280 /S. J. Smith — Arnj^hipodus generct, 



Edwards as the original JE. d'lfforinis. It is probably the form char- 

 acteristic of the old males, though tlie individuals are often smaller 

 than those with the second gnatliopods in the less differentiated con- 

 dition, in which the body of the carpus is more nearly quadrangular 

 in outline, the spine arising near the piopodal articulation, and the 

 propodus shorter and stouter than in the other form and with two 

 conspicuous prominences on the inferior edge. This is the form de- 

 scribed as Cerapus IIuH.teri, by Bate and by Boeck. In the large 

 series of specimens before me, there is every gradation between these 

 two forms, and between the latter and the female. In one case, an 

 individual had one of the second pair of gnathopods in the most dif- 

 ferentiated form, while the other was somewhat smaller and in the 

 less differentiated form — evidently having been lost and reproduced. 

 The only European specimens which I have examined were received 

 from the Rev. Mr. Noi-man, and are from the Northumberland coast, 

 England, and among these all the adult males agree better with the 

 Hnnteri than with the more differentiated form. 



The habit of the animal and the character of the tubes are well de- 

 scribed by Stimpson. In life, the proximal parts of the flagella of 

 the antennulae aud antennae are bright red, and the color usually re- 

 mains for some time in specimens preserved in alcohol. 



The genus TJnciola. 

 Unciola Say. 

 Unciola Say, Jour. Acad. Nat. Soi. Philadelphia, i, p. 388, 1818 {irrorata the 

 only sp.) 

 Milne-Edwards, Ann. Sci. nat., Paris, xx, p. 383, 1830 (=Say). 

 Dana, Amer. Jour. Sci., II, viii, p. 139, 1849, and xiv, p. 309 (^ Glauconome) ; U. 



S. Expl. Expd. Crust., p. 832, 1853. 

 Bate, Catalogue Amphip. Crust. British Museum, p. 279, 1862 (^Glauconome). 

 Glauconome Kroyer, Naturh. Tidsskrift, II, i, pp. 491-501 (letKopis the only sp.) 

 Boeck, Christiania Videnskabs-Selskabs Forhandlinger, 1870, p. 259 (179); Scan- 

 dinaviske og arktiske Amphip., p. 636, 1876. 

 '■^ Cyrtlwpium Danielssen, Beretning om en zoologisk Reise, 1857, Nyt Magaz. 

 Naturvidensk., xi, p. 8, 1861," (Boeck). 



Kroyer's name Glauconome is not only more recent than Say's 

 TTnciola, but it had been used at least twice before Kroyer employed 

 it, once in mollusks and once in polyps. 



Unciola irrorata Say. 



Unciola irrorata Say, Jour. Acad. Nat. Sci. Pliiladelphia, i, p. 389, 1818. 

 Milne-Edwards, Hist. nat. Crust., iii, p. 69, 1840 (=Say). 

 Stimpson, Marine Invertebrata of Grand Manan, p. 45, 1853. 



