312 PROCEEDINGS OF THE NATIONAL 3IU8EUM. vol.37. 



tribution, and A. rosea, with eight otocysts, of much smaller size 

 and of somewhat more southerly occurrence. Up to the present 

 time the greatest size attained by A. rosea was supposed to be about 



12 mm., whereas A. digitale, which has three or four well-marked 

 geographical races, is known to grow to at least twice that height. 

 Both species are known from both sides of the North Atlantic, but 

 A. rosea has been recorded from the coast of America only once 

 (Hargitt :05, A. conica, Woods Hole, Massachusetts). Inasmuch as 

 A. digitale has been recorded from Massachusetts Bay and northward 

 I expected the series in the present collection to belong to that species. 

 But to my surprise all the specimens examined have eight otocysts, 

 one in each octant, and must therefore be referred to A. rosea. 



AGLANTHA ROSEA (Forbes). 



Circe rosea Forbes, '48, p. 34, pi. 1, fig. 2. 

 Aglantha rosea Browne, '97, p. 833. 



For the synonymy and history of this species, see Maas (:06). 



Between Cape Sable and Cape Race, July 19, about 700 specimens, 

 1.5-8 mm. high; St. Pierre, off Newfoundland, October 1, about 100 

 specimens, 2-10 mm. high; Fogo Island, off Newfoundland, July 29, 

 about 275 specimens, 2-7 mm. high; Gready Harbor, Labrador, 



13 specimens, 13-25 mm. high; Cape Harrison, Labrador, August 13, 

 1 specimen, 21 mm. high; 30 miles southeast of Nain, Labrador, 

 August 15, 129 specimens, 8.5-29 mm. high. 



The series is extremely interesting, since it suggests that with 

 regard to size and number of tentacles Aglantha rosea falls into two 

 distinct races. The smaller of these agrees with A. rosea, as de- 

 scribed by Browne ( :03) and by Maas ( :06) . In this form gonads are 

 first visible in specimens 2-3 mm. high, and are well developed in 

 individuals 6-8 mm. high with 75-80 tentacles. The second race, 

 in dimensions and number of tentacles, closely resembles A. digitale, 

 var. occidentalis Maas, from which it can be distinguished only by 

 the number of otocysts. Fortunately the present specimens were 

 so well preserved that I was able to count these organs in many of 

 the large individuals; otherwise I would no doubt have recorded 

 them under the latter name. In this race, as is shown in the table, 

 gonads first appear in specimens 7-10 mm. high, and they are well 

 developed in specimens 14 mm. or more high. The largest individual 

 in the series is 29 mm. high, a size previously thought to be attained, 

 in this genus, only by A. digitale. In this specimen there are 214 

 tentacles. Such individuals, except for the number of otocysts, are 

 indistinguishable from A. digitale as described by A. Agassiz ('65). 



