46 University of California Publications. [zoology. 



the coenosarc. The proximal set has about one-half (12) its 

 adult number; the distal approximating their final number quite 

 closely (15-18). This regenerative process, interesting to the 

 naturalist because among other reasons it occurs constantly in 

 nature, is doubly so because it departs so widely from the method 

 of development of the tentacles in the egg embryo. In the latter 

 the tentacles arise as buds, not ridges. The distal tentacles 

 appear in successive alternating whorls of four each (quartettes) . 

 The proximal arise in a less orderly fashion, one or two at 

 a time; probably a secondary modification of the quartette type, 

 since the first two tentacles are opposite, and the actinula has a 

 symmetrical eight tentacle stage. Both proximal and distal ten- 

 tacles are capitate for a time, which is true also for Pennaria and 

 the regenerated distal tentacles of Gorytnorpha. The questions 

 of relationship which these facts suggest have been considered in 

 another place (p. 42). 



There is at present no explanation for this difference between 

 regeneration and embryonal development. Driesch ('01) has 

 seen the tentacles appear as ridges on a small naked piece of 

 Tubularia stem which seems to exclude the possibility that con- 

 finement within the perisarc might be the determining factor. 

 The question needs further investigation however. 



Tubularia marina, sp. nov. 



PI. III. Figs. 24, 25. 



Trophosome. Stems rising in clusters, from a creeping hydrohiza to a 

 height of 30-50 mm.; moderately stout, unbranched, increasing in diameter 

 distally; more or less annulated; annulse more frequent and regular in 

 proximal half. Hydranths with 22-26 proximal and 18 distal tentacles. 



Gonosome. Colonies dioecious. Gonophores in about ten pendulous 

 racemose clusters which may be as long as the proximal tentacles, and 

 contain more than twenty gonophores each, in well developed specimens. 

 Male gonophores very broadly ovate with four small apical processes slightly 

 flattened laterally. Female gonophores more narrowly ovate than male, 

 with four stout, stiff tentacles with bulbous bases, sometimes forking near 

 their ends and as long as the gonophore. Actinulse(S. F.). 



Distribution. Trinidad, (June), San Francisco, (Dec, Jan., 

 Feb.) and Pacific Grove, (Dec.) Cal. 



This species is easily recognized by the unusually long ten- 

 tacles on the female gonophores. A. Agassiz, in his Illustrated 



