NO a.J DESCRIPTION OF THE FOSSILS. 65 



concentric lines of growth, White mentions very fine radial lines, visible only 

 in a very favourable light. The American species differs from our own in 

 the greater length of the valve. 



LIMEA, Goldfuss. 

 ? Limea cf. duplicata Goldf. 



PI. I. fig. 11. 



Cf . 183440 Limea duplicata Goldfuss, 'Petrefacta Germanise', vol. II. p. 103, 

 pi. CVIII. fig. 9. 



The coarse, straight ribs mark the figured cast as being that of a 

 right valve of a species of Limidse. The same relation that is found 

 here between the ribs and the broad, smooth intercostal spaces, is observed 

 in the genus Limea, especially in the both horizontally and vertically wide- 

 spread species, Limea duplicata Goldf. x The present piece is probably closely 

 allied to this species. Small, oblique impressions in the upper part of the 

 vertical, scarcely hollowed-out Lunula, which correspond in position to the 

 small, lateral denticles of the Limea, confirm me in my opinion that the pre- 

 sent fragment is a Limea. 



Our piece cannot be identified with Limea duplicata. Limea duplicata 

 is generally smaller, more equilateral, and as a rule has more ribs from 

 2 to 17, generally 16 on the valve, and 13 or 14 on the cast (our form has 

 only 11 ribs on the cast). 



Lima consobrina d'Orb. 2 , which resembles our form in outline, is too 

 flat, and too closely ribbed to be compared with the piece before us. 

 Moreover, d'Orbigny's species is a true Lima, and no Limea. Neither can 

 the Lima cf. duplicata Sow. gp. 3 from Spitzbergen, figured by Lundgreen, 

 be connected with our form, as it exhibits on the cast sharp-edged ribs. 



1 Upper Bajocian to Oxfordian ; Western Europe, Balin and Koscielec near Krakow (G. 

 C. Laube, 'Die Bivalven des bruunen Jura von Balin.' Denkschr. d. Akad. d. Wiss. Wien, 

 vol. XXVII. p. 13 [21], gives only Lima duplicata Sow. sp. From Laube's list of syno- 

 nyms, it is evident that he also classes Limea duplicata Goldfuss with this species. 

 At Balin and Koscielec occur both Lima duplicata and Limea duplicata), Popielany in 

 Lithuania, the island of Ando, Central Russia, Novaya Zemlya, Cape Stewart in East 

 Greenland. 



3 Murchison, Verneuil et Keyserling, 'Geologic de la Russie,' vol. II. Pal^ontologie, p. 

 477, pi. XLII. fig. 5, 6, 7. 



* B. Lundgreen, 'Bemerknungen Ubcr die von der Schwedischen Expedition nach Spitz- 

 bergen 1882 gesammelten Jura- und Trias-Fossilien.' Bihang till K. Svenska Vet.-Akad. 

 Handl. vol. 8, No. 12, p. 18, pi. 2, fig. 10. 



9 



