366 MR. C. SPENCE BATE ON NEW FRESHWATER PRAWNS. [JMaV 28, 



crossing when impinged against the curved margins of the digital 

 process of the propodos, the entire appendage heing thickly studded 

 with small tubercles that appear generally to be ranged in longi- 

 tudinal rows, of which those on the inner and lower sides are con- 

 siderably the more prominent. Last three pairs of pereiopoda 

 moderately robust, and furnished on the posterior margin of the 

 propodos with a few equidistant solitary spines, and interspaced with 

 hairs. Posterior pair of pleopoda having the denticle of the ex- 

 ternal plate not produced beyond the margin of the distal articula- 

 tion. Telson smooth, slightly compressed, furnished with a depres- 

 sion and small fasciculus of hairs near the base, and two sublateral 

 spines on each side beyond the middle. 



The length of this species is about 5 inches. It has been in the 

 collection of the Plymouth Athenfeum for many years ; but no 

 habitat is recorded with it. 



Macrobrachium africanum. (Plate XXXI. fig. 3.) 



Carapace half the length of the animal, rostrum depressed ; apex 

 slightly elevated, surmounted by nine small teeth, of which the an- 

 terior are the smaller, and only the posterior one behind the orbital 

 arch ; the interspaces furnished with short, stout cilia on the under- 

 side of the rostrum ; near the apex are three small teeth ; at the 

 inferior angle of the orbit is a small, sharp tooth, between which 

 and the infero-anterior angle of the carapace is a suture that passes 

 to a considerable depth into the carapace, but its limit is not defined 

 by a spine as is very generally the case in this genus. The superior 

 antennse have the peduncle nearly as long again as the rostrum, 

 having the first joint as long as the other two, concave upon the 

 npper surface, and produced into a strong spine upon the outer distal 

 extremity. The smallest flagcllum united with the largest to about 

 one-eighth of an inch from the base. Inferior antennae one-fourth 

 longer" than the animal ; squamous process internally distended near 

 the middle, receding towards the apex, which reaches nearly for one- 

 half its length beyond the peduncle of the superior antennae, and 

 subapically armed with a tooth on the upper and outer side. First 

 pair of pereiopoda are slender, and have the carpus longer than the 

 meros, and four or five times as long as the propodos. Second pair 

 of pereiopoda unequal, the right being considerably more long and 

 robust than the left ; but otherwise they resemble each other. The 

 right leg as long as the animal, the left about one-third shorter ; car- 

 pus about half the length of the propodos, minus the digital process, 

 in the right, but nearly as long as the propodos in the left. Meros 

 longer than the carpus, and both right and left thickly covered with 

 sharp anteriorly directed spinous tubercles. Dactylus and digital 

 process long and slender, armed at the extremity with a distinct 

 spine, and along the inner margins with three corresponding tuber- 

 cles. Posterior three pairs of pereiopoda robust, and furnished 

 with numerous small spines on the dactylus and posterior margin 

 of the propodos. Posterior pair of pleopoda having the articulation 

 of the outer plate waved, and the denticulated jjrocess continuous 



