STEBBING— ISOPODA 91 



Gen. GYATHURA, Norman and Stebbing. 



188b". Cyathura, Norman and Stebbing, Trans. Zool. Soc. London, vol. xii., pt. 4, 

 p. 121. 



1904. Cyathura, Stebbing, Spolia Zeylanica, vol. ii., pt. 5, p. 9. 



5. Cyathura pusilla ? juv. Stebbing. 



1 904. Cyathura pusilla, Stebbing, Spolia Zeylanica, vol. ii., pt. 5, p. 9, pi. 6 B. 



A specimen, measuring only 3 mm. in length, obtained by Mr Crossland at Wasin 

 from ten fatboms depth, fairly agrees with the Ceylon species, except that it has evident 

 dark eyes. It exhibits the organs near the base of the telson described by Thienemann as 

 statocysts (Zool. Anzeig., vol. xxvi., p. 406, tigs. 1, 2, 1903). It has, I think, been already 

 pointed out that the species to which they are attributed is not really Anthura gracilis 

 (Montagu). In re-examining Cyathura pxisilla from Ceylon, I find that the dissected 

 specimen now shows them very conspicuously, in full agreement with Thienemann's 

 illustration. 



Gen. GALATHURA, Norman and Stebbing. 



1886. Calathura, Norman and Stebbing, Trans. Zool. Soc. London, vol. xii., pt. 4, 

 p. 122. 



1887. Calathura, H. J. Hansen, Vidensk. Meddel., p. 181. 

 1897. Calathura, Sars, Crustacea of Norway, vol. ii., pt. 3, p. 44. 



1900. Calathura, Stebbing, Ann. Nat. Hist., ser. 7, vol. v., p. 13. 



1901. Calathura, Whitelegge, Mem. Australian Mus., vol. iv., pt. 3, p. 225. 

 1901. Calathura, H. Richardson, Proc. U.S. Nat. Mus., vol. xxiii., p. 509. 



1901. Calathura, Ohlin, Bihang till K. Svenska Vet. Akad. Handl., vol. xxvi., No. 12, 

 p. 17. 



1904. Calathura, Stebbing, Gardiner's Maldive and Laccadive Arch., vol. iv., pt. 3, 

 p. 700. 



1905. Calathura, H. Richardson, Bull. U.S. Nat. Mus., No. 54, p. 71. 



To the four species of this genus which I distinguished in 1904 should have been 

 added the Australian C. gigas, Whitelegge, nearly the largest of all, since it attains a 

 length of 42 mm., while for its northern rival, C. brac/tiata (Stimpson), next to it in size, 

 the greatest length recorded by Hansen in 1887 was 40"5 mm., but in 1901 Ohlin met 

 with a specimen 43 mm. in length. Ohlin regards C. brac/u'ata as quite blind, and 

 Whitelegge says of C. gigas, "eyes undistinguishable, destitute of pigment." The new 

 species about to be described will not compete with either of these giants in size, and 

 its eyes are beyond dispute. By the shape and much greater length of the masculine 

 appendix in the second pleopods it is well separated from C. borradailei, and by the 

 acutely ending telson from C creuulata, Richardson, in which the telson is round-ended. 



6. Calathura sladeni, n. sp. (Plate 7 a.) 



The antero-lateral corners of the head are well rounded, the head itself about two- 

 thirds as long as the first segment of the perceon. The second segment of the pera?on is 

 elongate urn-shaped, with a tuft of setie at each front corner. The fourth, fifth and 



12—2 



