36 . 
Geryon quinquedens, S. I. Smith. 
1879. Geryon quinquedens, S. I. Smith, Trans. Connect. Acad., 
Vol._V.,.Pt: I, p. 35, Plig, figs. 2 la, a2. 
1881. Geryon quinquedens, S. I. Smith, Pr. U.S. Mus., Vol. 
LORS poly 
1882. Geryon quinquedens (? part), S. I. Smith, Bull. Mus. 
Comp. Zoél., Harvard, Vol. X., p. 6. 
1886. Geryon quinquedens, S. I. Smith, Rep. U.S. Fish. Comm., 
for 1885, p. (27). 
1894. Geryon quinquedens, A. Milne-Edwards and Bouvier, 
Crust. Decap. de l’Hirondelle, Camp. Sci. Prince 
de Monaco, fasc. 7, p. 41, figs. B.D. in text. 
1900. Geryon quinquedens, M. J. Rathbun, American Naturalist, 
Vol. XXXIV., No. 403, p..586, figs an text. 
The species is distinguished from G. affinis by smaller size, 
and by the absence of the marked dorsal and ventral channel- 
ling of the fingers, which the latter species exhibits in the walk- 
ing legs. Milne-Edwards and Bouvier further say that in 
G. quinquedens the third, fourth, and fifth segments of the pleon 
in the male have a tendency to coalescence. That is not borne 
out by the two specimens of that sex from South Africa. The 
South African specimens show the obtuse tubercle at the base 
of the finger of the larger cheliped, which Smith mentions, but 
which is not mentioned or figured in regard to G. affints. In 
our specimens there is a fine dorsal denticulation on the fourth, 
fifth, and proximal part of the sixth joints of the walking legs. 
Between the right and left chelipeds the hands show little 
difference as to length or breadth, but the right one is the 
thicker. 
In the largest male the length along the middle of the cara- 
pace, therefore not including the frontal teeth, is 53 mm., the 
breadth between the apices of the hindmost teeth of the antero- 
lateral margins 66mm. The length of the nght hand is 43 mm. 
In the largest female the corresponding measurements are 
60 mm., 66 mm., 38 mm._ S. I. Smith records a series of male 
specimens in which the length of the carapace varies by succes- 
sive increments from 30 to 130 mm., the largest intervals being 
between those which measured respectively 54 and 81, and 94 
and 116mm. _ The breadth varied from 37 to 152 mm. Milne- 
Edwards and Bouvier give for G. affinis a length of the carapace 
reaching 133 mm., by a breadth (apparently without the lateral 
spines) of 153 mm. Thus, either the size cannot be relied on 
for distinguishing G. affinis from G. guinquedens, or Professor 
Smith has included both species under one name. Between 
these alternatives the greater probability seems to he with the 
