24 CEYLON PEARL OYSTER REPORT. 



1890, Rocinela, H. J. Hansen, 'Vid. Selsk. Skr.,' ser. 6, vol. 5, pp. 298, 316, 406. 

 1893, Rocinela, Stbbbing, 'History of Crustacea,' p. 34*. 



1896, Rocinela, Bonnier, " Edriophthalmes du 'Caudan,'" 'Ann. Univ. Lyon,' vol. 26, p. 578. 



1897, Rocinela, H. J. Hansen, ' Bull. Mus. Comp. Zool.,' vol. 31, p. 108. 



1898, Rocinela, H. Richardson, ' Proc. Amer. Philos. Soc.,' vol. 37, No. 157, p. 8. 



1899, Rocinela, Sars, 'Crustacea of Norway,' vol. 2, p. 65. 



1899, Rocinela, H. Richardson, 'Proc. U.S. Mus.,' vol. 21, p. 827. 



1900, Rocinela, H. Richardson, 'American Naturalist,' vol. 34, No. 399, p. 218. 



1901, Rocinela, H. Richardson, 'Proc. U.S. Mus.,' vol. 23, pp. 520, 523. 



1902, Rocinela, H. F. Moore, 'Bull. U.S. Fish Commission,' vol. 20 (for 1900), pt. 2, p. 171. 



1903, Rocinela, H. Richardson, 'Bull. U.S. Fish Comm. for 1903,' p. 49. 



1904, Rocinela, H. Richardson, 'Proc. U.S. Mus.,' vol. 27, p. 33. 



In 1898 Miss Harriet Richardson reckoned the then known species of this genus 

 at nineteen, of which she provided a useful analytic key. Bonnier's blind species, 

 R. typhlops, 1896, had probably at that time not come under her notice, as it is not 

 included in the list. On the other hand, one of the accepted nineteen is the 

 Tasmanian species which G. M. Thomson named R. spongicola in 1892 (1893). 

 Since this has about fourteen joints to the nagellum of the first antennae and a 

 distinct third joint to the maxillipeds, it should be transferred to the genus AZga. 

 In 1899 Miss Richardson made R. alashensis (Lockington) a synonym of 

 R. belliceps, which Stimpson had assigned to the genus ASga. In 1903 she described 

 R. hawaiiensis as a new species, near to R. orientalis, and in 1904 established a new 

 species, R. affinis, near to Harger's R. oculata, and gave the name R. angustata to a 

 form which she had previously supposed identical with Hansen's R. laticauda. In 

 1902 Lanchester instituted R. mundana ('Proc. Zool. Soc. London,' p. 378, pi. 35, 

 figs. 9-9). 



Rocinela orientalis, Schiodte and Meinert. Plate VI. (C). 



1879, Rocinela orientalis, Schiodte and Meinert, 'Naturhist. Tidsskr.,' ser. 3, vol. 12, pp. 383, 



395, pi. 13, figs. 1, 2. 

 1898, Rocinela orientalis, H. Richardson, ' Proc. Amer. Philos. Soc.,' vol. 37, No. 157, pp. 9, 1 1. 



This species belongs to a group distinguished by the Danish authors as having the 

 eyes clearly separated, the nagellum of the second antennte composed of fourteen to 

 sixteen joints, and the sixth joint in the first three pairs of trunk-limbs armed 

 with three or four spines. To distinguish it from its neighbours in this group, 

 Miss Richardson notes that the frontal margin is not produced as it is in R. dumerilii 

 (Lucas), and that, whereas Schiodte and Meinert's R. maculata and R. americana 

 have the telsonic segment " linguate," and both branches of the uropods crenulate on 

 their exterior margins, in the present species the telsonic segment is subtriangular 

 and the branches of the uropods are not crenulate on their exterior margins. The 

 Danish authors mention the crenulation in the two former species, but neither deny 

 nor affirm it in regard to R. orientalis, the telsonic segment of which they describe as 

 subtriangular, with rounded sides, a phraseology quite as applicable to their figures of 



