340 NEOTROPICAL PSELAPHIDAE 



Elytra with obtuse humeri. Each elytron with two large, circular, pubescent 

 basal foveae, an entire sutural stria and a long dorsal stria, at bottom of dorsal 

 impression, which extends beyond the middle of elytral length. 



Abdomen with five visible tergites in a length ratio of 7/2.5/1.5/1/2 with 

 first three margined as usual. 



Six stemites with proportions and shape as illustrated. The sixth stemite 

 is deeply incised at middle of apical margin to hold a discoid penial plate. 



Metastemum deeply, broadly sulcate with each sulcal wall forming a prom- 

 inent tumidity. 



Anterior legs: trochanter with a short, stout triangular tooth at apex of 

 ventral face ; femur with a sharp, high longitudinal carina which occupies the 

 median half of the ventral face ; tibia arcuate. 



Intermediate legs: coxa with a densely setose spinoid tubercle at ventro- 

 posterior face; trochanter with a very long, thin spine at apex of ventral face; 

 tibia arcuate. 



Legs otherwise simple and normal for tribe, with the tarsi having two large, 

 arcuate, equal tarsal claws. 



Allotype Female. Similar to holotype save that (1) the abdomen is slightly 

 broader and shorter; (2) elytra more punctate; (3) stemite ratio differing, as 

 illustrated, with the terminal (sixth) stemite short and simple. 



Erected on three specimens collected from nest or galleries of the termite, 

 Coptotermes niger Snyder, on Barro Colorado Island, Panama Canal Zone. 

 Holotype and allotype collected by the author at Armour 7 (July 6, 1936) and 

 paratype female collected by Alfred Emerson on September 6, 1935. Named for 

 my friend James Zetek, resident custodian of the B.C.I, laboratory. 



* * * » * 



In closing this section on neotropical Tyrini the author is tempted to write 

 a few words regarding the maxillary palpi as indicators of speciation. This is 

 done in full recognition of the possibility that structural features of the oral and 

 tarsal areas may not be the best regions for this purpose, and also that one struc- 

 ture is necessarily limited in its bearing. On the other hand these palpi offer such 

 a range of generically limited characters that proper examination must have 

 some value. 



There appear to be two basic types of neotropical maxillary palpi in the 

 Tyrini (PI. XX) : the tyrine type in which the second and third palpomeres are 

 similar in shape, pedunculate, with the fourth or distal segment subfusiform and 

 nonsulcate; and the hamotine type in which the third palpomere is short, tri- 

 angular and the distal segment is obliquely truncate at base and with a longi- 

 tudinal sulcus on the internal face. In the former case the palpal cone is more 

 or less apical and inserted in a variably developed apical tmncature. In the 

 latter case the palpal cone is set very obliquely within the apex of the palpal 

 sulcus. Virtually all palpomeres vary among the genera, and within generic lim- 

 its there is considerable variation among the species. Few and minor are the 

 sexual variations of the palpi, and within the species population there is no 

 significant variation. 



