1903.] FROM ZANZIBAR A\D BRITISH EAST AFRICA. 103 



between them is occupied by a loose spongy i-eticulum of proto- 

 plasm with few nuclei. At its proximal end the penis receives 

 the very short duct which opens into it from the prostate (pr.), 

 which with its duct is ensheathed in a continuation of the 

 muscle- wall of the penis, which at this level again fuses with the 

 muscles of the outer sheath. 



Text-fig. 3. 



Sketch of anatomy of Faraplanocera aurora, sp. nov. 



a.v., accessory vesicle ; hr., brain ; i.e., bursa copulatrix ; m., mouth ; p., penis ; 

 j)»*., prostate ; «.(^., vas deferens ; -y.s., vesicula seminalis ; i., tentacle. 



The prostate is large. There is a pair of thin- walled vesiculte 

 seminales (y.s.) outside the sheath. From each of these a short 

 duct runs, piei'cing the sheath, and uniting with its fellow to 

 enter the commencement of the prostatic duct. 



The terminal parts of the female apparatus are exactly similar 

 to those of P. langi, structurally and histologically. However, in 

 the present species I cannot find any indications of the shell- 

 glands. 



DisPAROPLANA DUBiA, gen. et sp. nov. (Plate IX. fig. 2.) 

 A single specimen. 



Length 12"5 mm. 



Breadth 3-0 „ 



" Mouth" from anterior end 4*0 ,, 



S aperture from " mouth " 1'5 „ 



$ ,, „ male -4 „ 



The external characters of this species are shown in text-fig. 4 

 (p. 104). 



There are no tentacles The eye-spots are arranged in two 



