BY H. LEIGHTON KESTEVEN. 



453 



Nos. 4 and 6 of this series are Australian Tertiary species 

 (34, 122, 126). 



An attempt has been made in the accompanying tables to show 

 at a glance the intricate relationship existing between the various 

 groups. 



lotorium 



I 

 j)yium 



cynocephalus 



I 

 sarcostoma 



I 

 exaratus 



I 



I 

 vespaceus 



gemmatus 



I 

 mundum 



pilearis 



tranquebaricus 



waterhousei 



gemmatus 



I 

 intermedius 



I 



quoyi 



I 

 verrucosum 



spengleri 



I 

 doliarium 



I 

 chemnitzi 



I 

 succinctus 



cingulatus 



I 

 etc. 



I 

 chlorostoma 



thersites 



I 

 orientalis 



I 

 crispus 



I 

 quoyi 



i 

 verrucosum 



eburneum 



oligostirus 



I 

 philomelae 



I 

 tumulosus 



! 

 subdistortus 



I 



nodiferus 



I 

 tritonis 



dunkeri 



I 

 tuberosus 



I 

 encausticus 



I 

 caudatus 



I 

 exaratus 



lotorium 



I 

 pyrum 



dunkeri 



I 

 tuberosus 



I 

 encausticus 



i 

 caudatus 



I 

 exaratus 



I 

 vespaceus 



I 

 gemmatus 



I 

 intermedius 



I 

 quoyi 



i 

 crispus 



orientalis 



thersites 



I 

 chlorostomus 



I 

 exaratus 



I 

 sarcostoma 



cynocephalus 



I 

 pyrum 



I 

 lotorium 



These tables, judged by the form of the shell, are, I submit, 

 correct, and serve to prove the impossibility of dividing the 

 genus into four. 

 30 



