450 INSECTA. 



Here the thorax is narrow, either cylindrical or in the form of an 

 elongated heart, truncated at both ends. Such are 



Tagenia, Lat. Stenosis, Herbst. Akis, Fab. 



Where the antennae are almost perfoliate with the third joint 

 hardly longer than the following ones, and the eleventh or last very 

 small or united with the preceding one. The head is elongated 

 posteriorly, and borne on a kind of neck or knot. The thorax is in 

 the form of an elongated heart truncated at both ends. The abdo- 

 men is oval(l). 



PSAMMETICHUS, Lat. 



Where the antennae are composed of turbiniform joints, of which 

 the third is much longer than the following ones, and the eleventh 

 or last, as large as the preceding, is very distinct. The head and 

 thorax form a long square of equal width. The abdomen is almost 

 oval, and truncated at its base(2). 



There, the thorax is at least as wide as the abdomen, and of an 

 almost orbicular or square form, rounded laterally, and either iso- 

 metrical or wider than long. 



Scaurus, Fab. 



Where the last joint of the antennae is ovoido-conical and elon- 

 gated; where the thorax is almost isometrical, and where the ante- 

 rior thighs are strongly inflated and frequently dentated in the males. 

 The tibiae are long and narrow. 



These Insects are peculiar to the hot and western parts of the 

 eastern continent(S). 



Scotobius, Germ. 



Where the last joint of the antennae is hardly longer than the pre- 

 ceding and in the form of a reversed top; where the thorax is evi- 

 dently wider than it is long, and the lateral edges are strongly arcu- 

 ated; where the thighs differ but little in size, and when the anterior 

 tibiae are in the form of an elongated triangle, and angular. 



These Heteromera are peculiar to South America(4). 



The other Pimeliariae, with moniliform antennae and the mentum 



(1) Lat, Gener. Crust, et Insect, II, p. 149; Herbst, Col., VIII, cxxvii, 13. 



(2) A subgenus established on some undescribed Insects from Chili. 



(3) Oliv , Col., Ill, No. 62; Lat, Gener. Crust et Insect, II, 159; Encyc. 

 Method., article Scaure. 



(4) Germ., Insect. Spec. Nov., p. 136. 



