NEW ACTINIANS FROM BRITISH COLUMBIA. 967 



and it is not improbable that tlie two forms are identical. It 

 must be noted, however, that Faurot (1895) identifies P.hoeckii 

 with P. hastata, and until anatomical da,ta are furnished it will 

 be well to regard it as a distinct form. Finall}', in the Medi- 

 terranean P. tricapitata the conchula is composed of tiibei'cles ; 

 and while the correctness of its original identification by Andres 

 (1881) -with P. triphi/Ua must still be regarded as a jjossibility, 

 it seems advisable for the present to regard it as a good 

 species. 



A provisional arrangement of the known species of Peachia 

 may then be stated thus :— 



Tentacles 12. 



CoDcliular lobes 6-20, irregular P. hastata. 



Couchular lobes 3, lamellar, 



sessile P. tripliijlla. 



borne on tubular prolongation of siphonoglyph . F. hoeckii. 

 Concliular lobes tuberculiform, 



three in number P . tricapitata. 



five in number P. quinquecapitata. 



? P.carnea. 



Tentacles 8 P. Icoreni. 



BiCIDIUM /EQUORE^, sp. n. (PI. XOVIII. figs. 5-7.) 



This form is not uncommon as a parasite npon the bell of the 

 Leptomedusa JEquorea forskalii, which is of very common occur- 

 rence in the waters of British Columbia. The column (fig. 5) 

 has a rounded base, is somewhat conical or urn-shaped and 

 wrinkled transversely by contraction in examples preserved in 

 formalin. Proximally it usually shows some faint longitudinal 

 grooves which mark the lines of insertion of mesenteries, but no 

 signs of veiTucpe or other adhesive oi^gans could be seen. The 

 margin, which is indistinct, is occupied bj' a single series of twelve 

 short and obtuse tentacles. The mouth (fig. 6) is usually 

 widely expanded, so as to completely hide the disk, and shows a 

 single siphonoglyph ; no conchula was present. 



Size. — Length about 7 mm., greatest diameter 4 mm. 



Colour. — There was no trace of colour in any of the examples 

 seen. 



Structure. — 'J'he column mesogloea is thinner than either the 

 ectoderm or endodernn and has a homogeneous or finely fibrillar 

 structure, cells being scattered throughout the ground-substance. 

 The ectoderm is of uniform structure thioughout its entire 

 extent, no verrucal areas being distinguishable. There are no 

 ectodermal muscle-fibres, and those of the endodermal surface are 

 arranged in a simple layer, there being no mesoglceal lamellse for 

 their support and no indications of a sphincter muscle. The 

 musculature of the tentacles is also very feeble, the ectodermal 

 fibres being arranged in a single uniform layer, while the endo- 

 dermal ones are hardly distinguishable. 



The single siphonoglyph is prolonged somewhat below the level 



