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PACIFIC SCIENCE, Vol. VII, January, 1953 
Carpal articles of second legs with ratio 
10 : 6 : 3 : 3 : 6. 
Ischium and merus unarmed; merus 4-5 
times as long as broad; propodus tapering 
distally, with proximal end about 1.5 times 
width of distal; inferior margin with 6-8 long 
slender spines; dactylus slender, 0.25 length 
of merus, simple, with slight convexity on 
inferior margin at point where lower unguis 
would be expected. 
Telson with sides rather straight and with 
pronounced taper, 1.8 times as wide as long 
at posterior margin. External spine of uro- 
pods almost always brown to black. 
Specimens in collection, range to 18 mm. in 
length. In life, body and chelae transversely 
banded with broad gray bands of red and blue 
chromatophores; eggs brilliant yellow. Trans- 
verse bands red in preserved specimens. 
DISCUSSION: This species varies in a num- 
ber of characteristics. The rostrum, which in 
most extends only to the middle of the visible 
portion of the first antennular article, in some 
specimens reaches to the end of that article 
and in one specimen extends to one third of 
the second article. In some specimens there is 
a faint trace of an obtusely angular dorsal Ca- 
rina on the rostral base. The orbital teeth vary 
in breadth and length, sometimes being al- 
most as long as the rostrum and sometimes 
only half as long (contrast Fig. 2^a and c); in 
all cases, however, the teeth arise abruptly 
from a uniformly curved anterior margin of 
the orbital hood. There are variations, as 
would be expected, in the lengths of the sty- 
locerite and of the lateral spine of the basicer- 
ite, the latter in a few cases exceeds the length 
of the rostrum. The small and large chelae 
vary somewhat in their proportions but their 
general form and armature remain constant as 
shown. The second carpal article of the sec- 
ond legs varies from 0.5 to 0.7 the length of 
the first, with a similar variation in the other 
articles as well. On the third legs the variation 
of the breadth of the merus and the number 
of spines on the propodus is noted above. 
Variations were also noticed in the propor- 
tions of the telson where a series of six speci- 
mens gave differences in the ratio of the width 
of the posterior border to the greatest width 
of 1. 6-2.0, and in the ratio of the width of the 
posterior border to the length of 2. 4-3.0. A 
most peculiar variation was observed in the 
external spine of the uropods: in 40 specimens 
all but 5 have brown to black spines, 2 have 
spines with faint color, and 3 have colorless 
spines. This change of color is not the result 
of the solvent action of the preserving fluid 
(formaldehyde or alcohol), as some specimens 
preserved over 14 years still have the spines as 
dark as the newly preserved ones. Perhaps the 
variation may be the result of moulting, for 
several of the specimens with slightly colored 
or colorless spines have what appears to be 
softer chitin. 
The varietal name refers to the lack of a sec- 
ondary unguis on the dactylus of the third leg. 
RELATIONSHIP: There have been four de- 
scriptions published for this species and its 
varieties. The type specimen first described by 
Heller was subsequently redescribed by de 
Man ( 1911 ), who corrected some errors found 
in Heller’s description and also extended the 
original description. Coupled with this rede- 
scription, de Man also described a tentative 
variety, C. gracilis var. luciparensis which he 
distinguished from Heller’s type specimen 
chiefly by minor differences in the proportions 
of the various appendages and by the external 
spine of the uropods being black instead of 
brown. It is interesting that the variations 
noted above are sufficient to bridge these dif- 
ferences. Coutiere (1905) described C. gracilis 
var. alluaudi from Mahe which was distin- 
guished from the main species by the lack of 
a secondary unguis, and on all other points 
”ces specimens me paraissent impossibles a 
distinguer de V A. gracilis!' One is at a loss to 
know whether the specimens were exactly 
like Heller’s erroneous description, therefore 
different from the type specimen, or exactly 
like the type specimen. 
The Hawaiian form here described is dis- 
tinguished from the original species and from 
