the genus Crioceplialus. 163 



progression in their burrows, and for working at their 

 excavation. 



Bhagivm bifasciatum. This larva is abundant in the 

 New Forest, and unlike the larvae of Crioceplialus and 

 Asemum is easily obtained owing to its totally different 

 habits. The Rhagium lives only in the soft wood that has 

 commenced to decay. 



I will here call attention to a very remarkable variation 

 that lias been detected by Mr. Gahan during the progress 

 of this memoir. By the courtesy of the Director of the 

 British Museum (Natural History) I am able to figure it. 

 I have in the preceding pages formed the group Crioce- 

 phalinss for certain forms that have only one spur on the 

 front tibia (Plate IX, fig. 14), instead of two as is usual in the 

 Cerambycidse (Plate IX, fig. 13). In the British Museum 

 collection Mr. Gahan has detected a female Crioceplialus 

 rusticus having two spurs (Plate IX, fig. 15) on the tibia of 

 the left front-leg. Unfortunately the right front-leg is 

 missing in this specimen, but when the individual was first 

 observed it possessed both anterior legs, and Mr. Gahan 

 and myself are pretty certain that both legs possessed the 

 two spurs. 



There appears to be nothing else abnormal about this 

 individual. It ma} r be described in brief as a specimen 

 that departs from character of its species, genus and tribe ; 

 taking on the character of another tribe. The character 

 abnormal in this specimen is normal in Cerambycid 

 Coleoj)tera generally. 



It would be almost useless to discuss the nature of this 

 variation without further information. Some will see in 

 it a case of "reversion." Mr. Punnett has suggested to 

 me that it is probable that other specimens similarly 

 " abnormal " may be found in the locality where this C. 

 rusticus comes from, and if so the case might be viewed as 

 one of more continuous heredity. 



On the other hand, it must not be forgotten, that two 

 spurs are normal on the other legs of Crioceplialus; so 

 that it is possible to view the abnormality as a case of 

 homceotic variation (Baleson). 



Summary of changes and additions made in the pre- 

 ceding paper: — 



Crioccplialinm, new group separated from Ascminaz. 

 Cephalallus, n. g., C. obcrthuri, n. sp., Yunnan. 



