20 JUBASSIO FAUNA. 



The shell consists of low, slightly inflated whorls, very gradually increasing in 

 height. They overlap each other to a little more than half their height, thus producing 

 a moderately wide umbilicus. The umbilical wall is rather high, the umbilical 

 edge rounded. The sides are flattened and slope from the umbilical edge towards 

 the rounded siphonal side. The ribs are straight and begin at the umbilical edge, 

 where they are fairly thick and rounded ; very soon, however, they become flatter, 

 and a little above half the height they divide into three thinner branches of equal 

 strength, which pass in a straight line round the siphonal side. 

 Neither body-chamber nor sutural line is preserved. 



Locality and stratigrapMoal position. — Mazar Drik ; Folf/phemua-limestone, 

 Bemarks. — This species is very closely related to PerispMnctes balinenaisi 

 Waagen ; in fact, in the case of a single specimen which has been damaged or is 

 badly preserved, the distinction between the two species is so slight that it is 

 sometimes extremely difficult to decade to which species it belongs : however, on 

 comparing a number of both species the difference is at once apparent : Perisphinctes 

 baluchistanensis spec. nov. has a much smaller umbilicus than PerispMnotea 

 balinensis, Waagen. In fact, in this respect this species bears a much greater re- 

 semblance to Neumayr's Peresphinctes balinensis than Waagen'« Perisphincies 

 balinensis does to Neumayr's species with which it has been identified. 



As I remarked above, I should have preferred to identify Perisphincies balinensis, 

 Waagen, with Perisphinctesfurcula, 'Neumajr,andia. this case the species of Peri- 

 sphincies here described under the name of Perisphincies baluchisianensis might 

 have been referred to Perisphincies balinensis, Waagen. I fear, however, that this 

 would create such confusion that, without actually comparing the specimens from 

 Baluchistan with those from Balin, in order to make it absolutely certain whether 

 my view is correct or not, I do not think I should be justified in pressing my 

 opinion in opposition to Professor Waa gen's v ews. Should my view prove correct, 

 however, the specimen here described as Perisphincies baluchisianensis, spec, 

 nov., should be called Perisphincies balinensis, Neumayr, and the form described as 

 Perisphincies balinensis, Waagen, by myself and that author should be called 

 Perisphincies fur cula, Neumayr. 



Pebisphinctes recupbroi, Gemmellaro, Plate XIII, fig. 4. 



]875. Perisphinotes recuperoi, Waagen, Palseontologia Indica, Jurassio Fauna of Kntoh, Vol. I, p. 173, PI. XLIU, 

 fig. let, b, 2a, b. 



Dimensions. j_ jj_ 



Diameter of the shell . , t . 56 48 



„ of the umbilicus ...... ...23 18 



Height of the last ifhorl from the umbilical suture 17 16 



» » » from the preceding whorl p p 



Thickness of the last whorl •......, 19 16 



