls flat, axial ribs straight. 
While it is admitted that these genera are far too comprehensive, it is 
striata can scarcely have led to a shell with the growth-lines of Ps 
melania, and it may perhaps be considered as a parallel development. The 
alidae arose at about the same time as a development of the Loxo- 
nematidae (3), but these are characterized by the strengthening of the 
axial ribs, and the New Zealand specimens must not be regarded as in 
any way related to such early members of the Scalidae as Proscala (4), 
which is үтү ae progressing from smooth to costate 
Loxonematidae are not unknown from Cretaceous rocks. Unfortunately, 
cannot properly be made out. Cretaceous shells which should apparently 
referred to the Loxonematidae have been described by Stanton (5) and 
Stoliezka (6), among others, but these shells are costate throughout and "s 
are without the oblique growth-lines that characterize К. obliquestriata. ` 
The discovery of gasteropods with such distinetly Jurassic affinities 1D 
rocks that may be of Cretaceous age is interesting in view of the sug- 
gestion, recently disputed by Dr. Trechmann (7), that New Zealand faunas 
often show archaic features. : 
REFERENCES. 
1. M. Cossmann, Essais de paléoconch. comp., 8 (1909). : 
2. A. I. MoDoxarp and A. E. TRUEMAN, The Evolution of certain Liassic Gasteropods, 
Quart. Jour. Geol. Soc., vol. 77, p. 325. 
3. J. S. GARDINER, On Cretaceous Gasteropoda, Geol. Mag., 1876, p. 76. 
4. M. Cossmann, Esaias de paléoconch. comp., 9 (1912), p. 101. 
5. T. y M ее Formation and its Invertebrate Fauna, Bull. U.S. Geol. 
Ж „р. А 
6. F. Sroraczxa, € us Fauna of Southern India, іі, Palaeont. Indica (1868), р. 285. _ 
TRECHMANN, Cretaceous Mollusca from New Zealand, Geol. Mag., 1917, p- 296: p 
