4 PEOCEEDINGS OF THE NATIONAL MUSEUM vol.72 



the ventral side close to the periphery with a distinct lip and 

 short neck. 



Diameter, 0.40 mm. ; thickness, 0.22 mm. 



Holotype. — (Cushman Coll. No. 6725) from the interior matrix 

 of a Cerithiv/m gigpnitev/m from the Eocene, Calcaire grossier of 

 Grignon, France. 



It may be noted here that Terquem figures a species of Sifhonina 

 from the Eocene of the Paris Basin. ^ The measurements given are 

 somewhat larger than our type. The figures given by Terquem are 

 very evidently patterned after the type figures of Reuss but are 

 reversed in drawing. 



In Paris, through the kindness of Dr. G. DoUfus, I was enabled 

 to examine the specimen figured by Terquem. It is a much smoother 

 form than the figure indicates, and is not at all well drawn, a criti- 

 cism that will apply to most of Terquem's figures with which I com- 

 pared the original specimens. 



In this Middle Eocene species there is an advance in the greater 

 development of the apertural characters over those of the lower 

 Eocene. 



SIPHONINA HOWEI, new species 



Plate 3, figs. 6 a-c 



Test small, nearly circular, nearly equally biconvex, much com- 

 pressed, periphery angled, sharply acute and with a distinctly serrate 

 keel, lobulate, chambers usually six in the last-formed volution, the 

 last few very slightly inflated on both sides ; sutures distinct, depressed, 

 slightly limbate, very slightly curved; wall distinctly spinose with 

 short blunt spines and the periphery very serrate; aperture broadly 

 elliptical, occupying nearly the whole height of the last-formed 

 chamber, with a distinctly thickened lip and short neck. 



Diameter, 0.30 mm. ; thickness, 0.10 mm. 



Holotype. — (Cushman Coll. 6726) from Lower Claiborne, Cane 

 River formation at Natchitoches, Louisiana. The species is named 

 for Dr. Henry V. Howe, who has done so much work on the pale- 

 ontology of Louisiana. 



This species is easily distinguished by its high degree of ornamen- 

 tation and much compressed test. 



SIPHONINA CLAIBORNENSIS, new species 



Plate 3, figs. 5 a-c 



Test small, nearly circular, nearly equally biconvex, somewhat com- 

 pressed, periphery angled, sharply acute, with a very slightly de- 

 veloped keel, lobulate ; chambers usually five in the last-formed volu- 



iM6m. G6ol. Soc. France, ser, 3, vol. 2, 1882, p. 84, pi. 8 (16), flg. 16 Or-c. 



