CHAP. IV. HARPULA, VOLtJ T1LITHES, SCAPHELLA. 107 



the Harpula fulminata, has much the shape of a Fascia- 

 laria, but with the top of the outer lip slightly angulated 

 and dilated, something in the same way as Valuta 

 Scapha and Cym. mitis. The enlarged, knob-like form 

 of its apex immediately reminds us of Valuta papillaris; 

 while in its markings, and in the thickness of the outer 

 lip, internally, it perfectly resembles Scaph. undulata. 

 The numerous plaits, however, clearly show it is a Har- 

 pula. Another, our H. lyriformis, is the only recent 

 volute whose spire is longer than the aperture ; and a 

 third aberrant type, the H. buttata, stands at the con- 

 fines of this genus, and forms a passage to the next. 



(97.) VOLUTILITHES, so far as is yet known, is a 

 genus found only in a fossil state ; unless, indeed, Va- 

 luta nucleus Lam., peculiar to the Australian seas, be 

 considered as coming within its limits : it exhibits 

 none of the delicate plaits on the pillar of Harpula ; so 

 that one half of its characters belong to that genus, and 

 the other half to this. The typical characters of Volu- 

 tilithes have already been detailed (92.) ; and as we shall 

 particularly notice the subordinate types hereafter, we 

 may pass onward to the next group. 



(98.) The last of the primary divisions is the Aus- 

 tralian genus SCAPHELLA ; the best known type being 

 the Scaphella undulata (fig. 11. a). All of these hitherto 

 discovered, are natives of the South Pacific Ocean. 



We are not aware that any of these shells have an epi- 

 dermis, and their uniform smoothness leads us to con- 

 clude they are partly covered by the dilated lobes of the 



