221 



hairiness of the animal, it seems alinost certain, that Ceratoplax laevis Miers ^) is identical with 

 the present species, a surmise ah-eady expressed by Miers himself, and perfectly suggested by 

 the author's figure. Unfortunately it is not stated, whether the eye-stalks are movable or not. 

 The species has been originally recorded from New Caledonia; the "Challenger" dredged 

 it from a depth of 28 fathoms south of New Guinea ; Alcock obtained a specimen from the 

 Persian Gulf. '^Ceratoplax" laevis was secured in the Arafura Sea, depth 22 — 26 fathoms. 

 The Leiden Museum contains two specimens (<ƒ and 9) of ^- nitidus, coUected by Dr. Semmelink 

 near Banda in 1881. 



N" I and 2 are from Stat. 47, n" 3 and 4 from Amboyna, n" 5 from Stat. 285 ; the 

 latter specimen is hearing eggs, which are of nearly exactly the same size as those of the 

 following species (0.37 mm.). 



2. Notonyx vitreus Alcock. 



1900. Notonyx vitreus Alcock. Journ. As. Soc. Bengal, v. 69, prt 2, p. 319. 



1903. Notonyx vitreus Alcock. 111. Zool. "Investigator", Crust. prt 10, pi. 61, f. 3. 



Stat. 51. Madura Bay, west coast of Flores. Depth 69 — 91 m. i 9 with eggs. 

 Stat. 164. South of Salawatti, near north-west New Guinea. Depth 32 m. i cf juv. 



In the following particulars this species differs from the preceding : 

 1° The carapace is proportionally narrower, its breadth being not more than 1.2 times its 



length; the postero-lateral margins are subparallel, not somewhat converging backward; the 



antero-lateral margins are more obtuse than in A^. nitidus and keeled only along a very 



short distance behind the external orbital angles ^). 

 2'' The merus of the external maxillipeds is indeed shorter than the ischium (Alcock), more 



distinctly so than in N. nitidus^ and the antero-external angle of the former is more 



pronounced, thougli not at all prominent, and less rounded off. 

 3" The meropodite of the chelipeds is without a transverse ridge near the distal end of the 



upper border, and the feathered hairs, observed in N. nitidus along upper and inner border 



are nearly absent in the present species. The inner angle of the wrist is not prominent. 

 4" The meropodites of the walking legs are slightly broader and the various joints are even 



more destitute of hairs than in the preceding species ; the dactyli of the last pair are slightly 



curved, not straight. 

 5° The abdomen of the cf is oblong, not triangular, with the lateral margins not much con- 



1) Zool. H. M. S. "Alert", 1884, p. 244, pi. 25, f. C. See p. 203. 



2) It must be a slip of the pen, that Alcock says: "front nearly half the breadth of the carapace"'; in reality it is much nar- 

 rower, and, like in N. nitidus^ slightly less than half the fronto-orbital distance. 



73 



SIBOGA-EXPEDITIF. XXXIX c'. 29 



