TRAGARDH: ON THE NEW GENUS CERATOACACUS EWING (ACARINA). 187 
Subsequently, OUDEMANS (Tijdschr. voor Entomologie, 
Bd. 46, p. 132—134) proved that already in 1776 SCHRANK 
(Beitr. zur Naturgeschichte, p. 125, pl. 6, fig. 8) had described 
a species, belonging to this genus, and about the same time 
the author (Zool. Anz. Bd 28, n:o 18, 1904, p. 565—567, figs. 
I—4) tried to prove that Ladzdostoma cornuta CAN. & FANZ. 
had been described by KOCH under the name of Raphz- 
gnathus ruber (Deutschlands Crustacéen, Myriapoden und 
Arachniden. fasc. 20, pl. 20). 
Consequently there exists a literature on the genus, pub- 
lished in German, Italian and English and the more sur- 
prising it is to learn that none of these papers is known in 
USLA: 5 
Labidostoma is a very isolated genus and its systematic 
position and its affinities have not yet been ascertained. 
The brothers CANESTRINI placed it at first amongst the 
Gamaside (Parasitide), subsequently amongst the Oribatide 
and it is know raised to the rank of a family. 
It is, however, very interesting to learn that the Labido- 
stomide are representated also in North America. Up to the 
present time the family has only been recorded from Europe, 
but the author has found a species, not yet described, not unc- 
ommonly in South-Africa. 
It is therefore evident, that the family has a very wide 
distribution. 
Entomol. Tidskr. Arg. 35. H. 3—4 (1914). 13 
