CLASSIFICATION OF THE RHYNCHOPHOROUS COLEOPTERA. 457 



sometimes finely carinate, not expanded at tip ; the antennal 

 grooves are very narrow, parallel at their origin, and usuall}- sud- 

 denly deflexed, though sometimes (Phyllobius) very short and 

 straight. Tlie eyes vary in form and the prothorax is lobed or 

 not. The prothorax is usually bisinuate at base, with the hind 

 angles acute, though sometimes truncate. The elytra are usually 

 free, with prominent humeri, and the wings well developed : 

 though sometimes they are connate, with rounded shoulders. The 

 accessory mandibular piece is long and falcate' in both, and the 

 support at the tip of the mandible is circular and not prominent ; 

 characters of great moment when associated with the peculiar form 

 of body. 



Two tribes are indicated by a difference in the outer stria of the 

 elytra : 



Outer stria of elytra entire Phylloehni. 



Outer stria of elytra abbreviated or interrupted . . Tanymecini. 



The first tribe is represented by Pachnoeus, and Phyllobius in 

 the Atlantic States, and by Scythropus on both slopes of the con- 

 tinent. Of these Pachnseus has the eyes transverse, and the pro- 

 thorax lobed at the sides in front, while in the others the eyes are 

 rounded, and prominent, and the front outline of the prothorax 

 is straight. The species are all winged, and the humeral angles 

 are obtuse and well defined. The base of the prothorax is trun- 

 cate in all the genera except Pachnffius, where it is distinctly bi- 

 sinuate. 



Macrostylus, a Brazilian genus recently found in Texas, is an 

 anomalous member of this tribe. The antennae are very long and 

 slender, and the joints of the club seem to be quite separate and 

 free. It is of very small size, and has the elytra connate and the 

 humeral angles not prominent; the beak is not channelled, but 

 otherwise resembles the beak of other members of the tribe. The 

 claws are connate almost to the tip, as in Phyllobius, etc., while 

 they are separate in Pachnteus. There are thus three groups in- 

 dicated. 



Prothorax lobed in front ; claws separate : . . . Pachua3i. 

 Prothorax not lobed ; claws connate : 



Humeri prominent, elytra free : Phyllobii. 



Humeri not prominent, elytra connate : ... Macrostyles. 



The Tanymecini resemble in form the Phyllobiini, but are readily 

 distinguished by the outermost stria of the elytra being confluent 



