194 HUGH WATSON. 



Sci., 1884, vol. iii, p. 81, pi. xvii, fig. a ; Tryon, Man. of Concli. 



(2nd ser.), 1885, vol. i, pp. 17, 251, pi. ii, fig. 95 ; Cockerell, Ann. 



Mag. Nat. Hist. (Oth ser.), 1890, vol. vi, p. 390. 

 Chlamydophorus gibbon si Binn.; Tryon, Struct, and Syst. 



Conch., 1884, vol. iii, p. 13, pi. ci, fig. 47. 

 Apera gibbonsi (Binn.); Heynemann, Jalirb. d. Deutscli. Mai. Ges., 



1885, vol. xii, p. 17, pi. ii, figs. 5-7; Collinge, Ann. S. Afr. Mus. , 



1900, vol. ii. p. 4; ColUnge, Ann. Natal Mus., 1910, vol. ii, p. 165; 



Connolly, Ann. S. Afr. Mus., 1912, vol. xi, p. 63. 



External Characters (PI. YII, figs. 1, 2 ; PI. VIII, figs. 14, 

 15). — Animal slender, tapering to an acute angle at the hind 

 end. Back rounded, without keels. Outer lip of respiratory 

 opening almost concealing the inner lip. Skin coarsely 

 reticulated. Dorsal grooves usually about 1 mm. apart, 

 separated by a single row of rugse, but united for about 4 or 

 5 mm. in front of the respiratory opening. Lateral grooves 

 irregular, rather near the dorsal grooves, and seldom extend- 

 ing as far as the head. Radial grooves conspicuous, some 

 being forked. Oblique sub-lateral grooves also conspicuous, 

 and rather numerous ; these and the radial grooves termi- 

 nating in the single peripodial groove. 



In the typical form the body is mottled with brown, the 

 small patches of colour being chiefly concentrated dorsally, 

 but leaving a paler band, very sparsely mottled, along the 

 centre of the back from the head to the respiratory opening. 

 Laterally the brown pigment becomes confined to the sides of 

 the grooves in the skin, and dies out completely some distance 

 above the peripodial groove. The ground-colour is pale 

 yellow in specimens preserved in spirit, but living examples 

 are tinged with dull orange, the colour being deepest on the 

 back. 



The type was described by Mr. Gibbons as being rather 

 more than 3 in. long when fully extended. The following are 

 the dimensions (in alcohol) of two specimens that I have 

 examined, but the reproductive organs of the smaller one 

 were not quite fully developed. 



