TYRINI 321 



Maxillary palpi large; first three segments as in costaricensis. Fourth 

 (distal) palpomere obliquely truncate at base, internal face straight, external 

 face convex to rounded apex to form the usual elongate-oval outline. Internal 

 face with an entire, longitudinal sulcus and a large palpal cone inserted within 

 apex of sulcus as usual. This distal segment 0.19 mm. long by 0.09 mm. wide. 

 It is covered with a thin pearly secretion which became hardened after im- 

 mersion in alcohol. This palpal secretion has been not^d on many species of 

 Hamotus and suggests a sensory function. 



Antennae one-half the body length (0.9 mm.) and simple; I elongate- 

 cylindrical; II similar but smaller; III-VIII subequal, monilifomi; IX and X 

 as in key; XI much longer than wide, subconical, not quite as long as three 

 preceding united. 



Pronotum shorter and wider than head, slightly transverse, subglobose. 

 Base with small distinct median fovea and large lateral fovea each side ; foveae 

 nude and connected by a rudimentary transverse sulcoid depression of varying 

 breadth and depth, at no time cleanly cut and always difficult to follow. 



Abdomen with five visible tergites in a length ratio of 6/1/1/1/1.5 with 

 first two with strong lateral margins. Base of first with a pair of strong, 

 straight, slightly divergent basal carinae which are two-fifths as long as seg- 

 ment and separated by one-half the segmental width. Six simple sternites in a 

 length ratio of 1/2.5/1/1/1/.5. 



Metasternum elongate, tumid each side of a subglabrous broadly concave 

 depression ; apical margin finely incised at middle. 



Posterior coxae and intermediate coxae separated by one-third the median 

 metasternal length. Legs simple and the posterior tibiae are not spined or 

 spurred. Tarsi of typical Hamotus proportions, with two large, equal claws. 



Described on two specimens of doubtful sex, both collected by the author 

 in decayed log mold in rain forest of Barro Colorado Island, Gatun Lake, 

 Panama Canal Zone. Type July 25, 1936, at Drayton 13; paratype July 29, 

 1936, at Zetek 3. The paratype had recently pupated. 



Alleei runs to Group XI but has little affinity with other species. With 

 more time it may form the type of a new genus. The general habitus, 

 pubescence, head from above, antennae, pronotum and elytra, and especially 

 the maxillary palpi are Hamotus. The very long first tergite is Apharus. The 

 vestigial pronotal sulcus places the species near the genotype lateritius rather 

 than the extremes of Hamotus but lack of tibial spurs and nude foveae incline 

 it to Hamotoides. The ventral surface of the head, punctation, and basal ab- 

 dominal carinae are nonhamotine. It is a pleasure to name this distinctive 

 pselaphid for my friend. Professor Warder Clyde Allee. 



Hamotus (Hamotus) sandersoni new species 



Type. Measurements: Head 0.37 x 0.38 mm.; pronotum 0.37 x 0.43 mm.; 

 elytra 0.47 x 0.80 mm.; abdomen 0.63 x 0.80 mm.; total length 1.84 mm. 



Uniform light brownish-yellow. Pubescence abundant, fine in texture, sub- 

 appressed, dark golden in color. Integument lightly punctulate. 



