680 Coleopterological Notices, IV. 



sides of the buccal opening beneath ; the upturned apex is very 

 coarsely and deeply notched. It can be readily seen that in this 

 position, the condyles have the largest and most powerful muscular 

 attachment permissible under the circumstances. The habits of this 

 species, as well as Balaninus, necessitate a slender cylindrical boring 

 tool, not at all enlarged at apex, and, if the condyles were horizontal 

 in their plane of motion, they would, because of their slight lateral 

 development, be very feeble in muscular action ; they have there- 

 fore been gradually turned into a position as nearly vertical as pos- 

 sible, simply to allow of a broader base for the attachment of the 

 muscles. Mandibles of this kind are of course incapable of grasp- 

 ing or pinching to any useful degree, and can be used only in cut- 

 ting and scraping a passage for the advancing beak, and it does not 

 follow at all that because the mandibles are similar in their action 

 to those of Balaninus, that there is any special relationship between 

 these genera. In point of fact the remaining structural characters 

 of the body, including the form of the mandibles themselves, are 

 so widely different in Balaninus and Eunyssobia, that there cannot 

 be the least affinity between them, except in the method of using 

 the beak as a boring instrument. 



The buccal fissure is very narrow and deep, being, at the anterior 

 extremity, not more than one-fourth as wide as the rostrum, and 

 the mentum is long and extremely slender ; the remaining organs 

 of the mouth appear to be atrophied or very feebly developed. The 

 prosternum is broad, strongly, transversely constricted behind the 

 apex but not otherwise modified, and separates the rather small 

 coxae by nearly twice their own width. The legs are normal, the 

 tarsi very slender, with the two basal joints elongate, feebly ob- 

 conical and subequal, the third small, scarcely wider than the apex 

 of the second, deeply emarginate, the fourth with its basal node, 

 about as long as the first two together ; claws rather slender, arcu- 

 ate, simple and divergent. Pygidium completely concealed. 



1 Eunyssobia ecliidna Lee— Proc. Am. Phil. Soc, XV, p. 320 

 (Euchce.tes) . 



Oval, convex, very uneven, black, the antennae brown; slender 

 portion of the beak rufous; body extremely densely clothed through- 

 out with a crust of large, closely adherent, scale-like plates, varie- 

 gated white, brown and blackish in color and sparsely clothed with 

 very long, stiff and erect spiniform bristles. Beak three-fourths 



