560 Transactions. 
The last eight species form a distinct group. They are smaller and 
have a more restrained apertural callus than the others The umbilicus 
is restrieted and generally quite filled by the narrow funicle and callus, 
on whieh there are two almost parallel grooves (sometimes one or both 
obsolete). The arrangement of the umbilical callus is rather like that 
in the subgenus Mammilla, which, however, has a more distended aperture. 
It is possible that the relationship is closer to it than to Uber s. str. 
Uber huttoni (von Ihering). (Plate 58, fig. 10.) 
1873. Natica solida Sowerby : Hutton, Cat. Tert. Moll., p. 9 (not of Sowb.). 
1886. Natica solida Hector, Outline of N.Z. Geol., p. 51, fig. 9, No. 19. 
1886. Natica (Neverita) gibbosa Hutton, Trans. N.Z. Inst., vol. 18, p. 334 (not of 
а). 
1907. Polynices huttoni v. Ihering, Ann. d. Museo Nac. de Buenos Aires, serie 3, 
tomo 7, p. 154, pl. 5, fig. 16. 
1915. Polinices gibbosus (Hutton): Suter, N.Z. Geol. Surv. Pal. Bull. 3, p. 9, 
pl. 5, figs. 1, 2. 
Type in Museo Nacional, Buenos Aires. 
Height, 68 mm.; diameter, 64 m. (taken from Hutton’s plesiotype of 
N. solida Sowb. — N. darwini Hutt.). 
‚ Localities.—Broken River, Trelissick Basin (type); 165, White Rock 
River, Pareora; Target Gully shell-bed, Oamaru; Tangarakau River, 
two miles below large waterfall (Mokau beds); Maungamatukutuka, | 
44, Conus beds, Brewery Creek, Mokihinui River; Chatton, Southland, 
sharp-spired form (R. A. Sutherland); Waikaia, sharp-spired form; 65, 
бс, бр, 7B, 7с, 8a, Clifden, Southland. 
yP 
deposition of the Matapiro beds (— Nukumaruian). 
open umbilicus not invaded by callus, such as those (N. suteri 
itaki Valle 
The two - 
names are therefore synonymous; and, as N. gibbosa was already occupied — 
Round U. huttoni are grouped a large number of variable forms, for — 
which satisfactory specific divisions have not yet been found. Among . 
the material available no absolute line could be drawn between such | 
extreme forms as U. unisulcatus and U. intracrassus (= N. callosa utt.) 
At Chatton there is a large shell with a high, sharp spire; at Waikala — 
and in several horizons at Clifden are somewhat similar though smaller — 
ones apparently grading into a much broader type with a low Spy - 
Perhaps some of the differences are due to sex, but there is variation _ 
in shells from different localities. Both forms are represented at Target 
Gully with slight differences in outline. The shells of White Rock Rivet, - 
| Pareora, are of more uniform character, being cylindrical in shape, with — 
а low spire, and reaching a very large size (like the typical Broken River — 
specimens). There is considerable variation, however, in the comp mát = 
length and callosity, a process carried to extreme in the U. inéracr 
a 
» Lore 
