200 PROCEEDINGS OP THE MALACOLOGICAL SOCIETY. 



distally to the diapliragm near its light border. In all the other 

 Achatininae examine! the penis retractor seems to be a branch of the 

 right ocular retractor. 



The following genera, Pseudachatina, Columna, Metachatina, and 

 Perideriopsis, are, according to Pilsbry, still unknown anatomically, 

 as is also Callistopepla, with the exception of the radula, which was 

 worked out by Adolf d'Ailly (Moll. terr. et d'eau douce de Kameroun). 

 In the present state of our knowledge the genus Burtoa, as 

 exemplified by Nilotica. seems to fit in very nicely where it is, 

 between Achatma and Limicolaria 



In concluding, I must offer my thanks to Mr. E. A. Smith, 

 Mr. E. R. Sykes, and Mr. R. H. JBurne for kindly assistance with 

 literature and advice. 



REFEREXCES. 



D. de Ferussac et G. P. Deshayes : Histoire Naturelle Geuerale et Particuliere des 

 Mollusques Terrestres et Fluviatiles, etc., Paris, 1820-51. 



M. J. R. Bourguignat : Mollusques de I'Afrique E'quatorial de Moquedouchou, etc., 

 Paris, 1889. 



H. A. Pilsbry: Manual of Conchology, vols. x\'i and xvdi, October 6tb, 1903- 

 June, 1905. 



EXPLANATION OF PLATE XVIL 

 Fig. 1. — General view of pallial organs with the pericardium laid open. 

 ,, 1 A. — Cloaca and lower portions of the rectum and ureter of another specimen 



laid open to show their relative positions. Also the thick mascular 



fold and furrows leading to ureter. 

 ,, 2. — General view of the genital system with the organs in their natural position. 



The final portion of the albuminiparous gland was missing, and is 



approximately shown by dotted Knes. The ovotestis and its duct were 



missing, but the CiBCum is there. 

 ,, 2 A. — Albuminiparous gland with the ovotestis and its duct and csecum from an 



unimpregnated or recently impregnated animal. 

 ,, 2 B.— Penis divested of the muscular sheath, showing muscle attached to 



vas deferens. 

 ,, 2 C. — Lower portion of the reproductory system of another impregnated animal, 



laid out. 

 ,, 2 D. — Spermatheca from an unimpregnated or recently impregnated animal. 

 ,, 3 A. -Jaw. 

 ,, 3 B.— Radula. 



,, 3 C. — Median and first lateral teeth of radula. 

 ,, 3 D. — Two lateral teeth from half-way between centre and margin of radula. 



A. Anus. P. Penis. 



A.Gl. Albuminiparous gland. Pr. Prostate. 



Ce. Cfecum. F. V. Pulmonary vein. 



J^. I, i^. II. Grooves leaving ureter in Re. Rectum. 



the cloaca. R.F. Longitudinal folds on inner surface 

 F. Od. Free oviduct. of rectum close to tlie vent. 



M. Heart. R.M. Penis retractor. 



M.B. Muscular band. Sp. Spermatheca. 



M.F. Muscular fold in cloaca. Sp.l). Spermatheca duct. 



M.S. Muscular sheath of penis. Ur., Ur. i, Ur. ii. Ureter. 



Ne. Kidney. Ut. Uterus. 



Ot. Ovotestis. V.D. Vas deferens. 



Ot.D. Duct of ovotestis. Vg. Vagina. 



