74 



ZOOLOGY OF THE FAR EAST. 



Family ATYIDAE. 

 Genus Caridina, Milne-Edwards. 

 All the species recorded below possess epipods at the base of the first four 

 peraeopods and a gill-formula which is apparently the same as that given for the genus 

 by Caiman and Bouvier.' 



Caridina propinqua, de Man. 



1908. Caridina propinqua, de Man, Rec. Ind. Mus., II, p. 227, pi. xix, figs. 6, 6.1-/. 

 1913. Caridina propinqua, Bouvier, Trans. Linn. Soc. Zool. (2), XV, p. 463. 

 1915. Caridina propinqua, Kemp, Mem. Ind. Mus., V, p. 309. 



The specimens agree closely with those from the neighbourhood of Calcutta. In 

 young individuals the rostrum extends little, if at all, beyond the end of the basal 

 segment of the antennular peduncle, whereas in adults it almost or quite reaches the 

 end of the second segment. On the upper border there are from 11 to 20 teeth,' of 

 which from 2 to 4 (usually 3 or 4) are situated on the carapace. On the lower border 

 there are from o to 4 teeth (usually 2). 



The carpus of the first peraeopods is from 2-8 to 3-2 times as long as broad. In 

 the third pair the propodus is from 27 to 3-2 times the length of the dactylus ; the latter 

 segment is slender and is armed with 6 or 7 spines, the terminal claw included. The 

 propodus of the fifth peraeopod is from 2-4 to 2-8 times the length of the dactylus, the 

 latter segment bearing from 43 to 55 spinules. There are from 11 to 16 movable spines 

 on the outer uropod. 



The eggs are from 0-64 mm. in length by 039 mm. in breadth, when freshly ex- 

 truded, to 070 mm. in length by 0-44 mm. in breadth, when on the point of hatching. 

 Ovigerous females vary greatly in size, being from 12 to 20 mm. in total length. 



Dr. Annandale found Caridina propinqiia in abundance in the Tale Sap in January 

 and February, 1916. It occurred among weeds in all parts of the lake, both in the 

 inner portion where the water is in all probability fresh throughout the year and in the 

 outer lake near the island of Koh Yaw in water of low sahnity. There are also numer- 

 ous specimens in the collection from the Patani River, below the town of Patani in 

 the Siamese Malay States. The water in this locality, though fresh at the time the 

 specimens were obtained, is subject to tidal influence. 



1 Bouvier, Ann. Set. France Belgique, XXXIX, p. 68 (1905). 



2 In fifty specimens the numbers o£ rostral teeth are as follows: — 



Dorsal teeth. 

 2 specimens have 1 1 teeth. 



.. 13 



,, 14 



.. 15 



,, 16 



,, 17 



6 ' ,, „ 18 



3 .. ,. 19 



Ventral teeth. 



I specimen has no tooth. 



6 specimens have i ,, 

 30 ,, ,,2 teeth. 



12 ,, ,, 3 ,, 



I specimen has 4 ,, 



