98 



ANTHOZOA HYDROIDA. 



Hob. On old shells, corallines, and ascidia in deep water. At 

 Scarborough, rare, Mr. Bean. Frith of Forth, Dr. Coldstream. 

 Frequent in Berwick Bay, G. J. Coast of the Isle of Man, E.Forbes. 

 11 Frequently trawled up off Howth and Lambay, in deep water, and 

 but rarely cast upon the shore," Hassall. Coast of Cornwall, com- 

 mon, Couch. Near Aberdeen, " often brought up by the fishing- 

 lines from deep water," J. Macgillivray. Lamlash Bay, Rev. D. 

 Landsborough. " Several specimens were dredged from about forty 

 fathoms at Sana Island, near the Mull of Cantire, by Mr. Hyndman, 

 in June 1842 : one specimen springs from the stem of Thuiaria 

 articulata." W. Thompson. 



This equals PL pinnata in size and delicacy, but differs from it 

 very obviously in having opposite pinnae, which, instead of being 

 arched, bend inwards, so as to render the general form of the coral- 

 line concave on a front view ; an appearance produced by the pinnae 

 originating, not from the sides, but from the anterior face of the 

 stem. The stem itself is straight or slightly bent, jointed, pellucid, 

 filled with a granular fluid matter ; and, in which it differs from its 

 congeners, bearing cells ; there being always one at the base and 

 between the insertion of the pinnae, and generally another on the 



interval between them. Be- 

 Fig. 1 7. 



tween the cells there is a 



series of minute tubular or 

 tooth-like cells, visible only 

 with a high magnifier. The 

 ovarian vesicles are produced 

 in summer : they are stalk- 

 ed, shaped like a pear or 

 vase, solitary, scattered, and 

 originating always at the 

 base of a polype cell. From 

 the intermediate cellules, 

 particularly from the one 

 next the polype cell, there 

 often grows up a small 

 trumpet -like tube ; and I 

 have seen, in one specimen, 

 all the ends of the branches 

 terminated by four of these tubes diverging in pairs. Mr. Peach 

 has sent me specimens of PI. Catharina from Cornwall, in which the 

 stem is simple, or rather where there is no stem, but a development 



