474 Rev. T. Hincks's Contributions towards a 



and function of the origellce * to assign to them the high 

 systematic value which is here claimed for them. The 

 tenuity of the operculum is shared bj many other forms, and 

 is not in itself of any special importance. 



Apart from these family characters, in which of course it 

 participates, the genus Arachnopusia rests on a single pecu- 

 liarity, the presence of a tall articulated spine (sometimes 

 replaced by an avicularium) on each side of the orifice, a 

 character of merely specific value. 



I should be inclined to place Lepralia monoceros, Busk, in 

 the same group as Hiantopora ferox (see note 2, p. 472). 



Additional Localities. Elizabeth Island, Straits of Magellan, 

 6 fath. ; Tom Bay, near Madre de Dios Archipelago (teste 

 Stuart 0. Ridley) : Port Jackson, 35 fath. ; off Marion 

 Island ; Tierra del Fuego ; coasts of Patagonia ; Cape Horn ; 

 north of Van Diemen's Land ; Crozet Islands ; Pacific Ocean, 

 3125 fath. [Busk). 



Ibid. (p. 58 Sep.). 

 Microporella mucronata, MacGillivray. 



This species proves to be identical with the Eschara coscino- 

 j)Jiora of Reuss (Wien. Tertiiir. 67), and his name must 

 therefore supersede MacGillivray's. In conformity with views 

 which I have stated elsewhere fj 1 should refer this and 

 kindred forms to the genus Adeona, Lamx., and to the sub- 

 section of it which includes species destitute of the flexible 

 stem. 



Ibid. (p. 58 Sep.). 

 MoNOPORELLA, gen. nov. 



The name Haploporella having been previously employed, 

 the above has been substituted for it (' Annals,' ser. 5, vol. viii. 

 p. 135, note 2) (p. 78 sep.). 



Ibid. (p. 59 Sep.). 

 Monoporella lepida, sp. n. 



Waters in the first instance identified tliis species with 

 Memhranipora perforata, MacG., but subsequently admitted 



* '' Des bourgeons charuus developp6s sur I'endocyste ; elles s^cretent 

 du calcaire sur leur pourtour seulemeiit, en produisant des pores plus ou 

 moins r^guliers sur le bord des zooecies" (Jullien, BulI.Soc.Zool.de 

 France, t. xi., 1886). 



t See " Critical Notes on the Polyzoa," Ann. & Mag. Nat. Hist, 

 sei". 5, vol. xix. p. 150. 



