62 ME. E. J. MIEES ON GEEENLAND CEUSTACEA. 



lated, and the minute denticules interposed between the teeth on 

 the upper margin of the rostrum are far more numerous ; there 

 are four small teeth at the distal extremity of the rostrum, and 

 one or two on the inferior margin. Compared with the much 

 larger specimens obtained during the British Arctic Expedition, 

 the dentic illations are more numerous and the dorsal carina not so 

 prominent ; yet I do not doubt that the species are identical. 

 On account of the variability of the rostral teeth, I am inclined to 

 doubt the distinctness of H. securifrons, Norman (H. Liljeborgi, 

 Danielssen and Boeck), from H. spinus. Many species, it has 

 been observed, increase in size as they advance into the colder 

 regions of the extreme north ; and at the same time considerable 

 variation may often be noted in the sculpture and armature of 

 the body. In addition to the localities mentioned in my Report 

 on the Crustacea of the Arctic Expedition, I may note that 

 Stimpson and Smith record this species as common on the coasts 

 of Maine and Massachusetts, and also in the Grand Manan. 



HiPPOLYTE POLAEIS. 



Alpheus polaris, Sabine, Append. Parry's 1st Voy. x. p. 60, pi. ii. 



figs. 5-8 (1821). 

 Hippolyte polaris, Ross fy Owen, Append. Ross's 2nd Voy., Zool., Crust. 



p. lxxxv (1835); M.-Edw. Hist. Nat. Crust, ii. p. 376 (1837); Kroyer, 



Monogr. Hipp. nord. Art. p. 116, pi. hi. figs. 78-81, pi. iv. (1842); 



Miers, Ann. # Mag. Nat. Hist. (ser. 4), xx. p. 61 (1877). 

 Hippolyte borealis, Owen, Append. Ross's 2nd Voy., Cr. p. lxxxiv, pi. B. 



fig. 3 (1835); Miers, Ann. # Mag. Nat. Hist. (ser. 4), xx. p. 61 



(1877), 6. 



Several specimens were dredged off Hare Island. The only 

 two perfect specimens have the rostra ^--toothed, and thus agree 

 more nearly with Kroyer's diagnosis than do the specimens col- 

 lected in the Polar Sea by the late British Arctic Expedition. 



Prof. S. I. Smith, in his " Report on the Crustaceans of the 

 Atlantic Coast," records the occurrence of this species on the 

 coast of Labrador, Nova Scotia, and Massachusetts. 



Hippolyte geoenlandica. 



Astacus groenlandicus, J. C. Fabr. Syst. Ent. p. 416 (1775). 

 Cancer aculeatus, O. Fabr. Fauna Grcenlandica, p. 289 (1780). 

 Hippolyte aculeata, Owen 8f Ross, Crust, in Append. Ross's 2nd Voy. 

 p. lxxxiii (1835); M.-Edw. Hist. Nat. Crust, ii. p. 380 (1837): 



