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PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



a depth, of rather less than one-third of the corresponding height of 

 the whorl, almost straight on the periphery, with an annular lobe. 

 Siphuncle small, near the periphery. Test smooth on the lateral 

 area, but ornamented on the peripheral area with subangular 

 longitudinal waved raised lines, which in the young shell extend on 

 to the lateral area ; sides of the umbilicus with coarser longitudinal 

 ornaments crossed by distinct growth lines. 



Dimensions. 



Diameter ... 



Height of outer whorl 

 Height of outer whorl 

 above preceding whorl 

 Thickness ... 

 Width of umbilicus 



(i) 



159 mm. 

 94 ,, 



(ii) (iii) 

 136mm. about 145mm. 



about 69 



about 78 

 14 



82 



about 60 



72 

 13 



89 



about 67 



78 

 14 



Fig. VIII. — Nautilus crasszsinuatus, n.sp. a, lateral view of an imperfect but ■well- 

 jDreserved example, showing the suture-line and the ornaments of the test; 

 d, peripheral view of the same. Inferior Oolite : Bradford Abbas, Dorset. 

 Drawn from an example in the British Museum Collection [C. 4501]. Eather 

 less than one-half natural size. 



Jieniarhs. — This species is represented in the British Museum 

 Collection by three specimens — No. C. 4112 (i), No. C. 4500 (ii), 

 and JSTo. C. 4501 (iii) — the dimensions of which are given above. 

 They are all from the Inferior Oolite of Bradford Abbas, Dorset. 

 Mr. S. S. Buckman has examined two of them, viz. C. 4500 and 

 C. 4501, and considers them both to be from the " concavus-zone 

 (probably Mi/perlioceras-heds) : Bradford Abbas," a somewhat lower 



