PELECYPODA. 41 



Locality and straiigraphical position. — D^s valley, horizon 8. 



Remarks. — Although the only specimen which has come under examination is 

 much damaged, partly by weathering and partly through crushing, I have not the 

 slightest doubt that it represents a Spondylus. As a considerable part of the 

 substance of the shell is still preserved, its ornamentation, as above described, can be 

 made out with some accuracy. The only species which has an ornamentation of 

 the shell answering to the above description, is Spondylus santoniensis, d'Orbigny, 

 to which species I have therefore referred the specimens from Baluchistan. 



Spondtltjs, spec, indet. PL XI. fig. 4i-4a. 



Besides the specimen above described, there is an ill preserved cast, which 

 though belonging to the same genus, certainly represents another species. The shell 

 was apparently of smaller size than that of Spondylus santoniensis, and the 

 ornamentation of the left valve consisted of numerous filiform, somewhat irregular 

 radiating ribs, separated by interstices of their own breadth and crossed by some 

 strongly marked concentric striae of growth. Whether the ornamentation of the 

 right valve was the same cannot be ascertained ; there were undoubtedly fine radiat- 

 ing ribs, but it is impossible to say at present whether there existed also stronger 

 spines or not. , 



Locality and straiigraphical position. — Mazdr Drik, horizon 8. 



Remarks. — It is to be regretted that this specimen is not better preserved, be- 

 cause it seems to bear the strongest resemblance to Spondylus filosus. Ley. This 

 form, however, diflFers by the strength of the ribs, which are much broader than those 

 of the Baluchistan form. The interstices are of smaller breadth, than the ribs in 

 Spondylus filosus, while they are of the same breadth, or even a little broader than 

 the ribs in the above species. Leymerie's original is apparently not well preserved 

 either, and it is quite possible that the two forms are identical ; at any rate they bear 

 a strong relationship to each other. 



3. Family: PECTINID^. 

 1. Genus : HINNITES, Defran. 



HiNNiTBS (?) roLiACBUs, spec. nov. PI. IX. fig. 7, 8. 



The shell is irregularly circular, slightly inequilateral, and inequivalve. The 

 beaks are very small, depressed, and hardly extend above the cardinal margin. The 

 right (?) valve is only slightly inflated, nearly flat ; the left (?) valve is flat, even 

 somewhat concave. The ornamentation is apparently the same on both valves ; it 

 consists of numerous, closely set, fine, irregular radiating ribs, which are crossed by 

 numerous more or less strong concentric striae of growth, in such a way that the 



