204 



ZOOLOGY. 



near the mouth. The umbrella is gradnally withdrawn inta 

 the mouth, so that eventually only a crown of short tooth- 

 like projections surrounds the mouth. Finally the whole 

 umbrella is swallowed, the arms at the end of the body dis- 

 appearing, while the end of the intestine projects far out 

 from the body behind the mouth. By this time the Phoro- 

 nis form is clearly indicated, the body being long and slen- 

 der and the mouth surrounded by a crown of short tentacles, 

 the end of the intestine being entirely withdra'mi within thfr 

 body. These changes are rapidly effected. The larra or 

 Echiurus is formed on the Annelid tj-pe. 



In Phascolosoma cmmentarium (Quatrefages), the body is 

 much shorter than in P. Goul- 

 dii J the worm lives in compara- 

 tively deep water (10 to 50 fath- 

 oms), in dead, deserted shells, 

 building out the aperture bv a 

 conical tube of sand. In Sipun- 

 culus (S^Tins) the tentacles are^ 

 fringed or lobed. It does not 

 occur in American waters. 



In Uchi'unis the intestine ends 

 at the end of the body, and thcrfr 

 is a circle of bristles at the pos- 

 terior end, while Bonellia differs 

 in having an enormous proboscis, 

 and only a few bristles near the- 

 head. In Bonellia rtridis Ed. 

 of the ilcditerranean (Fig. 141),. 

 the prolioseis is deeph" forked ; 

 the intestine is very long, convo- 

 luted, and into the cloaca emptr 

 two excretory organs. The ovarv 



boscif ; i,i. digestive is a cord-like Organ, which in the- 



jnlenal threads (only . ? i ' -, 



nterior end of the dl- posterior part 01 the body IS fjist- 



Pig. m.—BOTtellia viiidis ; the 

 proboBcis coiled Fevenil times, p^ 

 fore end of the proboscis ; Jt, ^, fnr- 

 row in the probi 

 cnnal : m, mesen 

 ehown on the an 



gestive canal) ; ff, organs of excre- i i_ l_^ ■ 



tiou; c, cloaca; u. ovidnc —After eUCU tO tlie intCStllie. 

 Lacaze-DtLthiers : from Gegenbaur. rn ^j i ■-!• i i t * 



LhcEiouerma ntiiduJinn LoveiL 

 occurs in 20-40 fathoms off the coast of Europe and 

 Northern Xew England. The body is long, cylindrical, ami 



