126 TJEOMITEA. 



characterizes the later -whorls. These latter are nearly flat, 

 ■with an impressed suture, ornamented with subacute, longi- 

 tudinal ribs and small, closely- set strias, crossed by uneven spiral 

 threads. The body-whorl is subangulate, constricted anteriorly, 

 and attenuated so as to form a rather long canal, which is 

 encircled by prominent spiral ridges ; aperture small, prolonged 

 anteriorly ; outer margin slightly sinuous, thin ; columella with 

 four plications, increasing in size antero-posteriorly. 



Dimen&ions. — Length 16 mm. ; breadth 6 mm. ; length of 

 aperture 6 mm. 



Form, and Loc. — Eocene : Muddy Creek, Yictoria. 



G. 4249. Two specimens. Presented ly John Bennant, Esq. 



G. 9362. A series illustrating stages of growth. Purchased. 



Uromitra paucicostata, Tate (sp). 



1889. Mitra [Costellaria) paucicostata, Tate, Trans. Eoy. Soc. South Aust. 



vol. xi. pp. 136, 141, pi. V. fig. 2. 

 1893. Mitra paucicostata, Tate and Dennaut, id. vol. xvii. pt. 1, p. 220. 



Protoconch as in U. leptalea. In the neanic stage the columella 

 has three plications ; but as the adult form is attained four make 

 their appearance by the development of a fold anteriorly. The 

 shell differs primarily from that of the species mentioned, in 

 having the longitudinal costfe farther apart, more convex and 

 turriculate whorls, and in the body-whorl being biangulate. The 

 aperture is lirate within. 



Bimensions. — Length 12 mm. ; breadth 4 mm. ; length of 

 aperture 4 mm. 



Form, and Loc. — Eocene : Muddy Creek, Victoria. 



G. 9364. Two specimens. Purchased. 



Uromitra exilis, Tate (sp.). 



1889. Mitra [Costellaria) exilis, Tate, Trans. Eoy. Soc. South Aust. vol. xi. 



pp. 135, 140, pi. viii. fig. 5. 

 1893. Mitra exilis, Tate and Dennant, id. vol. xvii. pt. 1, p. 220. 



Protoconch similar to that of U. leptalea. In the brephic stage 

 it must be difficult to separate this species from young individuals 

 of TJ. paucicostata, and they are unquestionably of common origin. 



