622 DR. BR. V. ERLANGER, 
front wall of the pericardium is seen from behind, and shows the left kidney 
by transparency, and the inner opening of the reno-pericardiac duct. &. 
Fic, 4.—Mantle cavity of Trochus turb., opened andextended. Ventral 
view of the gill, pericardium, nephridial ducts, and rectum. 22. 
Fic. 5.—Pericardium of Fissurella cost., opened dorsally; heart cut 
out. Both kidneys seen in situ by transparency. &, 
Fic. 6.—Mantle cavity of Fissurella cost., in transverse section, display- 
ing the shape of the mantle cavity, the position of the gills, anus, nephridial 
papillz, and basibranchial sinus. 
Fic. 7.—Transverse section through the pericardium and both kidneys of 
Trochus turb., showing the reno-pericardiac canal. 32. 
Fie, 8.—Transverse section through the basibranchial sinus and both 
kidneys of Trochus turb., showing the reno-pericardiac canal. 32. 
Fic. 9.—Horizontal section through the pericardium and both kidneys of 
Haliotis tub. 32. 
Fic. 10.—Ventral view of the mantle cavity and pericardium of Fissurella 
max. ‘The pericardium is opened ventrally; the heart is displayed. +. 
Fig. 11. Dorsal view of Emarginula Huzardi, after removal of the 
shell. Anatomy seen by transparency through the mantle. 1. 
Fic. 12.—Transverse section through the basibranchial sinus of Trochus 
turb., showing the reno-pericardiac canal opening into the pericardium. 32, 
Fic. 13.—Transverse section through the basibranchial sinus of Trochus 
turb., showing the reno-pericardiac canal opening into the left kidney. 32. 
Fie. 14.—Dorsal view of Patella coer, after removal of the shell, pig- 
ment, and hood; displaying the relations of the pericardium and both kidneys, 
the papille of the anus and both kidneys. 4. 
Fie. 15.—Transverse section through the pericardium and both kidneys of 
Puncturella spec.? 22. 
Fie. 16.—Transverse section through the pericardium of Fissurella gibb., 
showing the right kidney opening into its papilla. 32. 
Fie. 17.—Tectura spec.? viewed from the left side after removal of the 
shell, showing the position of the pericardium. +. 
Fic. 18.—Papilla and genital duct of Fissurella cost., cut transversely 
and viewed from behind; a bristle has been introduced into the genital duct, 
and comes out through the duct of the right kidney. 42. 
Fic. 19.—Left kidney of Fissurella cost., dissected out. 42. 
Fic. 20.—Transverse section through the pericardium and subanal tract of 
the right kidney in Patella coer. 2. 
Fic. 21.—Transverse section through the right renal papilla and genital 
duct of Fissurella gibb, +99. 
