152 SESSII.IA. 



Coronula diadema — The CaowN Coronula. Plate XIX. 

 fig. 12. Somewhat compressed, with six prominent longitudin- 

 ally ribbed valves ; alternating with as many depressed trans- 

 versely striated ones. Found attached to the skin of whales in 

 the North seas. 



Genus 7.— TV BlCmELL A.— Lamarck. 



Generic Character. — Body inclosed in a shell, with small 

 setaceous and unequal cirri. — Shell univalve, tubular, straight, 

 and somewhat narrowed towards the base ; surrounded with 

 nearly equidistant transverse ribs ; truncated at both ends, and 

 open at the top, and provided with a bottle-shaped operculum ; 

 consisting of four valves ; base closed by a membrane. 



Tuhicinella balcenarum.— The Whale Tueicinella. Plate 

 XIX. fig. 13. Tubular, with transverse ribs, and a ring-shaped 

 margin ; operculum bottle-shaped. Found buried in the fat of 

 the skin of whales in the South American seas. The operculum, 

 and a portion of the upper part of the tube being only visible. 



