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PACIFIC SCIENCE, Vol. XXI, October 1967 
differs notably from that of the West Indian 
Coenobita clypeatus in having a well developed 
exopodite on the third maxilliped and in not 
having an extremely long terminal seta on the 
antennal flagellum (both the reduced exopodite 
and the long terminal seta probably are generic 
or familial characters of the land hermit crabs 
(Provenzano, 1962^). The glaucothoe of T. 
magnifcus differs from those of the Pacific 
Dardanus scutellatus and the West Indian D. 
insignis and D. venosus (Provenzano, 1963^ 
1963^) in size (all of which are much larger), 
in eye shape (in Dardanus the cornea is wider 
than the eyestalk, not narrower) , in not having 
their peculiar armature of the ambulatory dac- 
tyls, in having a shorter telson, and in having 
a reflexed palp on the endopodite of the 
maxillule, which those species lack. The glau- 
cothoe attributed to the West Indian Petro- 
chirus dio genes (Provenzano, 1963^) was 
erroneously identified (Provenzano, in prepara- 
tion), but the true glaucothoe of Petrocbirus (a 
genus represented in the eastern Pacific by P. 
californiensis) probably differs from that of 
Trizopagurus in those same features as does 
Dardanus. 
The glaucothoe of Clibanarius erythropus 
from the Mediterranean (Dechance, 1958) dif- 
fers from that of T. magnifcus in being smaller, 
in having a suboval telson, in lacking a promi- 
nent spine on the protopodite of the uropod, in 
having a smaller number of segments on the 
antennal flagellum, and in details of setation. 
The four species of Paguristes for which glau- 
cothoes have been described, P. turgidus Stimp- 
son, from the northeastern Pacific (Hart, 
1937); P. oculatus (Fabricius), from the Medi- 
terranean (Issel, 1910 and Pike and William- 
son, I960); P. abbreviate Dechance, from 
the western Indo-Pacific (Dechance, 1963); 
P. sericeus A. Milne-Edwards, in the West 
Indies (Rice and Provenzano, 1965), all differ 
from that of T. magnifcus in having longer 
dactyls on the second and third pereiopods, in 
armature of the chelipeds, in having a very 
small number of segments in the antennal 
flagellum (8 segments or less), and in having 
only 2 segments in the ventral ramus of the 
antennule. Glaucothoes of Calcinus — specifi- 
cally, C. ornatus (Roux), in the Mediterranean 
(Pike and Williamson, I960); and C. tibicen 
(Herbst), in the West Indies (Provenzano, 
1962^) — apparently bear closest resemblance 
to that of T. magnifcus , but when the eastern 
Pacific glaucothoes of Calcinus have been stud- 
ied, probably there will be size differences and 
details, such as armature of the protopodite of 
the uropod, by which these forms may be dis- 
tinguished. 
An apparently unique feature of the glau- 
cothoe of T. magnifcus is the patch of granula 
tions on each chela. 
The only other diogenid genera occurring in 
the range of T. magnifcus, and for which no 
glaucothoes have been described from other 
regions, are Allodardanus (A. bredini Haig and 
Provenzano, 1965), Isocheles (several species), 
An i cuius (A. elegans Stimpson) and Can cell us 
(C. tanneri Faxon). In Allodardanus and Iso- 
cheles the dactyls of the second and third 
pereiopods are rather long, and it is likely, 
though not certain, that the glaucothoe will 
show the same condition. Both Aniculus elegans 
and Cancellus tanneri have very short dactyls, 
but neither species has a reflexed palp on the 
endopodite of the maxillule, and so their 
glaucothoes should be distinguishable from 
that of Trizopagurus. 
Particularly important characters for the fu- 
ture discrimination of diogenid glaucothoes 
should be the overall body size, the shape and 
armature of the telson, the armature of the 
protopodite of the uropods, the shape of the 
eyes, the relative lengths of the dactyls and 
propod i of pereiopods two and three and the 
armature of these dactyls, the length of the 
setae on the antenna relative to lengths of 
antennal segments, presence or absence of a 
reflexed palp on the endopodite of the maxil- 
lule, and the armature of the chelipeds. 
REFERENCES 
Boone, L. 1932. The littoral crustacean fauna 
of the Galapagos Islands. Part 2. Anomura. 
Zoologica 14:1-62, 19 figs. 
Bouvier, E. L. 1898. Sur quelques Crustaces 
anomoures et brachyures recueillis par M. 
Diguet en Basse-Californie. Bull. Mus. Hist. 
Nat. Paris 4:371-384. 
Boyd, C. M., and M. W. Johnson. 1963. 
Variations in the larval stages of a decapod 
