﻿JURASSIC AND TRIASSIC BRACHIOPODA. 



83 



Brachiopod. At any rate it does not belong to the same species as his fig. 4. Had not 

 two species been confounded under the same designation, the name lavis would have held 

 priority over that of reflexa. 



Mr. R. Tate informs me that the shell we now consider to be " the type of the species 

 under description is from the sandy beds surmounting the Upper Lias cement-beds at Blue 

 Wick (Sup., PL X, figs. 1,2). These beds have been classed by Dr. Wright in the 

 Upper Lias ; but, as they contain Am. Murchisonice and other characteristic fossils of the 

 Inferior Oolite, we remove them from the Lias. Associated in the same transition strata 

 are Linyula Beanii and Hit. cynocepJtala. 



Phillips and Simpson quote B. reflexa from the Upper Lias. The larger number of 

 specimens from the last-named formation are more or less flattened by pressure, in 

 which condition they agree with Distinct {Patella) papyracea of Miinster, Goldfuss, 

 Quenstedt, and others, and to which species Oppel referred specimens from the Alum- 

 shale of Whitby. I have no hesitation in placing Patella lavior, Fleming, and Helcion 

 sublcevis, d'Orb., among the synonyms of B. reflexa. 



I may add that there seems to exist a small concave curve in the posterior margin of 

 the specimens from the Inferior Oolite, which is also observable in some of those from 

 the Lias. 



It is possible, as Mr. R. Tate supposes, that the Biscina orbicularis and B. 

 Bavidsoni, Moore, may be young shells of the species under description ; but, as we know 

 so little with reference to them, it may be better to record their existence provisionally on 

 the authority of Mr. Moore. 



In addition to Whitby, the Peak, and Cleveland, B. reflexa has been found by Mr. 

 Tate at Lofthouse, Skelton Park Pit, Saltburn, Carlton Moor, Stokesby, &c. 



Very fine black, highly polished, and shining examples may also be seen in the 

 British Museum and in that of the School of Mines, attached to Leda ovum from the 

 Upper Lias of Grantham, Lincolnshire. This Biscina has also been met with by Mr. 

 Charles Moore in the Upper Lias of Ilminster. Some few examples showing the interior 

 of the smaller valve have been obtained from the Lias of Yorkshire. 



12. Discina orbicularis, Moore. Sup., PL X, figs. 9, 9 a, b, 10. 



Discina orbicularis, Moore. The Geologist, vol. iv, p. 99, pi. ii, figs. 16 — 18, 1861. 



I know very little respecting this species (?), which Mr. R. Tate suggests, in vol. vi of 

 the ' Geological Magazine' for December, 1869, may possibly be the young of Biscina 

 Holdeni : I may add, more probably the young of B. reflexa. Mr. Charles Moore 

 describes his species in the following words : 



