620 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 113 
MEASUREMENTS: Carapaces of males 3.2 mm. long and 3.2 mm. 
wide to 7.0 mm. long and 7.2 mm. wide, of female without eggs 3.3 mm. 
long and 3.3 mm. wide, of ovigerous females 3.5 mm. long and 3.6 mm. 
wide to 6.8 mm. long and 7.3 mm. wide. 
Remarks: Itwill be noted that all 18 females with carapace lengths 
and widths greater than 3.3 mm. were ovigerous, whether collected in 
July, August, or September. All but one of the specimens collected 
in 1958 still retain enough of the original color to show the character- 
istic white spot on each anterolateral angle of the carapace; the 
exception apparently had the carapace uniformly red everywhere. 
DistrisuTion: Otherwise known from the Gulf of California to 
Ecuador and Isabel, Tres Marias, Revilla Gigedo, and Galapagos 
Islands. 
Petrolisthes haigae, new species 
FicureE 1 
Petrolisthes galathinus Boone, 1932, p. 45 (not fig. 13).—-? Hult, 1938, p. 10. Not 
Porcellana galathina Bosc, 1801. 
Petrolisthes marginatus Schmitt, 1939, p. 16—Hertlein and Emerson, 1957, 
p. 5.—Haig, 1960, p. 47 (part), pl. 20, fig. 1. Not P. marginatus Stimpson, 
1859. 
Marertat: Northeast shore, rocks south of landing place; July 
21, 1938; Sta. 9; W. L. Schmitt; 6 males, 12 females (10 ovigerous).— 
October 1956; C. Limbaugh; 6 males, 2 females.—Northwest end, 
reef; August 14, 1958; Sta. W58-288; Reese, Baldwin, and Winter- 
steen; 2 females (1 ovigerous)—KEast end, coral reef; August 15, 
1958; Sta. W58-289; Reese, Baldwin, and Wintersteen; 3 males, 1 
ovigerous female [1 male is holotype, USNM 107840].—Northeast side, 
45 feet; August 28, 1958; Limbaugh, Chess, and Hambly; 5 males, 5 
females (1 ovigerous).—Northeast side, low intertidal to 6 feet; 
September 4, 1958; Limbaugh, Chess and Hambly; 2 males.—EKast 
side, reef flat, margin or ridge, 0-2 feet; September 14, 1958; Lim- 
baugh and Chess; 1 male.—Northeast side, 50-60 feet; September 
20, 1958; C. Limbaugh; 1 female. 
Description: Carapace longer than wide, except in largest speci- 
mens. Surface pubescent and without rugae, except for usual ridge 
across anterior gastric region and inconspicuous lines on lateral 
branchial regions. A single, sharp epibranchial spine on each side. 
No supraocular spines. Front sinuously triangular with crenulate 
margin. Lateral wall of carapace entire and provided with three or 
four strong, longitudinal carinae. 
Chelipeds slightly unequal, similar. Merus with inner lobe tri- 
angular; a single, sharp spine on distal dorsal margin and a second, 
