THE MEDUS.E. 175 



tentacle-stumps in each octant. Eight sense-organs, one in each octant ; they 

 are external, fairly large, and have a short stalk. 



Size : Umbrella about 3 mm. in width and 25 mm. in height. 



(d) This specimen is in rather bad condition. It is about the same size and probably 

 about the same sliape as specimen c. It shows the lower wall of the stomach in 

 an expanded condition, and also shows that the mouth is capable of closing. I 

 presume the specimen to be a male with unripe gonads, which are situated upon 

 the radial canals quite close to the stomach. The radial canals in the proximity 

 of the gonads are sac-like, and upon the outer wall of the sac a gonad is situated 

 as a semi-globular swelling. Two sense-organs were found in one octant. 



Occurrences : 100 to fathoms. 24 e (1 specimen). 



200 to fathoms. 36^(1). 



250 to fathoms. 36 A (1). 



350 to fathoms. 36 I (1). 



Distribution. — Between Iceland and Greenland, lat. 60° N., ' National ' Plankton 

 Expedition ; Norway, Skjerstadfjord, wdthin the Arctic Circle, 230 to fms. and 270 to 

 fms. ; Byfjord, near Bergen, 55 to 110 fms. 



Our knowledge of the distribution of this species is at present rather limited. It seems, 

 however, to like rather cold water, and prefers to live below 100 fathoms. 



Aglantha rosea (Eorbes), 1848. 



Circe rosea, Forbes, 1848, p. 34, pi. 1. 



Aglantlia rosea, Browne, 1898, p. 833, pi. 49 ; 1903, p. 23. 



This species is one of the commonest forms in the collection. There are nearly 

 200 specimens ; about half of them are in fair condition, but only a very few are 

 perfect. 



The smallest specimens are a little less than one millimetre in length and are quite 

 early stages. Most of the specimens are about 5 to 7 mm. in length, and a few are 

 larger. The umbrella of the largest specimen measured 11 mm. in length and 5 mm. in 

 width. A specimen 10 mm. in length and 5 mm. in width has about 72 tentacles, and 

 one measuring 6 mm. in length and 3*5 in width has about 64 tentacles. 



In the search for sense-organs I found a few specimens which possessed sense-organs 

 in adjacent octants, and also had the satisfaction of counting eight sonsc-organs in one of 

 the largest specimens. This established beyond doubt the identification of the species. 

 It is only in the most perfect specimens and in those with the margin of the umbrella 

 nicely expanded that more than half the sense-organs are likely to be seen. The sense- 

 organs, like the tentacles, are usually broken off in the tow-net, and even when present 

 their minuteness renders them hard to find if the margin of the umbrella is curleJ 

 inwards. 



Some of the larger specimens have gonads" about 1 mm. in length, and many of the 

 smaller specimens (about 5 to 7 mm. in length) show the gonads forming on the radial 

 canals at the base of the peduncle of the stomach. 



SECOND SEKIES. — ZOOLOGY, VOL. X. 30 



