Tlutix. | GASTROPODA. 423 



Subgen. 2. STRAMONITA, Schumacher. 1817. 



Stramonita, Schuin., Essai d'un Nouv. Syst., 1817, 226. Type : 

 Jtcemastoma, L. 



Shell ovoid-conic ; spire moderately elevated : whorls nodulous, 

 reticulated in the interspaces between the spiral ribs ; aperture oval, 

 large, with a channel above, sometimes limited by a spiral rib, and a 

 basal canal, which is rudimentary, very little contracted, and deeply 

 notched ; outer lip lirate and subdentate within ; columella nearly 

 vertical, slightly twisted below ; inner lip flattened, not excavated. 



KEY TO SI-ECIES. 



A. Shell large, white or light brown, with predominating spiral ribs 



and without axial costse . . . . . . . . succincta. 



B. Shell small, fulvous with darker bands, with about 12 distinct 



axial costse . . . . . . tritoniformis. 



2. Thais succincta, Martyn, 1784. Plate 48. tig. 4. 



Buccinnin succinctuni, Mart., Un. Conch., ii, 1784, f. 45. /'wr/wm suc- 

 cincta, Lam., A.s.V., ed. 2, x, 62 ; Kiener, Coq. Viv., lAirpura, 183H, 

 Id.") ; Reeve, C'onch. Icon., iii, pi. 5, f. 23 ; Krauss, Siidair. Moll., 1848, 118 ; 

 Dieff. N.Z., 232 ; C.M.M., 10 ; M.N.Z.M., 56 ; T.N.Z.I., xvi, 221 ; Man. 

 Conch. (1), ii, 170, pi. 51, f. 118-120, 107, 125, 113. hiriniuii orbita, 

 Gmelin, Syst, Nat,, ed. xiii, 1790, 3490. Purpuni tuxtiliova. Lam., A.s.V., 

 vii, L822, No. 24; Blainville, Ann. de Mus., i, 1832, 249; Voy. Astro!., 

 ii. 1833, 552, pi. 37, f. 1-3 ; Kiener, Coq. Viv., Purpura, 1836, 104 ; 

 Reeve, Conch. Icon., iii, pi. 12, f. 66; C.M.M., 16; M.N.Z.M., 56 ; 

 T.N.Z.I., xvi, 221. P. succinctn, Mart, : Pritchard and (Jatliff. P.R.S. 

 Vic., x (n.s.), 258. 



Shell large, ovate-ventricose, solid, spirally ribbed, aperture large, 

 white. Soil /it art- consisting of 8 distant rounded spiral ribs, with a 

 few fine grooves, the interstices of the same width as the ribs, deeply 

 excavated and with traces of a few spiral threads (typical succincta) ; 

 or the interstices shallow, much broader than the ribs, with numerous 

 (up to 6) unequal spiral cords, the whole crossed by fine crispate growth- 

 lamellae, reticulating the spirals in the interstices (typical textiliosa) ; 

 fasciole prominent, separated from the inner lip by a broad and mode- 

 rately deep groove, both transversely lamellate. Colour white or 

 light brown ; outer lip yellowish-white inside, banded with white 

 and brown in the brown-coloured specimens. Spire low, gradate, 

 conoidal, usually a, little more than half the height of the aperture. 

 Protoconch small, papillate, of 2| convex and smooth whorls. Whorls 

 about 8, first slowly increasing, the last large, ventricose ; there is 

 a distinct flattish or concave depression below the suture, last whorl 

 convex ; base very little contracted below. Suture impressed on the 

 upper whorls, frequently channelled further down. Aperture large, 

 oval, channelled above, with a rudimentary widely open canal below-. 

 Outer lt'i> convex, thick, crenulated by the spirals and grooved inside, 

 oblique, broad, somewhat excavated, lightly twisted below 



