PELECYPODA, H 



with No. 45. Dr. Buckland 1 who subsequently described the fossil 

 Tories, mentions this fossil as a Cyrena but does not distinguish it 

 by a specific name. Nearly thirty years later the late Dr. Oldham 

 visited Yenangyoung together with the members of the mission to 

 Ava, and although he searched for the Cyrena bed, he could not find 

 it. 8 This is quite intelligible to any one acquainted with the 

 country round Minlindoung, cut up by numerous ravines winding 

 in the most erratic manner. It takes weeks to search for a certain 

 place in this country, the exact location of which is not known. I 

 only discovered it when systematically mapping the country around 

 Yenangyoung, and so 67 years after its first discovery Cyrena^ or 

 as it is now named Batissa crawfurdi, comes to be described. 



BATISSA PETROLEI, Spec, nov., Plate II, Fig. 5-5^5 Plate III, 



Fig. 2-3. 



The shell is oval, not very inequilateral, the beak being slightly 



in front of the median line. The anterior margin is rounded and 



passes gradually into the slightly curved ventral margin ; the posterior 



margin is somewhat curved, but does not form such a marked angle 



with the ventral margin as in Batissa crawfurdi, sp. nov. The beaks 



are depressed and only slightly inflated ; sometimes they are deeply 



eroded. Ligament moderately long. Hinge much less strongly 



developed than in Batissa crawfurdi ; arrangement of teeth the same 



as in the former species, but the cardinal as well as the lateral teeth 



are much more delicate. The valves are only slightly inflated, rather 



thin and covered with strongly marked striae of growth, crowding 



on the anterior side. 



Dimensions. 



Height. Length. Thickness. 

 34 mm. 41 mm. 20 mm. 

 37 11 42 „ 21 „ 



Locality. — Together with Batissa crawfurdi, but less common at 

 the same place. 



1 Crawfurd's Journal of an Embassy to the Court of Ava, London, 1826, Appen- 

 dix XIII, page 85, reprinted from the Transactions of the Geological Society. 

 • Yule, Narrative of the Mission to the Court of Ava, London, 1858, page 315. 



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