OF WESTERN SIND. 159 



Bemarhs. This form has some affinities with E. suhconica, nobis, and also with 

 that group of Echinolampads of which E. Escheri, Agassiz, and E. suhcylmdricus, 

 Desor, are the representatives. It is distinguished from E. suhconica by the form of the 

 test, the position of the apical summit, and the trend of the posterior petals, as well as 

 by the position of the periproct and the general tumidity of the lateral regions of the 

 test and of the actinal surface. It is readily distinguished from both E. Escheri and 

 E. suhcylmdricus by the form of the test and by the character, outline, and position of 

 the ambulacral petals. It is probably, however, the eastern representative of the last- 

 named species, although the differences between them are very great. 



Dimensions. 



millim. 



Length of the test 71 



Breadth of the test 57 



Height of the test 42 



Breadth of the postero-lateral petal ... 8 



„ „ antero-lateral petal ... 7 



Locality. In the Khirthar series of strata. Twenty-four miles west of Kotri 

 (entering the hills on the road to Bula Khan's Thana). Survey-number ^~. 



Illustrations of the Species in Plate XXVIII. 



Fig. 12. Abactinal view of the test : natural size. 



13. Actinal view of the test: natural size. 



14. Longitudinal profile of the test : natural size. 



15. The apical disk : magnified, 



16. A portion of a petal about midway between the apex and the extremity : 



magnified. 



4. EcHiNOLAMPAS SiNDEisrsis, d'ArcMac. Plate XXIX, Figs. 1-10. 



Test usually of moderate size, but occasionally attaining large proportions. 

 Marginal contour oval, well rounded in front, sometimes rather flattened along the 

 sides, and faintly rostrated posteriorly. The breadth is in the proportion of 86 per 

 cent, of the length. Apical disk excentric in front and corresponding with the apical 

 summit of the test, its distance from the anterior extremity being 40'6 per cent., or a 

 little more than two fifths of the length of the test. The dorsal surface is moderately 

 high and well arched, measuring at the summit a little more than 45 per cent., or nine 

 twentieths of the length of the test. Seen in longitudinal profile the dorsal outline 

 shows a well-rounded convexity, the anterior slope being more precipitous than the 

 posterior, the posterior slope rounding gently and then curving rapidly over the 

 posterior rostration. The transverse profile shows a regular and almost semi- 

 circular curve. The margins are tumid and rather sharply rounded on to the actinal 

 surface, which is more or less plain, excepting a gentle depression around the peristome, 

 and the rounding which masks the imperceptible junction of the margins and the 



actinal surface. 



t2 



