110 Proceedi7igs of the Royal Society of Victoria. 



each of wliich has a medial finer thread with a pair of still tiner 

 threads on either side of it. The posterior third is occupied by 

 from about ten to fifteen very fine spiral threadlets, also the fine 

 lines of growth of the sinus are in this space. Both costfe and 

 spiral threads are traversed by the fine oblique forwardly directed 

 lines of growth. 



Dimensions. — Length, 27 min. ; breadth, 8 mm. ; length of 

 aperture, 6 mm. ; breadth of aperture, 3 mm. ; length of canal, 

 8 mm. Some of the young examples of this species in the collec. 

 tion have only attained the length of 13 mm. 



Locality. — Not uncommon in the eocene beds of Table Cape, 

 Tasmania, also in the lower beds of the lower eocene series at 

 Spring Creek, near Geelong, Victoria. 



Observations. — This species, as is commonly the case in the 

 genus to which it belongs, shows a considerable range of varia- 

 tion, especially in the ornament. In the present form the costaj 

 and spiral threads vary in number and in strength. In some 

 examples the former become so weak on the anterior whorls that 

 it would not be surprising, should examples subsequently tuni up, 

 in which the costse had become altogether obsolete on the body- 

 whorl. I am not at present acquainted with any living species 

 which shows any marked affinity with the present form. 



60. Drilia cpeniilaroides, sp. nov. Plate III., figs. 6 and 7. 



Shell moderately large, narrow-elongate, spire many-whbrled 

 and longer than the aperture and canal, whorls nodulosely 

 costate, with a i-ather well marked subsutural concavity, sinus 

 in this region well-defined, moderately broad and deep, canal 

 rather short and straight. 



Apical angle about twenty-five degrees. Embryonic whoi'ls 

 unfortunately missing. Spire consisting of about eight convex 

 whorls, greatest convexity about the middle of each whorl, 

 the posterior third of each whorl rather deeply concave imme- 

 diately under the suture, which gives the appearance to this 

 part of the shell of rather a strong overlap of the whorls, 

 anterior two-thirds convex, most marked at the costie. 



Aperture oval, somewhat contracted posteriorly, and gradually 

 drawn out anteriorly into a short, slightly curved and open 

 canal, which is about the same length as the aperture. Outer 

 lip thin and slightly crenulated at the outer edge with a very 



