356 



THE FRESH-WATER MUSSEL 



II 



FIG. 94. Dissection of Anodonta, made by removing the mantle - 

 lobe, inner and outer gills, wall of pericardium, and auricle of the left 

 side, and dissecting away the skin, muscles, c. of the same side down 

 to the level of the enteric canal, kidney, nervous system, &c. Part of 

 the enteric canal is laid open, as also are the kidney (kd} and bladder 

 (bl). The connection between the cerebro-pleural (c. t>L gn) and 

 visceral (v. gn} ganglia is indicated by a dotted line. 



a, anus ; a. ad, anterior adductor ; a. ao, anterior aorta ; a. v. ap, 

 auriculo-ventricular aperture ; bl, urinary bladder ; c. pL gn, cerebro- 

 pleural ganglion : d. d, duct of digestive gland ; d. gl, digestive gland ; 

 d.p. a, dorsal pallial aperture ; ex. sph, exhalant siphon ; ft, foot ; g. ap, 

 genital aperture ; gon, gonad ; gut, gullet ; i. I. j, inter-lamellar junc- 

 tion ; in. sph, inhalant siphon ; int, intestine ; kd, kidney ; m, mantle ; 

 mth, mouth ; p. ao, posterior aorta ; p. ad, posterior adductor ;pc, peri- 

 cardium ; pd. gn, pedal ganglion ; r. ap, renal aperture ; r. an, right 

 auricle ; ret, rectum ; r. p. a, reno-pericardial aperture ; st, stomach ; 

 ty, typhlosole ; v, ventricle ; v. gn, visceral ganglion ; w. t, water- 

 tubes ; x, aperture between right and left urinary bladders. 



(From Parker and Haswell's Zoology. ) 



and above the posterior adductor, finally discharging by the 

 anus (a) into the exhalant siphon, or cloaca. The wall of 



