Mr. Westwood on the Affinities of Clinidium. 225 



In the produced formation of the underside of the head the two genera 

 are, however, alike, as also apparently in their trophi. I was not, how- 

 ever, able either to examine those organs or the tarsi so accurately as I 

 could have wished. 



Of the other genera, hitherto placed in the family Cucujida:, the 

 nearest approach to the two preceding groups is made by 



Passandra, 

 founded by Dalman in the Appendix to the 3rd volume of Schonherr's 

 Synonymia Insectorum, p. 146, and figured in Tab. 6, fig. 3 of that 

 work. On its affinities Dalman merely remarked, " Statura sublinearis, 

 " depressa, et facies fere Passali." Latreille, in the Families Naturelles, 

 p. 398, correctly places the genus, without any remark upon its indivi- 

 dual characters, in his family Platysomes (Cucujipes.) There is, how- 

 ever, the following interesting observation made in that work upon that 

 family, " Ces Coleopteres, ainsi que les Trogosites et les Prostomis 

 " (Megagnathus) , se rapprochent sous quelques rapports des Lucanides." 

 The chief of these " rapports" appear to me to consist in the pentame- 

 rous tarsi and general character and habits of the insects; and in the for- 

 mation of the labium and maxillse of Rhysodes, as well as in the charac- 

 ters of Passandra, other and much greater resemblances are discoverable. 



In the new edition of the Regne Animal, Vol. V. p. 101, Latreille 

 has, however, altered the situation of the genus Passandra, and has in- 

 cluded it in his third division of the Xylophages, placing it as the last 

 genus after the Trogositarii, with the remark, " Ces insectes sont evi- 

 " demment le passage de cette famille (Trogositae) a la suivante (Cu- 

 " cuji or Platysomes). lis ne different meme des Platysomes que par leurs 

 " antennes." It is evident that Latreille here alludes to the increased size 

 of the last joint of the latter organs, fig. 3, C. In every other respect, 

 not only in general formation, but also in the similarity of structure of 

 the under side of the head, (which I have figured in Tab. Supp. xlvi. fig. 

 3, A,) it will be perceived, that a most intimate connexion exists between 

 this genus and the two preceding, and the description of the trophi given 

 by Dalman tends to confirm this affinity. If Latreille, however, was 

 anxious to shew the affinity between his Trogositarii and Cucujipes, there 

 are other and much more satisfactory links (as I shall subsequently en- 

 deavour to prove) to establish the connexion, than the mere incrassation 



