595 



sending off from its base below, a long, spur-like process obtusely acuminate 

 at the tip; palm straight and terminating anteriorly in a short, triangular 

 lappet, dactylus very large and flexuous, impinging, when closed, against the 

 tip of the spur-like process. The 2 anterior pairs of pereiopoda comparatively 

 short and stout, with the basal joint somewhat laminar, and the meral joint 

 considerably expanded in front; the 3 posterior pairs rather robust, and 

 successively increasing in length, with their outer part edged with fascicles 

 of stiff bristles: basal joint oval in form. Last pair of uropoda with the 

 inner ramus distinctly hooked, and having 2 recurved secondary teeth at the 

 upper edge near the tip. Telson very small, triangular, with a pair of small 

 bristles on each side of the acutely produced tip. Colour somewhat variable, 

 being, as a rule, somewhat darker in females than in males, with irregular 

 patches of a brownish hue changing to a light red. Length of adult female 

 8 mm, of male 9 mm. 



Remark. The rather pronounced sexual difference in this form has 

 caused the establishment of several species. The male has even been described 

 by Sp. Bate under 2 different names, according to age, viz,, as P. falcatus 

 and P. pulcheUus, the latter being the fully adult form, the former the still 

 young, not yet sexually developed male. The female, too, is by the same 

 author recorded as a 3rd species, viz., P. pelagicus.. The P. calcaratus of 

 Rathke is undoubtedly the adult male of this species; on the other hand it 

 appears to me somewhat doubtful, whether P. monodon of Heller is, as believed 

 by Boeck, referable to the same form. The species is easily distinguished 

 from the 2 succeeding ones by its much larger size,, and by the long and 

 narrow thumb-like process of the posterior gnathopoda in the adult male. 

 Some of the detail-figures given by Boeck in his great work would seem more 

 properly to belong to the next species. 



Occurrence. The species occurs not infrequently along the whole 

 south and west coasts of Norway, as also in the Trondhjemsfjord, in com- 

 paratively shallow water among alg*. According to Boeck it has been found 

 by Dr. Danielssen at Tromse; but I am inclined to believe, that this statement 

 is erroneous, and caused by a confusion with the next, nearly allied species. 



Distribution. - British Isles (Mont.), Bohuslan (Bruzelius), Kattegat 

 (Meinert), Dutch Coast (Hoek), coast of France (Chevreux), Mediterranean 

 (Costa), Azores (Barrois). 



