A FEW CGELENTERATES OF WOODS HOLL. Ill 



by the foregoing comparisons. Fig. 12 gives a general view of 

 the medusa as seen from the subumbrellar surface. 



Aglantha conica. — This species was collected by the writer 

 in August, 1902, and described shortly after (Biol. Bull., Vol. 

 VI., p. 21). It has not since been taken till the present summer, 

 or spring, when, April 25—30, it appeared in small numbers in 

 the tow at Woods Holl. These specimens agreed in all essen- 

 tials with those of 1902, except in a slightly larger range of size. 

 In the former specimens the average height of bell was given 

 5-6 mm. In the specimens of this year, only about a dozen in 

 number, the average was about 8 mm. in height. The marginal 

 tentacles were quite as in the earlier description, and there were 

 no apparent morphological differences between the smallest 

 specimen taken, of 5 mm., and the largest, measuring 12 mm. 

 These facts seem to confirm the previous somewhat provisional 

 designation of the species as new, and warrant the belief that A. 

 conica is a well-defined species, distinct from the only other indige- 

 nous species, A. digitalis. Its occurrence at such widely different 

 seasonal periods as August and April is a point of some biolog- 

 ical interest. The gonads were about equally developed in the 

 specimens of each season, and this may also suggest that it has 

 no sharp limits as to seasonal relations. 



As a supplementary note it may be added that again specimens 

 have been taken at Crab ledge in late July, 1907, in considerable 

 numbers by towing, as in my original collections, and agreeing 

 in every respect with the original type specimens. 



Eutima. — Two species of Eutima have been recognized by 

 earlier students of Hydromedusae, namely, E. mira McCrady, and 

 E. limpida A. Agassiz. In notes by the present writer (Am. Nat., 

 Vol. XXXVI. , p. 554), reference was made to E. limpida as 

 " Fairly common at Woods Holl, but sexually immature." Upon 

 later and more critical comparison of these medusae I found it ex- 

 tremely difficult to distinguish more than a single species, and so 

 designated it as E. mira McCr. (cf. Bull. U. S. Bureau of Fisheries, 

 1904, pp. 45, 46), though listing E. limpida, on the authority of 

 Agassiz, but with the suggestion that it was probably at most but 

 a regional variety of E. mira. Still later observations have 

 served to confirm this impression. 



