Aiistralian and Tasmanian Malacodermidac. 59 



it will be noticed that the true third joint is very dif- 

 ferent to what it is in fig. 16 (other joints are also 

 diiferent), but I have seen so many intermediate forms * all 

 diifering to a slight extent from each other, and forming 

 distinct links between these two forms, that to regard the 

 two figures as distinct would make it necessary to regard 

 hosts of others as distinct. In several specimens before 

 me the true third joint is even shorter than in fig. 16, 

 with its ramus still longer ; whilst I have seen others in 

 which the third joint is still longer than in fig. 18 with its 

 ramus still shorter. 



The rami are very variable, especially when long, and 

 are seldom, if ever, alike in both antennae. When the 

 rami are shorter, they are often simple or almost simple, 

 but frequently are terminated by several minute projections, 

 which often appear more distinct than they really are, 

 owing to being supplied with setose hairs. 



The prothorax in the largest males often appears dis- 

 proportionately small when compared with that of smaller 

 specimens ; in the type of rliipidius for instance (which 

 measures 19 mm. in length) it is actually no larger than 

 in one measurinof but 13 mm. in length. At its base it is 

 not much wider than across the middle of one elytron, 

 whilst in many others it is almost as wide as the width of 

 both elytra across the middle. 



The elytra also vary in their proportionate width to 

 length. 



In a pair from Forest Reefs, pairs from Sydney and 

 Albany and pairs from Tasmania (all taken in cop), the 

 punctures across the middle of the elytra in the male are 

 not much wider than long, and with more or less rounded 

 corners ; in the females they are strongly transverse, more 

 sharply defined and much more regular. But the punc- 

 tures appear to be always much more transverse and 

 regular in the larger than in the smaller specimens of both 

 sexes. The male from Forest Reefs has the antennae much 

 as in fig. 18, but its female has them much shorter with 

 the joints considerably wider than usual in the female. t 



The second and sixth elytral costae (counting the smaller 

 ones as true costae) are especially liable to variation in 



* I have critically examined some hundreds of specimens from 

 many parts of Australia, and have seen many thousands. 



f It is the only female I have seen in which the 4th- 10th joints 

 are all distinctly transverse. 



