TYRINI 323 



and antennal club which are subscabroid. Pubescence long, silky, abundant, 

 and yellowish-brown. 



Head with width and length subequal with long oblique tempora. Eyes 

 medianly placed, reniform in lateral view, moderately prominent and com- 

 posed of about 58 moderately large facets. Vertex high, prominently and evenly 

 vaulted into a dome between the eyes. A pair of very small, nude, punctiform, 

 vertexal foveae on a line through anterior third of eyes, mutually separated 

 by a distance greater than either from its adjacent eye. Antennal tubercles 

 small and separated by a simple median depression, at the bottom of which 

 is the small median fovea. Front, clypeus, labrum, ventral surface of head 

 and maxillary palpi as in costaricensis. 



Antennae short and thick; I subelongate-subcylindrical, being shorter than 

 usual; II smaller and subquadrate; III-VIII transverse, moniliform to trapezoi- 

 dal; IX and X gradually larger, transverse, trapezoidal; XI truncate at base, 

 very rounded at apex, one-third longer than wide, as long as preceding four 

 united. 



Pronotum and elytra as in costaricensis. 



Abdomen with five visible tergites in a length ratio of 5/3.5/2/2.5/2 

 with the first three strongly margined as usual. Four tergite with a large 

 circular, pubescent fovea in each latero-basal angle. Fifth tergite distinctive: 

 transversely flattened in basal half and slightly tumid in apical half, with a 

 short blunt dentoid tubercle at center of apical margin. 



Six simple sternites in a length ratio of 2.5/3/1. 8/1/1/.8 and since the 

 last four are slightly flattened medianly the sex is probable male. 



Metastemum as in alleei. Posterior coxae separated by one-half, and inter- 

 mediate coxae separated by one-fourth the median metasternal length. Legs 

 simple save that the posterior tibiae each bears an apical spur. These spurs 

 consist of about six long, thick, truncate setae arranged in an angulated, 

 truncate bundle. Tarsi as for genus. 



Described on a single specimen collected by the author on Barro Colorado 

 Island, Gatun Lake, Panama Canal Zone, from beneath the bark of a log at 

 Armour 8 on July 26, 1936. 



This species is readily separated from its allies. The domed vertex, long 

 silky pubescence, conspicuously fewer ocular facets and the terminal tergite 

 distinguish castanalus from costaricensis. The shorter terminal antennomere 

 separates it from aztekus among other characters noted. The only other near 

 relative is centralis of Brazil which has the pronotum distinctly longer than 

 wide, while castanalus has the pronotum slightly transverse. 



Hamotus (Hamotus) aztekus new species 



Type Male. Measurements: Head 0.40 x 0.40 mm.; pronotum 0.40 x 0.50 



mm.; elytra 0.50 x 0.78 mm.; abdomen 0.70 x 0.84 mm.; total length 2.00 mm. 



Shining reddish-brown; integument subimpunctate save for elytra which 



