474 



GASTROPODA. 



[Pectinibranchia. 



convex, thickened or varicose, with a moderately deep sinus at the 

 depression of the shoulder ; columella straight, callous ; very often 

 a small swelling on the parietal wall near the channel. 



KEY TO SPECIES. 



A. Height of spire equals about that of the aperture with 



canal. 



a. Shell without axial sculpture. Whorls with a 

 smooth upper and a gemmate lower keel ; 

 protoconch smooth ; spire little higher than the 

 aperture with canal 

 act. Shell with axial sculpture. 



b. Axial riblets about 15 on a whorl, crossed by 

 (37 spiral lira on the penultimate whorl ; 

 suture bimarginate 



bb. Axial riblets about 9, nodulous, with 1 spiral 

 thread below the suture, and 23 spirals, 

 crossing the riblets, further down ; suture 

 margined below 



B. Spire about 1^ times the height of the aperture with 



canal. 

 a. Whorls with about 5 nodulous spirals and about 20 



oblique axial riblets 

 aa. Whorls with about 15 very strong oblique axial 



ribs, crossed by a few spiral ridges 



C. Spire about twice the height of the aperture with canal. 



a. Whorls with about 14 median nodules, incised on the 

 lower whorls by a median spiral groove ; proto- 

 conch spirally striate, the second whorl with a 

 keel 



aa. Whorls with about 21 axial riblets and 3 spiral 

 lirse on the spire- whorls, points of intersection 

 beaded ; protoconch smooth 



multiplex. 



Buchanani maorum. 



verrucosa. 



novcB-zelandice. 

 Trailli. 



chordata. 



optabilis. 



1. Drillia Buchanani, Hutton, subsp. maorum, E. A. Smith, 1877. 

 Plate 46, fig. 22. 



Drillia (?) maorum, E. A. Smith, A.M.N.H. (4), xix, 1877, 497. D. Buchanani, 

 subsp. maorum, Suter, J. Mai., xii, 73 ; Murdoch and Suter, T.N.Z.I., 

 xxxviii, 282. Surcula Buchanani, subsp. maorum, Smith : Suter, P. 

 Mai. S., vi, 200. Drillia Buchanani, Hutton, J. de Conch., xxvi, 16; 

 M.N.Z.M., 42, not of Cat. Tert. Moll. Pleurotoma Buchanani, Hutton, 

 Man. Conch. (1), vi, 208; not of Cat. Tert. Moll. Drillia maorum, 

 Smith, M.N.Z.M., 44 ; P.L.S. N.S.W., x, 116. Surcula Trailli, Hutton : 

 Suter, T.N.Z.I., xxxi, 90 ; xxxiv, 211 : Index, 71 ; not of Hutton. 



Shell fusiform, turreted, axially obliquely costate and spirally 

 striate, fulvous. Sculpture consisting of crowded obsolete axial ribs, 

 rather oblique above at the excavation, where they vanish, about 15 

 on a whorl, not continued over the base ; they are crossed by spiral 

 lirse, 6 to 7 on the penultimate whorl, about 15 on the body-whorl, 

 the interstices now and again with one or two fine spiral threads ; the 

 lirse are inequidistant and of variable strength ; a fine spiral thread 

 below the suture, the excavated shoulder smooth except for crescent- 

 shaped growth-lines. Colour fulvous ; aperture inside of the same 



