DIPHASIA ROSACEA. 69 



other objects, throwing up stems, curving and 

 tendril-like towards the tips, which grasp any 

 object for support. Side branches, which 

 hardly differ in size from the stems, are given 

 off alternately; the receptacles are tubular 

 and occur on both sides of the stem oppositely. 

 The apertures are furnished with a lid or 

 operculum. The capsules differ in each sex ; 

 the male is cylindrical in shape, lobed 

 lengthwise, and surmounted by a crown of 

 spines ; the female is somewhat pear-shaped, 

 with a supplementary chamber for the 

 maturing ova, and with two prominent 

 incurved spines at the crown. Specimens 

 showing both forms of capsule are exhibited 

 in the glass-topped boxes. 

 Common in the trawl. 



Sertularia pumila, Linnaeus. (PLATE V.) 



2 dry specimens on sea-weed. 



SPECIMENS Sertularia pumila covers with 

 47, 48. great profusion, various sea- weeds 

 between mid and low tide. It is of a stronger 

 and closer build than S. gracilis, but shorter 

 and more branching, the branches often being 



