AMERICAN COLEOPTERA. 87 



ture of their antennae, maxillae, labium, etc. Of those two groups we 

 possess, as far as I am aware, only two good descrptions of larvae : 

 Mulsant's of the larva of Geolrupes sfercorarius and Chapuis' of the 

 larva of Trox carolinus. If we were to base our opinion upon these 

 two descriptions only, it would incline in favor of a relationship of our 

 larva with the Trogirlse,, rather than with the Geotrupidse. Chapuis' 

 description of the larva of Trox carolinus agrees quite well with our 

 larva; the description of <he labium especially (levre inferieure forniee 

 d'un menton et d'une piece palpigere fondus en un real corps allonge) 

 seems to indicate a structure somewhat analogous to that in our larva. 

 On the contrary, Mulsant's description of the larva of Geotrupes dis- 

 agrees with ours in several points. The antennae are said to be four- 

 jointed, the maxillae to have two almost cylindrical lobes, the legs are 

 described as bilobed at the end, etc. Finally, if it be true that the 

 larva of G-eotrupes has only two pairs of well developed legs, the third 

 being almost atrophied, as Frisch (but not Mulsant) describes it, this 

 would constitute another important difference. 



Altogether, the materials at hand for comparison are too meagre for 

 a final decision upon the relationship of the larva. 



Before concluding I would advert once more to the singular fact 

 that the shape of the mandibles changes after moulting. A similar 

 peculiarity has been already observed among larvae of other orders of 

 insects. That the shape of the earlier mandibles is merely due to its 

 being more worn is a supposition which will hardly be entertained by 

 any one who has compared the two mandibles- 



EXPLANATION OF THE FIGURES. 

 Fig. 1, — Larva from the side, natural size. 

 Fig. 2. — Head from above. 



Fig. 3. — Labium, maxilla, and in front of them, the mandible after moulting. 

 Fig. 4.— Leg. 



On the CIJPESIDii: of IVorth America. 



BY JOHN L. LECONTE, M. D. 



PRIACMA, n.g. 



Since I have seen the Australian genus Omnia, I recognize in 

 Cupes serrata (Lee. Proc. Acad. Nat. Sc. Phila., 1861, 351) a dis- 

 tinct genus, intermediate between that and Capes. From the latter it 

 dififers by the antennae less approximate at base, shorter and stouter. 



