(I iiiinute new Voleopterons Insect. 35 



puncture ; they are rounded and entire at the apex. Tlie legs 

 are hitescent, the tibise compressed, with the external margin 

 towards the apex slightly toothed. The tarsi are very interest- 

 ing in. their structure, being pentamerous ; the first joint is ra- 

 ther indistinct, the two following joints compressed and rather 

 broad, having the underside armed with strong hairs, but in no 

 wise bilobed ; the fourth joint is small and rather indistinct, 

 whilst the fifth is long and subclavate, w'ith two simjile ungues. 

 In the formation of the tarsi and other characters, this insect, there- 

 fore, more nearly apj^roaches Tomicvs than the other genera of Sco- 

 lytidce ; but the structure of its antenna; (which is the chief character 

 emjoloyed by Latreille to separate the allied genera Hylurgvs, Tomicvs, 

 and Ptatypus,) is very different from any of these genera, the clava 

 in Hylurgus commencing at the 8th, in Platypus at the Gth, and 

 in Tomicus at the 7th, whereas in this insect it clearly commences 

 with the 5th joint. The minute .size of the insect, moreover, as well 

 as the diversity of colour, distinct habits, and rounded apex of the 

 elytra, induce me to separate it, at least svibgenerically, from To- 

 micus, under the name of Hypotlicnemus, derived from v-tto siibtus, 

 i)', and vefiu) pasco. 



I know of no insects more worthy of minute investigation than 

 these XylopJiaga, affording as they do an interesting series of affini- 

 ties, which may materially tend to the discovery of the natural dis- 

 tribution of the Coleoptera. In the three great Linna^an genera 

 Chrysomela, Curculio, and Ccrambyx, the tarsi present a jDcrfect uni- 

 formity of structure, M'hich has been termed tetramerous ; but as they 

 are five -jointed, the fourth joint being very minute and hidden be- 

 tween the lobes of the third, this peculiar formation may be termed 

 sub tetramerous. In Scolytus and Hylurgus, eminently wood-boring 

 insects, the same form of tarsi and cibarian organs exists ; these ge- 

 nera, in fact, being CurculionidcE without snouts. Tomicus is precisely 

 similar in its habits and trophi ; but here we find the first departure 

 from the subtetramerous type, the tarsi not being in the least bilobed. 

 A still greater departure, both in the tarsi and trophi, takes place in 

 Platypus ; but these formations are comjiletely lost in Bostrichus-, 

 Apate, &c. Indeed, so far from placing these latter insects in the 

 same family with the former (as is done by most modern entomolo- 

 gists), I feel great hesitation in thinking them allied by any other tie 

 than that of analogy. It is, however, only by the discovery of the 

 larva? that we can hope to gain a knowledge of their real affinities. 



These circumstances can lead to no other conclusion than that the 

 location generally assigned to the Xylophaga between the CtircuHo- 

 nidce and Cerambycidce is not a natural one, but that, on the contrary, 



d2 



