AGERONIA. 



just as the instrument was on the point of closing, and thus escaped. But a far move singular fact, is the power which 

 this insect possesses of making a noise. Several times when a pair, probably male and female, were chasing each other 

 in an irregular course, they passed within a few yards of me, and I distinctly heard a clicking noise, similar to that 

 produced by a toothed wheel passing under a spring catch. The noise was continued at short intervals, and could be 

 distinguished at about twenty yards' distance. I cannot form a conjecture how it is produced ; but 1 am certain there 

 is no error in the observation." 



After having carefully examined every species of the genus which lias been recorded as producing this noise, I can 

 discover no structure which seems intended to produce it. All of them offer one peculiarity. Immediately above the 

 costal ncrvure, quite at its origin, on the under side of the wing is a small round cavity, smooth inside, covered with a 

 very delicate membrane, stretched across it like the parchment of a kettle-drum, which the cavity resembles in shape. 

 Another peculiarity occurs in the swollen part of the costal nervule, in Ageronia Arethusa. This part of the nervule 

 is divided by numerous transverse membranaceous diaphragms, placed obliquely so as to present, when the nervure is 

 rendered transparent, the appearance of a screw, with a very loose worm, enclosed in the nervure. I cannot imagine 

 any connexion between either of these peculiarities in structure and the sound produced by the insect. 



Having recently observed in some species of the Fabrician genus Glaucopis, a structure almost identical with the 

 drum of the Cicada?, and having found a similar structure in Hecastesia Thyridiou, which is known to produce a sound, 

 I have carefully examined the base of the abdomen in all the species of the present genus, but there is no trace of any 

 drum, or cavity. From the examinations of dried specimens, I hope for no further results ; but as I expect shortly to 

 receive specimens preserved in spirits, I shall be able more carefully to dissect them, and the results will be given in the 

 introductory chapter. 



This genus is peculiar to the tropical parts of America, and most of the species have a wide range both of latitude 

 and longitude. 



AGERONIA Hubn. 



1. Ao. Epinome. 



Amphichlora Ep. Boisd. MSS. 

 Brazil. B. M.? 



2. Ag. Mtioi:. 



Amphichlora IE.n. Boisd. MSS. 

 Peru. 



3. Ac. Amphichloe. 



Amphichlora Amp. Boisd. MSS. 

 Guayaquil. B. M. 



4. Ag. Ferentina. 



Nymphalis Fer. Godt. Enc. M. ix. 428. n. 248. 



(1819). 

 P. Feronia Var. Cram. t. 362. f. A. B. 

 Ag. Februa Hubn. Samml. Exot. Schmett. (1806- 



27). 

 Venezuela, Brazil. B. M. 



5. Ag. Fornax Hilbn. Samml. E.tot. Schmett. (1806-27). 



Double/lay Sj Hewitson, t. 10. f. 1. (1847). 

 Mexico, Venezuela, Brazil. B. M. 



6. Aq. Feronia Hubn. Verz. bek. Schmett. 42. (1816). 



P. Fer. Linn. Syst. Nat. n. 770. n. 140. 

 (1767). 

 Cram. t. 192. f. E. F. (1779). 

 Fab. Ent. Syst. hi. i. 226. n. 710. (1793). 

 Nymphalis Fer. Godt. Enc. M. is. 428. n. 247- 

 (181!)). 

 Mexico, Venezuela, Brazil. B. M. 



7. Ag. Amphinome Hubn. Verz. bek. Schmett. 42. (1816). 

 P. Amph. Linn. Syst. Nat. n. 77.0. n. 176. 



(1767). 



Cram. t. 54. f. E, F. (1 ??.%). 

 Fah. Ent. Syst. in. i. 131. n. 404. (1793). 

 Nymphalis Amph. Godt. Enc. M. ix. 427. n. 

 246. (1819). 

 Venezuela, Guiana, Brazil. B. M. 



8. Ag. Chloe Hubn. Samml. Exot. Schmett. (1806-27). 

 P. Chi. Stoll, t. 5. f. 1, 1. a. (1791). 

 Nymphalis Ch. Godt. Enc. M. ix. 429. «• 249- 



(1819). 

 Honduras, Brazil, New Granada. B. M. 



9. Ag. Arethusa. 

 $ P. Ar. Cram. t. 77- f. E. F. (1775). 



3 Fab. Ent. Syst. in. i. 42. n. 130. (1793). 

 $ J Nymphalis Ar. Godt. Enc. M. ix. 427. n. 245. 



(1819). 

 ? $ Peridromia Ar. Boisd. Sp. Gen. i. t. 7- C. f. 5. 

 (1S36). 

 ? P. Laodamia Cram. t. 130. f. A. (1776). 

 $ Ag. La. Hilbn. Verz. bek. Schmett. 42. (1816). 



Hubn. Samml. Exot. Schmett. (1806-27). 

 Mexico, Venezuela, Guiana, Brazil, Bolivia. 



B. M. 



10. Ag. Arete Doubleday % Hewitson, t. 10. f. 2, 3. (1847). 

 Peridromia Ar. Boisd. MSS. 



Mexico ? Brazil. B. M, 



