DEEP-SEA CONOIDEAN GASTROPODS 



25 



below the shoulder (2 on the spire whorls and 18 on the body 

 whorl plus canal). The cords are separated by 2-3 times wider 

 intervals. They are often subobsolete in interstices between axial 

 folds but very strong when overrided the latter. On the body 

 whorl, the cords gradually diminish in width and prominence 

 towards the canal end. There are 1-4 (usually 2) thin threads in 

 the interspaces between cords, except between those on the 

 canal, and 3-4 low rounded threads on the subsutural slope. 

 Strong rounded tubercles are formed at the intersection between 

 axial folds and spiral cords resulting in a beaded appearance of 

 the spiral sculpture. The aperture is rather narrow, gradually 

 narrowing towards the canal. The inner lip bears about 13 weak 

 transverse plicae in its lower part, the plicae become closer to 

 each other towards the canal end. There is a moderately 

 developed parietal callus pad which is weakly tuberculate in its 

 lower part. The outer lip has a sharpened edge, with a strong 

 varix behind. Inside the aperture, there are 5 transverse plicae 

 most prominent in the region corresponding to the varix, and a 

 strong tubercle just below the anal sinus. The sinus is 

 semi-tubular, U-shaped, broad and rounded, directed outside in 

 relation to subsutural slope. The canal is long, slightly twisted, 

 and obliquely truncated at the end. H = 22.6, Hb = 13.4, Ha = 

 11.3,D = 7.9mm. 



Paratypes vary in minor details of sculpture, e.g. in the 

 prominence of axials on the subsutural slope, and in more or less 

 strong nodules at the intersections between spiral and axial 

 elements. The largest paratype is 22.6 mm high (protoconch 

 missing). 



The new species is quite similar to G sultana (Thiele, 1925) 

 from East Africa, differing in the more slender shell (H/D ratio is 

 2.70-2.91 vs. 2.55 in the holotype of G. sultana) and in the 

 presence of weakened but distinct axial folds on the subsutural 

 slope. A peculiar feature of the new species is the presence of a 

 second keel encircling the suture on last protoconch whorls. 



Distribution. Gulf of Aden, 655-732 m. 



Subfamily DAPHNELLINAE Deshayes, 1863 

 Genus CRYPTODAPHNE Powell, 1942 



Type species: Cryptodaphne pseudodrillia Powell, 1942 (original 

 designation) 



Cryptodaphne gradata (Schepman, 1913) 



Fig. 108 



Pleurotomella gradata Schepman, 1913, p. 445, pi. 30, fig. 2. 

 Cryptodaphne gradata (Schepman) - Shuto, 197 1 , p. 1 1 , pi. 2, figs 

 4-6. 



Type locality. 'Siboga', stn 159, Halmahera Sea, 411m. 



Material, stn 176, 1 shell. 



The shell from the JME material basically conforms to the 

 description and illustrations of the holotype given by Schepman 

 and Shuto (see synonymy). However it differs from the latter in 

 some remarkable characters. The shell is much larger than that in 



the holotype (18.5 mm vs. 10.0 mm), with a proportionally 

 higher spire, at approximately the same number of teleoconch 

 volutions (6+ vs. 6). The anal sinus is deeper, with its apex 

 situated lower on the subsutural slope. The initial three whorls 

 of the teleoconch bear oblique axial folds below the peripheral 

 angulation. These folds form nodes on the angulation, making it 

 crenulated, and rapidly weaken towards the lower suture. On 

 subsequent whorls, they become less developed and disappear 

 on the body whorl. The spiral sculpture lacks a regular 

 alternation of strong and weak spirals mentioned by Shuto. The 

 sculpture has a cancellated appearance due to the intersection 

 with growth lines. Also there are widely spaced, thin, and weak 

 but distinct spiral threads on the subsutural slope which were 

 not described by either Schepman or Shuto. 



Nevertheless, these differences are not essential and seemingly 

 do not extend beyond the range of intraspecific and 

 geographical variability of C. gradata. 



Distribution. Halmahera Sea and Gulf of Aden, 41 1-732 m. 



Genus FAMELICA Bouchet & Waren, 1980 



Type species: Pleurotomella catharinae Verrill & Smith. 1884 

 (original designation) 



Famelica tajourensis Sysoev & Kantor, 1987 



Fig. 112 



Famelica tajourensis Sysoev & Kantor, 1987, p. 1257, fig. g, d, e, 

 zh. 



TYPE LOCALITY. 'Akademik Kurchatov', stn 1095, Tajoura 

 Rift, Gulf of Aden, 1330-1406 m. 



Material, stn 188, 1 shell. 



The JME shell agrees well with the type material and differs 

 mainly in having thin and transparent shell walls compared with 

 rather thick and solid in the type specimens. 



The species is rather different from the type species of the 

 genus Famelica, but very similar to F. monotropis (Dautzenberg 

 & Fischer, 1896), which was included into Famelica by the 

 authors of the genus (Bouchet & Waren, 1980). On the other 

 hand, the genus seems to be rather heterogeneous in respect to 

 species originally included into it. Nevertheless, I do not know 

 any other genus which can accomodate F. tadjourensis. A similar 

 genus is Pagodidaphne Shuto, 1983, but it differs in having a less 

 distinct keel on the whorl shoulder and much less elongate body 

 whorl with a short canal. 



Distribution. Gulf of Aden, 528-1406 m. 



Genus GYMNOBELA Verrill, 1884 



Type species: Gymnobela engonia Verrill, 1884 (subsequent 

 designation Cossmann, 1896) 



Figs 102-112 Clathurellinae and Daphnellinae. 102, 103 - Glyphostoma maldivica Sysoev, new species, holotype; 104, 105 - G. supraplicata Sysoev, 

 new species, holotype; 106, 107- Gymnobela adenica Sysoev, new species, holotype (106) and paratype, stn 185, H = 7.1 mm (107); 108- Crypto- 

 daphne gradata (Schepman, 1913), stn 178, H = 18.5 mm; 109-111 - Gymnobela africana Sysoev, new species, holotype (109, 110) and paratype, stn 

 1 18, H = 68.0 mm (111); 112 - Famelica tajourensis Sysoev & Kantor, 1987, stn 188, H = 10.6mm. 



