OF WESTEEN SIND. 85 



bare ambulacral areas are comparatively narrow ; and, finally, the peristome is situated 

 further from the margin. 



In the variety (Plate XX, Fig. 4) the resemblance to L. Arizensis is still closer, 

 excepting that the height of the test is greater and more tumid, and the actinal surface 

 is also more tumid, the ambulacra are less deeply sunken, and the posterior pair are 

 comparatively a shade longer than in the type. This form is unquestionably the repre- 

 sentative of L. Arizensis in the Eanikot strata. 



This Linthia is distinguished from L. Sindensis, Duncan and Sladen*, from belovp 

 the Trap, in the angle made by the antero-lateral ambulacra, the size of the posterior 

 ambulacra, and the position of the peripetalous fascicle. There is also a great distinc- 

 tion in consequence of the difference in the position of the apical system. 



The older form has vpider-apart antero-lateral ambulacra than the species Indica, 

 and it has the apical system well in front of the centre. This is not the case in the 

 Eanikot form, which, in the position of the apical system, resembles somewhat the 

 Schizasters. 



Linthia Indica is an approach to the genns ScMzaster ; and had it a more attenuated 

 posterior part, and the antero-lateral ambulacra closer to the anterior, and the pores 

 crowded in the odd ambulacrum, it would be a ScMzaster. 



2. Linthia, sp. Plate XX, Fig. 9. 



A specimen much worn on the upper surface, and nearly entirely destroyed 

 actinally, is in the collection from the Eanikot series. There are. some points about 

 the form which ally it with some of the large Nummulitic Linthias; but until better 

 specimens are obtained it is not necessary or advisable to give it a specific name, 

 especially as it has considerable affinities in some points with lAntMa Delanouei, of 

 De Loriol, from the Nummulitic of Egypt. 



The shape of the outline of the test is cordiform, about as long as broad, slightly 

 broadest in front, with a slanting rostrum posteriorly. The apical system is nearly 

 central from the periproct to the slight anterior notch, but eccentric in front from the 

 lower end of the rostrum to the same position in front. 



The anterior groove is moderately deep near the apical system, and broader and 

 shallower towards the front, where it faintly notches the ambitus. The pores in it are 

 small, separate in pairs, with a rounded costal elevation between each pair on the slope 

 of the side of the groove. There are about 20 pairs of pores; and the pores of each 

 pair are separated by a small tubercle. 



The antero-lateral petals are large, long, deep, and straight ; they are broadest on 

 the outer third ; and the anterior poriferous zone is more curved than the posterior, 

 which is slightly the shortest. The pores are numerous, are on the vertical sides of the 

 ambulacra, are large, very conjugate, and separated by wide ridges ; they are smallest 

 near the ocular plate. There are about 40 pairs in the anterior poriferous zone, which 



* See Plate IV. Part I. EcMnoidea from the infra-Trap. 



