DEEP-SEA CONOIDEAN GASTROPODS 



11 



having a slightly larger shell with shorter and broader canal, 

 shorter spire (its height is less than that of aperture plus canal), 

 and long axials with characteristic reversed-sigmoid curvature 

 and less strong and more numerous nodules. 



Distribution. Gulf of Aden, 1270 m. 



Comitas elegans Sysoev, new species 



Fig. 27 



Material, stn 176, 1 shell (holotype, No. 1993094). 



Description. The shell is medium size, fusiform, slender, with 

 a high turreted spire, solid, white under a grayish-brown 

 periostracum, and consists of 8 whorls. The protoconch is 

 missing. Whorls are roundly angled at the shoulder, with 

 conspicuous subsutural fold, slightly concave subsutural slope, 

 and almost vertical lateral sides. Sutures are shallow, wavy, and 

 slightly channelled. Axial folds (12 on the body whorl and 1 1 on 

 the penultimate one) are strong, oblique, broad, and rounded. 

 They rapidly disappear on subsutural slope and slightly weaken 

 towards the lower suture. On the body whorl, the folds are 

 present on the whorl periphery and fade on the upper part of the 

 shell base. Intervals between folds are narrower than the folds 

 themselves. Spiral ribs are low, broad, rounded and divided by 

 narrow interstices in the upper part of whorls below the 

 subsutural slope. Towards the lower suture and on the shell base 

 they become narrower, thread-like, and more widely spaced. 

 Subsutural slope is smooth except for indistinct spiral grooves in 

 the middle. Growth lines are numerous, thin, prominent on the 

 subsutural slope. The shell base is almost flat; weakly curving, it 

 passes smoothly into a long and straight canal. The aperture is 

 narrow, elongate-oval and not differentiated from the canal. The 

 inner lip is almost straight along most of its length, covered by 

 wide but thin callus. The anal sinus, judging from growth lines, is 

 rather deep, V-shaped, with the apex situated just below the 

 middle of subsutural slope. H = 38.3, Hb = 24.7, Ha = 19.0, D = 

 11.6 mm. 



The new species is very similar to Drillia imestigatoris 

 E.A.Smith, 1899 and differs in having a much smaller shell (65 

 mm in the unique holotype of D. investigatoris) with subsutural 

 slope devoid of spiral sculpture. 



Distribution. Gulf of Aden, 655-732 m. 



Comitas sp. 



Material, stn 184, 1 shell. 



A single broken shell (H = 24.4, upper spire whorls missing) is 

 rather similar to C. trailli (Hutton, 1 873) from New Zealand, but 

 the worn condition of the shell hampers its proper identification. 



Genus LEUCOSYRINX Da\l 1889 



Type species. Pleurotoma verrilli Dall, 1881 (original 

 designation) 



Leucosyrinx claviforma (Kosuge, 1992) 



Fig. 28 



Comitas claviforma Kosuge, 1992, p. 165-166, pi. 58, figs 7-8. 

 Type locality, off Port Hedland, Western Australia, 376 m. 

 Material, stn 158, 1 shell. 



The JME shell differs from the unique holotype in having 

 slightly less angled whorls, lower spire (though the shell is 

 smaller: H = 28.0 mm vs. 38.1 mm in the holotype), and reddish 

 brown colour (ashy white in the holotype). However, all other 

 conchological characters agree with original description and 

 illustrations. 



The species was described as Comitas, but the narrow, turreted 

 shell with angled whorls and the anal sinus scars indicating a 

 deep sinus with greatly projected outer lip are more typical of the 

 genus Leucosyrinx. 



Distribution. Western Australia and Maldive Islands, 

 376-1 170 m. 



Subfamily CRASSISPIRINAE Morrison, 1966 

 Genus INQUISITOR Hedley, 1918 



Type species: Pleurotoma sterrha Watson, 1881 (original 

 designation) 



Inquisitor nodicostatus Kilburn, 1988 



Fig. 49 



Crassispira aesopus (non Schepman, 1913) - Kilburn, 1973, p. 



572, fig. 13a. 

 Inquisitor nodicostatus Kilburn, 1988, p. 259-261, figs 36, 42, 



213-214. 



Type locality. Natal, South Africa (29°43'S, 31°05'E), 

 164-169 fms. 



Material, stn 106, 1 shell. 



Distribution. South Africa and Zanzibar, 183-310 m. 



Inquisitor adenicus Sysoev, new species 



Figs 2 & 50-53 



Material, stn 33, 1 paratype No. 1993096/1; stn 34, 7 

 paratypes No. 1993096/2-8; stn 193, holotype No. 1993095 and 

 4 paratypes No. 1993096/9-12. 



Description of holotype. The shell is medium sized for the 

 genus, claviform, thin but solid, with a high spire, covered with 

 olivaceous-brown periostracum, and consisting of 8 whorls. The 

 protoconch is missing and the upper whorls are eroded. Whorls 

 are obtusely angled at the shoulder and moderately convex. 

 Subsutural slope is broad and concave and the subsutural fold is 

 weak and indistinct. Sutures are shallow and wavy. Axial folds 

 are strong and rounded, slightly oblique, with interstices 

 narrower than folds. Folds extend from the lower suture to the 

 lower part of subsutural slope where they rapidly disappear. 

 There are ten folds on each of two last whorls. Growth lines are 

 thin, prominent on the subsutural slope. Spiral cords are strong, 

 rounded, almost equally developed on axial folds and in 

 interstices; they are much narrower than the interspaces between 

 them. The cords are absent on subsutural slope and become 

 narrower, closer and much weaker on lower part of the shell base 

 towards the canal end. There are four cords on the spire whorls 

 (five on the penultimate one, the lowest cord submargins the 

 suture), five on the body whorl periphery, and, below a wider 

 interval, about 12 on the shell base and canal. The aperture is 

 elongate-oval, rather narrow, becoming slightly narrower as it 

 passing into the canal. Outer lip with thin edge; inner lip 



