8 CEYLON PEARL OYSTER REPORT. 



ISOPODA GENUINA. 



Tribe : FLABELLIFERA. 



Family : ANTHURID^E. 



Calathura, Norman and Stebbing. 



1886, Calathura, Norman and Stebbing, 'Trans. Zool. Soc.,' London, vol. 12, pt. 4, p. 122. 

 1897, Calathura, Sars, 'Crustacea of Norway,' vol. 2, p. 44. 



1901, Calathura, Whitelegge, ' Mem. Australian Mus.,' vol. 4, pt. 2, p. 225. 

 1901, Calathura, H. Richardson, ' Proo. U.S. Mus.,' vol. 23, p. 509. 



To the species Calathura brachiata (Stimpson) Sars has added his C. nor neglect, 

 Whitelegge his C. gigas, and Miss Richardson her C. crenulata. Bonnier's 

 C. affinis (1896) seems rather to belong to Paranthura. 



Calathura, sp. 



Two specimens occur in the collection, one from weed-bearing oysters off south-east 

 of Modragam Paar, the other from north end of Chilaw Paar, February 2, 1902, 



9 to 11 fathoms. Both have dark eyes. The former is about 14 millims. in length, 

 the latter about 9 millims. They may be the species which Haswell has described 

 in 'Proc. Linn. Soc. N. S. Wales,' vol. 5, p. 478, plate 10, fig. 5, 1881, as 

 Paranthura (?) crassicornis, sp. nov. The Australian Anthuridse will no doubt before 

 long be more fully described, and I have therefore left over these specimens till a 

 more favourable opportunity offers for their specific identification. 



Family : GNATHIID,F. 



Gnathia, Leach. 



1814, Gnathia, Leach, ' Edinb. Encycl.,' vol. 7, p. 402. 



1835, Gnathia, Westwood, Loudon's 'Mag. Nat. Hist.,' vol. 8, p. 273. 



1885, Anceus, Haswell, 'Proc. Linn. Soc. N. S. Wales,' vol. 9, pt. 4, p. 1005. 



1887, Anceus, H. J. Hansen, ' Dijmphna-Togtets Krebsdyr,' p. 205. 

 1896, Gnathia, Bonnier, 'Ann. Univ. Lyon,' vol. 26, p. 571. 



1900, Gnathia, Stebbing, in Willey's ' Zoological Results,' pt. 5, p. 625. 



1901, Gnathia, Ohlin, 'Bihang K. Svenska Vet.-Akad. Handlingar,' vol. 26, No. 12, p. 20. 



1902, Gnathia, Hodgson, 'Nat. Hist, of the "Southern Cross,'" p. 241. 



The references here given are supplementary to the much longer list supplied in 

 Willey's ' Zoological Results.' As the material in the present collection is limited to 

 a single small specimen, it would not be a suitable opportunity for an extended 

 review of the genus. Especial attention, however, should be directed to (inathia 

 ferox (Haswell), since it is evidently a near ally of the species about to be described. 

 The details of the mandibles are similar in the two, but by the relative size and 

 position of these features the appendages in question are strongly distinguished. 

 The maxillipeds and first gnathopods of G. ferox are as yet undescribed. It is not 



