310 NEOTROPICAL PSELAPHIDAE 



typical of moist, well-decayed log mold and there are few records of their 

 being taken at lights at night; some species have adjusted to the rapacious 

 army ant society (ecitophilus), others live with termites as noted later. 



The largest pselaphid known to the author belongs in this genus. This 

 giant is Hamotus (Hamotoides) ecitophilus Raffray of Brazil which measures 

 5.5 mm. in length and lives with Eciton. 



The comparative anatomy of the genus is not given here as the numerous 

 descriptions of new species which follow serve to give the range of structural 

 diversity. It should be pointed out, nevertheless, that, although the diversity 

 is extensive, the central habitus of Hamotus is unmistakable and the species 

 vary in the quantitative development of such features as the length of the 

 palpal sulcus, length ratio of tergites, color of pubescence, proportions of the 

 antennomeres, development of the pronotal foveae, and sulcus. 



Sex is poorly differentiated by secondary characters. Only rarely are the 

 males distinctive from the females on clear cut modification of the antennae, 

 tibiae, or metasternum. Much more commonly the secondary sexual differences 

 are subtle differences in the proportions of the antennal club or abdominal 

 contour. Therefore long series of a species are greatly to be desired in the 

 genus, and direct dissection necessary. 



On the other hand, what at first appear to be slight differences in anten- 

 nomeres of insufficient value for species separation, prove to be relatively 

 stable in a long series of specimens. Raffray (1904) stated that these slight 

 antennal differences were quite reliable for species separation. I have been at 

 some pains to check this view. Having at hand several species represented by 

 both sexes in series of a dozen or more, I used an ocular micrometer at high 

 magnification to measure the length and width of the last three antennal seg- 

 ments. A summary of these data are given later under the species concerned, 

 but it should be said here that the reliance of Raffray, Reitter, and Schaufuss 

 on antennal segments has been justified in my own work. 



Finally, it is pleasing to find at least a tenth of the known species are 

 known from several adjacent countries, that is, the genus is becoming suf- 

 ficiently known to have the distribution of its components partially delineated. 

 Some species have a great range. Thus monachus is known from Costa Rica to 

 Mexico; tritomus from Colombia to Mexico; hirtus from Grenada, St. Vincent, 

 and Guadeloupe; bryaxoides from Colombia, Venezuela, and Brazil. In time 

 such information, it is to be hoped, will appear comparatively scanty; this 

 calls for much expeditionary labor and taxonomic discrimination. 



As late as 1908 Raffray recognized Hamotus of Aube and Hamotoides 

 (Schaufuss, 1887) as subgenera, but between 1909 and 1917 Raffray treated 

 them as genera. I feel that this latter treatment is a mistake. Hamotus and 

 Hamotoides differ in several ways but the differences are gradual, lacking any 

 precise break in a qualitative sense. The chief character for their separation 

 is the presence or absence of the transverse pronotal sulcus. Now the transition 

 between having or lacking this sulcus is fully bridged by lateritius, decipiens, 

 longepilosus, micans, longiceps and alleei. In these species, which are placed 



