802 MISS HELKN PIXEI-L OX 



Numerous specimens on tubes of Serpnla columhicma from 

 Departure Bay. The opaque tubes are pressed together with 

 their ends standing erect, their bases being overgrown with an 

 encrusting sponge ; the surfaces aie free from regular markings, the 

 apertures being circular and measuring about 1 mm, in diameter. 



The animals vary in colour, some being almost coloui'less, but 

 were generally some shade of red or bi-own. 



The setse of the 2nd and 3rd thomcic segments have long, very 

 narrow, delicately serrated blades (tig. 16 c). A few of the 3rd 

 are shorter, with small posterior blades ; these probably represent 

 straightened sickles (fig. 16rf). 



There is a deep collar and a wide thoracic membrane on the 

 right side only — this traverses the ventral surface obliquely 

 towards the end of the thorax and covers over several segments 

 of the abdomen. The gill rachises are thick and have long 

 pinn83, the seven normal respii'atory ones are rather taller than 

 the one bearing the opercuhnn. The latter is protected at 

 its extremity by a convex calcareous cap which extends nearly to 

 the base of the brood-pouch on the ventral side. The top is 

 quite opaque and slightly bilobed. Fifteen or more large reddish 

 ova were contained. Abdominal segments 20-29 with normal 

 geniculate setae. 



17, Spieorbis variabilis Bush (3), 1905 ; Sitka. 

 Specific characteristics : — 



1. Collar setse eoa,rsely seri'ated blades with posterior fins. 



2. Operculum without brood -pouch. 



3. Talon of operculum without projections. 



On stones and tubes of Serpnla columhicma from DejDarture 

 Bay and neighbourhood. Thick tubes about 1 mm. across with 

 the oviter whorl spi^eading over the others to some extent ; surface 

 markings were not very distinct. 



General colour brick-red, with cerise ova along the dorsal 

 surface. 



Branchise 8 (including operculum), are neai'ly hidden by the 

 high collar. The thoracic membrane on the right side is very much 

 developed. The opex'cidar plate had a. mai'ked concavity on its 

 outer side, and a small almost central talon projecting iuAvards. 

 The setse agree with those described by Bush (3). The abdominal 

 segments varied a great deal in number, from 15 to 28. 



18. Spirorbis quadrangularis Stimpson (25), 1853. 



Spirorhis quadrangularis Mbrch (20), 1863, and Bush (3), 



1905. 

 Spirorhis fahricii Malmgren (14), 1867. 

 Spirorhis carinatus Levinsen (10), 1883 + (ll)j 1886 + 



Montagu (16), 1803. 

 Spirorhis affinis Levinsen (10), 1883. 

 Spirorhis gramdatvM Moore (17), 1902 + (?) Cnullerv & 



Mesnil (5), 1H97. 



