42 



28.* ALDERINA IMBELLIS (Hincks). Callopora, Levinsen. 

 Plate I., Figs. 3 and 3a. 

 Two colonies on shells, one from Station VII. and the other 

 from Station VIII, have been referred to this species, of which they 

 may be a variety. They differ from those figured by Hincks, chiefly 

 in the form of the ocecium. The quadrate area in front which Hincks 

 describes as being depressed is in one of these colonies the most 

 prominent part, and is covered with little nodules similar to those 

 on the margin of the cell. The thickened margin of the ocecium 

 surrounding this area is divided into two parts by a small space 

 just above the bottom of the ocecium on each side. In the other 

 colony which I have, the front portion of the ocecia appear to 

 have been rubbed off by some means or another. The lower front 

 edge of the ocecium is in some cases produced downwards into a 

 point. The zocecia are closer together than in Hincks' figures, and 

 the margins are very decidedly crenate and covered with small 

 protuberances. In this respect and in shape and thickness the 

 margin agrees with my specimens of Callopora aurita, and it is also 

 very like, though thicker, than the margin of some colonies of Am- 

 phiblestrum flemingii. In Vol. I. of the Nat. Hist. Trans, of North- 

 umberland and Durham, Alder records the dredging of Mem- 

 branipora imbellis, but gives neither description nor figure by which 

 it might be ascertained whether his specimens were of the normal 

 type or resembled this variety. 



29. AMPHIBLESTRUM FLEMINGII (Busk) = Callopora, Levin- 



sen. 31 embranipora flemingii, Busk. 

 On shells, stones, Flustrae, &c, from between tide marks to 

 deep water ; common. Alder (a). 



From Stations VII., VIII. and IX. Also from shells of Nep- 

 tunea, occupied by hermit crabs, from 16 fathoms south-east of St. 

 Mary's Island. 



Ocecia — May, June and August. 



30. TEGELLA UNICORNIS (Fleming). Membranipora unicornis 



(Fleming). 



On old bivalve shells, on stones, and on test of Ascidia sordida ; 

 frequent. Alder (a). 



On Ascidia sordida from 36 fathoms east of Newbiggin, and on 

 shells from 16 fathoms south-east of St. Mary's Island, and 29-32 

 fathoms east by south of the Tyne. 



