CEYLON ALPHEID, 185 
In A. strenuus a line joining the two palmar ridges of the large 
claw divides the hand into two equal parts. In A. audowini the 
distal portion of the hand is comparatively shorter, and such a line 
divides the hand in the proportions of 6: 5. 
The second pereiopod shows a difference in the proportions of 
the first and second parts of the carpos in the two forms. In A. 
strenuus the first segment is only slightly longer than the second 
(1°12: 1). In A. audowin the proportion is 1°6: 1. 
The third pereiopod of the present species is not so robust as in 
A. strenuus, and the propodite does not bear so many spines. 
The following are the dimensions of this form :— 
Ot OO fry, (ih Meh) Games 
bu] mm. b= 262; mm. 
O22 olomm. Gy ==) Feb mia. 
6? = 2:3 mm. e' = 4:0 mm. 
b2 = 2 -62).mm. e2 = 3°5 mm. 

b> — 1-6 mm. | 
Dimensions of second pereiopod :— 
t = 2541; 462 c* = 396; 363 
m = 2640; 462 ce = 693; 396 
G — 1584; 363 p = 1452; 429 
c2 = 990; 363 d = 825; 198 
c8 = 495; 363 
Dimensions of third pereiopod :— 
m = 3300; 627 | p = 2442; 363 
c. = 1914; 396 | d = 1023; 165 
General Distribution.—Indo-Pacific. 
ALPHEUS STRENUUS, Dana. 
(Plate VII., Fig. 6.) 
A. strenuus, Dana. U.S. Expl. Exped., 1852. 
A. strenuus, Coutiére. Fauna of Mald. and Lacc., 1906. 
Localities.—One specimen, from Weligama ; November, 1905. 
One specimen, from the Pearl Banks ; February, 1911. 
Five specimens, from Mandativu, Jafina; July, 1903. 
One specimen, from Nachchikuda, Tamblegam ; September, 1908. 
Six specimens, from Delft ; June, 1903. 
Nine specimens, from Kapalturai, Tamblegam ; October, 1907. 
This is a fairly common form, and is the largest of all the Ceylon 
Alpheids. It is closely related to A. edwardsi and A. audouini, 
but differs from them both in the relative lengths of the second and 
third antennular articles. The second article is twice as long as the 
third, and the first article is intermediate in size. The antennular 
scale reaches to the extremity of the first article. The antennal 
peduncle is longer than that of the antennule. The spine of the 
2B 6(11)11 
