802 MISS HELEN PIXELL OX 



Numerous specimens on tubes of Serpula columhiana from 

 Departure Bay. The opaque tubes are pressed together with 

 their ends standing ei'ect, their liases being overgrown witli an 

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

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



The animals vary in colour, some being almost colourless, but 

 were generally some shade of red or brown. 



The set<e of the 2nd and 3rd thoracic segments have long, very 

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

 are shorter, with small posterior blades ; these probably represent 

 straightened sickles (fig. \&d). 



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

 right side only — this traverses tlie 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 

 pinnae, the seven normal respiratory ones are rather taller than 

 the one bearing the operculum. The latter is protected at 

 its extremity by a convex calcareous cap Avhich extends nearly to 

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

 quite opaque and slightly bilobed. Fifteen or more large reddish 

 ova were contained. Abdominal segments 20-29 with normal 

 geniculate setse. 



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

 Specific characteristics : — 



1. Collar setse coarsely serrated blades with posterior fins. 



2. Operculum without brood-pouch. 



3. Talon of operculum without projections. 



On stones and tubes of Serptda columbiava from Departure 

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

 the outer whorl spreading over the others to some extent ; surface 

 markings were not very distinct. 



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

 surface. 



Branchiae 8 (including operculum), are nearly hidden by the 

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

 developed. The opercidar plate had a marked concavity on its 

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

 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 Morch (20), 1863, and Bush (3), 



1905. 

 Spirorbis fahricii Malmgren (14), 1867. 

 Spirorhis carinatus Levinsen (10), 1883 -f (11), 1886 -|- 



Montagu (16), 1803. 

 Spirorbis affinis Levinsen (10), 1883. 

 Spirorbis gramdaivs Moore (17), 1902 + (?) CauUery & 



Mesnil (6), 1897. 



