192 DR. W. 'T. CALMAN ON THE MACRUROUS [Mar. 6, 



is " slightly excavated distally on the inner side." While this is 

 quite correct and holds good also for the new species described 

 below, it should be pointed out that this very slight excavation, 

 not visible from the outer side, is very different from the marked 

 excavation of the anterioi" margin of the carpiis found in most of 

 the species, at least, of the allied genera. Since, however, the 

 excavation is about equally slight in some of the species of 

 Caridina, it does not seem advisable to include this character in 

 the generic definition. In all cases the terminal brushes of seise 

 on the fingers of the chelte are more scanty than in any species 

 of Caridina which I have seen. 



Key to the Species of Limnocaridina. 



A. Fingers of chelaj five to seven times as long as tlie 



palm, with very long marginal seta. 



a. Rostrum about equal to antennular peduncle J>. retiarius, n. sp. 



b. Rostrum less than half as long as first segment of 



antennular peduncle L. •parvula, n. sp. 



B. Fingers of clielaj not more than twice as long as the 



palm ; setae not very long, confined to distal part. 



a. Length of sixth abdominal somite more than twice 



its depth. 

 a. Rostrum much longer than the carapace, with 



10-20 teeth below i. tanganyikce Caiman. 



h. Rostrum about equal to carapace, with 3-6 teeth 



below i. similis, n. sp. 



c. Rostrum less than one-third of length of carapace, 



unarmed below L. Iatij)es, n. sp. 



b. Length of sixth abdominal somite little more than 



one and a half times its depth. 

 a. Rostrum nearly equal to carapace; merus of last 



three legs with one spine L. socius, n. sp. 



I. Rostrum little more than half length of carapace ; 



merus of last three legs with 2-3 spines JD. spinipes, n. sp. 



Limnocaridina retiarius, n. sp. (Plate XI. figs. 2-8.) 



Description. — Body slender; sixth somite of abdomen a little 

 shorter than the carapace, length more than two and a half times 

 its depth. Rostrum (Plate XI. fig. 2) about equal to or a 

 little shorter than antennular peduncle, two-thirds as long as 

 carapace, decurved at base, then horizontal or slightly recurved 

 towards tip, teeth "' J^.3 — , unarmed above for nearly half its 

 length from tip. Antero-lateral spine of carapace set well back 

 from front edge. Antennular peduncle reaching to external 

 tooth of antennal scale. Distal edge of scale (Plate XI. fig. 3) 

 projecting beyond external tooth. Third maxilliped extending 

 to end of second segment of antennular peduncle, exopod not 

 longer than ischium, terminal segment slender biit a little shorter 

 than preceding segment. First per^eopods (Plate XI. fig. 4) 

 reaching to tip of third maxillipeds, breadth of carpus two-thirds 

 of its length, chela about three times as long as carpus, palmar 

 portion less than one-fifth of leng-th of fingers. Second perfeopods 

 (Plate XI. fig. 5) reaching a little beyond first, breadth of carpus 

 little more than two-fifths of its length ; chela a little more 



