A COLLECTION OF HYDKOIDS. 



315 



Diameter of main stem below the first branch 0"401 mm., 

 thickness of perisarc 08 /<. Diameter of a branch about in 

 the middle of its length, and measured just below a hydro- 

 thecte and at the middle of an internode, 0'282 mm. 



Hydrotheca3. — Sub-opposite, long, tubular, with the 

 greater part of their adcauline edge parallel to the branch, 

 and sunk in it, the upper portion being abruptly bent outwards 

 and ending in two large, opposite, lateral teeth (text-fig. 12, B). 



Text-fig. 12. 



T li 11 i a via t u 1 > u 1 i f o r m i s (M. — - Ta rneretscli er) . 



Operculum two-valved. There is a distinct tendency for the 

 hydrothec^ to arrange themselves in groups resembling those 

 seen in P a s y t h e a . 



Length, measured parallel to abcauline edge, 0"667 mm., 

 greatest bi-eadth 0*182 mm. 



Hydranth. — Tentacles about 19. Nematocysts at the tips 

 of tentacles 5*2 jx in length, and 1*2 /.i in breadth. 



GrONOSOME. — Gonaugia originate from main stem or branches 

 immediately below a hydrotheca. Ovate, with a constricted 

 curved neck and round terminal aperture {B, S)- 



Greatest length 1'330 mm., and greatest breadth 0'646 mm. 



VOL. 1, PART 3. 23 



