724 ME. W. E. LANCHESTER ON CRUSTACEANS [June 19 



10. Hyastenus oryx A. M.-Edw. 



Hyastenus oryx, A. M.-Edw. Nouv. Arch. Mus. t. viii. p. 250, 

 pi. xiv. f. 1 (1872) ; Hasw. Cat. Austr. Crust, p. 20 (1882) ; 

 Walker, Journ. Linn. Soc, Zool. vol. xx. p. 109 (1887). 



Hob. Singapore ; littoral. Two males and two females, one 

 with ova. 



Dim. 6*5-75x9. 8 4-5x7. $6-5x10-5. $5-25x8. 



11. Hyastenus planasius Ad. & White. 



Pisa planasia, Ad. & White, ' Samarang ' Crust, p. 9, pi. ii. 

 ff. 4, 5 (1848). 



Hyagtenus planasius, A. M.-Edw. Nouv. Arch. Mus. t. viii. 

 p. 250 (1872); Walker, Journ. linn. Soc., Zool. vol. xx. p. 109 

 (1887). 



Hob. Singapore ; 2-3 fins. A female and two males. 



On two of these is found a species of Tubularia, fixed to the 

 upper and outer margins of the ambulatory legs. 



Dim. 8 8-75x12-5. 8 6x9. $ 12-5x17-5. 



IX. Genus Chlorinoides Haswell. 



12. Chlorinoides aculeatus M.-Edw. 



Chorina aculeate, M.-Edw. Hist. Nat. Crust, t. i. p. 316 

 (1834). 



Paramithrax (Chlorinoides) aculeatus,\ar. armatus, Miers, ' Alert ' 

 Crust, p. 193, pi. xviii. i. A (1884). 



Chlorinoides aculeatus, Henderson, Trans. Linn. Soc, Zool. vol. v. 

 p. 345 (1893). 



Hab. Singapore and Malacca ; 10-18 fms. Hough bottom. 



One large and one small male from Singapore ; and two smaller 

 males from Malacca, in which the spines of the carapace and 

 meropodites are relatively less developed. 



Mr. Miers's variety armatus is founded on — (a) a small tooth-like 

 expansion on the posterior margin of the postocular spine, and 

 (6) the " existence (usually) of two spines at the distal ends of the 

 merus-joiuts of the ambulatory legs " (t. c). As regards (b), 

 M. -Edwards describes the ambulatory legs as " garnies i'une forte 

 epine a l'extremite des troisiume et quatrieme articles " ; and 

 Mr. Miers's two spines are not invariably found. In my specimens, 

 the larger male from Singapore has the second spine well deve- 

 loped, the smaller male very much less so. In the two still smaller 

 males from Malacca the second spine is absent, though the post- 

 ocular tooth still bears a small tooth on its posterior margin. I 

 hardly think the slight difference in the postocular tooth is sufficient 

 to admit of accepting a distinct variety. 



Prof. Henderson points out the similarity between the post- 

 ocular tooth of var. armatus and that of a form figured by 

 de Haan as Maia (Chorinus) aculeata j but the arrangement of the 

 dorsal spines in this figure show that it is wrongly referred to 



