OCR Text |
Show 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 anterior margin of the carpus 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 setae on the fingers of the chelae are more scanty than in any species of Caridina, which I have seen. Key to the Species of Limnocaridina. A. Fingers of chelae five to seven times as long as the palm, with very long marginal setae. a. Rostrum about equal to antennular peduncle L. retiarius, n. sp. b. Rostrum less than half as long as first segment of antennular peduncle L. parvula, n. sp. B. Fingers of chela? 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 L. tanganyikce Caiman. b. Rostrum about equal to carapace, with 3-6 teeth below L. similis, n. sp. c. Rostrum less than one-third of length of carapace, unarmed below L. latipes, n. sp. b. Length of sixth abdominal somite little more than one and a half times its depth. a. Rostrum nearty equal to carapace; merus of last three legs with one spine L. socius, n. sp. b. Rostrum little more than half length of carapace; merus of last three legs with 2-3 spines L. spinipes, n. sp. LIMNOCARIDINA RETIARIUS, n. sp. (Plate XL 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 X L 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 Jg" -, 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 X L 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 but a little shorter than preceding segment. First peraeopods (Plate X L 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 length of fingers. Second peraeopods (Plate X L fig. 5) reaching a little beyond first, breadth of carpus little more than two-fifths of its length; chela a little more |