162 J. E. S. MOORE. 



an internal brood-pouch which had been observed iu Tangan- 

 yikia rufofilosa. But in the M. episcopalis the pouch 

 is directly above the esophagus, and median instead of being 

 below and to the left side as iu the former case. (Compare PI. 

 16, figs. 1 and 2.) 



I do not think, however, that this relative change observed 

 in the position of the brood-pouch between T. rufofilosa and 

 M. episcopalis is of much morphological importance, for the 

 whole series of structures is far too similar in both cases to 

 admit of the slightest doubt that they must be regarded as 

 morphologically the same. 



In two small Melanias (species?) which had been collected 

 by Mr. Cummings from the fresh waters of the Philippine 

 Islands similar grooves were present in the females, and in 

 like manner these were connected with median dorsal brood- 

 pouches. 



In a male Faunus, also lent to me by the authorities of the 

 British Museum, there was a most pronounced groove (PI. 15, 

 fig. 11, g. V.) ; but, as I have had no opportunity of examining 

 the female, I am naturally ignorant whether the groove is 

 here connected with a brood-pouch or not. 



From all this it is evident that in some Prosobranchs, T. 

 rufofilosa, M. episcopalis, and several other forms, there 

 exists in the female a complex accessory reproductive apparatus, 

 which consists of an external ovigenetic groove in direct rela- 

 tion with an internal brood-pouch, which is either median and 

 dorsal, or lateral and on the left side. In the males of these 

 forms these structures are represented by spermatic grooves 

 exactly similar to those of the Struthiolaridse, the genera 

 S trombus, Pteroceras, and the like. But so far as at present 

 known the complete female apparatus is only represented in 

 Spekia and the so-called Melanias which I have named. In 

 various female Prosobranchs, however, more or less of the groove 

 at any rate appears. In the female S trombus gigas there 

 is a very pronounced groove leading downwards across the foot, 

 which is figured by Haller.^ Also in the female Littorina I 

 ' 'Morpli. Jalub.,' Bd. xix, 1893, Taf. xix, fig. J 7. 



