MOLLUSCA — IIEDLEY. 



383 



Fis. 95. 



scales white, tlicslioU piilc imrjilc Whorls three, plus a five-wh(iil((l 

 siiiusij,'era jjrotocoiicli. Sculpture: there are seven or ci^ht 

 obscure longitudinal ribs, marked by the 

 scales in pei'fect shells, and apparent only 

 on worn specimens. Along the angle of 

 the shoulder runs a line of sul)tubular 

 imbricating scales, each expanding an 

 erect hood, from under which issues the 

 succeeding scale. Beneath are six spiral 

 lines of much smaller scales, each con- 

 nected by lamellie, with the scales above 

 and below. Between the suture and the 

 shoulder are two similar lines. The pro- 

 toconch is of the " sinusigera " type, with 

 four keels on the last whorl, two of 

 which ascend the spire ; the two first 

 whorls smooth, the others crossed 

 obliquely by numerous delicate lamellae 

 which cross the keels ; the aperture 



is thickened and reflected, a peripheral tongue 

 intervenes between two deep bays, within which 

 the adult sculpture develops. Length of 

 specimen figured, 6-5 mm. ; breadth, 4-5 mm. 

 Another and worn specimen — length, 9 mm. ; 

 breadth, 4-5 mm. 



Probably the largest of the series before me 

 is still immature, and I have, therefore, refrained 

 from describing the aperture. Though similar 

 sculpture is described by Watson in Murex 

 aedonius, \iy Pritchard and GatlifF in Coralli- 

 ophila loilsoni, and prevails in Tro2)honJiindersi, 

 Ad. ifc Angas, it appears to distinguish the 

 present species among Purpura. Had not my 

 material included the protoconch, I should ha^e referred the 

 species to Murex, but the sinusigera apex claims for it a place 

 in Purpura. I share the opinion of my friend, H. L. Kesteven, 

 who, referring to the protoconch of Ptirpura tritoniformis, con- 

 cludes that : — " Since the only three embryos of this extra- 

 ordinary type that have been followed to their later stages have 

 proved to be those of Purpura, such an apex may surely be 

 taken as a guide to the generic position."* The sculpture of 

 this sinusigera distinguishes it specifically from those already 

 known. 



Purpura is regarded as characteristic of the zone between tide 

 marks ; I do not know that it has before been noted from so deep 

 as 100 fathoms. 



* Kesteven — Proc. Linn. Soc. N.S. Wales, xxvi., 1901, p. 537. 



