Murex.] GASTROPODA. 403 



Subgen. 2. PTEROPURPURA, Jousseaume, 1879. 



Pleropurpura, Jouss., " Revue de Zoologie," 1879. Type : Murex macropttrus, 

 Desh. Pteronotus, Swains., 1840 ; not of Gray, 1838, nor Swains., 183!). 

 Triplex, Humphrey, 1797, in Newton, 1891 ; not of Perry, 1811. Pur- 

 purellus, Jouss., 1879 ; not Purpurella, Desv., 1853. Triremis, Bayle, 

 1884. Plerymurex, Rovereto, 1899. 



Shell triangular, with 3 varices, which are fin-like or foliated ; 

 whorls rounded ; spire elevated ; canal moderately straight or some- 

 what curved, nearly closed ; aperture oblong-ovate, the outer lip 

 generally simple, but sometimes crenulated. 



Sect. 1. ALIPURPURA, Bayle, 1884. 



Alipurpura, Bayle, in Fischer's Manuel, 641. Type : Murex acanthopterus, 

 Lam. 



Shell fusoid, elongated ; protoconch paucispiral, with a, rather 

 large and papillate nucleus ; varices discontinuous and spinous above ; 

 canal moderately long, almost straight and open. 



3. Murex Angasi, Crosse, 1863. Plate 46, fig. 14. 



Typhis Angasi, Crosse, J. de Conch., xi, 1863, 86, pi. 1, f. 2 ; Murex Angasi, 

 Crosse : Angas, P.Z.S., 1867, 186 ; Sowerby, Thes. Conch., iv, Murex, 

 1879, 26, pi. 21, f. 189, 190 ; Hutton, M.N.Z.M., 47 ; Tryon, Man. 

 Conch. (1), ii, 88, pi. 40, f. 522 ; Kesteven, P.L.S. N.S.W., xxvi, 711, 

 pi. 36, f. 6, 7 (protoconch). M. (Pteronotus) Cordismei, Watson, J.L.S., 

 xvi, 1883, 601 ; Chall. Rep., xv, 156, pi. 10, f. 5. 



Shell small, fusiform, scalar, thin, with 3 foliated and spinous 

 varices, pale. Sculpture consisting of 3 foliated, slightly discontinuous 

 varices, which at the angle of shoulder rise into a semitubular, up- 

 turned, and slightly reverted spine ; between each two varices and 

 almost at a level with the spines are 3 large rounded tubercles ; lines 

 of growth very fine and dense ; besides the carination of the shoulder, 

 there is on the base a slight angulation, and sometimes a number of 

 low and distant spiral liree. Colour light yellow, sometimes with a 

 violet band. Spire high, conical, scalar, about the same height as 

 the aperture with the canal. Protoconch of about three-quarters of 

 a whorl, defined by a varix, surface polished ; obtusely angled high 

 up, the varix prominent up to this angle, tip of nucleus depressed. 

 Whorls 6, slowly increasing, feebly angulated, with a sloping shoulder ; 

 base slightly constricted. Suture linear, a little impressed. Aperture 

 oblong, rounded above, where to the right a canal runs out into the 

 labial spine ; pointed below, produced into a nearly straight, mode- 

 rately long, open, and recurved canal. Outer lip arched, thin. Colu- 

 mella lightly concave. The inner lip continuous above with the outer 

 lip ; on the body it expands with a thin edge, which below, near the 

 canal, rises into a thin lamina, and is then bent over to the inner edge 

 of the canal. 



