104 Transarfioiis of the Smith African PJiilnanpliical Society. 



and a height of 3. The yellow mandibles as in the PL euchroa. 

 The rasp of the tongue, clear yellow, seemed to contain 20 series of 

 plates, the sheath about a like number ; in the lateral series about 50 

 plates. The plates yellowish ; the breadth of the median 0-075 mm. 

 by a height of 0-05, the height of the thin outermost lateral 0055. 

 The median plates (figs. 19, 20) with 8-10 denticles on each side of 

 the pointed hook, which had a strong denticle at its root. The 

 lateral plates of common form, with mostly 8-10 pointed denticles 

 (fig. 22), the 10-15 outermost somewhat slender, without denticles. 



This form differs from the other, particularly in the very small 

 size of the plates of the rasp. 



PECTINIBRANCHIATA. 



MARSENIID.?^]. 



R. Bergh, Malacolog. Untersuch., iv. (Supplementheft iii., 1, 2), 

 1886-1887, with 14 plates. 



MARSENIA, Leach. 



1. Mars, perspicua (L.). 



PI. XIV., figs. 5-9. 



A specimen was sent, taken off Umhlanga River mouth by shrimp- 

 trawl. It was somewhat contracted, nearly semiglobular. Later 

 five specimens were fished at Cape Point (N. 50° E., 18^ miles), 

 among which was one male. The largest was 3-3 cm. long by a 

 height of 1*5 and a breadth of 2-7 cm. 



The length of the first mentioned, male, specimen was 12 mm. by 

 a breadth of 8 and a height of 5. 



The colour of the smooth back was gray with rather numerous 

 more or less large blackish spots ; the rest of the body yellowish. 

 The inside of the mantle spotted blackish. The fihell of usual form, 

 8 mm. long by a breadth of 6, thin and very fragile. 



The form of the body quite as in the typical Marsenia. The large 

 penis projected forwards, 6 mm. long. 



The buccal tube 2 mm. long. The hulhus jjhari/ngeiis 2 mm. long, 

 its form quite as usual, the long rasp-sheath rolled up to the right 



