PLATE XVI. 



Class MOLLTJSCA. 



LAMELLIBRANCHIATA. 

 THE FRESH-WATER MUSSEL (Anodoii). 



FIG. 1. VALVES OF THE SHELL, x \. 



. anterior end : p. posterior end : h. hinge on the dorsal aspect : 

 m. 1 , m. 2 position of the anterior and posterior adductor 

 muscles: u. umbo. 



FIG. 2. VIEW ON REMOVAL OF PART OF THE MANTLE. THE DOTTED LINE SHOWS 

 WHERE THE MANTLE HAS BEEN CUT.' X |. 



v. right valve laid up : li. position of the heart : g. gills on the right 

 side: a. a. anterior adductor muscle: a.f. anterior foot- 

 retractor : /. p. foot-protractor : m. mouth : p. labial palps : 

 /. foot : ma. mantle : b. branchial siphon : a. anal siphon : 

 p. a. posterior adductor muscle : p.f. posterior foot-retractor. 



FIG. 3. DISSECTION SHOWING THE OPENINGS OF THE GENITAL GLAND AND THE 

 ORGAN OF BOJANUS. x J. 



g*,g. z gills on the right and left sides : m. mantle : /. foot : p. labial 

 palps : a. anterior adductor muscle : 6. 1 bristle in the opening 

 of the organ of Bojanus : b. 2 bristle in the opening of the 

 genital gland. 



FIG. 4. POSTERIOR VIEW, x --. 



a. anal siphon : b. branchial siphon. 



FIGS. 5, 6, 7. HEART AND RECTUM, x 1. 



a. right auricle : v. ventricle : b. bristle in the opening of the organ 

 of Bojanus into the pericardium: a. 1 anterior aorta: . 2 

 posteiior aorta: r. rectum: o. openings from the auricles into 

 the ventricle. 



FIG. 8. DIAGRAM OF THE ORGAN OF BOJANUS. 



on. posterior adductor muscle : p. pericardium : v. ventricle : i. 

 internal opening of the organ : e. external opening of the 

 organ : g, genital opening : k. " kidney " or glandular portion 

 of the organ : n. non glandular portion. 



FIG. 9. DISSECTION FROM THE LEFT SIDE : PARTLY DIAGRAMMATIC : TO SHOW 



THE ALIMENTARY SYSTEM, x |. 



/ foot : g. gills : m. mouth : s. stomach surrounded by the " liver " : 

 i. coils of intestine : p. pericardial sac : r. rectum. 



FIG. 10. NERVOUS SYSTEM, x |. 



p. s. parieto-splanchnic ganglia : c. cerebral ganglion on the right side : 

 p. pedal ganglia : c.s. commissure : a. anus : g. gills. 



