^Q4t Prof. Allman on the Construction and 



vested by a chitinous periderm. Polypites developed from the 

 summits of the branches, " vase-shaped, destitute of proboscis " 

 (metastome), and having the tentacles in a single verticil round 

 the margin of the distal end of the vase-shaped body. " Coral- 

 lum (periderm) body, mouth, and lower half of each of the tenta- 

 cles clothed in an opake brown membrane." (Dr. T. S. Wright.) 

 Gonosome. — Gonophores adelocodonic, developed from the 

 coenosarc. 



Some years ago (Ann. Nat. Hist. July 1859) I constituted a genus, 

 under the name of Manicella, for a singular Hydroid which I had 

 discovered in the Firth of Forth. Simultaneously with the publica- 

 tion of Manicella, Dr. Strethill Wright published his genus Bimeria 

 for a Hydroid which he had previously described and characterized 

 as a new genus under this name at a meeting of the Royal Physical 

 Society of Edinburgh, but of which no published account existed. 

 On seeing Dr. Wright's description of his Bimeria, I was at first 

 disposed to regard the two genera as identical, and to believe that we 

 had been, independently and unknown to one another, describing the 

 same form. Further consideration, however, of Dr. Wright's descrip- 

 tion of Bimeria has shown me that, besides differing in some minor 

 points, this description is in one very important point quite inappli- 

 cable to Manicella ; for while Manicella possesses a well-developed 

 metastome, it is stated by Dr. Wright that there is no metastome in 

 Bimeria. 



I have had no opportunity of inspecting authentic specimens of 

 Dr.Wright's Hydroid. It is quite possible that the metastome of 

 Bimeria may have been overlooked ; this question can be decided 

 only by further examination. Until, however, the absence of a 

 metastome in Bimeria be confirmed, I should hesitate to give Mani- 

 cella the position of an established genus ; and I shall therefore for 

 the present retain it as entirely provisional. 



Bimeria vest it a, Wright. 



4. Garveia, Strethill Wright. 



Trophosome. — Coenosarc invested by a periderm, and con- 

 sisting of a branching hydrocaulus, which is rooted by a filiform 

 hydrorhiza, and towards its base composed of aggregated tubes. 

 Polypites fusiform, developed on the summits of the branches, 

 and having the tentacles in a single verticil round the base of a 

 long conical metastome. 



Gonosome. — Gonophores adelocodonic, borne on the summits 

 of short branches, which spring from the sides of the hydro- 

 caulus. 



Garveia nw^ans, Wright, = Eudendrium {Corythamnium) bacci- 

 ferum, Allm. 



