Alpheid Shrimp, ¥ — BANNER and BANNER 
137 
two genera should be regarded as valid. In the 
following key we have not combined any species 
for which we have no specimens. We also do not 
include the few non Indo-Pacific species, but we 
do include those species from the Pacific that 
are nontropical 
KEY TO THE INDO PACIFIC SPECIES OF 
Athanas 3 
1. Palm of large chela cylindrical or 
subcylindrical in section; carpus 
of second legs with five articles.... 2 
Palm of large chela flattened, def- 
initely higher than broad in sec- 
tion, carpus of second legs with 
four or five articles 22 
2(1). Legs of first pair, when fully devel- 
oped, carried directed forward; 
merus short, not excavate 3 
Legs of first pair, when fully devel- 
oped, with chelae carried folded 
against an excavate and expanded 
merus 6 
3(2). Supracorneal teeth present 
A . areteformis Couriered 
Supracorneal teeth absent 4 
4(3). Dactylus of third legs biunguicu- 
late.... A. grand Coutiere 
Dactylus of third legs simple, but 
may carry an articulated spinule at 
usual point of biunguiculation. . . . 5 
5(4). Dactylus of third legs simple; with 
both extra- and infracorneal teeth 
A. crosslandi Tattersall 
Dactylus of third leg carrying an 
articulated spinule; with only ex- 
tracorneal teeth (originally de- 
scribed as infracorneal teeth ) 
A* gracilis Boone 
6(2). Supracorneal teeth present 
A. djiboutensis Coutiere 
3 Athanas tenuipes de Man is omitted from the key 
as the type specimen, the only specimen known, lacked 
both legs of the first pair. Otherwise, it is character- 
ized by five articles in the carpus of the second legs, 
the lack of supracorneal teeth, the presence of extra 
and infracorneal teeth; its rostrum reaches to the mid- 
dle of the second antennular article; and third legs 
and telson of slender and elongate form. 
'•'Those species whose names are in italic are dis- 
cussed in this paper. 
Supracorneal teeth absent 7 
7(6). Dactylus of third leg biunguiculate.. 8 
Dactylus of third leg simple 9 
8(7). With infracorneal tooth 
A. parvus de Man 
Without infracorneal tooth or pro- 
jection A. jedanensis de Man 
9(7). Carpus of first leg longer than palm 
in mature females 10 
Carpus of first legs equal in length 
to palm, or shorter, in mature 
females 15 
10(9). Ischium of first legs with strong dis- 
tal spine... A. orientalis Pearson 
Ischium of first legs not so armed.... 11 
11(10). Palm of chela in female less than 
1.5 times length of fingers 12 
Palm of chela in female 2.0 or more 
times length of fingers 13 
12(11). Palm of chela in female shorter than 
fingers; stylocerite reaching to 
end of third antennular article; 
dactylus of third legs one-third 
length of propodus 
A. setoensis Kubo 
Palm in female equal to fingers; 
stylocerite reaching slightly past 
end of first antennular article; 
dactylus of third legs more than 
half length of propodus 
A. polymorphus Kemp 
13(11). With extracorneal tooth strong and 
acute; infracorneal projection 
almost as long as extracorneal 
tooth, but rounded 
A. stebbingi de Man 
With only extracorneal tooth (or 
infracorneal tooth) produced and 
acute ...14 
14(13). Rostrum reaching to end of second 
antennular article 
A. dimorphus Ortmann 
Rostrum a little longer than anten- 
nular peduncle 
A. monoceros (Heller) 
15(9). Infracorneal projection at most 
slight and rounded... 16 
Infracorneal projection present and 
acute 18 
