220 HUGH WATSON. 



THE OCCURRENCE AT CAPE TOWN OP 

 TESTACELLA MAUGEI FEB. 



This well-known species ^ is the only carnivorous slug, in 

 addition to those belonging to the genus Apera, which is 

 kuown to occur in South Africa, for it is probable that 

 Ceratoconchites schultzei {Siviroth) is the larva of a 



The genus Testacella can be distinguished at a glance 

 from all the other g*enera of slugs known to inhabit South 

 Africa, because in this form alone the hind end of the back is 

 covered by an external shell. In some respects the anatomy of 

 Testacella resembles that of Apera, but it is so well known 

 that it is unnecessary for me to describe it here. More than 

 a hundred years ago Cuvier'^ gave an account of the internal 

 organs of one member of the genus ; and since then the re- 

 searches of Gassies and Pisclier, de Lacaze-Duthiers, Plate, 

 Simroth, and others, have given us a fuller knowledge of the 

 anatomy of Testacella than of almost any other carnivorous 

 snail or slug. 



The following are the principal characters by which 

 Testacella maugei can be distinguished from the other 

 species of the same genus : (1) the comparatively large size 

 of the shell, and its length and convexity; (2) the widely 

 separated origin of the lateral grooves ; (3) the presence ol" a 

 central tooth in the radula; (4) the small number of the 

 buccal retractors ; (5) the unusual length of the tentacular 

 retractors, and the fact that they both arise to the left of the 

 middle line; (6) the swollen anterior end of the receptacular 



' See Apj)endix for the more important references to Testacella 

 maugei. 



■^ Simroth, H., 'Zool. Auz. Leipzig.' 1907, vol. xxxi. pp. 794, etc.; 

 Simroth, H., 'Deutsche Siidpolar Exped.," 1910, vol. xii, Zool. iv, p. 172 ; 

 Bottger, O., 'Abhandl. Senckenb. Naturf. Ges. Frankfurt,' 1910, vol. 

 xxxii, p. 433. 



3 ' Ann. Mus. d'Hist. Nat.,' 1804, vol. v, pp. 435-444. pi. xxix, figs. 

 6-11. 



