26 "ENDEAVOUR" SCIENTIFIC RESULTS. 



Hartlaub says in his key to the species that #. divaricata 

 has gonaiigia like those of 8. subdichotoma but with shorter 

 tube. The shortness is apparently proportionate rather than 

 absolute, for according to the figures the greater width in 

 S. divaricata is the most conspicuous difference. The wide 

 bowl-shaped mouth of No, 5 in the foregoing list is in fact higher 

 than any of the narrow funnel-shaped forms. My identification 

 of the var. subdichotoma with S. subdichotoma, K., is verified by 

 Hartlaub. 



Comparison of the nine forms which I have described convinces 

 me that they must all be referred to S. dircr/rata, unless we take 

 such a restricted view of the species as would result in other 

 forms, as well as var. subdichotoma, being accorded specific rank. 

 Var, dubia, owing to the difference in the gouangia, seems to me 

 to be at least as distinct as var. subdichotoma, and in some 

 measure to make an approach to N. johnstoni. 



No. 7, which is practically identical with var. subdichotoma 

 so far as the gonangium is concerned, resembles it perhaps least 

 of all the varieties in the trophosome. Some of the forms which 

 have been referred to S. subdichotoma should probably be ranked 

 under the typical S. divaricata, e./j. the form mentioned by 

 Jaderholm in his report on the Swedish South Polar Expedition, 

 which he says has a wide aperture, a characteristic of the type, 

 not of var. subdichotoma. 



Several other species have been founded on distinctions which 

 seem scarcely sufficient to take them out of range of S. divaricata, 

 as here defined. S. magellanica, M.-T. is considered by Hartlaub 

 to be synonymous with S. subdichotoma, and S. cumberlandica, 

 Jaderholm, is referred by Vanhoffen to the same form. These, 

 and a number of others closely related, are not included among 

 the synonyms, as I have had no opportunity of examining 

 them, 



I formerly suggested that it might be found necessary to unite 

 8. divaricata to 8. johnstoni. For the present I regard them as 

 different species, rather on Hartlaub's authority than from my 

 own observations, as I have seen no specimens of N. johnstoni 

 other than that described above, which appears to me sufficiently 

 distinct, Biit according to New Zealand observers S. Johnston i 

 seems to vary considerably. Hilgendorf's account is rather 

 contradictory. He describes the gonaugia as large, with from 

 six to ten ridges, but he also states that the gouaugia of 

 Thuiaria snbarticulata have six to eight ribs " exactly as in 

 S. johnstoni though here the ribs are much fewer." 



