226 



ME. It. M'LACIILAN ON A SYSTEMATIC 



brous, deeply concave behind, the sides denticulate and fringed ; 

 the eyes are twelve in number, six on each side, placed on the 

 produced anterior angles of the head. The thoracic and abdomi- 

 nal segments are each furnished with a long, slightly curved, 

 flattened lamina, densely fringed with spines, the first thoracic 

 lamina longer and broader than the others ; the abdomen very 

 broad and thin, somewhat transparent in the dry larva, con- 

 vex above and concave beneath ; the legs entirely hidden 

 under it. 



In an example of Proctarrelabris annulicomis, from Natal, in the 

 British Museum, a note is attached in the handwriting of its captor, 

 Mr. Guienzius, stating that the species hides by day in chinks of 

 the bark of old trees, and at dusk flies about the trees hawking 

 insects. An example of Idricerus decrepitus, from North India, in 

 my collection, is ticketed (by Capt. A. M. Lang, R.E., who gave it 

 to me) as having been taken in the twilight. 



Mr. Bates, who had ample opportunities of observing these in- 

 sects when on the Amazons, informs me that the species were 

 most numerous in the dry sandy country of the Tapajos, and much 

 rarer in the humid virgin forests of Para and the Upper Ama- 

 zons. Of the Haploglenii he says the flight is short but rapid in 

 the shades of the forest in the daytime, the insects reposing with 

 the wings expanded, as in Libellula (a most valuable observation), 

 and resting head upwards. Of the Ululce and Colobopteri he 

 remarks that they are mostly found in dry woods and dry grassy 

 savannas, resting during the day on twigs of dead trees or bushes, 

 with the wings tectate, as in all genera excepting Haplogenius, and 

 head downwards. 



In the foregoing notes, I think, is incorporated every biological 

 observation of any importance that has yet been made. Their 

 paucity should stimulate observers to further investigations. 



Generic Characters. 



Antenna. — The principal points to be noticed are the compa- 

 rative lengths, form of the club, presence or absence of serration 

 or denticulation in any portion of them (a character that can 

 only be applied to the <S ; in the $ there is never either denticu- 

 lation or serration), presence or absence of verticillate hairs on 

 the basal portion, and, lastly, whether in the <S they are straight 

 or nearly so, or present bendings or twistings of some portion. 



Eyes. — Whether simple or divided by a groove into two por- 



