HYDROMEDUSAE 277 



tentacles 1-45 mm. (most of them lost), basal part of tentacle about 0-45 mm., lower 

 branch i-o mm., upper branch 0-45-0-6 mm. (3) Diameter i-2 mm., tentacles i-i mm., 

 twenty-three or twenty-four in number. (4) Diameter 1-15 mm., tentacles 1-35 mm., 

 twenty-two or twenty-four in number. (5) Diameter o-8 mm., tentacles 0-9 mm., 

 seventeen in number ; four of the tentacles are smaller (younger) than the others, the 

 smallest being 0-15 mm. in length, divided into two branches, the upper branch with 

 a small terminal cluster of nematocysts ; the other young tentacles are in intermediate 

 stages. (6) Diameter o-8 mm., tentacles i-omm., fifteen or sixteen tentacles, four of 

 which are smaller than the others ; moreover, there are, on the margin of the umbrella, 

 three minute knobs, each of which is placed between two fully developed tentacles ; they 

 are undoubtedly rudiments of tentacles in their very first stages of development ; there 

 is no reason to believe that they are young medusa buds. In this specimen six radial 

 canals can be faintly traced. The remaining specimens have lost almost all their 

 tentacles ; two of them have been stained in paracarmine and examined anatomically ; 

 they both have seven radial canals. 



As in the type specimen, the maximum number of tentacles in the specimens taken 

 in 1 90 1 is about twenty-four. When young tentacles are present, they are of different 

 sizes, and they are placed at irregular intervals on the umbrella margin. 



There is no indication of medusa buds being developed in any of the specimens from 

 the Falkland Islands. 



Comparison with other species. The following species of Staurocladia have been 

 described : 



S. vallentini (Eleutheria vallentini Browne, 1902). Falkland Islands. 



S. charcoti {Wandelia charcoti Bedot, 1908, Eleutheria charcoti Browne, 1910, p. 26). 

 Wandel Island, Graham Land, Antarctic. 



S. hodgsoni {Eleutheria hodgsoni Browne, 1910, p. 28). McMurdo Sound, Antarctic. 



iS. kerguelensis {Eleutheria vallentini Vanhoffen, 191 1, p. 201 and I9i2rt, p. 357; 

 Cnidonema kerguelensis Gilchrist, 1919, p. 521). Kerguelen Island. 



S. capensis {Cnidonema capensis Gilchrist, 1919, p. 509). Cape of Good Hope. 



S. haswelli {Cnidonema haswelli Briggs, 1920, p. 97). Port Jackson, Australia. 



S. oahuensis, bilateralis, acuminata, and alternata (Edmondson, 1930). Hawaii. 



These species are distinguished by various characters of more or less doubtful 

 taxonomic value. The internal anatomy has been studied in S. kerguelensis (by Miiller, 

 191 1, Taf. Ill, fig. 4, Vanhoffen, 191 1, text-figs, ^a, 5c, and by Lengerich, 1920, 

 figs. 6-10, and 1922Z), figs. N i-Q i), capensis (by Gilchrist, 1919, pi. 30, figs. 3-7), and 

 haswelli (by Briggs, 1920, pi. 17, figs. 2-4; pi. 18, figs. 1-5). An examination of the 

 specimens taken at the Falkland Islands in 1900 shows that the anatomy of S. vallentini 

 agrees perfectly with that of the other species as described and figured by these authors. 

 The gonads surround the stomach in the same manner and are not restricted to its 

 aboral part, which, according to Gilchrist, was supposed to be the main feature dis- 

 tinguishing S. valletitini from capensis. 



