CLIPPERTON ISLAND DECAPODS—CHACE 619 
“correction” of Say’s description of the cheliped of C. major: “what 
he calls first joint of the hand is really the carpus; his carpus [merus] 
is the third joint or segment, and so on.” Gibbes’s reference to 
“distant granules” on the lower edge of the ischium could hardly be 
applied to the long, prominent spines on that segment in Balss’s 
specimen. Hult’s understandable difficulty in reconciling the charac- 
ters cited by Schmitt (1935) with Balss’s description and figure was 
caused by the inadvertent transposition of the names in the last 
couplet of the key; it will be seen that the characters given in the first 
half of that couplet for C. longiventris agree with those given by Balss. 
De Man noted the similarity between C. placida and C. coutierei 
Nobili, but the different form of the eyes is probably sufficient to 
distinguish the latter species. 
The telson shows considerable variation in the six Clipperton 
specimens. The non-ovigerous female with a carapace length of 9.0 
mm. has the posterior margin very like that in the specimen figured by 
De Man, sinuously transverse with the median lobe extending slightly 
beyond the posterolateral lobes. In all of the other specimens, the 
posterolateral lobes distinctly surpass the median lobe, so that the 
margin is sinuously concave; in the male and the largest ovigerous 
female, the median lobe is obsolescent, so that the margin is deeply 
and almost regularly concave. 
DistRIBUTION: Otherwise known from the East Indies (Savu and 
Obi Major), Hawaiian Islands, Galapagos Islands (?), and West Indies 
(Jamaica) (?). 
Family Porcellanidae 
Pachycheles biocellatus (Lockington) 
Petrolisthes (Pisosoma) biocellatus Lockington, 1878, p. 403. 
Pisosoma aphrodita Boone, 19382, p. 53, fig. 17. 
Pachycheles biocellatus Glassell, 1937a, p. 84.—Schmitt, 1939, p. 16.—Haig, 1960, 
p. 144, pl. 32, fig. 1. 
MavreriAut: Northwest shore, rocks south of landing place; July 
21, 1938; Sta. 9; W. L. Schmitt; 11 males, 8 ovigerous females.— 
Northeast transect, 36 feet; August 27, 1958; Chess and Hambly; 1 
ovigerous female.—Northeast transect, 78 feet; August 27, 1958; 
C. Limbaugh; 1 male, 1 ovigerous female.—Northeast side, 45 feet; 
August 28, 1958; Limbaugh, Chess, and Hambly; 7 males, 4 females 
(3 ovigerous).—Northeast corner; August 29, 1958; C. Limbaugh; 1 
ovigerous female.—Northeast corner, 45 feet; August 30, 1958; 
Limbaugh, Chess, and Hambly; 2 ovigerous females.—Coral reef, 
intertidal; August 1958; E. S. Reese; 2 males.—Coral at 20 to 40 feet; 
August 1958; Allison and Limbaugh; 1 ovigerous female.—Kast side, 
reef flat, margin or ridge, 0-2 feet; September 14, 1958; Limbaugh and 
Chess; 2 males, 1 ovigerous female. 
