FOREGUT ANATOMY AND CLASSIFICATION OF CONOIDEA 



141 



be formed from two pieces as in Ptychobela suturalis (see 

 above). Lack of material precluded further study of this and 

 the type iii wishbone teeth. 

 c) Hollow teeth 



There is a great diversity of detailed variation in the form of 

 hollow marginal teeth even within a single genus (see for 

 example, James (1980) and Nybakken (1990) for Conus and 

 Bogdanov (1990) for Oenopota). However, for the purposes 

 of this analysis we recognise only five main types of hollow 

 teeth, (i) Teeth of this type are long, slender, and enrolled, 



with a small base. The base is not differentiated morphologi- 

 cally and is not solid. The distal end of the tooth may be 

 simple, or more or less, elaborately barbed (Figs 22e,g). 

 There is an opening near the distal tip and a second opening 

 placed more or less terminally at the proximal end. The shaft 

 oiHastula hectica is perforated by holes (Taylor, 1990, fig. 2). 

 For some Conus species, Nybakken (1990) has shown that 

 during ontogeny, the hollow, rolled teeth develop from open, 

 guttered forms and become progressively more elaborately 

 barbed. Hollow teeth of Type i are found in species of 



Fig. 20. Radulae of Clavinae and Crassispirinae. a. marginal tooth of Drillia rosacea. Scale bar = 50 (xm. b. Funa latisinuata; blade-like 

 marginal teeth with thin accessory limb. Scale bar = 50 \xm. c. Vexitomina garrardi; part of blade-like marginal tooth with accessory limb 

 (arrowed). Scale bar = 10 ^m. d. enlargement of (d) showing accessory limb. Scale bar = 10 \im. 



