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PACIFIC SCIENCE, Vol. XX, April 1966 
A. mail eodig itus 
2nd ant. art. 3rd ant.arf . 
. Obesomanus group; relative proportions 
ame to the antennal peduncle in three spe- 
n ate: length of squame in relation to the 
1 third antennular article. Abcissa: number 
chela and that of the fingers more than 3 as 
opposed to a little shorter than the palm. . . 
less than 3”). The graphs show that, while 
there may be statistical differences, this charac- 
teristic cannot be used for separation of indi- 
vidual specimens. Analysis showed no differ- 
ences between the sexes, and so these are not 
differentiated on the graph. 
Second leg (Fig. 15). Between the two 
species, A. malleodigitus and A. obesomanus , 
the characteristic that seems to give the best 
differentiation is the ratio of the first two carpal 
articles: in A. malleodigitus the ratio is less than 
1:2 (usually about 1:1.5), while every speci- 
men of A. obesomanus has a ratio of more than 
1:2 ( usually about 1:3). The few specimens of 
A. microstylus, however, seem to fall into the 
range of A. obesomanus. 
Third leg (Figs. 16 and 17). In these the 
length-breadth relationship of both the merus 
and the carpus are graphed and no sharp dif- 
ferentiation is found. 
Telson (Fig. 18). When the length of the 
telson is contrasted with the breadth of the 
tip, a measurement often used in this genus as 
a specific characteristic, extreme variation is 
noted; it is doubtful if this should ever be used 
as a characteristic within this group. 
With this knowledge of the variation in these 
three species, the separation of the Indo-Pacific 
species and varieties has been reviewed. The 
characteristics of those species not represented in 
the collection were derived entirely from the 
litrature. These species are listed in the order 
of their consideration in the section which 
follows. 
A. obesomanus japonicus Ortmann, 1890:478. 
A. microstylus (Bate), 1888:566, pi. 101, fig. 
6; Coutiere 1899: Figs. 270-272, 400 (listed 
as A. obesomanus or A. malleodigitus ); 
Coutiere, 1905:884, pi. 76, fig. 23; de Man, 
1911:344. 
A. microstylus var ? de Man, 1911:345, pi. 14, 
fig. 68. 
A. lutini Coutiere, 1905:885, pi. 76, fig. 24; 
de Man, 1911:346, pL 14, fig. 69- 
A. species 2 Banner, 1956:351, fig. 15. 
