84 JOHN B. SMITH. 



figures a compound mandible without attempting to name the parts 

 or to homologize its sclerites with those of other appendages. 



In many of the Lamellicorns, the divisions beeon)e well marked 

 with proper treatment, and the homologies are, I think, fairly evi- 

 dent. In Copris Carolina they are not so distinct as in some other 

 species, but they will answer my present purpose. Reference should 

 be made to fig. 4, of PI. II, where the pieces are named in accordance 

 with the following explanatioji : At the base, outwardly, is a large, 

 corneous sclerite, to which are attached, inferiorly, most of the mus- 

 cles and tendons controlling the entire organ. This may be called 

 the basalis, or basal piece, and it is the homologue of the stipes in 

 the maxilla. There is, in some species, an intermediate piece be- 

 tween the basalis and the head, which represents the cardo of the 

 maxilla, and which I propose to call the stih-hasalis, or tendon bearer; 

 the former on account of its position, the latter as expressive of func- 

 tion. The muscular attachment is, however, to the basalis as well 

 as to the sub-basalis even when the latter is present. Another of 

 the basal pieces, united to the basalis and forming the inner inferior 

 part of the entire organ, I propose to call the molar, or grinder. I 

 believe it to be homologous with the subgalea, and the function is 

 expressed by the names. The food is not cut or broken by any other 

 organ, and indeed needs little cutting. But to get into the gullet it 

 must pass between these grinders and is there fitted for swallowing. 

 In the present species the molars are ridged and dissimilar. The 

 one grinding face is convex, the other is concave ; the convex surface 

 fitting accurately into the opposite concavity. 



In Macrodadyhis, Cetonia and some other genera, these molars are 

 much larger, proportionately, fitted for scraping as well as for grind- 

 ing or chewing. Between the molar, which is always well chitinized 

 in all the forms I have seen, and a flattened, more membraneous 

 piece, also attached to the basalis, is a small sclerite which I have 

 thus far found in Copris only ; and this I call the conjundivus, or 

 connecting piece. It has no other function that I can find, and does 

 not seem to occur where there is a greater development of the molar. 

 It most likely represents the basal joint of the galea, and is obscured 

 where the molar is largely developed. The flat, membraneous piece 

 forming most of the inner and part of the outer margin of the man- 

 dibles toward the tip, is the homologue of the galea, and I have 

 called it the terebra, or piercer. In this species it is quite closely 

 united to the basalis, and is fringed with long, dense and fine hair. 



