16 Messrs. R. B. Newton and G. 0. Crick on some 



absence of these same cliaracters prevents a full comparisc 

 with the Niti examples, which H. F. Blanford referred 

 Ammonites torquatas'^ and A. hiple.v\, two forms verF*^ 

 closely allied, if not identical, the only characters by which .f 

 that author distinguished the two forms being the thicker and^' 

 more depressed whorls of the former, accompanied by a slighig| 

 notching of the ribs in the median line of the periphery. ^^E 

 did not figure A. torquatus, but figured two examples a|SP 

 A. hiplex. Of these, the specimen depicted in pi. xi. fig. 1 a J ■ ( 

 more closely resembles the Arabian form, especially in the 

 coarseness and direction of its ornaments, but being a more 

 widely umbilicated shell, its outer whorl bears a greater 

 number (55) of principal ribs than that of the Arabian fossil. 



Compared with Waagen^s figure § oi Perisphinctesmartelli, 

 Oppel, from the Kuntkote Sandstone, the measurements of 

 which agree fairly well with those of the Arabian specimen, 

 the latter possessed coarser and more curved ornaments, and 

 apparently had more inflated sides than the Indian form ; 

 further, the bifurcation of the ribs appears to have been nearer 

 the margin of the periphery in the Indian than in the Arabian 

 form. 



Another Indian form with which the Arabian specimen 

 may be compared is Waagen's Perisphinctes virguloides \\, 

 but compared with Waagen's figure (pi. xlix. figs. 1 a, 1 b] 

 the Arabian fossil is more narrowly umbilicated and its ribs 

 are less numerous per whorl and more forwardly-directed in 

 crossing the lateral area. In Cutch, Waagen^s species is 

 restricted to the Kuntkote Sandstone. The Arabian fossil 

 agrees still more closely with Pavlow^s figure of a specimen, 

 which he refers to Waagen's species, from the zone of 

 Aspidoceras acanthicum from the East of Russia ^. 



It also closely resembles de LorioFs figure** of Perisphinctes 

 eupalus (d'Orbigny) from the zone of Oppelia tenuilohata of 

 Oberbuchsitten (Soleure) ; its relative dimensions are about 



* H. F, Blanford, in J. W. Salter and H. F. Blanford, Palajont. Niti, 

 1805, p. 80. 



t H. F. Blanford, op. cit. p. 79, pi. xi. figs. 1 a, h, c, pi. xii. tigs. 1 «, b, c. 



X Now in British Museum collection, register no. 0. 5033, 



§ W. Waagen, op. cit. pt. 4, 1875, pi. Iv. figs. 3 «, b. 



II W. "Waagen, op. cit. pt. 4, 1875, p. 203, pi. xlvii. figs. 4rt, b, pi. xlix, 

 figs. 1 a, b. 



% A. Pavlow, "Les Ammonites de la zone a Aspidoceras acanthictnn 

 de Test de la Russie," Mem. Com. G6ol. St. Petersbourg, vol. ii. no. '■',, 

 1880, pp. 28 & 85, pi. vii. figs. 3 a, 6. 



** P. de Loriol, " Monographie pal6ontologique des couches de la zoin' 

 a Amvionites tenuilobaf us (Badener Schichten) d'Oberbuchsitten et dej 

 Wengen (Soleure)," pt. i., 1881 (Mem. Soc. Pal. Suisse, vol. vii.), pi. iii.| 

 figs. 2, 2 a, 



