240 



BUSH 



SPIRORBIS LANGERHANSI Caullery and Mesnil 1897. 

 Type locality. — Panama. 



Scattered over the surface of specimens of Crucibulmn imh?'icatum 

 Sby. and Callopoma from Panama, are numerous isolated tubes hav- 

 ing a regularly coiled sinistral form spreading at the base, often form- 

 ing a thin border around it. Four-sided in section, with the outer wall 

 oblique and not perpendicular to the inner one, each shoulder of the 

 comparatively narrow, flattened, dorsal area defined by a carina vary- 

 ing in size in different individuals ; occasionally one occurs which is 

 not regularly spiral, forming a small central cavity. The entire sur- 

 face is often roughened by conspicuous transverse lines. No animals 

 were found. Caullery and Mesnil give the collar setse as similar to those 

 in S. marioni and the plate on the operculum not unlike that found in 

 6". vitreus Fabricius. 



SPIRORBIS MORCHI Levinsen 1883. 



p1. XXXVII, figs. 15, 24; p1. xli, figs. 15, 16, 21, 24, 25; pi. XLiv, figs. 20, 21. 



Type locality, — Greenland. 



Sinistral, dull, opaque unsculptured tubes, forming low coils, with 

 small central cavity, sometimes with upward turned aperture, are not 

 readily identified without their animals, as they are usually more 

 symmetrical than the form figured by Levinsen. They do not, 

 however, differ essentially from eastern specimens on stones from 

 the Grand Banks of Newfoundland and on Chlamys islandicus from 

 Greenland. 



The collar setas have a form similar to that given by Levinsen ; a 

 long, tapered, coarsely serrate blade with conspicuous, fin-like basal 

 portion. Setae in the second and third fascicles, long, tapered, delicately 

 serrate blades, a few in the third with odd comb-like ends. Uncini 

 with comparatively coarse teeth. 



Operculum not unlike that found in the eastern examples, in which 

 it is a brood-pouch protected by a very convex, bilobed, opaque cal- 

 careous cap with a long shield-shaped posterior or inner portion, 

 shallow at the back and extending nearly the length of the operculum 

 in front ; the eggs visible only in a back view. 



Sitka, on tubes of Crucigera; Prince William Sound, at Orca, on 

 the tubes of Serpula; also on a specimen of Pachypoma from Queen 

 Charlotte Island, British Columbia, collected by the Geological Survey 

 of Canada. 



