WILLEMOESIA INORNATA. 125 



by reference to the descriptions and figures of those species by Bute and 

 Smith. 



But an East Indian species, Polt/cheks bcaumotiiil* bears the closest like- 

 ness to P. (/ranuMiis. Indeed, the resemblance between these two forms 

 is so great that I am inclined to regard P. beaumontii as, at most, but a geo- 

 graphical race of P. gramihtus. P. beaumontii is known through a single male 

 specimen captured at a depth of 675 fathoms, off Colombo, Ceylon. I have 

 no doubt that its most striking peculiarity, viz. the absence of the usual in- 

 ternal lobe or " scale " of the basal segment of the antennule, is due to 

 malformation or mutilation. The other characters which distinguish this 

 species from P. grmmlatus are very slight : the number of lateral spines on 

 the carapace is 7 (or 8) — 3 — 13 in P. beaumontii, 9 (or 10) — 3 — 15 in 

 P. granuMus ; the ophthalmic sinuses are a little broader in the former 

 species than in the latter; the arrangement of the spinules in the median 

 line of the gastric area of the carapace is 1. 2. 1 in the former, 2. 2. 1 in 

 the latter ; the larger spines on the lower margin of the merus of the great 

 chelipeds are rather nearer the proximal end of the segment in P. beaumontii 

 than in P. granulatus. 



As there is but one specimen of Pohjclieles granuMus in the " Albatross " 

 collection, I have not examined the arrangement of the branchiae in detail. 

 I have noted, however, that the normal epipods are present and well 

 developed. 



WILLEMOESIA Grote. 



Deidamia W.-SunM, Nature, VIII. 51, 1873 (iwm. praoc). 

 Willemoesia Grote, Nature, VIll. 485, 1873. 



Willemoesia inornata Fax. 

 Plate XXXIL, Fig. 2; Plate XXXIII.. Fig. 8. 



Bull. Mus. Comp. Zool., XXIV. 195, 1893. 



Similar to W. leptodactgla (W.-Suhm), but readily distinguished from that 

 species by the small number of spines on the margin and dorsal ridges of 

 the carapace. The armature of spines may be formulated as follows : — 



Marginal 5 to 8 — 2 to 3 — to 6. 



Median ridge . . 1 to 5 — 0. 



* Pentacheks beaumontii Alcock, Ann. Mag. Nat. Hist., Gtli Ser., XIII. 236, 1894; 111. Zool. R. I. 

 M. S. '• Investigator," Crustacea, Plate VIII., Fig. 3, 1894. 



