90 ATRACTYLIDJE. 



The polypary of this species is extremely delicate, yield- 

 ing like a mere skin to the movement of the polyp ites. 



Hab. On the stems of Halicornaria setacea, from about 

 12 fathoms, Torbay (G. J. A.) : on rocks and Laminaria, 

 under the lower ledges, Capstone, Ilfracombe ; Filey Brigg 

 (T. H.). 



Species doubtfully referred to this genus. 



P. (?) LINEARIS, Alder. 



ATRACTYLIS LINEARIS, Alder, Supp. North. Cat. in Trans. Tynes. F. C. v. 230, 



231, pi. x. figs. 1-3. 

 PERIGONIMUS ? LINEARIS, Attman, Ann. N. H. for May 1864. 



Plate XVII. fig. 3. 



STEMS linear, horn-coloured, unbranched, (?) nearly smooth, 

 a little undulating, and slightly wrinkled on the lower 

 part; POLYPITE slender, retractile with 8 long tentacles, 

 alternately elevated and depressed; GONOPHORES pear- 

 shaped or subglobular, set two or three together on the 

 stem. 



GONOZOOID. UMBRELLA globose, slightly truncated below, 

 with a contracted aperture ; MANUBUIUM inconspicuous, 

 branched at the base; MARGINAL TENTACLES 4, subcla- 

 vate, springing from semicircular yellowish lobes. 



Height of zoophyte \ inch. 



THE stems of this species rise much higher, and are pro- 

 portionally more slender, than those of P. repens, and 

 are not so much expanded at the aperture. In the young 

 state, however, it is difficult to distinguish the two species. 

 The gonozooids are very different; but we need a fuller 

 and more precise description of those of P. linearis than the 

 condition of Mr. Alder's specimens permitted him to give. 

 Hab. On Turritella communis, Astarte Danmonia, and 

 other shells from deep water, Cullercoats (J. A.). 



