CRUSTACEA CASPU. 425 



ciliated margin. The basal lobe is rather small and has 2 ciliated apical 

 setae. The palp- is not very large, with the terminal joint but little 

 expanded. 



The 2nd pair of maxillae (fig. 9) have the outer lobe considerably larger 

 than the inner, and only setous at the tip. The inner lobe is finely ciliated 

 inside, and carries, in addition to the terminal bundle of bristles, a strong 

 spine somewhat beyond the middle. 



The maxillipeds (fig. 10) have the palps less strongly developed than in 

 the arctic species, but otherwise exhibit a very similar structure. 



The anterior gnathopoda (fig. 11) are not nearly so strong as in P. lit- 

 tomlis, differing also conspicuously in the shape of the propodos. The latter 

 (see also fig. 11«) is scarcely as broad as the carpus, and is not at all ex- 

 panded, being on the contrary somewhat narrowed distally. The palm is 

 rather short and somewhat oblique, with only a single slender spine issuing 

 from the lower corner. The dactylus is also much smaller than in the said 

 species. 



The posterior gnathopoda (fig. 12) are very slender, and likewise differ 

 somewhat from those in P. littoralis in the shape of the propodos (fig. 12a), 

 which is not, as in that species, transversely truncated at the tip, but is 

 somewhat produced at the lower corner, where the minute chela is formed. 



The pereiopoda are considerably shorter and also less densely setous 

 than in the arctic species. The 2 anterior pairs (fig. 13) are more slender 

 than the posterior ones, and have the moral joint slightly produced at the 

 end anteriorly. The propodal joint is about the length of the 2 preceding 

 joints combined. The antepenultimate pair (fig. 15) have the basal joint ir- 

 regularly oval, and like that of the 2 posterior pairs, produced at the infero- 

 posteal corner to a rounded lobe. Along its anterior edge is a row of about 

 10 short spines. The 3 succeeding joints are comparatively short and, com- 

 bined, but little longer than tlie propodal joint. The penultimate pair (fig. 16) 

 somewhat exceed in length the antepenultimate one, and have the basal joint 

 comparatively more elongated, though scarcely broader. 



The last pair (fig. 1 7) are a little shorter than the penultimate one, and 

 have the basal joint rather large, fully as long as the remaining part of the 

 leg, and of an oval form, slightly narrowed distally. The posterior edge of 

 the joint, as in the 2 preceding pairs, is divided into a limited number of 

 serrations, scarcely more than 7. 



The 2 anterior pairs of uropoda (fig. 1 8) are of similar structure, though 

 somewhat differing in size, the rami in both pairs being simple mucroniform, 

 and provided with scattered spines. 



4l8.-MaT. CTp. 255. 5 



