36 Prof. J. O. Westwood's descrijAions 



endorsed by Mr. C. Waterhouse and M. H. Deyrolle. 

 In this diversity of opinion I have thought it Avould be 

 considered of interest to publish a 'series of figures repre- 

 senting the structural details of the insect, which I have 

 been enabled to make upon a dissection of a s]3ecimen 

 presented by Dr. Leconte to Major PaiTy, amongst 

 which will be especially considered worthy of notice the 

 following characters not hitherto remarked upon, namely, 

 the simple internal margin of the mandibles, destitute of a 

 molar plate, the entire condition of the eyes, the finely 

 crenulated lateral margin of the prothorax, the small size 

 of the teeth of the outer edge of the fore tibijB, except the 

 two terminal ones, and the remarkable form of the mentum 

 especially when seen laterally. These characters certainly 

 bespeak an affinity with some of the small obscure Austra- 

 lian Lucanid(B, such as Ceratognatliiis ; but a comparison 

 of the details here given with those of various genera of 

 Trogidoi, published in my memoir in Trans. Ent. Soc. 

 vol. IV. pi. 11, especially those o^ Apalonychus, Westw. 

 fig. 5, appears to prove (as it seems to me) the near rela- 

 tionship of Nicagus to those insects. In its details, also, 

 it does not very much disagree with those of Achloa, given 

 by Erichson, Entomographien, pi. 1, fig. 6. This diver- 

 sity of opinion will, I think, render my series of illustra- 

 tions of the characters of the genus acceptable to Coleop- 

 terists. 



DESCRIPTION OF THE PLATES. 



Plate I. 



Fig. 1 . Ca lometopns nyassce, the female ; 1 a, mandible ; 1 h, maxilla, without 

 the palpus; \c, mentum and palpi; IfZ, extremity of posterior 

 tibia and base of tarsus. 



Fig. 2. Valgus furcifer magnified; fig. 2tf, the anterior tibia ; 2b,2)ropy- 

 gidium and pygidmm seen sideways ; 2c, the same seen from 

 behind. 



Fig. 3. Cyplionocephalus smaragdulus, the dark purple variety of the 

 male of the natural size. 



Fig. 4. CypJionocephalus smaragdnlvs, the female of the natural size; 4fl, 

 the head of the female magnified, seen from above ; 4?>, the 

 same seen sideways ; 4c, the maxillaj without the palpus ; 4rZ, the 

 mentum ; ie, mesosternal process. 



Fig. 5. CycUdinva velutinus maguificd ; 5a, the head and prosternal 

 process seen sideways; 5i. mandible; bc, maxilla; M, mentum 



