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



Ovarium ( fi". 40. o. ), sub caelcris inlestinis [lositura , habet colorem albidum at- 

 que formam irregulärem et dissimilcin. 



Oi<if/uGlus ( Cg. 40. M. M. ) , postqiiatn aliquot conlorsiones fecerit, orificio exlerno , 

 quod et illi organo et ductui excrelorio vesiculae ( fig. 40. y. ) commune est , apo 

 rilur. 



In Onchidio Typhae (i) hcrraaphrodilismus non locum habet, uti memorat Bii- 

 rhanan, cui tarnen hac de re Cuvierius et Ferussaci us non plane confidunt. 

 Quod putat Buchanan de organis generationis illius animahs , sequentibus exprimi* 

 verbis : « This is not , like many olhers of the worm kind , an hermaphrodite animal , 

 ,« for Ihe male and female organs of generation are in dislincl individuals. I have 

 « not yet perceived any mark to distinguish ihc sexes while lliey are not in copula^ 

 « lion , as, in both , the anus and sexual organs are placed in a perforalion ( cloaca 

 « communis ) in the under part of Ihc tail , immcdiately behind the food : but diiring 

 « coition the distinction of sexes is very evident, the penis protruding to a greal 

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

 « gard to Ihe geslalion of Ihc female , or how she produces her young." 



§- 8. ' 



PLANORBIS. (Brug.) 

 (fig. 43 et 44.) 



In Ptanorbc ooitieo {i) testicittus (%. 4.3. a.) ultiraam corporis parlem occti>- 

 pat, quocirca etiam. formam ultimarum Cochleae convolutionum exhibet. Colorem ba- 

 tet album cinereum , externa convolutionis pagina punclis parvulis nigris instnvHii» 

 est, interna vero vas deferens oriri vidimus; in caeteris autem cum Helieisj\v»c\\.\r». 

 eonvenit. 



Vas deferens (fig. 43. e. ) ejusdem , ac testiculus, coloris , priraum multis tubu« 

 lis , illud organon circumdantibus , inslruclum est , qui paulalim breviores reddili me- 

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



Hoc loco ductus seminalis ( fig. 43. /. ß f. f-^ incipit per oviductum proeurrcns , 

 quocum nonnuUas contorsiones init; prope oviductus finem glandula proslattca (fig.. 

 43. e. ) ei adhaerel. Glandula illa habet formam ovatam , elongatam atque colorem 



al> 



(i) Buchanan, Transactions ef tbe tinnean Society ^ London, t^". i8oo. Vol. 5. pag, iSü. tab. V. 

 fig. I , a et 3, 



(a) Lam. Tom. YI. P. 3. p. i5a. Draparnaud, Uisloire nalureUe des Mollusques terreslres et 

 ßuvialilti de la France y Paris, i8o5. 4°. p. 43» tab. \, ßg,. 4»».44. 



