796 MISS HELEN PIXELL ON 



Specific cliaractevistics : — • 



1. Last thoracic segment on the right has no dorsal seta?. 



2. Collar setae with fin-like expansions at base of deeply serrated 



blades. 



3. Some setje of third segment bladed sickles. 



4. Embryos incubated in the tube. 



This species was quite common on stones and i-ocks from the 

 Departure Bay region and from Victoria. 



The tubes vaiy a good deal but are always ti\anslucent, Avith 

 the whorls piled on one another. The whole tube measures 

 about 2"5 mm. in diameter and the aperture about 1 mm. across. 

 There are various markings on the exterior. Sometimes a 

 ridge along the median line ends in a sharp pi'ojection above 

 the aperture — in the grooves on either side of this there may 

 or may not be scalariform markings. Young specimens have 

 shells as figured for this species by Levinsen (10. fig. 11), older 

 ones were ridged more like /Sp. cancellatns (10. fig. 18). The living- 

 animals were bright pink in colour. Gills 7, each with six pairs 

 of long opposite pinme, opercular plate a shallow funnel. About 

 20 abdominal segments. 



Sub-genus Dexiospira (Oaullery & Mesnil, 1897). 

 Characteristics : — 



1. Tubes dextral. 



2. Thorax with 3 setigerous segments. 



8. Sptrorbis spirillum Linne, 1767. (PL LXXXVIII. 

 figs. 8rt-8c.) 



Serpida sinriUum Linne (12), 1767 ; Fabricius (7), 1780. 

 tSpiroybis spirillum Malmgren (14), 1867; Levinsen (10), 



1883; Caullery& Mesnil (5), 1897; Moore (17), 1902; 



Bush (3), 1905. 

 Spirorbis Imldus Montagu (16), 1803; Morch (20), 1863; 



Malmgren (14), 1867." 

 Circeis armoricaiia Saint- Joseph (24), 1894. 

 Spirorbis borealis Fewkes (8), 1885. 



Specific characteristics : — 



1. Collar setje geniculate (fig. 8 c). 



2. Operculum without brood-pouch. 



3. Concave plate of operculum has a slight projection (talon) 



on under side. 



Two vai-ieties of this species were fairly common in the Departure 

 Bay region and at Victoria, growing on calcareous polyzoa, 

 seaweeds, etc. The discoid form grows only on smooth surfaces, 

 Larainarian thalli being often extensively covered with specimens. 

 These were very fiat, regularly coiled tubes — the spiral with 

 I5 to 3 coils measuring "5 to 2 mm. in diameter (tig. 8 a). The 



