OF KACHH AND KATTYWAR. 71 



and is very slightly highest on the posterior keel. Length 30 millim., breadth 26-5 

 millim., height 19-5 millim. The test, rather flat above, slopes gradually to a narrow, 

 tumid, slightly notched anterior margin ; the low and only slightly convex keel of 

 • the posterior interradium slopes backwards and overhangs the posterior truncation of 

 the test ; and the sides are everywhere tumid. The posterior part is roundly truncated 

 and is reenteringly curved, being concave from above downwards ; the periproct, high 

 up and large, is visible on an actinal view;. Actinally the test is generally convex, and 

 especially from side to side over the plastron. 



The apical system is excentric and behind the centre, and the peristome is far in 

 front. The anterior odd ambulacrum is in a deep groove with nearly vertical sides and 

 about twelve pairs of pores placed at the angle of the floor and wall, and they are 

 moderately distant. The pores of each pair have a tubercle between them, and are in 

 the midst of a granular surface, which also covers the floor of the groove. Higher up 

 on the flanks of the groove tubercles, small and not very close, are seen. In front 

 the pairs of pores become very rare, the groove widens and almost ends, and there it 

 is traversed by the fasciole, whose curve is convex anteriorly. Beyond, the groove is 

 faintly traced to the peristome. 



The antero-lateral ambulacra are moderate in length, narrow, in deep grooves, 

 pointed at the distal end, and curved, convexity forwards and inwards ; they form an 

 angle of 90°. 



The interporiferous areas are narrower than the poriferous zones, which are on the 

 slope of the sides of the groove. The pairs of pores are distant, separated by broad 

 low costse, on which is a narrow row of miliaries or a simple ridge. The pores of 

 the pairs are large, obliquely placed, elliptical, and the outer are the longer ; often a 

 ridge or rim surrounds a pore. There are about 22 pairs of pores. 



The trace of the relics of the other ambulacra shows them to have been rather 

 wide apart and short. 



A well-developed peripetalous fasciole clings to the ambulacra in the lateral 

 interradia ; it then turns round the antero-lateral ambulacra, barely closing them, so close 

 are the distal pairs of pores. The fasciole then passes almost directly inwards to reach 

 the keel of the anterior groove, and passes forwards almost to the ambitus, and then 

 crosses. A lateral fasciole leaves the peripetalous one, and dips down to reach the 

 posterior part of the tuberosity at the end of the plastron; and it crosses beneath 

 the periproct above the tuberosity and below the concave, hollow, and highly orna- 

 mented infraperipr octal area. The peristome is crescentiform, and the plastron is 

 large. The areas of the posterior ambulacra on either side of the plastron are 

 curiously granulated. The ornamentation is generally small, and increases very regularly 

 in size at the anterior margin, being largest below in front of the peristome. The 

 tubercles are low, and have a perfect or imperfect raised scrobicular circle. The keels 

 of the anterior interradia are moderately developed, especially posteriorly. 



Locality. Geological position doubtful : in Alrasa, Western Kachh. Survey- 

 number c — ■? 



