20 M. C. V E R L R E N, 



Ovarium ( fig. 40. o. ) , sub caeteris intestinis positum , habel colorem atbidum at- 

 que formam irregularem et dissimilem. 



Oviductus (fig. 40. M. M. ) , postquam aliquol conlorsiones fecerit , orificio exlerno , 

 quod et illi organo et ductui excretorio vesiculae ( fig. 40. y. ) commune est , ape- 

 ritur. 



In Omhidio Ttjphae ( i ) hermaphroditismus non locum habet , uti memorat B u- 

 chanan, cui tamen hac dere Cuvierius et Ferussacius non plane confidunt. 

 Quod putat Buchanan de organis generationis illius animalis, sequentibus exprimiJ 

 Terbis : « This is not , like many others of the worm kind , an hermaphrodite animal , 

 « for the male and female organs of generation are in dislinct individuals. I have 

 not yet perceived any mark to dislinguisb the sexes while they are nol in copula» 

 « tion , as , in both , the anus and sexual organs are placed in a perforation ( cloaca 

 « communis ) in the under part of Ihe tail , immediately behind the food : but dming 

 « coition the distinction of sexes is very evident, ihe penis protruding to a gr^jat 

 « length , considering the size of the animal. I have as yet learned nothing with re- 

 « gard to the gestaUon of the female , or how she produces her young»" 



§ a. 



PLANORBIS. {Brug.y ' , 



(fig. 43 et 44.) 



Tn Planorbe corneo (2) tesdculus (fig. 43. a.) ultimam corporis patteai occu- 

 pat , quocirca etiam formam ultimarum cochleae convolutionum exhibet. Colorem ha» 

 bet album ciiiereum , exlerna convolutionis pagina punctis parvulis nigris instrucUis 

 est , interna vero vas deferens oriri vidimus ; in caeteris autem cum Heliois slructura 

 convenit. 



Vas deferens ( fig. 43, c. ) ejusdem , ac tesliculus , coIoTis , primum multis tubu- 

 lis, iHud organon circumdantibus , inslructum est, qui paulatim breviores redditi me- 

 dia fere vasis parte desinunt, deinde ad ovarium confertur, cui arcte adhaeret. 



Hoc lOGO ductus seminalis ( fig. AZ. f.f. f. f.^ incipit per oviductum procurrens, 

 quocum nonnullas contorsiones inil; prope oviductus finem glandula proslatica (figi 

 43. e. ) ei adhaeret. Glandula illa liabet formam ovatam., elongatam atque colorem 



al« 



(i) Buchanan, Transactions of the LiitMan Society , London, 4<». 1800. Vol. 5. pag. i32. tab. Y. 

 fig. I , Q et 3. 



(j) Lam. Toin. YI. P. a. p. iSa. Draparnaud, Hlsloire naltireUe des Mollusques terreslres et 

 jlimatiles de la France, Paris, iSo5, 4". p- 43, tab. t, fig. 4a — 44. 



