17 



LoxoNEMA MAGNUM, Whitfield. 



Loxonema magna, Vfhit&eld. 1878. Ann. Eep. Geol. Surv. Wise, 1877, p. 83. 



1882. Geol. Wise, Vol. 4, p. 317, pi. 24, fig. 1. 



Gait : B. Billings,. ISSt : one imperfect specimen, consisting of two 

 entire volutions, with the whole of the test preserved. Elora, T. C. 

 Weston, 1867 : a very perfect cast. Hespeler, T. C, Weston, 1867 : one 

 large but imperfect cast. 



CODONOCHEILUS.* (Gcn. Nov.) 



Shell tui-reted, subfusiform or pupoid : volutions of the spire rather 

 numerous, (about eight or nine in the typical species) compressed 

 laterally and closely enrolled : outer half of the body- whorl produced 

 obliquely outwards and downwards : lip thin and broadly expanded : 

 apertm-e apparently nearly circular : umbilicus small or entirely 

 closed : test thin. 



The above genus is constituted primarily for the reception of a little 

 shell which is abundant in the Guelph Limestones at some localities. 

 Casts of it are of frequent occurrence at Durham, but not more than 

 about a dozen specimens with the test preserved have been seen by 

 the writer, and only one of these is full grown. In this specimen, 

 which must be regarded as the type of the genus, the exact shape of 

 the apertm-e cannot be ascertained, as the ventral surface of the shell 

 is partly buried in the matrix. Although associated with j)urely 

 marine organisms and therefore probably itself marine, the dorsal 

 aspect of an adult example of Oodonocheilus, with its subfusiform or 

 pupoid spire, its obliquely spreading body-whorl and its expanded lip, 

 is exceedingly similar in a general way to that of several genera of 

 recent operculated land shells, such as Megalomastoma, Cataulus, and 

 Tomocyclus. It is probable that the Oerithium Helmerseni of DeVerneuil, 

 f from the Upper Silurian rocks, of Eussia will prove to belong to this 

 genus, but the body-whorl of that species is not preserved in the 

 specimen figured. 



CODONCHEILUS STRIATUM. (N. Sp.) 

 Plate 3, fig. 3. 



Shell small, about twice as long as broad, subfusiform or somewhat 

 pupoid, spire acutely conical or acuminate at the apex, and ven- 



* From aaduv, a trumpet, and ;te(/lof a lip. 



t " Geologie de la Eussie d'Europe et des Montagues de I'Oural," Vol. 2, p, 

 342, pi. 22, fig, 4. 



3 



