154 



NOTES ON PLYMOUTH HYDROIDS, 



from behind, are larger than the first and third. There is no apparent 

 intrathecal ridge. Supracalycine nematophores rather small, stout, 

 reaching to the level of the hydrothecal margin ; the mesial nemato- 

 phore springs from just below the margin of the hydrotheca, and 

 projects straight upward and outward, its truncated end reaching to the 

 level of the longest marginal teeth. There are two modified nemato- 

 phores on each hydrocladium near its base. 



Gonosome. (Description from Naples specimen.) Corbula thick and 

 short, with the leaves or ribs more closely soldered together than in 

 other small British species. Eibs six on each side, with a row of 

 nematophores on their distal edges. 



Habitat. Found growing on thick roots of marine plants taken from 

 Eddystone Eocks. 



Distribution. Naples and Eovigno (Marktanner-Turneretscher), and 

 Plymouth, England. 



