42 Mr. H. W. Bates ow 



angustato^ apice late rotundato, angulo suturali 

 spinoso ; supra opaca^ subtiliter alutacea, cinnamonea, 

 absque lineis elevatis. Corpus subtus nitidum, im- 

 punctatum, castaneum. Pedes nigro-castanei^ nitidi. 

 Long. $ (mandib. incl.) 28 lin. 



I am not aware that the male of this very rare species 

 has been heretofore described. It differs greatly from 

 the female in the punctuation of the thorax, and in the 

 size of the antero-lateral spine. A similar sexual differ- 

 ence exists in M. Jlavipennis (Chevrolat), the female of 

 which is named serridens in Chevrolat's collection, and 

 in M. Dejeanii (Gory); the male in all these species 

 having a finely punctured opaque thorax, with a glossy 

 space in the middle, and the female being uniformly 

 scabrous-punctate, slightly shining. 



I met with one example only of M. crenata on the 

 Amazons, near Bga. 



Genus Titanus. 

 Serv. Ann. Soc. Ent. Fr. 1832, p. 133. 



1. Titanus giganteus. 

 Linn. Mant. p. 531; Drury, 111. iii. p. 73, pi. 49. f. 1, ? . 



T. ( ^ , ? ) fusco-castaneus, thorace lateribus trispinosis, 

 supra punctato-rugoso, medio late impunctato, tibiis 

 (J intus multispinosis, ? Isevibus, antennis utroque 

 sexu dimidium corporis hand excedentibus, seg- 

 mento ultimo ventrali cJ in medio late exciso, ? 

 integro. 

 Long. 4^-6 unc. 



In addition to the sexual difierences mentioned in this 

 short diagnosis, may be mentioned the much greater 

 width of the tarsi in the ^ than in the ? . The tarsi of 

 the $ are of remarkable width, and the second joint is 

 transverse quadrangular, instead of triangular as in the 

 ? and in Longicorns generally. On the Amazons this 

 colossal Longicorn was found only near Manaos, on the 

 Rio Negro ; where it is occasionally picked up on the 

 shores of the river after a stormy night, the insect being 

 cast into the water whilst flying across.* 



* In the system of Lacordaire the group Ancistrotides follows the Tita- 

 nides, but in a note on a subsequent page (Genera, viii. p. 163) he justly 

 doubts whether they would not be better placed near the group Tragoso- 

 mides. The following new species of Acanthinodera (group Ancistrotides) 

 tends in favour of this emendation. 



