2 ^ SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. qS 
than in groove slight or wanting. Anterior margin of epistome armed 
with three spines, median and pair of laterals. 
B\ Groove very short, inconspicuous, scarcely a sixth of the length of the 
upper margin of p^lm or less planissimum (Herbst)." 
(Naturges. Krabben u. Krebse, vol. 3, pt. 4, p. 3 ^ P^- 59 - hg- 1804. 
Alcock, Journ. xVsiatic Soc. Bengal, vol. 69, p. 439 i IQOO-) 
Bl Groove longer, about a third (from a fourth to a half) the length of the 
upper margin of the palm gibbcsi Milne-Edwards. 
(Ann. Sci Nat., ser. 3, Zook, vol. 20, pp. 180, 146, 1853. Rathbun, 
Bull. 97 , U- S. Nat. Mus., p. 337 , pl- 105, 1918.) 
Gccorcinus planafus Stinipson 
One of the few land crabs seen. In former years this species was 
exceedingly abundant on Clipj^erton. It is possible that the diove of 
wild pigs loose on the island has so reduced tbeii nuinbeis that they 
now seem scarce. 
Sulivan Bay, James Island, Galapagos, July 24 (sta. 15-38) i 
shore and tide-pool collecting. 
LepeophtheirHS dissuiiulcitus Wilson 5 ? 
Crangon cylindricus Kingsley ^ 
Crangon inaUeator (Dana) ^ 
Svnalpheus nobdi Coutiere 3 
One of three specimens assigned to this species is but tentatively 
placed here. In many respects it resembles a closely related species, 
S. sanliicasi. As it does not have the stout legs characteristic of that 
species, this specimen has been placed here as a variant peihaps of 
A. nobili. 
^ This species of Pcrcnon and the next are very close and very simdar. There 
is some variation in the length of the pilose groove of the upper margin of the 
hand. The characteristically short groove of planissimum holds for all speci- 
mens of more than three-fourths of an inch in width. In some smaller or im- 
mature specimens, chiefly females, the groove appears relatively longer ^ than 
in larger, better-developed individuals. Specific distinctions are best exhibited 
in well-developed males. 
There is another character not referred to iil the key that seems to hold for 
many specimens of either of these two species of Pcrcnon, but not for all unless 
I am mistaken in some of my identifications. In P. planissimum the teeth of 
the lateral margin of the carapace, at least those following the one at the antero- 
lateral angle, dre more or less subequal ; the second and third teeth, counting 
the extra orbital tooth, measured on their outer margins are about of equal 
length. In P. gibbcsi the outer margin of the second lateral tooth, counting th^ 
one at the anterolateral angle of the carapace, measured on the outer margin 
is in general or in many specimens appreciably a little shorter than the third-. 
