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PACIFIC SCIENCE, VoL XX, April 1966 
phyrgianus; and the telson being more than 
3 times as long as broad. 
Nobili distinguished his species from A. 
phyrgianus in that the second antennular article 
was shorter and the scaphocerite was longer; 
however, both of these characteristics are 
variable, and the proportions stated for A. 
persicus fall within the range of A. malleo- 
digitus. Therefore A. persicus, also, should be 
considered a synonym. 
5. A. danae. The characteristics set forth by 
Coutiere are: second antennular article 2.5 
times the length of first, and 4.2 times as long 
as broad; scaphocerite and carpocerite equal 
in length, reaching to the middle of the second 
antennular article, with the squamous portion 
of the scaphocerite reaching only a quarter the 
length of that article; the large chela lost; the 
palm of the small chela 2 times the length 
of the fingers; the second carpal article of the 
second leg 1.3- 1.5 times the length of the 
first; the third leg almost identical to that of 
A . phyrgianus; the telson slightly broader than 
in A. phyrgianus, about 3.7 times as long as 
broad. 
This species, too, is very close to A. malleo- 
digitus but may be separated by the very short 
carpocerites; none of the specimens measured 
in our study approached the condition described 
for A. danae. It may be that this is merely an 
extreme variation, but at present this is not 
indicated. 
6. A. Samoa (described below). As stated 
below, this species is unique within the 
Obesomanus group in that the scaphocerite is 
almost vestigial, not reaching to the end of 
the first antennular article; otherwise the species 
also approaches A. malleo digitus. 
7. A. nobili (nom. nov.) = A. species Nobili. 
The few characteristics given by Nobili for 
this specimen were: antennular and antennal 
peduncles like those of A. microstylus (there- 
fore with the scaphocerite and carpocerite 
reaching beyond end of the antennular 
peduncle), but with the squamous portion of 
the scaphocerite reaching only to end of the 
second antennular article; the ratio of the first 
two carpal articles were 10:14 to 10:13; and 
the carpus of the third legs a little longer than 
the propodus. 
The combination of the characteristics of 
the antennal peduncles and second legs is un- 
like any other species in the group and, if the 
description is accurate, the specimen probably 
represents a new species; at least, it does not 
appear to be a variety of A. micro stylus as 
Nobili suggested. We have assigned the name 
A. nobili to the tentative species. 
C. Species with biunguiculate dactyli on 
posterior legs. 
1. A. per plexus Banner. This species is unique 
within the Obesomanus group in having, in 
addition to the biunguiculate dactylus, crests 
and depressions on the large chela that are 
similar to those of the Megacheles group; 
otherwise it is similar to A. obesomanus and 
A. malleodigitus. 
2. A. species, de Man. This is probably the 
same as A. perplexus (see Banner, 1956: 349). 
3 .A. chamorro Banner. This species, too, has 
a biunguiculate dactylus, but in general ap- 
proaches the species of the Crinitus group in 
most characteristics, although the large chela 
still retains a diminished hammer-shaped 
dactylus. 
II. Species without strong transverse articula- 
tions on the outer uropods. 
1. A. rathbunae (Schmitt). This Caribbean 
species can be characterized within this sub- 
group by the complete absence of a rostrum 
and the extreme elongation of the second 
antennular article, as well as the narrow tip 
of the telson. The dactylus of the large chela 
does not have a strong superior (or proximal) 
projection. 
2. A. idiocheles Coutiere. This species has a 
rostrum. The scaphocerite reaches to about the 
middle of the second article; large and small 
chelae are elongate, with dactylus of the large 
chela formed like a single-headed, not double- 
headed, hammer. 
3. A. baculifer Coutiere. This species, previ- 
ously known only by a female specimen, will 
