148 



Islands. In the British Museum is one shell labelled, "S. 

 morchi, Angas ; Port Jackson, G. F. Angas" ; it is not affirmed 

 to be a type ; but it quite agrees with Angas's description. 

 The axial and spiral ribs and ridges are of about equal pro- 

 minence, and there is no peripheral rib. There are varices 

 at irregular intervals which run downwards and backwards on 

 the spire; these are not noted in the definition of the type. 

 It recalls the S. suturalis, Hinds ; but this has a valid peri- 

 pheral rib, which appears as a lira in the suture, and its axial 

 costae are more marked, and it is a larger shell, being eight 

 lines in length, with ten whorls, instead of five lines with nine 

 whorls. Our S. Aust. examples vary very greatly. First the 

 peripheral rib is quite valid, and the axial costge end abruptly 

 upon it, and the base has only spiral Urge. In one this just 

 appears in the suture as a lira. In others this rib is less and 

 less marked, and may be quite absent. The axial costse also 

 differ in validity, much surpassing the spiral ridges, or equal- 

 ling them, or being less prominent ; they may end at the peri- 

 pheral rib, or extend beyond the periphery, and gradually 

 fade out on the base. The spiral ridges may vary in number 

 and in size and in the degree to which they modify the axial 

 costse. But all have the irregular varices and a minute punc- 

 tate surface. 



These considerations suggest the identity of S. morchi^ 

 Angas, with S. siUiiralis, Hinds. I do not know whether the 

 latter has the punctate sculpture, and as it is a much larger 

 shell, and comes from a remote region, this is left suh pidice. 

 Whether S. valida, Verco, and S. invalida, Verco, will also 

 come within the specific definition of S. morchi, Angas, must 

 be left until more material is gathered : at present intermedi- 

 ate forms are wanting. One example of *S. morchi supplied 

 an operculum, figured on pi. iv., figs. 1. 2, which is similar 

 to that of jS*. acideafa, Low., and tends to confirm the generic 

 position of this rather atypical Scala. 



Scala invalida, spec. nov. PI. iv., figs. 9, 10. 



Shell rather thin, translucent, elongate, imperforate, 11 

 whorls. Protoconch deflected, 2 whorls, nearly smooth : the 

 first round, the second angulate just above its centre, and 

 ending in a varix. Spire v^horls 8, regularly convex : suture 

 deep, simple. Body-whorl round with the merest peripheral 

 angulation. Aperture subrotund, flattened by the base of 

 the body-whorl, margin thickened externally. 



Scul'ptnre. — Very crowded, fine axial and spiral lirae, 

 punctating the whole surface. The axial Urge vary somewhat 

 in thickness ; they continue over the base and the callus of 

 the aperture, so as to reach nearly to its inner maroin, leav- 



