6 Messrs. R. B. Newton and G. C. Crick on some 



Area, Everest, Asiatic Researches, 1833, vol. xviii. pt. 2, pi. ii. fig. 27, 



p. 114. 

 Cucullcea virgata, Blanford, Journ. Asiatic Soc. Bengal, 1863, p. 136 ; 



Blanford and Salter, Palaeontology of Niti, Northern Himalaya, 



1865, p. 103 ; non J. de C. Sowerby, 1840. 

 Mac.rodon egertonianum, Stoliczka, Mem. Geol. Surv. India, 1865, vol. v. 



pi. viii. rig. 7, p. 89. 

 Paralleludon eyertonianus, R. B. Newton, Geological Magazine, 1896, 



pp. 294-296. 



From Stoliczka's diagnosis we understand this species 

 to be an obliquely elongate shell, convex, narrow, and 

 with radiating costae ; the costae are fewer and consequently- 

 wider apart towards the anterior margin and nearly obsolete 

 posteriorly ; concentric striae unequal, undulating, sometimes 

 lamellose. These characters are mostly well expressed in 

 the valves from Arabia now referred to this species, although 

 the posterior radiating costae are more apparent than in 

 Indian examples, a fact which is probably due to better 

 preservation. 



Rather more than eleven years ago I recognized this 

 species among the Bihin Limestone fossils of Somaliland, and 

 I then referred to a peculiarity of ornamentation seen only on 

 the right valve, which had not previously been noticed, viz. 

 the presence of intermittent ribbing between the primary 

 radial costae, a structure which I also observed at the same 

 time in some of the original Indian specimens in the British 

 Museum collected by the late Sir Richard Strachey, and 

 which is further observable in the valves from Arabia. I 

 now find the same sculpture in J. de C. Sowerby's Cucullcea 

 virgata from the Cutch Jurassic, a species which has already 

 been mistaken for egertonianus, although it represents a shell 

 of very different contour, being more or less quadrate and, 

 moreover, furnished with almost central umbones, and alto- 

 gether lacking the obliquity of the Spiti form. 



Very similar sculpture is present on the left valve of 

 Cucullcea lasti, described by Gr.Muller(in Bornhardt, 'Deutsch. 

 Ost-Afrika,' 1900, vol. vii. pi. xvii. figs. 1, 2, p. 533) from 

 the Kimeridgian of German East Africa ; but that form has 

 also more central umbones, less oblique radial costae, and 

 rather more inflated valves. 



This egertonianus is also quite distinct from Dr. Dacque's 

 Macrodon vufoz * from the Kimeridgian of Western Somali- 

 land (Atschabo and Harro Rufa), as pointed out by that 

 author, who further regards his species as showing a greater 



* "Beitrage zur Geologie des Somalilandes," Beitr. Palaontologie 

 Geologie Oesterr.-Ungarns Orients, 1905, vol. xvii. pl.xv. figs. 4-6, pp. 137, 

 138. 



