-ILS OF THE CARBONIFEROUS LIMESTONES. 



311 



Nautilus Avonensis, n. sp. (Fig. 124), coll. J. W. D., "Windsor, 

 Biinudie. — A large species, the outer chamber sometimes two inches 

 or mure in diameter. Whorls much flattened dorso-ventrally, slightly 

 angulated at inner edge. Siphuncle dorsal, septa convex, aboul one- 

 eighth of an inch apart. Belongs to genus QryptoceraSf D'Orbignv. 

 A-bundant at Windsor, and named after the Avon River, on the hanks 

 of which it occurs. 



Qyroceras Harttii, n. sp. (Fig. 125). A fragment of a small angulated 

 species, resembling N. sidcatus, Sowerby, coll. J. W. 1)., Windsor. — It 

 has the whorls somewhat quadrate, with two broad flutings at the 

 rides, and two narrower flutings at the edges of the flat dorsal surface. 

 Tin inner surface is regularly rounded, and the siphuncle is dorsal. 



Fig. 125.— Gyroceras Harttii, 



Orthoceras laterale, Phil., collected by Professor How at Kennet- 

 cook. — Resembles this species, as figured by De Koninck, too closely 

 to permit me to distinguish it. 



Orthoceras dotation, n. sp. (Fig. 12G), coll. J. W. D., "Windsor. — 

 Like 0. pygmaeum, De Koninck, in external form. Siphuncle mar- 

 ginal, slightly beaded; shell flattened at one side. Septa one-half 

 the larger diameter distant from each other. 



Fig. 126.— Orthoceras 

 dotation. 



Fig. 111.— Orthoceras 



Yindobuncnsc. 



Fig. 128.— Orthoceras 

 laqueatum. 



~e? 



Orthoceras Vindoboncnsc, n. sp. (Fig. 127), coll. J. "W. D., "Windsor, 

 tion nearly round. Siphuncle about one-third the diameter 



