. Bulletin of the Natural History Museum Zoology. 142 TAYLOR, KANTOR AND SYSOEV Borsoniinae, Clathurellinae, Toxiclionella (Clavatulinae), Conidae, and Terebridae (ii) Hollow teeth of this second type are often short with a large, solid base (Fig. 23). The tooth cavity opens laterally between the shaft and the base. There are frequently side projections around the base (hiked dagger form of Powell 1966), often with a large irregular solid 'root' projecting from the base (Fig. 23e,f). These teeth are often only partially enrolled. Barbs may be present. Marincovich (1973) records
. Bulletin of the Natural History Museum Zoology. 142 TAYLOR, KANTOR AND SYSOEV Borsoniinae, Clathurellinae, Toxiclionella (Clavatulinae), Conidae, and Terebridae (ii) Hollow teeth of this second type are often short with a large, solid base (Fig. 23). The tooth cavity opens laterally between the shaft and the base. There are frequently side projections around the base (hiked dagger form of Powell 1966), often with a large irregular solid 'root' projecting from the base (Fig. 23e,f). These teeth are often only partially enrolled. Barbs may be present. Marincovich (1973) records rows of holes in the teeth of Agathotoma ordinaria (Mangeliinae). Teeth of Type ii are found in the subfamilies Mangeliinae, Oenopotinae (Bogdanov, 1990, figs 407-438), Thatcheriinae, and the radulate Daphnellinae. (iii) Teeth of this type are partially enrolled at the base, but solid and blade-like in the distal part (Fig. 22b). This type of tooth is presently known only from Hastula bacillus (Taylor & Miller, 1990). It may represent a transitional form between the solid teeth found in the Pervicaciidae and the hollow teeth of the Terebridae. (iv) This type of tooth is loosely enrolled to form a central channel, with a simple barb at the tip. The tooth was first described in detail from Imaclava unimaculata (Clavinae) by Shimek & Kohn (1981 fig. 7). Imaclava other- wise has comb-like lateral teeth as in typical Clavinae. Similar teeth are present in other species of Imaclava (McLean, 1971, fig. 7). (v) Enrolled teeth with a complex appearance are seen in Pilsbryspira nympha (Zonulispirinae) (Fig. 21). Although these are hollow teeth with a small barb, the shaft is complex and appears to be formed by partial enrolling of two units (Fig. 21b). The tooth may be derived by the enrolling of the elongate wishbone teeth typical of the Crassispirinae. (vi) Vestigial teeth, semi-enrolled, with a gutter along the tooth. Teeth of this type are considered by Bogdanov (1990) as der
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