vii MOLLUSCA~THE PALLIAL COMPLEX 73 



reaching so far forward that the anus is found near the right edge of the mantle cleft 

 1 here is only one neplindial aperture to the left of the base of the ctenidium, far up in 

 the mantle eavity. The inner surface of the mantle, between the rectum on the right 



^\IIh^I:~^^^- f? ; '" '' ^''^'" °"^ °'' ""^ '''«" (^fter Souleyet). The mantle is cut open 

 rZ: 1 rj"'K "° ' '''''' ""' '^''^ ""^'^ ^" ^^' ^'^' ' "'« P°«iti°'i of the pallial organs is thus 

 I Zr. \ .; ^™^°?'' ^''"°"*= 3, foot; 4, penis; 5, seminal duct, which is continued at 15; 

 b floor of the palhal cavity = nuchal integument; 7, coluniellar muscle; 8, intestine; 9, heart'in 

 the opened pericardium ; 10, digestive gland (liver) ; 11, testes ; 12 an.l 13, renal organs ; 14, renal 

 aperture; 15 seminal duct; 10, rectum ; 17, hypobranchial gland ; 18, anus ; 10, cteni,lium (gill) ; 

 20, mantle ; 21, osphradium ; 22, respiratory siphon. 



and the gill on the left, is glandular, and rejiresents the slightly differentiated hypo- 

 branchial gland. The genital aperture lies close to the anus. 



Docoglossa.-In the PaMlh/a; (Figs. 69, 70) a short conical portion of the 



