8 Marine Investigations in South Africa. Vol. V. 



4. Apl. lobata, B. n. sp. 

 PI. II., figs. 8-12. 



One specimen was procured from Woodstock beach (Table Bay) ; 

 it was preserved in a rather contracted condition. 



It was 3 cm. long with a breadth of 2-5 and a height of 2 ; 

 the length of the mantle shield 2-3 with a breadth of 1'7, the length 

 of its hole 6 mm., the sipho about 8 mm. high with a breadth of 10, 

 the height of the foot-wings (on the inside) 14 mm., the breadth 

 of the foot 9 mm. The animal was dirty yellowish white in colour. 



The foot-wings with grossly undulated margin. They both showed 

 at about the middle of their length a perpendicular fissure with a 

 smaller one before and behind. They coalesced posteriorly, and in 

 front nearly covered the head with a prominent lobe 8 mm. long. 

 The mantle very large and prominent; the gill bent, 13 mm. long, 

 with a breadth of 7 and a thickness of 4. The whole body was 

 quite smooth. 



The shell (tig. 8) of usual form, 2*2 cm. long with a breadth 

 of 1-7, very thin, its calcareous layer broken in many small pieces. 



The foot- wings were of curious form, lobed and both so sym- 

 metrical that it scarcely could be by mutilation. The gill with 

 about twelve compound pairs of lamellae, the last third freely 

 projecting, the anus and the renal pore very distinct. 



The hulbus pharyngeus 8 mm. long with a breadth and a height 

 of 6 ; the mandibular plates 1*5 mm. broad, dirty yellow, their 

 elements (fig. 9) somewhat bent, of a height up to 0"22 mm. 

 with a diameter of 0"013, a little flattened at the point. The palate 

 thorns erect, plump, of a height up to 0*06 mm. The brownish 

 yellow rasp of the tongue contained 32 series of plates, in the 

 sheath 18, the total number of plates being therefore 50, the 

 number of plates in the series 15. The plates yellow, the median 

 0"35 mm. broad, the length of the basal part of the four outer lateral 

 plates 0"06-0-10-0-14-0"20 mm., and mounting up to 0-30, that 

 of the first (inmost) 0*28 mm. The median plates (fig. 10) with 

 three denticles at the base of the finely denticulated hook ; the lateral 

 plates (fig. 10) with finely denticulated hook, with one denticle at 

 the inside of its root, with 2-3 on its outside ; the 3(-4) outer lateral 

 plates (fig. 11) without hook. 



The masticatory stomach small, 4 mm. long with a diameter of 4 ; 

 it showed about five clear yellowish white pyramids of a height 

 of about 2-5 mm. ; close at the cardiac end 2-3 series of small 

 roundish tubercles. The liver yellow. 



The penis (fig. 12) 9 mm. long, no armature. 



This form seems to represent a definite species. 



