PUGET SOUND CRUSTACEA. 269 



as long as broad, and the palmar edge extends to about one- 

 half the length of the dactyl. 



The coxal plates of the second pair of pereiopods, which in 

 P. antarctica resemble those of the first pair in being produced 

 anteriorly into a long sharp spine, are here different, and have 

 the anterior process reduced to a short blunt lobe. 



The propodus of the third pereiopods differs in shape from that 

 of P. antarctica, the thumb-like process being much less promi- 

 nent and the anterior and posterior edges nearly parallel. 



The first maxillae have the palp composed of only one joint, 

 but Delia Valle has already pointed out (Monogr. Gammarini, 

 p. 579) that Stebbing was misled in ascribing a two-jointed palp 

 \.o P. antarctica. 



Length, 7 mm. 



8 specimens, all females bearing ova, "■ in nests in Ainar- 

 ceciiuny 



The various other species of Polyclicria which have been de- 

 scribed, are probably all referable to one, P. antarctica (Steb- 

 bing), with a wide distribution in the Southern Ocean (Kerguelen 

 Island, Antarctic Ocean, New Zealand, Australia). The occur- 

 rence of a second species in the Northern hemisphere is, there- 

 fore, interesting. 



At the suggestion of Professor D'Arcy Thompson I have 

 dedicated this interesting species to Professor H. F. Osborn, of 

 Columbia University, New York. 



Gammarid.*:. 



Msera dubia n. sp. 



(PL XXXII, Fig. 3.) 



Description. — Body moderately slender and compressed, 

 sparsely covered with very small scattered seta^. Lateral 

 lobes of head short, truncate. First pair of coxal plates pro- 

 duced forwards and pointed, slightly less deep than the cor- 

 responding segment. Fourth pair nearly twice as long as 

 deep, and about half as deep as the corresponding segment. 



