CLIPPERTON ISLAND DECAPODS—CHACE 611 
5 juveniles.—South shore, coral reef, sand; August 11, 1958; Sta. 
W58-285; Reese, Limbaugh, Baldwin, and Wintersteen; 2 males, 15 
females (8 ovigerous), 2 juveniles.—East end, coral reef; August 15, 
1958; Sta. W58-289; E. S. Reese; 39 males, 28 females (18 ovigerous), 
10 juveniles.—South shore, coral reef; August 19, 1958; Sta. W58-295; 
Reese, Baldwin, and Limbaugh; 11 males, 7 females (6 ovigerous).— 
Coral reef, intertidal; August 1958; E. S. Reese; 4 females (3 ovige- 
rous).—Northeast side, reef flat, low tide, 0-1 foot; collected with 
“Wndrin” insecticide; September 13, 1958; Limbaugh, Chess, and 
Hambly; 25 males, 39 females (34 ovigerous). 
MEASUREMENTS: Carapace lengths of males to base of rostrum 
3.6-12.5 mm.; of females without eggs, 3.8-7.8 mm.; of ovigerous 
females, 5.6-13.1 mm.; of juveniles, 2.2-3.5 mm. ‘Total length of 
largest male, about 37 mm.; of largest female, about 41.5 mm. 
Remarks: Males with carapace lengths ranging from 3.6 to 4.5 mm. 
have very smal] appendices masculinae. The smallest ovigerous 
female, with a carapace length of 5.6 mm., carries only two eggs, and 
all ovigerous females with carapace lengths of Jess than 7.1 mm., have 
few eggs. All 51 females with carapace lengths of more than 7.8 mm., 
are ovigerous, including those collected in August, September, and 
October. 
Most of the specimens, except the smallest and the largest, have a 
rather prominent, outstanding tooth on the outer surface of the major 
chela near the distal margin of the socket in the fixed finger. The 
few Hawaiian specimens of similar size that have been available for 
comparison also have this tooth, but it is obscure in the neotype. 
Two of the specimens in the present collection are so aberrant that 
they were first thought to represent a distinct species. One of them, 
a male with a carapace length of 8.6 mm., from Sta. W58-289, lacks 
a rostrum and has a very long and narrow major chela; the entire 
chela is more than two and a half times as long as broad, and the 
fingers are longer than the palm. The other, a male with a carapace 
length of 10.2 mm., from Sta. W58-295, has a normal rostrum but an 
even more elongate major chela; it is more than two and two-thirds 
times as long as broad, and the fingers are about as long as the palm. 
These two specimens fall within the normal limits of variation of 
A. pacificus in all other respects, however, so it is probable that they 
are merely abnormal specimens of that species, even though their 
correct identification would have been practically impossible had they 
not been associated with normal specimens. One of the ovigerous 
females taken on September 13, 1958, has two major chelipeds, the 
left slightly the larger. 
Disrrinution: Throughout the Indo-Pacific region from the Red 
Sea and Madagascar to Clipperton Island. 
