308 NEOTROPICAL PSELAPHIDAE 



HAMOTUS (Aube, 1844) 



AuBE (1844) 



Reitter (1882) 



Sharp (1887) 



SCHAUFUSS (1887) 



Raffray (1904, 1908) 



Fletcher (1932) 



Park (1935) 



Hamotus was erected by Aube on three species in 1844: the genotype 

 lateritius (p. 92), bryaxoides (p. 93), and hunieralis (p. 93). The last named 

 species was misplaced by Aube, and was early assigned to Tyrus. Tyrus was a 

 genus erected by Aube in 1833 and its genotype is mucronatus (Panzer). 

 LeConte and Horn (1883, p. 87) correctly placed Tyrus hunieralis (Aube) and 

 this course has been uniformly followed by American students. Tyrus humeralis 

 is widespread in the Nearctic Region, from Canada south into Florida, and west 

 to the Mississippi drainage basin. I have satisfied myself that humeralis (Aube) 

 is perfectly congeneric with mucronatus (Panzer) of Europe. My material in 

 the latter species comes from Germany and has been identified by Edmund 

 Reitter. Both species have the typical distal segment of the maxillary palpus, 

 that is, pedunculate-ovoidal in outline, with no longitudinal sulcus and with the 

 palpal cone set in the acuminate apex of the segment. 



The other two species of Aube, lateritius and bryaxoides, are typical 

 Hamotus. Both species have the distal segment of the maxillary palpus cyl- 

 indrico-ovoidal in outline, with the base obliquely truncate and the internal face 

 conspicuously longitudinally sulcate, with the palpal cone set obliquely within 

 the apex of the sulcus. 



Hamotus has received much attention from three distinguished students of 

 the family, Reitter, Schaufuss, and Raffray. The substantial increase in infor- 

 mation since 1904 has rendered a new treatment desirable. At the present time 

 the genus contains eighty-nine species and as a homogeneous aggregate of large 

 size ranks with Reichenbachia, Decarthron, Arthmius, and a few other genera 

 in the region under examination. 



Taxonomically it is one of the most important neotropical genera. It is dis- 

 tributed over the Neotropical Region from the tropic of Cancer to the tropic of 

 Capricorn, and its restriction to this fauna is complete with one exception, 

 Hamotus opimus Fletcher discovered in 1932 in peninsular Florida. Such a dis- 

 persal pattern is presumptive evidence of neotropical origin and, since there has 

 been great speciation in the genus, its confinement to this area indicates physio- 

 logical intolerance of extra-tropical environment rather than inability to dis- 

 perse or to compete with nearctic species. 



There is but one other species about which doubt can be entertained. 

 Brendel described Tyrus elongatus (Brendel and Wickham, 1890, p. 239) from 

 a male from Williams, Arizona. Leng (1920, p. 132) placed it doubtfully in 

 Cercocerus. Bowman (1934, p. 136) placed it in Hamotus. I agree with Bowman 

 that elongatus cannot be Cercocerus — a glance at Brendel's figure precludes such 



