350 PROF. E. FORBES ON LOWER GREENSAND FOSSILS. 



bigny, T. C. pi. 154. f. 1. A figure of our specimen is given to 

 draw attention to a remarkable species. 



Loc. Atherfield. 



133. Rostellaria Robinaldina, D'Orbigny. 



Loc. Atherfield, Shanklin, Peasemarsh, Pulborough. 



This is the Rostellaria Parkinsoni of British Lower Green- 

 sand lists. Under the name of Parkinsoni many species have 

 been confounded. 1st. The Blackdown species of which a good 

 figure is given in Dr. Fitton's Memoir, and which may be regarded 

 as the original species of Parkinson, the uppermost of the two 

 figures numbered 3 in plate 558 of the Mineral Conchology being 

 taken as representing the type. In the R. Robinaldina the keel 

 of the labial wing is continued over the body whorl, and the ribs 

 on that whorl are very short. In the Upper Greensand or 

 Blackdown species the body whorl is not carinated and the ribs 

 are long. 2d. The London clay species now called Rostellaria 

 Sowerbii. 3d. The chalk marl species figured and named Ros- 

 tellaria Parkinsoni by Dr. Mantell in his Geology of Sussex, who 

 however gives the same name to the Lower Greensand species. 

 The chalk marl form may be identical with, 4th, the species from 

 the Gault called Rostellaria marginata in Dr. Fitton's Memoir, 

 and which is the Rostellaria Parkinsoni of D'Orbigny. It has 

 two keels on the body whorl. 5th. The species before us, for 

 which D'Orbigny's name had best be retained. 



134. Rostellaria glabra. Sp. nov. (pi. iv. fig. 5.) 



Testa elongata, anfractibus 9, seperioribus oblique costatis 

 spiraliter striatisque, striis ad suturam profundioribus, ultimo 

 anfractu glabro, labro expanso, aliformi, triuncinato. 



Lon. 2\ ; lat. 1 \ unc. 



Shell elongated, whorls rather convex, those of the spire are 

 striated spirally, the strias near the suture being so deep as to give 

 them a marginated aspect, and crossed by oblong slender ribs 

 which are much less numerous than in the last species. The body 

 whorl is gently rounded and nearly smooth, or with a few spiral 

 striae only near the suture. The whorl next above it is also free 

 from transverse ribs. The lip is very large and expanded. It is 

 produced above into a long slender linear spur, which if attached 

 to the spire would have converted the shell into a Pterocera. In 

 front the lip has two other diverging spurs of a lanceolate form. 

 The canal is long and very slender. 



Loc. Atherfield. 



135. Pterocera retusa {Rostellaria sp.) Sow. in Fitton, G. T. 



2d ser. vol. iv. pi. 18. f. 22. 



Syn. Rostellaria bicarinata Deshayes ? (Pterocera bicarinata 

 D'Orbigny.) 



