Bibliographical Notices, &5 



more satisfactorily show the manner in which the author has treated 

 the subject in its various bearings ; we will therefore take the distri- 

 bution of the Coleoptera, which has lately been the subject of much 

 discussion, as an example of the manner in which the natural classi- 

 fication of insects is treated. After reviewing the arrangements of 

 Linnaeus, Latreille, MacLeay, etc. (that of the last-named author 

 being founded upon the analogical relations of the preparatory 

 states and the asserted inaccuracy of the tarsal system), the author 

 observes, in addition to our ignorance of the larvae of many import- 

 ant groups, " that Mr. MacLeay himself admits the existence of a 

 variation in the tarsal structure concurrent with the variation in the 

 form of the larvae, a circumstance dependent, as it seems to me, 

 upon the principle that modifications of the preparatory states of an 

 insect ought merely to be regarded as indications of corresponding 

 peculiarities in the final state, the former modifications being subor- 

 dinate to those observed in the imago, and having, in fact, been un- 

 dergone with a direct view to the perfection of the insect. We might 

 indeed carry the subject still further. Thus, whilst the intimate 

 connexion existing throughout the whole of the Tetramerous Beetles 

 cannot be denied, yet Cerambyx has a subvermiform and Chryso- 

 mela an anopluriform larva ; whilst the latter and Coccinella (Mr. 

 MacLeay's two examples of the Anopluriform Stirps), although 

 agreeing in the larvae, are totally diflferent in the habits and in the 

 structure of the tarsi of the imago." After some further observa- 

 tions, he adds, that " The Coleoptera are therefore divisible into the 

 four following sections : 1. Pentamera, in which all the tarsi are 5- 

 jointed, the fourth being of ordinary size ; 2. Heteromera, in which 

 the four anterior tarsi are 5-jointed, and the two posterior 4-jointed ; 

 3. Pseudotetramera (or Subpentamera, Tetramera, Latreille, Crypto- 

 pentamera, Burm.), in which the tarsi are 5-jointed, but the fourth 

 joint is exceedingly diminutive, and concealed between the lobes 

 of the preceding; 4. Pseudotrimera (or Subtetramera, Tetramera, 

 Latr., Cryptotetramera, Burm.), in which the tarsi are 4-jointed, the 

 third joint being very diminutive, and concealed between the lobes 

 of the preceding." 



As a specimen of the structural details, the following account of 

 the structure of the mouth of the preparatory states of the May-fly 

 {Ephemera vulgata) may be quoted : — ** Considering the rudimental 

 nature of the mouth of the imago, it is surprising that no one has 

 hitherto described the real structure of the mouth in the preparatory 

 states. Reaumur has attempted it, but his figures are so rude and in- 

 sufficient, that no idea can be gleaned as to their true structure ; 

 Swammerdam also passes them over undescribed. In the pupa 

 of E. vulgata the upper lip is of moderate size, with the anterior 

 angles rounded off and ciliated ; it is flat and quite membranous : the 

 mandibles are horny, armed with several teeth within, near the base, 

 which is dilated into a flattened molary plate, whilst the upper angle 

 of the mandible is produced into a long curved horn. The maxillae 

 are small, membranous, curved, pointed at the tip and internally se- 

 tose : the maxillary palpi do not extend beyond the front of the head ; 



