70 Mr. W. S. Macleay o» the Structure of the Tarsus 



three very natural groups is, that it consists of five articukitions, 

 of which the three first are dilated into cushions, the third being 

 liilobed, while the two last are filiform, the fourth being very 

 small. But if these insects be thus peîitamerous'*, our attention 

 will naturally be turned to the Trimera of the French school. 

 May not they also have erroneously been described? Latreille, in 

 characterizing the well-known genus Coccinella in Deterville's 

 Dictionnaire d'Histoire Naturelle, says, "Trois articles aux tarses 

 dont les deux premiers en cœur et garni des brosses." Yet on 

 examining the Coccinella 12-waculata of Java, we clearly see 

 that it is at least tetramerous, the two first joints of the tarsus 

 being dilated, and the two last filiform. De Geer has even given 

 a correct magnified figure of a similar structure of the tarsus in 



* On this paper being read before the Linnean Society, a short notice of its general 

 purport appeared in the PliHosophical Magazine for February last; and Mr. Kirby 

 having seen this notice, stated in the following number that he was aware of the facts 

 given to the public in my paper. To this effect lie quoted a passage from the forth- 

 coming third volume of his Inlroduction to Eiitomologi/. However, in a subsequent 

 communication inserted in the Philosophical Magazine for April, and intended to cor- 

 rect some mistakes of the former communication, Mr. Kirby, in speaking of the joint of 

 the tarsus in Coccinella figured by De Geer, but certainly not understood by that great 

 naturalist, says, " He (i. e. De Geer) regarded this joint not as a primary but as a secon- 

 dary joint, or the joint of a joint, as I am disposed to do myself, and therefore, in the 

 Introduction to Untomology, and upon other occasions, I speak of the Chrysomelida:, &c. 

 as tetramerous, and the Coccinellida: as trimerous." As Mr. Kirby thus continues to 

 consider the Chrysomelida-, &c. as tetramerous, and the Coccinellida: as trimerous, and 

 has thus abandoned all claim to that generalization upon which the whole use and 

 merit of this discovery, as I conceive, hinges, I have only to say, that 1 have not been 

 able to discover with him that Cassida has the same kind of tarsus as Ceramhyx or 

 Chrysomelu. In the above-mentioned passage, cited from the forthcoming volume of 

 the Introduction to Entomology, Mr. Kirby says, that in the Linnean genera CurcuHo, 

 Ceranibyj, Chrysomela, Cassida, &c. " the claw-joint consists of two articulations." 

 Judging from the affinity of Cassida to Chrysomela, I thought so myself at first, but I 

 certainly have not been able to confirm this reasoning by observation. — May 1825. 



his 



