104 A.TRACTYLIDJE. 



slender tentacles; GONOPHOIIES ovate, enveloped by the 

 polypary, borne on the summit of short branches, which 

 are wrinkled spirally. 



WE have two independent accounts of this zoophyte, from 

 Wright and Allman, who discovered it about the same 

 time. For I have little doubt of the identity of the Bimeria 

 vestita and the Manicel/a fusca of these authors, although 

 the former is described by Wright as destitute of a pro- 

 boscis, while the latter, according to Allman, has this organ 

 well-developed. The proboscis amongst the Hydroids is 

 constantly changing its form and assuming the most diffe- 

 rent appearances, being sometimes extremely prominent, 

 and at others so much contracted as to be scarcely visible. 

 As the two zoophytes perfectly agree in other characters, 

 it is probable that this slight discrepancy between the 

 descriptions merely points to a difference in the condition 

 of the specimens examined. 



The polypary of Bimeria, when divested of its earthy 

 coating, is transparent and of delicate texture. The whole 

 habit of the zoophyte is slender, the branching is very 

 regular, and there is no expansion towards the terminal 

 aperture. The most marked character is the membranous 

 envelope, or extension of the polypary, which involves the 

 body of the polypite and forms a rather thick sheath round 

 the lower portion of the tentacles. Dr. Wright has 

 remarked that the unclothed half only of the arms is fur- 

 nished with thread- cells. 



Hub. On the Bimer Rock, near North Queensferry, and 

 on Inch Garvie, Firth of Forth (T. S. W.): Firth of Forth, 

 " attached to other zoophytes and seaweeds near low water, 

 spring tides" (G. J. A.): Whitby, Yorkshire; Torbay and 

 Salcombe, South Devon, dredged on other zoophytes, not 

 uncommon (T. H.). 



