BIGELOW: COAST WATER EXPLORATION OF 1913. 311 



to this (Fig. 74). The directive influence which causes the regular 

 erect growth must be overcome in such a case since two of them grow 

 in a diametrically opposite direction. There seems to be no hindrance 

 to the growth of the hydranths, as they are found in various stages of 

 development as well as in the adult condition, and when they were 

 preserved several of them had undigested food in the enteric cavity. 

 The development of the gonophore is not interfered with either, as 

 medusae of different ages are found in the gonangia and some free 

 medusae were found just liberated in the plankton. All the gono- 

 phores were found either on the stolon or on original pedicels, none on 

 the regenerated portions. 



Regeneration is no new thing in hydroids as it has been noticed by 

 many observers, but I know of no case where anything on such a large 

 scale as this and in such a location has been recorded. It is quite 

 possible that some of the experimental work that has been done on such 

 forms as Tubularia cwcea and Hydractinia cchinata would have given 

 more satisfactory results if it had been done on Clytia cylindrica. 

 It may be that the election of gymnoblastic forms for such experiments 

 might have been improved upon by taking some of the simple calypto- 

 blastic species. I am very doubtful if under artificial conditions in 

 any case regeneration could be successfully brought about in over 99% 

 of the cases as it must have been here if one is to judge from the 

 generous sample that was collected. 



Obclia gcniculata (Linne). (Fig. 75-78). 



As this is a cosmopolitan form and as it has been described and 

 figured in so many instances, a description of a typical specimen from a 

 typical locality is quite unnecessary, but as many of the specimens in 

 this material are not typical and as the location is unique, mention is 

 especially made of the species here. 



Two lots of specimens were present, both attached to eelgrass. In 

 one case the stolon ran irregularly along throughout the whole length 

 of the fragment of eelgrass, on both sides, making rather a dense mass. 

 In the other case a few colonies were distributed among several colo- 

 nies of Sertularia cornicina. I do not know that 0. geriiculata is com- 

 monly found on eelgrass, as I do not remember having found it 

 there, or of having seen it recorded as so growing, but it does grow on 

 certain Algae and hence the difference in the nature of the support is 

 not sufficient to make this case remarkable. Other species, e. g., 



