FOREGUT ANATOMY AND CLASSIFICATION OF CONOIDEA 



161 



rather short, of 'candle flame' shape, open terminally. 



'Tomopleurid' group. Shell rather small to medium sized 

 (6-7 to 37 mm), claviform, with flattened whorls. Anterior 

 canal short. Anal sinus on the shoulder or just below it, 

 moderately deep. Columellar pleats absent. Sculpture 

 entirely spiral (except often raised growth lines), consisting of 

 well developed ribs or heavy keels. Protoconch pauci- or 

 multispiral. In the former case it is smooth or with minute 

 spiral striae or papillae, sometimes carinated; in the latter 

 case first 1-3 whorls with the same sculpture, later ones with 

 axial ribs and, sometimes, minute spiral striae. Operculum 

 with terminal or eccentric nucleus, sometimes absent. Radu- 

 lar teeth short or long and slender, without solid base, open 

 terminally. 



Subfamily Conorbinae De Gregorio, 1890 



Shell of medium size (up to 40 mm), biconic. Anterior canal 

 short, aperture long and narrow. Sculpture entirely spiral 

 except the growth lines. Anal sinus on the shoulder or almost 

 sutural, relatively deep. Protoconch multispiral, smooth or 

 spirally striated on later whorls. Operculum present or, 

 absent in Conorbis. 



Radula. Hollow, marginal teeth with barbed tips and nar- 

 row bases (Conorbis, Thiele, 192 fig 460; Benthofascis, 

 Powell, 1966, fig. 125). 



FOREGUT. These observations are based on Benthofascis. 

 Rhynchostomal sphincter posteriorly situated. Proboscis 

 moderately long, not folded telescopically as in Conus. Distal 

 sphincter of buccal tube absent, intermediate sphincter 

 present. Middle part of buccal tube lined with glandular 

 epithelium. Single acinous salivary gland with two ducts. 

 Single accessory salivary gland. Venom gland with uniform 

 histology, muscular bulb with two muscular layers. No snout 

 gland. 



Remarks. The status of this subfamily is uncertain due to 

 lack of any anatomical information on Conorbis. We have 

 excluded Genota on the basis of shell morphology and the 

 absence of the operculum. 



Snout gland present in many species. Distal buccal tube 

 sphincter absent, intermediate sphincter present. Middle part 

 of buccal tube is lined with glandular epithelium. Buccal mass 

 basal. Single acinous salivary gland with one or two ducts. 

 Single accessory salivary gland. Venom gland of uniform 

 histology, muscular bulb often with many muscular layers. 



Subfamily Oenopotinae Bogdanov, 1987 



Shell of small to medium size (usually 10-15, up to 30 mm), 

 oval to fusiform. Anterior canal rather short. Both spiral and 

 axial sculpture well developed. Anal sinus on the shoulder, 

 shallow, and often indistinct. Protoconch paucispiral, pre- 

 dominantly (sometimes entirely) spirally sculptured. Opercu- 

 lum with terminal nucleus present, vestigial, or rarely absent. 

 Egg capsules dome-shaped, with an operculum. 



Radula. Radular teeth with rounded or cylindrical solid 

 base and hollow shaft, sometimes with barbed tip; rarely 

 teeth vestigial; tooth cavity opens laterally between the shaft 

 and the base. 



Foregut. Proboscis either long, or short and folded in 

 contracted state. Distal sphincter present or absent. Buccal 

 lips large, may be inverted into the buccal cavity. Buccal mass 

 basal. Salivary glands paired, acinous, although shown as 

 tubular (probably erroneously) in Oenopota levidensis 

 Shimek (1975). Venom gland of uniform histology. Muscular 

 bulb with a thin outer muscular layer. 



Remarks. Species of this group were previously treated as 

 Mangeliinae, but were isolated as a subfamily primarily on 

 the basis of the presence of an operculum and a spirally 

 sculptured protoconch (Bogdanov, 1987, 1990). None of 

 these features are presently considered as being of subfamilial 

 importance. However, one more character was revealed in 

 our study, the structure of the salivary glands, which distin- 

 guished Oenopotinae from the Mangeliinae. We provision- 

 ally retain the subfamilial rank of Oenopotinae until the 

 systematic importance of this character becomes certain. 



Subfamily Coninae Fleming, 1822 



Shell of medium to large size (usually 30-50 mm, up to more 

 than 120 mm), biconic to conic. The inner shell walls are 

 partially resorbed. Anterior canal short, aperture usually 

 narrow, parallel-sided. Sculpture entirely spiral, usually weak 

 or obsolete, sometimes tubercules on the shoulder. Anal 

 sinus on the upper shoulder or almost sutural, shallow to 

 relatively deep, occupying a rather narrow zone. Protoconch 

 multispiral, smooth or spirally striated. Operculum small, 

 with terminal nucleus, rarelyabsent. Egg capsules, bilaterally 

 flattened, vasiform, arranged in clusters. 



Radula. Radular teeth harpoon-shaped, barbed or 

 unbarbed on the tips, without solid base, usually open 

 terminally (rarely laterally) at the base. 



FOREGUT. Proboscis moderately short and folded in con- 

 tracted state. Rhynchostome lacks definite sphincter and 

 rhynchodaeum can be greatly expanded to form a rostrum in 

 fish-feeding species. Radial muscles lie in rhynchodeal wall. 



Subfamily Mangeliinae Fischer, 1884 



Shell small (usually 5-12 mm, up to 20 mm), ovate to 

 fusiform. Anterior canal rather short. Both spiral and axial 

 sculpture well developed. Anal sinus on the shoulder, shallow 

 to rather deep, sometimes subtubular. Outer lip usually with 

 terminal varix, sometimes denticulate. Protoconch smooth or 

 variously sculptured. Operculum absent. Egg capsules dome- 

 shaped, with an operculum. 



Radula. Radular teeth hollow with a solid base, sometimes 

 with a semi-enrolled shaft; tooth canal opens laterally. 



Foregut. Proboscis moderately long, with a single or no 

 distal sphincter, intermediate and posterior sphincters some- 

 times present. Buccal tube introvert ('valvule') present. Dis- 

 tal lips of buccal tube can be inverted. Buccal lips large and 

 can be introverted into the buccal cavity. Buccal mass basal. 

 Salivary glands paired and tubular, accessory salivary glands 

 absent. Venom gland of uniform histology; muscular bulb 

 usually with a thin outer muscle layer. 



