Bull. not. Hist. Mus. Lond. (Zool.)62(l): 1-30 



Issued 27 June 1996 



Deep-sea conoidean gastropods collected by tjbesTORYMusEi 

 John Murray Expedition, 1933-34 pi jul 1996 







GENERAL Lli ^ ARy 



ALEXANDER V. SYSOEV 



Zoological Museum of Moscow State University, Hertzen Street 6, Moscow 103009, Russia 



Synopsis. Conoidean gastropod molluscs (formerly treated within the family Turridae) from 20 deep-sea (bathyal) 

 stations of the John Murray Expedition (North-Western Indian Ocean) are described. A total of 50 species from 11 

 families and subfamilies, and 3 1 genera and subgenera, have been found in the material studied. 1 7 species are described as 

 new. 



INTRODUCTION 



TAXONOMY 



The John Murray Expedition worked aboard the 'Mabahiss' in 

 the northwestern part of the Indian Ocean in 1933-34 and 

 collected invaluable biological material from the area which has 

 not been subsequently explored on such a large scale. However, 

 no account of the gastropods collected by that expedition have 

 ever been published. Through the courtesy of Dr John D. Taylor 

 of The Natural History Museum, London I was able to study the 

 conoidean gastropods from that collection. This paper deals 

 with deep-sea samples of that part of the Conoidea (= 

 Toxoglossa) which was usually treated as the family Turridae. 

 The Turridae s.l., unlike the Terebridae and Conus, are very 

 characteristic of the deep-sea molluscan fauna, of which they 

 comprise a considerable part. The material studied was 

 previously loaned to the late A.W.B. Powell who mentioned 

 some of the species in two parts of his revision of Indo-Pacific 

 Turridae (Powell, 1964, 1 969). However, none of Powell's species 

 identifications was found on labels accompanying the samples. 



MATERIAL AND METHODS 



The molluscs studied were collected at 20 bathyal (depth 

 183-2312 m) stations of H.E.M.S. 'Mabahiss' in the 

 North-Western Indian Ocean (Table 1). The classification of 

 Conoidea used in the present paper follows that adopted by 

 Taylor et al. (1993). All the material including the type 

 specimens of the new species is stored in the Natural History 

 Museum. 



ABBREVIATIONS USED IN THE TEXT 



NHM 



The Natural History Museum, 



London 



JME 



John Murray Expedition 





H 



shell height 





D 



shell diameter 





Hs 



spire height 





Hb 



body whorl height 





Ha 



aperture height 





Family DRILLIIDAE Morrison, 1966. ICZN pending 

 Genus DRILLIA Gray, 1838 



Type species: Drillia umbilicata Gray, 1838 (subsequent 

 designation Gray, 1847) 



Drillia altispira Sysoev, new species 



Figs 18 & 19 



Material, stn 176, 1 shell (holotype, No. 1993088). 



Description. The shell is rather large, claviform, with very 

 high spire exceeding half of the shell height, thick and solid, 

 light-brown, consisting of almost 12 whorls. The protoconch is 

 missing. The whorls are weakly convex and slightly angled; the 

 point of angulation is situated below the periphery in the spire 

 whorls, but shifts upwards on the last whorls. The subsutural 

 slope is concave, and the prominence of concavity increases 

 towards the body whorl. Sutures are clear, straight, and shallow. 

 Axial sculpture consists of oblique, narrowly crested folds 

 terminating on the subsutural slope. Some folds form weak 

 nodules just below the suture. The folds become subobsolete on 

 the last quarter of body whorl, probably as a result of preceding 

 shell damage. There are 14 folds on the penultimate whorl and 

 about the same number on the body whorl. Spiral ribs are 

 numerous, uniform, rounded, moderately strong, with 

 interspaces equal to them in width. The ribs cover the entire shell 

 surface but become narrower, closer, and weaker on the 

 subsutural slope. The shell base forms a weak bend in passing to 

 a moderately developed fasciole. The aperture is rather small, 

 inversely pyriform, with a distinct stromboid notch. The outer 

 lip with a thin edge, projects strongly and forms an alate 

 expansion between the anal sinus and stromboid notch. There is 

 no prominent prelabral varix, only a thin fold curved in 

 correspondence to growth lines is present. The inner lip is 

 covered by thick and wide glossy callus which is mostly free 

 along its outer edge and forms a shallow false umbilical cavity. 

 The parietal callus pad is large and rounded, constricting the 

 entrance to the anal sinus. The anal sinus is deep, U-shaped, with 

 spout-like edge, directed slightly adapically. The canal is short, 

 slightly bent to the right, shallowly notched and obliquely 

 truncated. H = 37.9, Hb = 1 7.5, Ha = 14.2, D = 1 1 .4 mm. 



) The Natural History Museum, 1 996 



