JR. BuUen Newton — Post-Tertiary MoUusca, Ceyhn. 509' 



The bed can hardly be described as ordinary raised beach, but 

 occurs at the same level as the usual sandy raised beach, which it 

 appears to replace rather than to over- or underlie. 



*** We subjoin a note on Mr. Coomarasw&.niy's fossils, which have been most 

 kindly examined by Mr. R. Bullen Newton, F.G.S. — Edit. Geol. Mag. 



VIII. — Note on some Post - Tertiary Mollusca from Ceylon. 

 By R. Bullen New^ton, F.G.S. , of the British Museum (Natural Histoiy). 



SOME marine shells, associated with crab-remains,^ Balani, and 

 small thread-lilce annelid tubes, from the Post-Pliocene deposits 

 of north-eastern Ceylon, have been entrusted to me for determination 

 by Dr. H. Woodward, F.R.S. They were collected by Mr. A. K. 

 Coomaraswamy, B.Sc, Director of the Mineralogical Survey of 

 Ceylon, and his description of the deposits containing the fossils 

 forms the preface of this communication. Lithologically it is 

 observable that there are two sets of specimens — those that occur 

 in hard, water-worn nodules of clay, and others that were obtained 

 from soft, dark, clayey beds found in situ. The fossils found in 

 the clayey material may perhaps be rather older than those found 

 in the nodules, but as two of the shells are common to each, viz. 

 Placuna placenta and Potamides fluviatilis, it is certain that no great 

 distinction in age is to be recognised. 



An examination of the species represented in the collection goes 

 to prove that they belong to the existing fauna of the Indian Ocean, 

 being similar to the life which is found in the creeks and back-waters 

 of that sea, and consequently bearing a littoral or an estuarine facies. 



It is interesting to know of the presence of corresponding Post- 

 Tertiary deposits crowded with shells forming the coastal areas 

 of the Madras Presidency of India, particularly at Pondicherry, 

 Cuddalore, Tangore, etc., for the history of which we are mainly 

 indebted to the late Mr. H. F. Blanford (Mem. Geol. Surv. India, 

 1862, vol. iv, pt. 1, pp. 192, 193). So numerous are the mollusca of 

 these beds that they are utilised by the natives for the manufacture 

 of lime. From lists given by Mr, Blanford it is ascertained that 

 these mainland deposits contain molluscan species identical with 

 those found in Ceylon by Mr. Coomaraswamy, a fact which not 

 only suggests a similarity of age, but also proves that the separation 

 of Ceylon as an island can be referred to a very modern epoch of 

 geological history. 



The following is a list of shells found in the Post-Pliocene beds 



1 The small, nearly perfect crab has been determined by Dr. H. "Woodward as 

 Macrophthalmus Latreillei (Desmarest), the 'Medicine Crab' of the Chinese 

 phannacopcEia (see Daniel Hanbm-y, " Notes on Chinese Materia Medica," Pharma- 

 ceutical Journal and Trans., July and August, 1860, and February, 1862, published 

 separately by the author, Febraary, 1862, Plough Court, Lombard Street, 

 E.G.) ; and the chelate pincer as belonging to Sctjlla serrata, De Haan, the 

 great Indian swimming crab. M. Latreillei is also found in the Post-Tertiary 

 clays of southern China (Island of Hainan), and S. serrata has been reported from 

 similar beds in the Philippine Islands. 



