400 



terminology, such as the Greek letters of Qtjenstedt, or the 

 topical appellative of Midford Sands, or Marnes de Pinperdu, 

 can never do. Well, as we accord the leadership of the Mollusca 

 of our present subdivision, the Spinatus Zone, to the Ammonite 

 named the AmaWieus Spinatus, of Brugtjieees, which gives its 

 name to the Zone, we would observe that this characteristic 

 shell is easily known, and may be verified in case of doubt, by 

 the peculiar fine crenulated markings on each side of the keel, 

 mentioned in his diagnosis of it, by Bruguieees, in 1789. It has 

 had given it the name of A. Costatus, by Eeinecke, which will 

 explain the occurrence of the word in our table of Synonyms. 

 A confusion may arise, if not pointed out, from its having been 

 named A. geometricus by Prof. Phillips,* a species which is our 

 well known A. semicostatus (Toting & Bird), and is a Lower 

 Lias species common at Churchdown by the Beddings, at the 

 level of the brook, and above the Bucklandi beds ; and elsewhere 

 always occupies the same horizon. Bruguieres A. Spinatus 

 also, is the A. HawsTcerensis (Young & Bird) of the older 

 Yorkshire geologists. Characteristic Ammonites associated with 

 A. Spinatus are the Harpoceras Normanianum (Waagen), and 

 the Harpoceras Thouarsense (Waagen), both FaJciferi, and both 

 species of A. d'Orb. They afford us model examples of what 

 QuENSTEDT styled, A. radians depressus in his Cephalopoda, plate 

 7, figs. 4 and 8. Several small examples of Stephanoceras 

 annulatum were met with in the upper part of the Spinatus 

 sands, they were the precursors of significant changes. 



A rare form of Cephalopod yielded by the Spinatus sands at 

 Churchdown, and in my possession, belonging to the family 

 Teuthidse, is a species new to our fauna ; to this I have given, 

 provisionally, the M.S. name Glevensis, after the ancient name 

 of Gloucester. The Beloteuthis Glevensis (Smithe), measures 3^ 

 inches by 2 inches ; it is nearly smooth, with fine striae curved 

 in an oblique direction to the keel, and on each side of it, and 

 except in the markings, is not unlike the B. suhcostatus, 



* Phillips' A. geometricus, according to Tate and Blake,— A. solitarius of Simpson. But 

 according to Brauns— A. spinatus, Brug. non Oppel, nee auctt. 



