84 G. 0. SARS. CRUSTACEA. [norw. pol. exp. 



Anterior antennae scarcely longer than the anterior division of the body, and 

 composed of 24 articulations only. Posterior antennae more strongly built 

 than in the type species. Anterior maxillipeds exceedingly large and power- 

 ful, with the 2 outer spines very long and claw-like. Posterior maxillipeds 

 scarcely as long as the anterior, 1st basal joint without any transformed seta 

 anteriorly. Last pair of legs with the incurved spine of the outer ramus 

 fully as long as the terminal joint, and finely denticulated in its outer part. 

 Length of adult female 3"35 mm. 



Remarks. This is a very distinct species, easily recognizable from the 

 other known forms by its unusually robust body, and the less elongated 

 anterior antennge. It is, however, a true Heterochceta, as shown by the 

 structure of the several appendages, Only female specimens have come 

 under my notice. 



Description of the Female. 



The length of the body measures 3-35 mm., and accordingly this form is 

 also somewhat larger than the type species, H. spinifrons, Glaus. 



The general form of the body (see PI. XXIV, figs. 1 & 2) looks rather 

 different from that of the preceding species, being much more robust and 

 compact, with the tail comparatively shorter. The anterior division of the 

 body is considerably tumefied and, viewed dorsally (fig. 1), of regular oval form, 

 with the greatest width equal to about half the length, and occurring somewhat 

 behind the middle. The anterior extremity appears obtusely rounded, the 

 posterior abruptly contracted, and slightly emarginated in the middle. The 

 rostral projection is comparatively smaller than in H. normgica, and in the 

 dorsal view of the animal (fig. 1) only causes a very slight nodiform promin- 

 ence in front. It is, however, of an essentially similar form, and carries on 

 the deflexed tip 2 straight tentacular filaments (see fig. 3). The cervical depres- 

 sion of the cephalic segment is clearly distinguishable in the lateral view of 

 the animal (fig. 2). The last pedigerous segment is very small, though more 

 distinctly defined than in the preceding species. 



The tail is comparatively short and thick, scarcely exceeding Vs of the 

 length of the anterior division, and has the genital segment very large and 

 dilated, the other 3 gradually diminishing in size. The caudal rami (see fig. 4) 

 agree in their form with those in H. norvegica, and, as in that species, are 



