354 BULLETIN 82, XTSITED STATES NATIONAL MUSEUM VOLUME 1 



inoiis from the Kola Fjord liavc the arms narrowly and regularly banded with more or 

 less deep brown. 



Characters of individual specimens. — Challenger station 48: According to P. H. 

 Carpenter the numerous examples from this station are by no means so large and well 

 developed as individuals which he has examined from higher latitudes, and notably those 

 obtained in the Barents Sea by the Dutch Arctic expeditions. The arm length of these 

 specimens does not exceed about 200 mm. and there are not more than 200 brachials. 

 The cirri and the lower pinnules are also fewer jointed and shorter in proportion, while 

 the arm bases are much less tubercular than in the more northern forms. Beyond the 

 third syzygy the brachials are very distinctly triangular, but they are considerably 

 wider than long, and this disproportion increases in the middle and outer parts of the 

 arms so that the successive pinnules are very closely set, and it is only quite at the 

 extremities of the arms that the brachials become at all quadrate. 



Jones and Smith Sounds: The cirri in the larger specimens are up to 65 mm. in 

 length and are composed of 51 segments. The diameter of the calyx reaches 32 mm. 

 The relative length of the lower pinnules is very variable. In one individual the pro- 

 portion between the Po and P3 on three of the arms varies between 1:0.78 and 1:1.19; 

 in another it varies between 1 :0.66 and 1 : 0.85; and in a third between 1 : 0.72 and 1 :0.92 

 on four of the arms. The calcareous plates in the perisome of the genital pinnules are 

 relatively more feeblj' developed than in specimens from the North Atlantic, and are 

 much more perforated and looser in structure. They also vary very considerably in 

 form and in relative development. In young individuals they are less developed than 

 in older ones, and whereas in the latter they form a continuous series in the former they 

 are separated. 



Willcm Barents station 17, 1881: The cirri are 60 mm. long, composed of 50 seg- 

 ments, of which the 20 following the few short basal ones are longer than wide, though 

 in gradually diminishing proportion. The radials are invisible, and but little can be 

 seen of the IBri. The axillaries are diamond-shaped, about as long as broad, more 

 than half of the length being on the distal side of the line joining the lateral angles. 

 The tubercular ornamentation of the arm bases is strongly developed. The arms are 

 250 mm. long, composed of more than 300 brachials which are distinctly broader than 

 long and triangular tliroughout until quite near the ends of the arms when they be- 

 come quadrate, but never longer than broad. Pi is about 30 mm. long; P2 and P3 are 

 from 35 to 40 mm. long, Pj being rather the longer, while P4 falls to from 30 to 35 mm. 

 The pinnules of the first four pairs have broad lower segments which are somewhat 

 longer along the ventral than along the dorsal edge which is slightly sharpened and not 

 in contact with those of adjacent segments. For the first 15 or 20 segments these pin- 

 nules taper rather rapidly, afterwards remaining tolerably slender and uniform until 

 near their ends, and the segments retain indications of the sharpened dorsal edge 

 which is produced in the later ones into a bluntlj^ angular process giving the end of the 

 pinnule a somewhat serrate appearance. After P3 the length diminishes considerably, 

 Pe barely reaching 20 mm. The basal segments of the pmnules then become longer as 

 well as broad, so as to support the large gonads, and the later ones are markedly longer 

 than broad. The pinnules also taper more slowly and agam increase in length, those 

 in the middle of the arm reaching 30 mm., after which they diminish again. The 

 dorsal surface of tliese middle and outer pinnules is nearly- smooth. 



