466 Transactions. 
anteriorly and bear several recurved spines. Not related to any other 
Australian species. The single fine specimen was collected for the writer 
by Miss Frances Milnes, after whom it is named. 
Trigonostoma waikaiaensis n. sp. (Plate 49, figs. 4a, 45.) 
Shell moderately large, subscalar. Thirteen axial ribs on body-whorl, 
rounded, rather low and sloping backwards, not obsolete on upper whorls, 
interstices about twice their width; they extend over the whole whorl, 
т and narrower but still strong on base. Axials crossed by rather 
inflected to the right. Inner lip strongly callous, thick anteriorly, but 
thinning and spreading above parietal wall; interior filled with hard 
matrix, but extremities of three oblique plaits can be seen, the upper two 
much stronger. Siphonal fasciole prominent, crenulated by axial ribs, 
strongly curved, leaving a decided umbilical chink between it and inner lip. 
eight, 32 mm. ; diameter, 20-5 mm. ; height of aperture, 18 mm. 
The holotype and two other fragmentary shells, from Waikaia, in 
author’s collection: 
The inflection of columella and aperture to right indicates a member 
of Trigonostominae, and for the present the species may be left in the 
wannonensis (Tate), which differs generically in having columella bent to 
left, and otherwise in its regularly rounded outline below shoulder, the 
fewer, narrower, higher, and more curved axial ribs, slightly different spiral 
sculpture, weaker umbilicus and fasciole, and much lower spire, the ratio 
чүч : spire in the New Zealand shell being 1-3 and in the Australian 
shell 1-9. 
Trigonostoma christiei n. sp. (Plate 49, fig. 5.) 
Similar in essential details to previous species, but larger, more sta ed 
and with much more numerous axial ribs. Protoconch of 2 slightly bulbous 
whorls, almost equal in size, but mamillate tip very small; then a brephie 
stage of $ whorl with only spiral cords ; then 6 whorls with adult sculpture. 
ighteen axial ribs per whorl, of similar character to those of last species, 
ut narrower; interstices 1-2 times the width of ribs. Spirals rather 
stronger than in T. waikaiaensis, but otherwise similar in number, character, 
