Crustacea Decapoda and Stomatopoda. 291 



produced to a tooth at its infero-external angle. The antennal scale is nearly three 

 times as long as wide and its outer margin is very slightly concave. 



The second maxiUipedes are remarkable for the possession of a large protruding 

 lobe, quadrate in outhne, at the proximal end of the propodite. The third maxiUi- 

 pedes reach to the end of the antennal scale, the exopod extending beyond the end of 

 the antepenultimate segment. 



In the first peraeopods (text-fig. 126) the carpus is equal in length with the palm and 

 its greatest breadth is about two-thirds its extreme length ; anteriorly it is very deeply 

 hollowed to receive the rounded proximal end of the chela. The second peraeopods 

 (text-fig. 12c) are long and slender, reaching a httle beyond the end of the scale. The 

 carpus is about one and a third times the length of the chela and is between 5^ and 6 

 times as long as its greatest breadth. The palm is two-thirds the length of the 

 dactylus. In the third peraeopods (text-figs. i2d, e) the merus bears four spines on its 

 lower margin and the carpus one near its distal end. The propodus is provided with a 

 series of spinules on the same margin ; it is about 8 times as long as broad and rather 

 more than 3J times as long as the dactylus (terminal spine included). The dactylus 

 bears in aU 5 or 6 spines, the outermost large and strongly curved. The fifth 

 peraeopods (text-figs. 12/, g) bear spines on the merus, carpus and propodus, much as 

 in the case of the third pair. The propodus is from 11 to 13I times as long as broad and 

 from 4 to 4J times the total length of the dactylus. The latter segment bears from 29 

 to 34 slender spines ; excluding these its length is a trifle more than three times its 

 breadth. 



The outer uropod is provided with a series of from 18 to 21 movable spinules. 



Well-grown specimens reach a length of about 17 mm. The eggs are large 

 and few in number : about O'qô mm. by 070 mm. in longer and shorter diameter. 



Caridina serrata is allied to C. parvirostris, de Man, and C. pareparensis, de Man, but 

 differs from both in the much greater proportionate length of the lateral process of the 

 antennular peduncle. In addition it differs from C. parvirostris in the large size of the 

 eggs and from C. pareparensis in the more deeply excavate carpus of the first pair of 

 legs. In Bouvier' s latest scheme of classification (1913) it would come nearest to 

 C. serratirostris, de Man, which it resembles in the length of the lateral process of the 

 antennule. From this species, however, it differs in many respects, notably in the 

 length and dentition of the rostrum and the form of the carpus in the first pair of 

 legs. 



Dr. Annandale informs me that, in life, the specimens were mottled with brown- 

 ish pigment and were consequently very difficult to detect on the rocks on which they 

 commonly sat. They were found in pools in very small streamlets of clear water, 

 devoid of weeds, on the Peak at Hong Kong, at altitudes of 1200-1500 ft. The 

 specimens were collected in September, three of the females being ovigerous. Two 

 additional specimens from the same locality, collected by Capt. F. H.Stewart, I. M.S., 

 have recently been presented to the Museum. 



Stimpson gives the habitat of his specimens as "ad insulam Hong Kong ; in 

 rivulis." 



