4 Annals of the South African Museum. 



forming a somewhat spatulate-shaped tail. All the keels are well 

 marked. The radiating lines from the respiratory orifice are very 

 plain, especially those directed posteriorly ; the two mid-dorsal ones 

 are also very prominent. Peripodial groove distinct. Generative 

 orifice below and behind the right lower tentacle. Foot-sole orange- 

 red, not differentiated into median and lateral planes. Tail flattened 

 and slightly overlapping the foot-sole, terminating bluntly. Rugae 

 small. Length (in alcohol) 65 mm. ; breadth of foot-sole 9-5 mm. ; 

 breadth of dorsum, mid-length, 10 mm., behind respiratory orifice, 

 13-5 mm. 



Shell internal, situated posterior to the respiratory orifice. 



Hab. Richmond, Natal. Rev. J. R. Ward, 1899. Type in 

 collection of South African Museum. 



This species differs from both A. gibbons i, W. G. Binn., and 

 A. bicrnujn, Fi. A. Sm., the only two known species of this genus, 

 in a number of particulars. Binney * mentions that the former is 

 "rather slender," and that "the foot is dull opaque white, with a 

 tallowy yellow tint, and with an indistinct bluish streak along 

 middle"; in both of these external features it differs from the 

 species here described. Externally it differs from A. burnupi in 

 the colour and general form of the body. As this latter species 

 has not been figured, I here give (plate I., figs. 5-6) two views 

 drawn from an alcoholic specimen very kindly sent to me by Mr. 

 Edgar A. Smith, of the British Museum. 



Binney in his original description of the genus {I. c. p. 331) 

 correctly states that there is no caudal mucous pore, but in the 

 same paper (p. 358) he refers to the " longitudinal furrows above 

 the margin of the foot, meeting over a caudal mucous pore." 



The shell is situated at the most posterior portion of the body 

 behind the pallial organs. In the specimen dissected it was broken 

 up into fragments, but so far as I could judge from these, it is a large 

 solid cap-like structure. 



In alcoholic-preserved specimens of Apera all the internal parts 

 are exceedingly brittle and contracted, so that probably in fresh 

 material, or if otherwise preserved, they would have a very different 

 appearance. Having only one example of A. natalensis, which I 

 wished to preserve as nearly whole as possible, I have only examined 

 the alimentary canal, pedal gland, and generative organs, for purposes; 

 of comparison with those organs in .1. buiiitqji, E. A. Sm., of which 

 I gave a short description in 1897.1 



* Bull. Mus. Comp. Zool., Camb., 1879, vol. v., pp. 331-32. 



t Ann. and Mag. Nat. Hist., 1897 (ser. 6). vol. xx., pp. 221-25, plate v. 



