Prof. E. HuU—The Permiaii and Trias. 



491 



obliquely from the front, dividing it into several (4) lobes. Cirrhi 

 and setee unknown. 



The particular characters of the species are the proportions of the 

 body and feet, and the shape of the latter. It is distinguished from 

 M. McLeaiji by its larger size and broader axis, and by its broad oval 

 feet. 



Locality and Formation. — ]\Iorben, near Machynlleth ; in the 

 Metalliferous Slate Series. 



Orthoceras, sp. PI. XL Fig. 18. 



I have not been able to determine the species of this Orthoceras, 

 for the shell itself is unknown, only internal casts being found. 

 The more mature part of the shell is similar to 0. vagans in its 

 distant septa, but it tapers more rapidly. In the younger shell, on 

 the other hand, the septa are closer set, and the shape is more cylin- 

 drical. Other cylindrical and slender Orthoceratites with distant 

 septa also occur, and if all these belong to one species it must be 

 very variable in form. 



Measurements. — Length, 3 inches ; breadth of broad end, 10 mm. ; 

 breadth of small end, 2^ mm. ; breadth midway, 4^ mm. ; distance 

 between septa midway, 3 mm. ; distance between septa near apex, 

 1 mm. 



Localities. — Corys ; Taren y Gesail ; IMelin Newydd Valley ; 

 Eglwys Each ; Cefn Hendre ; and Steddfa Gurig. 



EXPLANATION OF PLATE XI. 



Fossils from the Cardigansldre Group (LlaBdoveries). 

 Fig. 1. Buthotrephis major, Kpng., river side near Tal y bont. 



2. ,, ,, Tar. Llyn Fron Goch, Llantrisant. 



3. ,, minor, Kpng., Pont Erwyd. 



4. Algae from Mjnydd bach. 



5. Palceochorda tardijurcata, n. sp. Aberystwyth. 



6. Retiofueus extensus, n. sp. Cefn Cocli, Aberystwyth. 



7. ,, ,, young form, Allt wen, Aberystwyth. 

 8-11. Nemaioliles Edw^zrdsii, n. sp. Aberystwj'th. 



12ff. Nematolites dendroideum, n. sp. near Llantrisant, 



\2b. A part of same enlarged. 



13a. Bentalina. 



13J. The same magnified, Cwm Symlog. 



14. Textularia, magnified, Cwm Symlog. 



15. Rotnlia? magnified, Cwm Symlog. 

 16,17. Myrianites Lapworthii, n. sp. Morben, Machynlleth. 



18. Orthoceras, sp. Taren y Gerail, S. of Cader Idris. 



III. — Notes on the Permian and Trias. 



By Professor Edward Hull, M.A., LL.D., F.R.S., 



Director of the Geological Survey of Ireland. 



I "WISH to make one or two observations on the Kev. A. Irving's 

 paper on " The Permian and Trias," which has appeared in 

 the Geological Magazine, and of which he has been so good as 

 to send me a separate copy. 



My first observation refers to the geological age of the Sandstone 

 of the vale of the Eden, in which he quotes my name as a supporter 



