370 MAZATLAN TJNIVALYE3 



Tablet 1730 contains a fragment, intermediate in form be- 

 tween ? A. mutaus and PClirj^sallida clausiliformis, remarkable 

 for the sudden transition, after 4 whirls, from a perfectly 

 smooth to a highly sculptured surface. The smooth part 

 measures '045 by "023. 



Sab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 



433. PPAiiABA , sp. ind. (a.) 



Tablet 1731 contains a fragment of a somewhat large shell ; 

 the first four whirls swelling and smooth, like ?A. mutans ; 

 then with four whirls sculptured as in Chrj'sallida, with stout 

 radiating ribs decussated with spiral strise. ? May it however 

 have belonged to a Kassa. 

 Hab. — Mazatlan ; extremely rare, off Spondylus ; L'pool Col. 



434. PAlaba sp. ind. (h.) 



Tablet 1732 contains a fragment of a strong shell, "with 

 smooth, prominent, strong, elongated tuberous portion, (the 

 first whirls broken) followed by divergent, somewhat rounded 

 whirls, cancellated as in Phos. 



Sah. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

 Family OVULID^. 

 Genus OVULA, Brug. 



JEnc. Meth. vol. xv. no. Z7.—PMI. Kand. Conch, p. 162. 

 Amphiceras, (Gronov.) Gray, Proc. Zool. Sac. 1847, p. 143 : — 



= Amphiperas, March. 

 Volva (Boltcn) E. ^^ A. Ad. Gen. vol. i. p. 272.' 



435. OvtTLA TAEIABILI8, C. B. Ad. 



Ovula variabilis, C. B. Ad. Pan. Shells, pp. 31, 304, no. 4. 



(May, 1852.) 

 Ovula Californica, Soto. Proc. Zool. Soc. [teste Cuming : ? ubi.] 



This shell closely resembles the Atlantic species, O. imiph- 

 catum. Sow. (S. Caroluia), O. aciculare. Lam. (W. Indies) and 

 O. subrostratum, Sotc. (Honduras). The stria; at each end are 

 extremely fine, and are rarely traceable over the whole surface. 

 The shape is sometimes stunted and broad, sometimes acuniin- 



