COLEOPTERA. — HETERO.MERA. 281 



The family comprises only the three genera, Mastigus Latr., Cli- 

 dicus Laporte (from Java), and Scydmasnus. The insects of the 

 last named genus, which do not exceed one-eighth of an inch 

 in length, have attracted the attention of several entomologists on 

 account of their interesting structure and affinities. Mr. Stephens has 

 described several new species in his Illustrations and the Appendix 

 thereto, in which he has proposed to separate the Scyd. thoracicus K. 

 (^Denny, Mon. pi. W.Jiy. 3.), having the thorax very broad, dilated in 

 front, and the antennae with the eighth joint smaller than the seventh, 

 under the generic name of Megaladerus. It is the genus Tyttosoma 

 of M. Wesmael. 



In the genus Mastigus the elytra are united, and the basal joints 

 of the antenna; are very much elongated. M. palpalis Latr. is a 

 reputed British species. Dr. Waltl states that this species resides 

 amongst grass at the foot of walls, in society, and that they are to be 

 found lying, in heaps together like bees when swarming (Jieise nach 

 Tyrol, S^c, Passau, 1835.) Dr. Klug has published a monograph 

 upon this curious genus, in his Entomologische Monographien in 

 which he has described six species, one of which is figured in 

 Guerin's Icon. R. An. Ins. t. xvii.., and Dr. Waltl has added another 

 species in the work above quoted. I have observed two curious 

 minute insects embedded in gum anime ; which, from the large size 

 of the palpi ^appear to belongfthis family, forming two new genera. ,J^ 

 In one of these the antennae are terminated by a 3-jointed clava, 

 having the fifth joint considerably elongated, and in the other these 

 organs are short and perfoliated. 



Sect. ii. HETEROMERA. 



The second general section of the Coleoptera, or the Heteromera 

 of Latreille, comprises those beetles in which the four anterior tarsi 

 are 5-jointed {fg. 32. 5.) ; the posterior pair only 4-jointed {fig. 32. 

 6.) ; a character, which, notwithstanding the recent observations of 

 various French entomologists as to the artificial nature of the group 

 which exhibits it, appears to me to be of sufficient importance for 

 retaining the division, at least until we are more perfectly acquainted 

 w^ith the preparatory states of the various subdivisions of which it is 

 composed. Hence it is that I have not thought it proper to retain 

 Mr. MacLeay's name of Thysanuromorpha, the transformations of 



