W. a. HucUeston — On the Torkshire Oolites. 243 



116. — Che3initzia lineata-procera, var. Scarburgensis, Morris and 

 Lycett, 1850. Plate VI. Fig. 4. 



1850. Chemnitzia? Scarburgensis, M and L., Gt. Ool. Moll. p. 115, pi. xv. fig. 8. 

 1875. Chem. Scarburgensis, L. and M., Phillips, G. Y. 3rd edition, p. 257. 



Bibliography, etc. — This " species " was described from a flattened 

 cast, which is now in the Bean Collection at the British Museum. The 

 authors' figure conveys a false impression of the real shape, and causes 

 an appearance of a larger spiral angle than is warranted. If the 

 cast were restored to its proper shape, the angle would not be 

 materially larger than in the specimen described below, which is 

 unusually fine and in good preservation. 



Description. — Specimen from the Scarborough Limestone (zone 3). 

 Leckenby Collection. 



Length (restored) 138 mm. 



Width 24 ,, 



Length of body-whorl to entire shell 29 : 100. 



Spu-al angle 13°. 



Shell conical, elongate. Spire consists of about 15 whorls. These 

 increase in height regularly by one-third of a turn each time. The 

 apical whorls are flat, but presently the belt near the suture begins 

 to develope, and the median constriction to show. As the whorls 

 attain a more mature stage, the constriction is most marked in the 

 upper third ; anteriorly the whorl swells again before curving 

 inwards to meet the suture. In the last two whorls the belt is 

 very prominent and rounded (possibly from attrition or otherwise). 

 Certain rugose markings in connexion with lines of growth are 

 noticeable, principally on the penultimate whorl. No punctate 

 structure visible. 



The specimen, being involved in matrix, has been drawn in an 

 oblique position. 



Belations and Distribution. — I cannot see any real difierences, other 

 than those due to fossilization, between this specimen and specimens 

 from the Millepore Bed and Dogger. This is a very acicular form, 

 having perhaps rather a smaller spiral angle than the average of 

 specimens.^ 



The common Bajocian Chemnitzia of the Yorkshire Beds is dis- 

 tinguished by this small spiral angle from another and stouter form, 

 which really is perhaps entitled to be regarded as a distinct species. 



12. — Chemnitzia ? coarctata, Deslongchamps, 1842. 



1835. Melania Seddingtonejisis, Sow., Phillips, G. T. pp. 123 and 129. 

 1842. Melania coarctata, DesL, Mem. Soc. Linn. Norm. vol. vii. p. 226, pi. xii. 

 figs. 11 and 12. 

 Melania Seddingtonensis, (pars) Deslong., ibid. p. 225. 



^ One of the evils of having too many names for slight varietal differences is 

 illusti'ated in the tables of fossils given by Dr. Wright in his admirable and in- 

 structive paper on the Inferior Oolite of the South of England and of Torkshire 

 (Q. J. G. S. 1859) ; e.g. from the Humphresianits zone of Somerset the author quotes 

 Chem. lineata, Sow. (p. 36), from the Grey Limestone (zone 3) of Torkshire Chem. 

 Scarburgensis, Lye. and Mor. (p. 30), and from the Oolite Marl of Cheltenham 

 Chem. procera, Deslong. (p. 13). What, I wonder, is the real biological distinction 

 between these three? As a museum label for the cast of a Bajocian Chemnitzia in 

 a grey matrix, probably Ch, Scarburgensis may continue to do duty. 



