128 ORTMANN — AFFINITIES OF CAMBARUS. [April 13, 
dent in the following cases, where groups of species occupy a cer- 
tain range, but represent each other in the different parts of this 
range: (1) in the sficulifer-group of the subgenus Camébarus : spic- 
ulifer in northern and central Georgia, vervsu¢éws in central and 
southern Alabama, and in northwestern Florida, pubescens in eastern 
Georgia, angustatus in southeastern Georgia. (2) In the clarki- 
group: clarki, parallel to the Gulf coast from Texas to Florida, 
troglodytes in corresponding localities in Georgia and South Caro- 
lina. (3) Lemosus-section of Faxontus : tndianensts in southwestern 
Indiana, s/oavez in southeastern Indiana and Kentucky. (4) Pro- 
pinguus-group : propinguus has a western and northern distribution ; 
it is represented in western Pennsylvania by odscurus. (Between 
both possibly is C. propinguus sanborni, occupying an intermediate 
range.) (5) Rusticus-group: spinosus is southern and eastern 
(North and South Carolina, northern Georgia, northern Alabama 
and eastern Tennessee), while fwztzamz is more northern (Ken- 
tucky). (6) In the pa/meri-group the different species occupy dif- 
ferent parts of a range that includes Mississippi, western Tennessee, 
Arkansas, Indian Territory and northeastern Texas. 
Groups of allied spectes are often formed by a typical spectes, which 
shows a wide range, while the allied spectes forma fringe on the edge 
of this range thus representing local forms. ‘This is shown beauti- 
fully in the following natural groups: (1) Rusticus-group: the typ- 
ical form is vusticus, the local forms at the edge of its range are: 
forceps (southeast), weglectus (west and southwest), sfzmosus and 
putnam (southeast), Aylas (south), medius (south); probably also 
ertchsonianus (southeast). (2) Virilis-group: the typical form is 
virilis, the local forms are: meeki, longidigitus, nats, pilosus, all in 
thesouthwest. (3) artoni-section: bartont is the typical form, the 
local forms of it are: acuminatus (southeast), datzmanus (south and 
southwest); in this section also a mountain form has developed 
within the range (/omgu/us), and varieties are found in the southern 
section of the range, as well as at its northwestern edge. (4) C. mon- 
ongalensis is a local form developed at the northwestern edge of the 
range of C. carolinus. (5) In the dogenes-section, at least one 
species, C. whdert, seems to bea local form of the widely distributed 
C. diogenes, developed at the eastern extremity of its range. 
More or less closely allied species, occupying the same or nearly the 
same territory, generally possess different habits. In most of the 
