!'<•> 



+J? 



shows a distinct revolving band formed by 

 the backward bendingof the lines of growth 

 near the suture, the lip thus having a deep ; vt*ftviy',' 

 emargination or sinus, as in Pleurotomaria ; 

 the earl}' stages of the shell are typical of 

 the species; surface reticulate by revolving- 

 stria? crossed by the lines of growth. 



5 



Fiti. anOA. Platyoa 



to m ii I i n e '• tii, var. 

 riuiiri/iiiiiiii. Summit 



round associated with Stictopora and view - (OriginaL) 



Spirorbis, in the Demissa (?) bed (one specimen). 



Genus LOXONEMA. Phillips. 



[Ety. : Loxos, oblique ; nema, thread.] 

 (1841 : Pal. Foss. Cornwall, etc., p. 98.) 



Shell elongate, with a tall spire composed of many whorls. 

 The aperture is simple, narrow above, ample below. The 

 lines of growth are doubly curved, and there 

 is no umbilicus. 



LOXONEMA HAMILTONIvE. Hall. (Fig. 201.) 



(Pal. N. Y, Vol. V., Pt. II., p. 45, PI. XIII.) 



Distinguishing Characters. — Large number 

 (about thirteen) of volutions, gradually 

 increasing in size; ventricose body-whorl; 

 ovate aperture, narrowing below; distant 

 curving stria?, which bend gently backward 

 from the suture, and forward from the base 

 of the volution, with the greatest curve in the middle. 



Found * * * "at Eighteen Mile Creek" 

 * * * (Hall), in the Strophalosia bed 

 wherever exposed (common). 



LOXONEMA DELPHICOLA. Hall. (Fig. 



202.) (Pal. N. Y., Vol. V, Pt. II., p. 47, 

 Pis. XIII., XIV.) 



Distinguishing Characters . — Smaller 

 number of volutions than preceding (about 

 eight); flattening of whorls; strong stria?, 

 bent slightly back for a short distance JilhicZhi' (af(er' hX" 



Fig. 201. Loxone- 

 mti hamiltonice (af- 

 ter Hall). 



