(lHAP. X. 
coleoptera. 
379 
ribs are scraped by tlie posterior margins of the elytra, a 
small portion of which projects beyond the general out- 
line. In many Crioceridte, and in Clyihra k-punctata 
Fig. 24. Necropliorus (from Landois). r. The two rasps. Left-hand figure, part of 
the rasp highly magnified. 
(one of the Chrysomeliilse), and in some Tenebrionidae, 
& c \, 70 the rasp is seated on the dorsal apex of the abdo- 
men, on the pygidium or pro-pygidium, and is scraped 
as above by the elytra. In Heterocerus, which belongs 
to another family, the rasps are placed on the sides of 
the first abdominal segment, and are scraped by ridges 
on the femora . 71 In certain Curculionidae and Cara- 
bidte , 72 the parts are completely reversed in position, 
70 I urn greatly indebted to Mr. G. K. Crotch for haying sent me 
hunierous prepared specimens of various beetles bdongimr to these three 
families and others, ns well as for valuable information of nil kinds. He 
believes that the power of stimulation in the Clyihra has not been pre- 
viously observed. lam also much indebted to Mr. E. IV. Jnnson, for 
information and specimens. I may add that my son, Mr. F. Darwin, 
buds that Dermestes murinns stridulatcs, hut he searched in vain for the 
apparatus. Scoiytus has lately been described by Dr. Chapman as a 
stridulator, in the * Entomologist’s Monthly Magazine,’ vul. vi. p. 130. 
71 Scliiodte, translated in ’Annals and Mag. ot Nat. Hist. vol. xx. 
f&67, p. 37. 
72 Westring has described (Kroyer, ‘Naturbist. lidskrilt, B. ii. 1848- 
10, p, syl) the stridulating organs in these two, as well as in other 
families. In the Carabidar I have examined Elaphrui uliginoews and 
J'b-thisa multipunctata, sent to me by Mr. Crotch. In l.lethisa the 
transverse ridges on the furrowed border of tlie abdominal segment do 
n «t come interplay, as far as I could judge, in scraping tlie rasps on tho 
el ytra. 
