MR. WESTWOOD ON SOME NEW SPECIES OF BOLBOCERAS. 
Fig. 20. Bolboceras triangulum, Westw. 
Fig. 21. Bolboceras lineatus, Melly, MS. 
Fig. 22. Bolboceras nigerrimus, Westw. 
Fig. 23. Bolboceras plagiatus, Westw. 
Fig. 24. Bolboceras posticalis, Westw. 
Fig. 25. Bolboceras letus, Westw. 
Fig. 26. Bolboceras (Eucanthus) Melibeus, Fabr. 
