108 NEW YORK STATE MUSEUM 



PLATE 3 



Tentaculites (?) acus sp. nov. 



Page 28 

 Fio. 



1 A specimen which shows the smooth exterior and the 



annulated or insheathed cast of the interior. x3 



2 The exterior, showing low annular depressions 



3 The internal cast. x3 



4-7 Specimens of natural size, showing the generally smooth or 

 slightly corrugated exterior 



Tentaculites elongatus Hall 



Page 27 



8 The initial end of a specimen, showing its smooth exterior 



and the character of the internal cast. x5 



9 External and internal casts. x2 



10 Enlargement of the apical portion of the tube, showing 



the smooth area and gradual development of annulations 

 and concentric lines. xlO 



11 The character of the surface at maturity. x5 



12 A portion of the exterior, natural size 



Diaphorostoma desmatum sp. nov. 



Page 29 



13-15 Three views of an average specimen 



16, 17 Views of other specimens 



18 The upper surface of a larger shell, showing the lineation 



19 An enlargement of the surface characters. x6 



Cyrtolites expansus Hall 



Page 28 



20 Upper view of a slightly distorted specimen, for the most 



part an internal cast 



