10 
Psyche 
[March 
has used the last character as the main distinction between the “sub- 
families” Deltomeritae (represented in North America by genus 
Platidiolus, syn. Patroboidea ) and Patrobitae, in spite of the fact 
that Diplous is referred to the latter group which he defines as having 
constantly 8 setiferous punctures! In the three points mentioned 
above (1-3), Platypatrobus agrees with Patrobus in points 1 and 2 
but is intermediate in point 3, the marginal row consisting of 16 
punctures on each side in the male investigated and being less inter- 
rupted at middle than in Patrobus . 
Platypatrobus , though generically distinct, is closely allied to 
Patrobus and no “missing link” to Diplous. Its extreme rarity and 
restricted distribution undoubtedly give the impression of a relict, 
on the verge of extinction. On the other hand, it does not seem 
possible to tell whether Platypatrobus is the phylogenetically older 
genus. It should perhaps be regarded as “more simple” in general 
construction (lack of prothorax carinula, nearly continuous marginal 
row of setiferous punctures of elytra, simple internal sac of penis), 
but evolution sometimes goes toward simplification. How often is it 
actually defensible to state, without fossil evidence, what is “primi- 
tive” and what “derivative”? 
Literature Cited 
Darlington, P. J., Jr. 
1938. The American Patrobini (Coleoptera, Carabidae). Entomologica 
Americana (Brooklyn) (new series), 18:135-183. 
Jeannel, R. 
1941. Coleopteres Carabiques, 1. Faune de France (Paris), 39:1-571. 
Kuhnelt, W. 
1941. Revision der Laufkafergattungen Patrobus und Diplous. Ann. 
Naturh. Mus. (Wien), 51:151-192. 
Lindroth, C. H. 
1961. The Ground-Beetles (Carabidae, excl. Cicindelinae) of Canada 
and Alaska, 2. Opusc. Ent. (Lund), Suppl. XX: 1-200. 
