Alpheid Shrimp, Y — BANNER and BANNER 
Second Legs: In the merus the length-breadth 
ratio varies from 1:2=5 to 1:3.7, with most of 
the specimens bearing the ratio between 1:2.8 
to 3.0. Only in a small series the relative lengths 
of the carpal articles and hand were measured, 
and these show that the extent of variation is 
similar to that of the merus. 
Third Legs: Three characteristics of the third 
legs have been carefully observed: the length- 
breadth ratio of the merus varies from 1:2.5 to 
1 : 3.4, with most of the specimens with the ratio 
between 1:2.9' to 3.1. The final outer tooth of 
the inferior margin in no specimen is large and 
no specimen is lacking, with the maximal de- 
velopment being about that shown in Figure 5 h, 
while in the minimal development the tooth is 
barely visible, and is scarcely more than an ob- 
tuse irregularity; it also varies from slightly 
acute to obtuse. The length-breadth ratio of the 
propodus exhibits less variation than do the 
other measured articles, ranging from 1:4.0 to 
1:4.6, with most of the specimens grouping 
around 1:4.5. 
T els on: In all of the specimens except three 
the telson is found to be 3.2 to 4.0 times as long 
as the posterior margin is broad, with most 3-2 
to 33 times. In two specimens the telson is only 
3.0 times as long as broad, and in one it is 4.2 
times as long. 
The extent of this variation destroys the valid- 
ity of the separation of A. maruteensis and A. 
dorsalis. Coutiere separated his species (which 
he originally called A. dorsalis pacificus ) upon 
the following characteristics : 1. shape of ros- 
trum; 2. traces of extracorneal spines; 3. shape 
and armature of large and small chelae; 4. rela- 
tive proportions of the carpal articles and chelae 
of second legs (for this character it should be 
noted that in the specimens measured some 
would be like A. dorsalis in two of the relative 
measurements and like A. maruteensis in the 
third); 5. the length-breadth relation of the 
articles of the third leg, and the presence of a 
definite tooth on the merus as opposed to being 
"coupe a angle droit” in A. maruteensis . To these 
differences de Man adds, in his separation of the 
subspecies A. maruteensis salibabuensis the pro- 
portions of the rostrum and merus of the second 
and third legs. In the group of specimens meas- 
ured each of the characteristics was found to be 
153 
Fig. 6. Athanas dorsalis (Stimpson), variations in 
the development of the chelae, a, Male of 3-3 mm. 
carapace length; b, male of 3.5 mm. carapace length; 
c, male of 3.85 mm. carapace length; d, male of 4.95 
mm. carapace length; e, male of 4.95 mm. carapace 
length; f, male of 5.2 mm. carapace length. All drawn 
to same scale. 
