12n Canadian Arctic Expedition, 1913-18 



exhibited by the present series, which, however, add nothing, except by way 

 of confirmation, to the more extensive series already described and figured l.\ 

 me from the coasts of Labrador and Newfoundland. 



Having been recorded from Bering straits on the one hand (Brandt, 1838), 

 from Labrador and Greenland (Maas, 1906, Bigelow, 19096, Hartlaub, 1909), on 

 the other, as well as from Barents sea (Linko, 19046; the White sea (Birula, 

 1896) and from Spitzbergen (Gronberg, 1898, Maas, 1906), its occurrence off 

 the arctic coast of North America was to be expected. In fact, it is apparently 

 one of the most characteristic and widespread of Arctic Medusae. 



SCYPHOMEDUS.E. 



STAUROMEDUS^E. 



Family LUCERNARID^E Johnston. 

 Haliclystus stejnegeri Kishinouye. 



Plate II, Fig. 4. 

 Haliclystus stejnegeri Kishinouye, 1899, p. 126, fig. 1-3, Mayer, 1910, p. 535. 



Station 200, port Clarence, Alaska, August 4, 1913; 2-3 fathoms; 2 speci- 

 mens, both about 12 mm. broad, with well-developed gonads. 



Although this genus has been the subject of a great deal of study, not 

 only from the morphological (Clark, 1863, 1878; Gross, 1900), but also from 

 the varietal standpoint (Browne, 1895), it is still impossible to draw any 

 sharp lines between the several species generally recognized. 1 This is partly 

 due to the fact that the various studies on its variations were not undertaken 

 with this end in view; partly to the homogeneity of the genus as a whole, but 

 chiefly to the intergrading nature of the characters which have been used to 

 delimit " species." and to the changes which take place in them with growth 

 during the normal life of the Medusa, as well as after preservation. 



Among the four northern species recognized by Mayer (1910, p. 53), 

 H. auricula, so fully described by Clark (1878), is recognizable chiefly by the 

 fact that its eight adradial tentacle-arms are associated in pairs, whereas in 

 H. octoradiatus, H. salpinx, and H. stejnegeri they stand 45 apart, with the 

 interradial marginal notches as deep and broad as the perradial. Furthermore, 

 auricula has more tentacles per arm (100-120) than either octoradiatus or salpinx. 

 But, like them, the sexual saccules borne by its gonads are arranged in radial 

 rows, irregular, it is true, but still discernible, there being two rows per gonad 

 in octoradiatus, 4 in salpinx, 6-8 in auricula. In stejnegeri, on the contrary, 

 the sexual swellings are in the form of round sacs, of varying sizes, irregularly 

 arranged over the surfaces of the leaf-like gonads. 



The present specimens are identified as stejnegeri, chiefly because they 

 exhibit the gonad structure supposed to be typical of that species. That is, 

 each of the eight long leaf-like gonads, which extend from the base of the disc to 

 the extremities of the arms, is closely studded with a series of globular swellings 

 varying in size and irregularly arranged (pi. II, fig. 4). Of these there may be 

 from three or four to nine or ten abreast, and there is no trace of any radial 

 arrangement in rows, such as characterizes the gonad swellings of H. octoradiatus 

 and H. auricula (Clark, 1878; Mayer, 1910). 



I may also note (as a character separating stejnegeri from auricula) that 

 the arms in our specimens are 45 apart, the radial and interradial notches 

 being equally deep and broad. 



1 For summary of our present knowledge of this genus, see Mayer, 1910. 



