Notes on South African Mollusca. 165 



Animal of specimens from T'Kaigas : — 



Colour (in alcoliol) whitish, roof of mantle-cavity tinged with 

 grey near the edge and along the rectum. Pallial organs very 

 similar to those of D. coagulum (cf. PI. IV., fig. 5). Pedal gland 

 partially embedded in the muscles of the foot, especially at the hind 

 end (Text-fig. 1, C, D). 



Jaw 1-3 mm. long, rather narrow, thin, yellow-brown (PI. IV., fig. 23). 

 Radula of specimens, the shells of which measured about 21 mm. in 

 ■diameter, 3'9 x 1"3 mm. ; transverse rows of teeth trending slightly 

 forwards on each side of the middle line, where they form a very 

 obtuse angle ; teeth broad and short (PI. IV., fig. 15) ; ectocones are 

 present on about two-thirds of the teeth ; formula of one specimen 

 (35 + 1 + 37) X 128, of another (30 + 1 + 30) x 137. Crop and 

 salivary glands surrounded with darkly pigmented connective 

 tissue. 



Reproductive system (PI. V., fig. 7) : hermaphrodite duct long, 

 very slender, and closely convoluted ; vesicula seminalis rather 

 small ; free oviduct scarcely swollen ; receptaculum seminis small, 

 with a slender duct ; vagina long ; vas deferens rather closely bound 

 to the anterior half of the penis, but only loosely attached further 

 back ; penis rather small and slender, curved at the hind end. 



Hah. Little Namaland. T'Kaigas (Rogers). 



Type in South African Museum. 



Eight examples, the smallest measuring: Diam. maj. 18-3, min. 

 14-8 ; alt. max. 8 ; apert. 8'5 x 7'4 mm. 



I have founded this new species on a series of small shells in 

 perfect condition, of which some of the animals have been available 

 for dissection. It is possible, however, that the Type represents the 

 smallest race of a species which usually attains much greater dimen- 

 sions, for I have seen examples from Henkries District, Little 

 Namaland, apparently conspecific with those from T'Kaigas, but 

 attaining such dimensions as : — 



Diam. maj. 27-9, min. 21-7 ; alt. max. 12-2 ; apert. 11-0 x 11-4 mm. 

 and ,, 33-9, „ 26-8; „ 18-0; „ 18-5 x 14-2 „ 



The last of these is illustrated on PI. III., fig. 3. They are too long 

 dead to be classified with any certainty, but they agree in form with 

 the smaller shells, and show calcined traces of a mottling, which 

 would probably correspond, in life, to that which appears on the 

 early whorls of the Type set. 



Although connecting links may doubtless be found, all these shells, 

 large and small, can at present be clearly distinguished from other 



