266 



GILEEllT 0. BOURNE. 



'-P9 



Text-fig. 2. — Transverse sections through ^Enigma ajnignia- 

 tica to show the attachments of tlie gills to the body wall. A. Part 

 of a section through the anterior edge of the foot. B. A section 

 taken a short distance behind a. c. A section through the middle of 

 the byssus muscle, i). A section through the posterior edge of the 

 byssus muscle. E. A section taken through the heart. i\ The 

 tenth section of the series behind e. hm. Byssus muscle. /. Toot. 

 qo. Gonad, h. Left kidney. 7c'. Right kidney. U. Liver, l.g.l. 

 Left labial groove, l.g-r. Right labial groove, l.m. Left mantle 

 lobe. l.])g. Left pericardial gland, r.m. Right mantle lobe. v. 

 Anterior venous branch of the left auricle; the pericardial gland 

 forms a thickening of its outer wall. x. Membranous attachment 

 of tiie right inner demibranch to the lower, morphologically the left, 

 side of the foot and byssus muscle, z. Spaces serving as reservoirs 

 for water. I. Reflected lan\ella and — ii. Direct lamella of the left 

 outer dcmibraneh. iii. Direct lamella and— iv. Reflected lamella 

 of the left inner demibranch. v. Sutural union of the reflected 

 lamella of the right and left inner demibranclis. vi. Reflected 

 lamella and — vii. Direct lamella of the right inner demibranch. 

 viii. Direct lamella and— ix. Reflected lamella of the right outer 

 demibranch. 



