18(i8.] MR. C. SPENCE BATE O.N NEW FRESHWATER PRAWNS. 365 



pair of pereiopoda half as long again as the animal, having the carpus 

 longer than the meros and as long as the propodos, excepting the 

 digital process ; digital process curved slightly inwards, fringed 

 with a vow of hairs, and furnished with two dental tubercles within 

 the centre. Dactyhis curved ; the apex crossing the extremity of 

 the digital process of the propodos, and impinging against it through 

 the entire length, fringed with a row of hairs and with a single tu- 

 bercle. The entire appendage covered with small, yellow, trans- 

 parent, spinous denticles. Last three pairs of pereiopoda mode- 

 rately robust, and furnished with numerous small denticles along 

 the inferior margin. Posterior pair of pleopoda roughened with 

 small spines, as also the telson, which carries a small fasciculus of 

 hairs near the base, and two small sublateral spines beyond the 

 middle. 



The length of this species is about 4 inches. It has recently been 

 taken and brought home by Dr. Colliugwood, who procured it from 

 the River Tamsuy, in the Island of Formosa. 



Macrobrachium gangeticum, sp. nov. (The Chingra.) 



This species appears closely to resemble the preceding. I only 

 know it through a drawing given to me by the late Colonel Hamilton 

 Smith, who obtained it from a friend at Patna, a distance of 250 

 miles from Calcutta, where it was used as food, and was known 

 under the name of " Chingra," the Hindostanee, I believe of 

 " shrimp." Its length is about 6 inches, and the colour a bluish grey. 



Macrobrachium longidigitum, sp. nov. (Plate XXXI. fig. 2.) 



Carapace, including rostrum, nearly half as long as the animal. 

 Rostrum about half as long as the carapace ; upper surface armed 

 with eight teeth, two only of which are behind the orbital margin. 

 The teeth are widely separated from each other, and a few hairs 

 are situated immediately anterior to each denticle. The lower mar- 

 gin armed with five teeth and a copious fringe of hair. 



First pair of antennae having the peduncle one-third shorter than 

 the rostrum, the first joint of which is about half the length of the 

 peduncle, concave upon the upper surface, and armed with a sharp 

 distal tooth on the outer angle, and without conspicuous cilia along 

 the margin. The smallest branch of the flagella attached to the 

 largest for about one-fourth of an inch from the base. Second pair 

 of antennae as long as the animal, the peduncle being about half the 

 length of the peduucle of the upper pair. Squamiform appendage 

 not reaching to the extremity of the rostrum, and armed subapically 

 with a small, sharp tooth, that does not reach beyond the cilia that 

 thickly fringe the distal and internal margin. 



First pair of pereiopoda long and slender, having the carpus longer 

 than the meros, and three times as long as the propodos. Second 

 pair of pereiopoda not quite as long as the animal, having the carpus 

 a little longer than the meros, and the propodos, inclusive of the 

 digital process, as long again as the carpus, the dactylus being half 

 the length of the propodos, being pointed and curved at the apex, 



