98 THE OEDEE OF COLEOPTERA. 



be found which will enable us to establish it upon rational bases ; but 

 many months' assiduous labor comi^els me to declare that such characters 

 do not exist, and that we shall search for them in vain. We must trust 

 therefore to tradition to supply the inadequacy of science." 



They com^irise two well marked but very unequal sub-families, as 

 follows : 



First Sub-family, Eucnemides. Antennte inserted upon the front. 

 Head bent down upon the breast in repose. 



Second Sub-family, Elaterides. Antennae inserted under the margin of 

 the front. Head directed forwards. 



Snb-family EUCIOIMIDES. 



This sub-family is composed of a moderate number of small, compa- 

 ratively rare, black or brown insects, and more or less clothed with 

 minute yellow hairs. They resemble the Elaterides in their elongated 

 slender forms, but are distinguished by their vertical heads, the mouth 

 being inferior, and not anterior as in the Elaters. The antenna? also, 

 as a general rule, are more strongly serrate, and in the males often pec- 

 tinate or even flabellate. The palpi are often terminated by a widened 

 or hatchet-shaped joint. Whilst the perfect insects strongly resemble 

 the Elaterides, such of their larvae as are known have a striking resem- 

 blance to those of the preceding family of Buprestidte, both in form and 

 habits, being abruptly enlarged at their anterior extremity, and being- 

 found in wood in an incipient state of decay. 



The following tables exhibit those genera which are most common or 

 most numerous in species : 



A. Anteniiffi inserted in pits on the front, at some distance apart ; claws not serrate. 



B. Maxillary palpi with tlie last joint acute Melasis, 4 sp. 



B B. Maxillary palpi with the last joint dilated. 

 C. Grooves for the antennaj under the margin of the thorax. 



D. Antenna} serrate Eucnejiis, 3. 



D D. Antennae filiform Fokxax, 14. 



C C. Autennal grooves wanting Nematodes, 3. 



A A. Antennfe inserted close together on the front ; claws serrate CEitorn ytum, 2. 



Sub-family ELATEKIDES. 



A. Sternum with deep grooves for the reception of the anteun;B Adeloceua, 16 sp. 



AA. Sternal grooves obsolete or wanting. 



B. Mesosteruum connate with the metastemum ; very large species clothed with whitish scales, 



and with two eye-like spots on the thorax Alaus, 4. 



B B. Mesosternal suture distinct, and without the other above mentioned characters. 



C. Hind coxal plates suddenly dilated inwards, and prolonged into a tooth at the posterior an- 

 gle ; claws never pectinate. 



D. Prosternal .spine truncate ; scutelhim heart shaped Cakdioi'HOUUS, 32. 



D D. Pro-sternal spine acute ; scutelhim oval. 

 E. Anterior margin of the front not elevated ; coxal plates moderately dilated ; large species 

 with distinctly serrate antcnme LuDius, 5. 



