KYI: 



\: 

 Tribe 2. Pyxidicerini 



Raffray (1903, 1908) 



This is a small tribe of four genera, one of which {Bythinoplectus) is 

 American. The American species have the body elongate and flattened, and 

 the integument is usually shining. The head has the usual pyxidicerine fossa 

 on each dorso-lateral face, in which repose the peculiar maxillary palpi. These 

 palpi are four-segmented, and the segments are closely articulated irregularly 

 so as to form an oval or elongate-spherical mass. First segment medium ; sec- 

 ond large, basally slender, and slightly clubbed apically; third articulating 

 on the lateral face of the second, smaller, variable in form, geniculate ventrally 

 and inflated dorsally, this dorsal face being sulcate to receive the fourth or 

 distal segment; fourth segment irregularly elongate transversely and articulat- 

 ing to the third segment by a short petiole on the lower of the two transverse 

 faces. In repose these segments tend to fit into or upon one another, and the 

 palpus lies in the large palpal fossa of the head. 



The antennae are nine-segmented, with the distal segment enlarged to 

 form the antennal club; these organs are articulated on either side of the 

 elongate median antennal tubercle which is formed by the vertex and front. 

 The head is triangular, broad through the occiput and narrowing rapidly 

 anteriorly to the antennal insertion. 



Abdomen elongate, strongly margined, with six visible sternites of which 

 the first is small and visible only between the diverging but contiguous conical 

 posterior coxae. 



The tarsi are three-segmented, but this segmentation can be observed only 

 with difficulty. Dorsally, the tarsi are apparently two-segmented, since only 

 the first and third may be seen. The first segment is small, conical, and broadly 

 sulcate ventrally ; second segment minute, triangular, and articulates with the 

 first on its ventral face so that this second segment lies in the ventro-distal 

 cavity of the first; third segment is relatively very large, medianly slightly 

 inflated, bearing a single large claw. 



BYTHINOPLECTUS (Reitter, 1881) 



acutangulus Raffray. 1904. Granada, Windward Islands. 



denticomis Raffray. 1896. Mexico. 



formicetorum Raffray. 1912. Argentina, (con Atta lundi Guer.) Buenos 



Aires, cf. Bruch, 1929. 

 foveatus Reitter. 1883. St. Thomas, Virgin Islands. Genotype. 

 impressifrons Raffray. 1896. Brazil. 

 transver Sleeps Raffray. 1904. Brazil. 



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