168 
PACIFIC SCIENCE, Voi XX, April 1966 
In the summation of the characteristics of 
the species given below, the original description 
was used wherever possible; for some charac- 
teristics, especially proportions, the original 
figures were used; only where both of these 
were Insufficient were the later redescriptions 
used (of the type or supposedly similar speci- 
mens). The species have been divided into 
four groups for the purpose of this discussion: 
I. Those species with a strong articulation of 
the outer uropod. 
A. Those with simple dactyl! on the posterior 
legs, and with elongate second articles in 
the carpus of the second legs. 
1. A obesomanus Dana. This species, the 
first one described in the group, was charac- 
terized by having the second article of the 
an.teno.ular peduncle 1.5 times the length of 
the first, and 3 times as long as broad; the 
scaphocerite and the carpocerite barely reaching 
to the end of the second antennular article, and 
the squamous portion of the scaphocerite 
reaching to the middle of the second antennular 
article (according to Boone, 1935); the large 
chela smooth (although Boone described de- 
pressed areas ) ; the palm of the small chela 
A. mti 1 ieodig j t us 
W-"-' 
€|SI: 
1 
w. 
.... 
to 
Li. J&atl E 1 U sisa. 
A.mierostylus 
ss 3 t ' 3 " i -j pj T - k - ■» a o> p> -j 
ai® — > N © f.i-i ® Ot €6 > -j o 
Fig. 16. Obesomanus group; proportions of the 
carpus of the third leg of three species. Ordinate: the 
length of the carpus of the third leg divided by the 
breadth. Abcissa : number of specimens. 
was described as 3 times as long as the fingers 
but illustrated as 2.5 times as long; the first 
two carpal articles of the second leg with the 
ratio of 1:4. (Danas figures show a ratio of 
about 1:3.4 with the merus of the third leg 
armed, the dactylus simple.) 
This species, the most common one in our 
collections, was identified originally in this 
series of papers as A. lutini Coutiere (for 
characteristics see below), since almost all the 
specimens had longer scaphocerites and car- 
pocerites than those described by Dana (Figs. 
11 and 12). However, a few specimens of those 
measured approached the described condition 
of A. obesomanus , and other individuals not in 
the sample measured showed a gradation be- 
tween these and the condition described by 
Dana. Of seven specimens In a single collection 
from Tahiti (BD 13), one has the scaphocerite 
and carpocerite not quite reaching to the tip 
of the second antennular article; one specimen 
has them reaching to the end of this article; 
in two the parts reach to the first quarter of 
the third antennular article; and In another 
two, to the middle of this article; in the 
remaining specimens they reach almost to the 
tip of the article. 
This leaves the ratio of fingers to palm 
of the small chela as means of distinguishing 
between the two nominal species. These ratios 
were reported to be 1.0: 2.5 in A. obesomanus 
and 1:1.5 in A. lutini. However, Danas figures 
show a ratio of 1:2.5, and the measured speci- 
mens show a ratio of 1:1.5 to 1:2.5. Thus 
there is no differentiation. Other characteristics 
set forth by Coutiere are also bridged by the 
variation reported above. 
A neotype should be established from Fiji 
for this species, but all of the Fijian specimens 
at hand were more like the form described 
for A . lutini and none closely approached the 
characteristics given by Dana. 
2. A. obesomanus japonicus Ortmann. Ort- 
mann’s original description is very inadequate 
to characterize this species. The second anten- 
nular article is more than twice 1 as long as the 
first; the scaphocerite is ”sehr schmal, fast so 
lang wie die Stiele der ausseren, kiirzer die der 
inneren Antennen.” The fingers of the small 
