370 THE FOSSIL ECHINOIDEA 



softness it disintegrates rapidly and the usual features of the scenery are peculiar and 

 characteristic." Sometimes the clayey and calcareous strata are more or less horizontal 

 and at others they dip at considerable angles, and as the clay wears more rapidly than 

 the other constituents of the mass, the position of the strata determines flat-topped 

 hills and a very serrated appearance in the inclined beds. The Makran beds are 

 evidently of marine origin. They are usually highly fossiliferous, the most abundant 

 fossils being species of Ostrea, Pecten, and Balanus. Area, Cardium, Lucina, and 

 species of the family of Veneridce abound, but very often only occur as casts. Gas- 

 teropoda, though far from scarce, are less common — forms of Cerithium, Turritella, and 

 Natica being perhaps the most prevalent. Operculina is noticed as the common genus 

 of Foraminifera. Blanford noticed that the fauna differed from that of the Nummu- 

 litic rocks and that several of the fossils appeared to be identical with forms now living 

 in the neighbouring seas. Subsequently, in the ' Manual of the Geology of India,' 

 p. 470, he showed that the Makran group was probably a marine representative of the 

 Siwalik or Manchhar beds of Sind and northern India. Some of the Makran beds 

 were upheaved at least 2000 feet after the close of their deposition, and the upheaval 

 progressed during the formation of the Littpral concrete. 



The other localities where this formation is seen and where Echinoidea have been 

 found are Henjam Island and Kharak Island, in the Persian Gulf. Although there 

 can be little doubt that the rocks at both these localities belong to the same series as 

 those of the Makran coast, the precise horizon may be slightly different, perhaps rather 

 higher. 



So far as the Echinodermata are concerned, no older Tertiary species are found in 

 the Makran beds, and the Gaj fauna of Sind and of Kachh and Kattywar has but 

 one doubtful representative in them *. The facies is more recent than Miocene, most 

 of the species being closely allied to recent forms, and the genera are all represented 

 in the Asiatic and Australian seas. 



The deposit in which the Echinoidea were collected was a shallow-water one, and 

 most of the specimens are broken, and many are imbedded in a sandy matrix full of 

 comminuted shallow-water shells. 



The forms of Echinoidea which were collected and sent to us by the Geological 

 Survey of India are all generically, but not always specifically, determinable, and we 

 have carefully avoided giving a specific name to imperfect specimens. 



II. List of the Fossil Echinoidea of the Mahrdn Series. 



Order ECHINOIDEA ENDOCYCLICA. 



Family CIDARID^. 



Oenm Cidaeis, Klein, 1734. 



Cidaris, sp. (Goniocidaris ?) : p. 372. 

 , sp.: p. 373. 



* One of the Cidaridse is possibly common to the deposits. 



