COLEOPTEKA. 343 



alone received into the sternal grooves; the tarsi are similar to those 

 of Lissomus; the head is concealed underneath, and as if covered 

 by a semicircular thorax, into which it is plunged. Such is the 



Chelonarium, Fab. 



The antennae, when at rest, extend parallel to each other along the 

 pectus,* the first and the fourth joint are the smallest of all; the seven 

 following ones are of the same size, and, with the exception of the 

 last, which is ovoid, almost in the form of a reversed cone, and 

 equal. The body is ovoid, and the anterior tibiae are wider than the 

 others. 



All the species known are from South America(l). 



The last subgenus of this first division, or 



Throscus, Lat. Trixagus, Kugl. Gyll. Elater, Lin. 



Is distinguished from all others of this tribe by the antennae, which 

 terminate in a triarticulated club, and are lodged in a lateral and 

 inferior cavity of the thorax. The penultimate joint of the tarsi is 

 bifid, and the point of the mandibles entire(2). 



Our second division of this tribe will include all the Elaterides 

 whose antennae are exterior or exposed. 



We will separate, in the first place, those in which the last joint 

 of the palpi, of the maxillaries particularly, is much larger than the 

 preceding ones, and almost securiform. 



A single subgenus, the 



formed a little group, with various species of Elater, composed of three genera, 

 and characterized by the presence of the elongated and lobe-like pellets with 

 which the inferior surface of the four first joints of the tarsi are furnished. The 

 first of these genera, Lissode, or the Lissomus, Dalm., is distinguished from the 

 two others by the antenna: which are closely approximated at base; in the others 

 they are remote. Those of the genus Tetralobus are flabelliform in the males. 

 In the third or Pericallus, they are simply serrated in both sexes. The Elater 

 flabellicornis, Fab., belongs to the first, and consequently this genus is a division 

 of that which I have named Hemirhipus. The Elaterides ligneus, suturalis, fur- 

 catus, &c, Fab., belong to Pericallus, which will then comprise all the species of 

 my Ctenicera, whose tarsi present the general character above mentioned. 



(1) Fab., Syst. Eleut., I, 101; Lat., Gener. Crust, et Insect., I, viii, 7, and II, 

 44; Dalm., Ephem. Entom., 1824, p. 29. [This genus is also found in the southern 

 section of North America, where however it is very rare. The S. Lecontei, Dej., 

 now in my cabinet, is perhaps the only specimen known in the United States. 

 Am. Ed.] 



(2) Elater dermestoides, L.; E. clavicornis, Oliv., Coll. II, 31, VIII, 85, a, h; Der- 

 mestes adstrictor, Fab.; Panz., Faun. Insect. Germ. LXXV, 15. Its larva inhabits 

 oak wood. 



