388 Dr. H. Woodivard — On Fossil Shells from Sumatra. 



projecting here and there from the ribs. Dorsal valve somewhat 

 geniculated, following the curves of the opposite valve, a slight 

 median elevation corresponding to the sinus of the ventral valve ; 

 the visceral portion is usually somewhat flattened, while the anterior 

 portion of the valve becomes more or less abruptly bent upwards ; 

 the sculpture being similar to that of the opposite valve." 



Distribution : — This species is recorded as occurring in Great 

 Britain and Ireland, in Belgium, Russia, North America, the Punjaub, 

 and in Sumatra. 



This concludes our notes on the Palaeozoic fossils of Sumatra, and 

 we pass on to consider those of later date. 



5. Pecten, sp. PL X. Fig. 12. 



This species is represented by a single minute example, having 

 both valves united. The ribs upon one side have every second or 

 third more prominent with one or more intermediate smaller ribs. 

 On the opposite valve they are rather more uniform in size. 



We do not propose to name this species. 



Formation and Locality : — Tertiary Limestone, Sumatra. 



6. Pecten, sp. PL X.' Fig. 13. 



As only a portion of one valve is preserved, this specimen is too 

 imperfect to afford justification for specific description. The valve 

 exhibits about 24 rounded ribs broader than the interspaces, which 

 contain traces of fine linear striae. 



Locality and Formation — Tertiary Marl-clay, Island of Nias. 



7. Area VerbeeMi, H. Woodw. PL X. Fig. 9. 



Shell subquadrate — inequilateral, beaks prominent and anterior, 

 hinge-area moderately wide, between 20 and 24 strongly imbricated 

 ribs of about the same width as the interspaces — posteriorly oblique. 

 This form approaches most nearly to A. diluvii, Lamk. 



It affords me much pleasure to dedicate this elegant form to 

 Mynheer R. D. M. Verbeek, by whom it was collected. 



Locality and Formation: — From the clay-marls of (probably) 

 Miocene age. Island of Nias, Government of the West Coast of 

 Sumatra. 



8. Hemicardium, sp. PL X. Fig. 11. 



A somewhat gibbose triangular shell having 12-14 rounded costae, 

 posteriorly subcarinated and depressed as in the ordinary forms 

 referred to this section of Cardium. 



Locality and Formation : — From the Miocene Clay-marls, Island of 

 Nias, Government of the West Coast of Sumatra. 



9. Lunulocardium limaforme, H. Woodw. PL X. Fig. 16. 



This is a gibbose elongate shell with prominent umbones, slightly 

 recurved, having numerous rounded ribs, traces of which are, how- 

 ever, only faintly shown in the casts. Impressions corresponding 

 with the central and lateral teeth, and of the adductor muscles, are 

 also to be observed in the casts. 



I am unable to refer this shell to any already-described form, and 

 have ventured, therefore, to treat it as a new species. There are 

 several specimens, that figured in our PL X. Fig. 16, being one of 



