PHYLUM O ELENTERATA 



into the interior of the body, and terminates in a free edge. 

 This tube is called the gullet or stomodseum. Its inner 

 surface is marked with two longitudinal grooves (sgph), 

 known as the gullet-grooves or siphonoglyph.es. The gullet 

 does not simply hang freely in the interior cavity, but is 

 connected with the body-wall by a number of radiating 



?rtfti 



cefr. f 



s.m. 



>nest 



Fig. 54. — Tealia crassicornis. Dissected specimen; gon, gonads; gul, gullet; 

 /. in, longitudinal muscle; Ip, lappet; mes. I, primary, mes. 2, secondary, 

 tnes. 5, tertiary mesenteries; mes. F, mesenteric filaments; mth, mouth; 

 ost. J, ost. 2, ostia or aperture in mesenteries; /. >n y parietal muscle; sgpli, 

 siphonoglynhe; s. tn, sphincter muscle; t. in, transverse muscle. 



partitions, the complete or primary mesenteries (mes. i) ; 

 between these are incomplete secondary mesenteries (mes. 2), 

 which extend only part of the way from the body-wall to 

 the gullet, and tertiary mesenteries (mes. J), which are 

 hardly more than ridges on the inner surface of the body- 



