THE MALACODERMI. 149 



retractile, but hidden by the great bulk of the thorax 

 in front ; and the elytra are often obliquely truncate at 

 the apex ; in which last character (and in general facies) 

 they are exceedingly like certain of the Scolytida, wherein 

 the number of joints in the tarsi is different. 



Their larvse, also, appear to resemble those of the 

 Ptinidce, but to be less wrinkled transversely; having, 

 moreover, two four-jointed antennae and no eyes, whilst 

 the latter have exceedingly small two-jointed antennae 

 and very minute spherical eyes, situated in a depression 

 near the base of the mandibles. 



The large and very rare Boslrichus capucinus has re- 

 cently been taken near Highgate on a felled oak ; and 

 the little Rhizopertha pusilla, superficially very like a 

 Tomicus, but in which the structure of the tarsi is exactly 

 the same as in the Cioidte, occurs at Glasgow and else- 

 where, being probably imported. 



The LYCTID^E are sometimes associated with both the 

 next and the preceding family ; and have, also, been 

 placed among the Colydiadce and Cryptophagidce, to cer- 

 tain of the former of which they present a considerable 

 external resemblance. Their tarsi have five joints, the 

 first being very small, and the last as long as the four 

 preceding; the first abdominal segment is longer than 

 any of the rest ; the club of their antennae is two-jointed ; 

 and their body flat and elongate, with punctate-striate 

 elytra. 



This assemblage of characters causes them to fit un- 

 easily with any of their supposed allies ; and the diffi- 

 culty of assigning them to their correct position has 

 been increased by the discovery of the larva of one of 

 the species, which is fleshy, arched, cylindrical, and with- 

 out eyes or legs; resembling, in short, those of the 



