96 Transactions. 



Art. Xll.~New Fossil Mollusca. 



By J. A. Bartrum, Auckland University College, 



[Read before the Auckland Institute, 20th December, 1918 ; received by Editor, 

 30th December, 1918 ; issued sejjurately, 14th May, 1919.] 



Plate VI [. 



The following Mollusca have mainly been collected from fossiliferous 

 sands near the mouth of Kawa Creek, about fourteen miles south of the 

 mouth of the Waikato River, which are described by the author in 

 another paper in this volume (pp. 101-G). One — Chione auriculata n. sp. 

 — was collected by the author when in company with Dr. Marshall at 

 Pakaurangi Point, near Batley, Kaipara Harbour, in 1916 ; another- — 

 Bittium oamaruticum n. sp. — was within a large gasteropod collected by 

 Dr. Marshall from the Hutchinson's Quarry beds at Oamaru and given to 

 the author; whilst there is one — Raeta (enuiplicata n. sp. — which was 

 collected by Mr. E. P. Worley from the Okahukura Tunnel. All were 

 submitted to the late Mr. H. Suter for identification, and pronounced by 

 hnn to be new species. 



In addition to Chione auriculata n. sp. there was identified also by 

 Mr. Suter, from the Pakaurangi Point beds, along with other fossils collected 

 by the writer, a specimen of Mesalia striolata (Hutt.), a species not listed 

 by Dr. Marshall in his recent paper.* 



Bittium oamaruticum n. sp. (Plate VII, fig. 1.) 



Very small elongate tapering shell of 11 very slightly convex whorls 

 increasing gradually in size. Protoconch 2 J whorls, smooth : the other 

 whorls with strong subvertical rounded axial ribs subequal in width to the 

 interspaces, and made slightly nodular by 6 or 7 prominent rounded spiral 

 threads with linear interspaces. The radial costae are 13 in number on 

 later whorls, dying out on flattened base of body-whorl. Only one or 

 two spiral threads on base below the angle of the body-whorl. Sinuous 

 growth-lines distinct on base. Suture fairly deep, margined. Columella 

 smooth, oblique, imperfect. Aperture imperfect, one-third of body-whorl 

 being absent ; would appear to have been narrowly ovate and notched 

 jiosteriorly. Inner lip very narrow, a mere film on body- whorl. 



Length, approximately 5 mm. ; diameter, 1-7 mm. . 



Holotype in Auckland University College collection. 



Localitv : Hutchinson's Quarrv beds. Collected by Dr. P. Marshall, 

 1917. 



Remarks. — Classed as a new species of the genus by the late Mr. H. 

 Suter, though the lack of knowledge of the aperture appears to render the 

 generic position somewhat uncertain. If correctly placed, this genus is now 

 for the first time described fossil from New Zealand rocks. 



* P. Makshall, The Tertiary Molluscan Fauna of Pakaurangi Point, Kaipara 

 Harbour, Trans. X.Z. hist., vol. 50, pp. 263-78, 1918. 



