259 



minute threacllets separated by slightly wider intervals than 

 their width. 



Last whorl with a rounded periphery, ornamented with slender 

 transverse threadlets and stout spiral threads, the latter alternately 

 large and small, about 15 in number, or the intermediate ones 

 nearly equal in size to the primaries. The iDase is rather abruptly 

 contracted into a moderately long, but stout, canal, ornamented 

 with about eight distant spiral lirte, and transverse threadlets. 

 Aperture narrow-elliptic ; outer lip Urate within. Columella with 

 two oblique plaits, the anterior one at the origin of the canal ; 

 canal nearly closed by a horizontal plate-like extension of the 

 border. 



Length from 21 to 22 ; breadth from 6 to 6*5 mm. 

 Dredged in life one and a half miles off Edithburgh, St. Vincent- 

 Gulf, in three to four fathoms, by Mr. E, H. Matthews; also in 

 sliell-sand, Aldinga Bay (Kimber) ; Hardwicke and Encounter 

 Bays (Adcock). 



Diala magna, >ipec. nov. Plate xi. , fig. 9. 



Whorls nine ; apical whorls two and a half, convex, rapidly 

 diminishing, purplish-black ; spire-whorls flat, excavated at the 

 suture, slightly incrassated at the anterior suture, smooth, shin- 

 ing, whitish interrupted by axial flames of reddish-purple. 



Penultimate whorl with one to three spiral grooves bordering 

 the anterior suture ; the colour-stripes on the grooved surface 

 being broken-up into dots. 



Body-whorl with a rounded base ; the anterior two-thirds with 

 about nine encircling flat ridges, not so wide as the intervening 

 flat furrows, spotted with purplish-red in the sulci ; on the pos- 

 terior one-third the sulci are obsolete and the colour-spots are 

 confluent but in an alignment with the anterior dots ; the whole 

 forming axial bands sigmoidally curved, extending from the 

 suture to the extreme front. Growth-lines flne and regular, 

 conspicuous on the base. Aperture subrotund, outer lip thin, 

 peristome incomplete or thinly continuous, columella simple. 



Length, 13-0 ; breadth, 4*5 mm. 



JIahitat. — Deep water. Port Phillip Bay, Victoria (J, 21. 

 Wilson). 



This species is at once distinguished by its size, its furrowed 

 suture, and the flat distant ribs on the base. Its nearest ally is 

 D. laiita, A. Adams, certain individuals of which have a sliglitly 

 channelled suture, but the basal sulci are linear, and the colour- 

 spots never confluent. Its rounded base separates it from 

 D. suturalis, the only other species with distinctly-furrowed 

 suture ; whilst the arrangement of the colour is not seen in any 

 other species. 



