Coleopterous Suhfamily Dynastliice. J 69 



The insect for wliieli Bates formed the genus Barotheus 

 {B. andinus, Bates) appears to be without doubt the Anco- 

 gnatha castanea of Ericlison. The latter described the 

 auteunre as 9-jointed and the former called them 10-jointed, 

 tlie fact being that, as in the species next mentioned, the 

 number of joints is inconstant, and I have examined a 

 specimen in which there are nine joints to the right antenna 

 and ten joints to the left. The species must be called Baro- 

 theus castaneus, Er., Bates^s name, as well as the name 

 peruana, given by Harold, being synonymical. 



Ancognatha cequata, Bates, is synonymous with A. manca, 

 Lee, and the specimen to which the latter name was given by 

 Bates (Biol. Ceutr.-Amer., Col. ii. 2, p. 298) is a variety or 

 allied species in too fragmentary a state for exact determina- 

 tion. A. manca is described as characterized by having only 

 nine joints to the antenna. This is due to the more or less 

 complete fusion of the fifth and sixth joints, which occurs 

 also in other species, but is not constant. "When the fusion 

 is incomplete the antenna appears either 9- or 10-jointed, 

 according to the side on which it is examined. As in the 

 preceding case, 9- and 10-jointed forms may be found in the 

 same species, and in one specimen which I have examined 

 one antenna must be described as 9-jointed and the other as 

 10-jointed. 



Ancognatha vulgaris, sp. n. 



The species of which both sexes Avere figured by Bates 

 under the name of A. humeralis, Burm. (Biol. Ceutr.-Amer., 

 Col. ii. 2, p. 298, pi. 17. figs. 13, 14), is a quite distinct 

 species, altbough superficially very similar. 1 have seen a 

 long series of A. humeralis, Burm., from Cauca, Colombia. 

 In this form, as mentioned by Burmeister, the pygidium is 

 smooth, with a thick tuft of hairs at the end. The species 

 figured by Bates is larger and the pygidium is entirely 

 clothed with hairs in the male and fringed in the female. 

 The female has a very strong lateral lobe near the middle of 

 each elytron, which is absent in A. humeralis and all other 

 species of Ancognatha known to me. The unnamed species 

 may be called A. vulgaris. It ranges from Panama to Peru 

 and the Upper Amazons (Nauta). 



Bates has associated two species as the two sexes of 

 Ancognatha quadripunctata, Bates. I believe only the single 

 male specimen figured really belongs to it. The other 

 specimens are of very different appearance and not closely 



