22 Inteoduction 



retical grounds, especially as the totals run so close that any small 

 error would affect the result. I think, however, that this table shows 

 that Leconte's serricorn families are more primitive than his clavicorn 

 families so definitely that there remains no doubt his sequence should 

 be reversed in that section of his work. 



If Lamellicornia are compared, their formula would correspond 

 neither with the highest rank that Gangli^auer gave them nor the lowly 

 position assigned by Kolbe, but an intermediate place such as they occupy 

 in the Leconte system. Ganglbauer has maintained, and is apparently 

 supported therein by Dr. Gahan, that they are the most highly si:)ecial- 

 ized of all beetles, in the antennae, in the high degree of concentration 

 of the nerve ganglia, and in the social instincts displayed by their highest 

 tribe. He is opposed by Kolbe, who cites their 5- jointed tarsi and 

 abdominal structure as strikingly primitive characters, and he might 

 have included the frequent occurrence of the onychium. It appears 

 also by Ganglbauer's own statements that the nerve ganglia are highly 

 concentrated in the Rhynchophora also and he appears to have over- 

 looked the occurrence of lamellate antennse in certain Scolytids. I have 

 therefore no hesitation in adopting approximately as far as Lamelli- 

 cornia are concerned the results of the formulas given above, especially 

 since they only corroborate those reached by Leconte and coincide with 

 the sequence for the principal families to which we are accustomed. 



The internal structures have also been studied and confirm more or 

 less the results obtained from the study of the external structures. I 

 know these data only from Dr. Gahan's paper, already quoted, in which 

 he reviews the work of Escherich,' Emery ,^ Dufour^ and Bordas* 

 on sexual organs, ovaries and testes, Brauer^ and Wheeler^ on the 

 Malpighian vessels, and Blanchard,' Brandt'* and other anatomists on 

 the nervous system. Korshelt and Heider^ are also quoted as the 

 latest review of these internal structures. 



The phylogenetic deductions from the studies of internal struc- 

 tures by various authors are not entirely in accord, but taken as a whole 

 confirm the primitive character assigned to the Adephaga. Their 

 bearing upon the rank to be assigned to Lamellicornia is to elevate that 



1 Zeitschr. fur Wissensch. Zool. LVII, 1894, pp. 620-641. 



= Biol. Central. 151. V, 1885, p. 652. 



3 Ann. Soc. Nat. VI, 1825. 



' Ann Sc. Nat. Zool. et Pal. 8 ser. XI, 1900, pp. 28.3-448. 



5 Verh. zool. bot. Ges. Wien. XIX, 1869. 



8 Psyche, VI, 1893. 



' Ann. Sc. Nat. 3 ser. Zool. V. 1846, pp. 273-279. 



s Hor. Soc. Ent. Ross. XIV, 1878. 



' Lehrbuch der vergleichenden Entmcklungsgeschichte der wirbellosen Thiere, Jena, 1902. 



