410 TRANSACTIONS OF THE AMERICAN PHILOSOPHICAL SOCIETY 



In brief, whatever the taxonomic status of the several dwarf males referred to as 

 " Aceratiidse " may prove to be, it seems that this " family " must have diverged from Haplo- 

 phryne-Vike ancestors into three lines, as follows: 



(1) Development of a prominent rostrum and strong rostral bone moved by the former 

 basal illicial muscles; development of varied rostral denticles, opposing similar denticles 

 on tip of forwardly-prolonged mandible, thus producing a nipping type with small diastema; 

 eyes directed outward " Rhynchocer alias." 



(2) Elongation of the body, great growth of the nasal sacs, protrusion and forward 

 turning of the large eyes; rostral denticles dwindling; mouth remaining moderate. 



'' Aceratias." 



(3) Marked reduction in size of mouth, which acquires nipping edges; illicial muscles 

 weak, rostrum not ossified, olfactory sacs reduced; head becoming very broad, nearly circular 

 in vertical view, with much shortened rostrum; eyes directed outward and partly upward; 

 general appearance converging toward swell-fish type " Lcevocer alias." 



