the Atractjiis coccinca of T. S. Wright. 53 



No gonophores were found. HIncks (' Hydroid Zoophyte?,' 

 18(j8) provisionally transferred the species to the genus 

 Perigoniinus. AUraan does not mention it at all, and I have 

 not been able to find any subsequent record of it. 



In 1905 1 obtained near Millport Marine Biological Station 

 numerous specimens of what is almost certainly tlie Atracti/h's 

 coccinea of Wright. They differ from Wright's specimens in 

 having twelve equal tentacles, but they all have tlie hydrauth 

 set at an obtuse angle with the stalk, a very characteristic 

 point. 



The species was not figured by Wright, and his description 

 was in some respects incomplete. I therefore give here a 

 detailed description of my siiecimens and a ligure. 



The Sj)ecies must be assigned to the genus Wrightia, 

 Allman (1872). The genus Atractylis, Wright (1859), 

 contained forms which are now distributed among tlie genera 

 BougainvilUa^ Perigoniinus^ and Wrightia. Hincks's genus 

 AtractyUs is synonymous with Ailman's Wrightia, but the 

 name Wrightia is to be preferred, since Atractylis is the 

 long-established name of a genus of plants. Wrightia, when 

 constituted by AUinan, contained one species, Wrightia 

 arenosa {Atractylis arenosa, Alder, Suppl. Catalogue, p. 7, 

 pi. X. figs. 5-7), and the diagnosis of the genus contained 

 some of the syocciy^c characteristics of Wrightia arenosa (Aldei-), 

 namely, the fumiel-shaped stems, the retractile hydranth, and 

 the position of the gonophores on the hydrocaulus. I propose 

 the following definition of the genus, which is in all essentials 

 the same as Ailman's definition, but leaves out any reference 

 to the purely specific characters of either of the two species 

 which the genus contains, arenosa (Alder) and coccinea 

 (Wright). 



Wrightia. 



AtractyUs (iu part.), Wright, Edin. New Phil. Journ. ix. p. 106 (1859). 

 Atract'i/lis, Ilineks (1SC)8). 

 Wriyhlia, Allman (1872). 



Hydrocaulus erect, unbranched, arising from a creeping 

 liydrorhiza. Perisarc expanding ab^ve to form a protective 

 sheath which clothes the hydranth up to the base of the 

 tentacles. 



Reproduction by fixed sporosacs, which are partially or 

 wholly invested by a chitinous envelo[)e. 



Wrightia coccinea (Wright). 



Atractylis coccinea, Wright (1801). 

 Perigoniinus (?) coccineus, Ilincks (1868). 



