INTRODUCTION. 31 



system was afterwards applied by Dr. Kaup of Darmstadt 

 to the Passalid^ with sucli excessive confidence that he 

 ventured to foretell the precise number of species of that 

 family ultimately to be found in the world, namely 325. 

 Although this number has already been considerably exceeded, 

 new forms still persist in reveahng themselves. 



Macleay's five families were adopted in the ' Catalogue of 

 the Lucanoid Coleoptera in the collection of the Rev. F. W. 

 Hope,' published in 1845. The names occurring for the first 

 time in this work have been attributed to Hope, no author's 

 name being printed on the title-page ; but it is recorded by 

 G. Albers (Deutsche Ent. Zeitschr., vol. xxviii, 1884, p. 301) 

 that a copy of the work was sent by Westwood to Snellen 

 van Vollenhoven in which he had added to the title the words 

 " by J. 0. Westwood." As it is probable that Hope had some 

 share in the work, 1 have treated it as a joint production. 



In Lacordaire's ' Genera des Coleopteres,' vol. iii, (1850), 

 the families were reduced to the two now generally recognized, 

 and the term Pectinicornes was applied to them in contra- 

 distinction to the Lamellicornes. Gemminger and Harold's 

 Catalogue of the Coleoptera ' (vol. iii, 1808) united them 

 into a single family Lucanid^, subdivided into Lucanini 

 and Passalini. 



The reasons for regarding these two groups as forming a 

 suborder apart from the Lamellicornia, were argued at some 

 length by Lacordaire. Essentially they are three in number — 

 the want of mobility of the dub-joints of the antennae, the 

 separation of the ventral ganglia of the central nervous system 

 and differences in the larvae. The Passalid larva certainly 

 differs very greatly from all known Lamellicorn larvae, but 

 it differs in exactly the same way from the Lucanid larva, 

 which is of the ordinary Lamellicorn type, the most important 

 difference being in the longitudinal anal aperture, which is 

 not shared by the Passalidje. There is therefore no better 

 reason for attaching Passalid^ to Lucanid^ than to the 

 LameUicornia generally on account of their larvae. In the 

 nervous system, Lacordaire admits that the Passalid.e form 

 a link between the Lucanid^ and Scarab^id^ ; but since 

 we are completely ignorant of the internal anatomy of nearly 

 all the very various groups of that enormous assemblage of 

 forms, it is unsafe to draw any conclusions from it. The 

 antennae, therefore, alone remain to justify the suborder 

 Pectinicornia. A careful scrutiny of Lacordaire's definition 

 of this group reveals that, while his characters apply to the 

 Lucanid^, scarcely a single one is ajjpficable to the Passalid^, 

 not excepting that of the antennae, which indeed are so com- 

 pletely different in the two families that, if they are of decisive 

 importance, not one but two suborders must be recognized. 



