DYNASTIN.E 251 



except medially, the punctures extending obliquely to the apical 

 angles and thence along the sides to the base; apical bead very wide 

 at the apical angles; scutellum with the basal punctures setose; 

 elytra barely longer than wide, a little wider than the prothorax and 

 very nearly twice as long, rounded in posterior half, having feeble 

 traces of geminate series of fine punctures, the sutural stria deep and 

 entire; pygidium scarcely more than twice as wide as long, very 

 evenly and strongly convex, perfectly smooth, punctured and setose 

 near the base, the basal line evenly arcuate from side to side; hind 

 tarsi very slender, rather longer than the tibiae. Female larger and 

 stouter than the male; head larger but otherwise as in the male 

 throughout, including the mandibles and setae of the vertex, but more 

 densely and coarsely punctato-rugose throughout, the base smooth; 

 prothorax more transverse, the anterior oblique sides similar; surface 

 coarsely rugose in about apical, smooth in basal, half, and with a 

 simple, transversely oval, not very deep anterior concavity, a third 

 the total width and extending to the middle; apical tubercle shorter 

 and more obtuse than in the male and binodulose; scutellum very 

 concave and rugose in basal half, except at the margins; elytra 

 oblong, barely longer than wide, rounded in less than apical half, 

 barely wider than the prothorax and not quite twice a? long; py- 

 gidium much shorter and more transverse but similarly with arcuate 

 upper margin, strongly convex in upper, concave in lower, half; hind 

 tarsi thicker and relatively shorter than in the male. Length (cf ) 

 24.5, (9) 26.0 mm.; width (cf) 14.5, (9) 16.2 mm. Kansas 

 (Medora). A single pair of this very rare species was kindly sent to 

 me by Mr. Knaus. [? bosci Beauv.j mormon Burm. 



As is frequently the case among the Coleoptera, the female in 

 this genus serves much better in the definition of the species than 

 the male; in the latter sex there is a very large amount of intra- 

 specific diversification, but it may be remarked in passing that 

 the least developed form resembles the female much less closely 

 than it does in the preceding subgenus, there always being a pro- 

 nounced sexual difference in the form of the pronotal cavity, even 

 when there is no trace of the posterior processes. The female, on 

 the other hand, is virtually constant, not only in size and outline 

 but in the conformation of the thoracic impression, and this differs 

 unmistakably in all those species of which the female is known, as 

 in antceus, pinorum and septentrionis, described above. Maimon 

 Fabr., is said by Burmeister to be a variety, or in greater likelihood 

 the depauperate stage, of the Antillean syphax Fabr.; so it can be 

 disregarded in discussing our American forms. Bosci Beauv., is 

 said to be the same as mormon Burm., by the Munich catalogue, but, 

 in view of the difference in habitat, bosci having been described as 



