BURNE : SOUTH AFRICAN APLYSIIDJE, 



57 



Digestive organs : The radula is small, and has the formula 

 10 : I : 10. The individual teeth, though few in number, are 

 relatively large, and are sti-ongly cusped, the cusps being similar in 

 number and arrangement to those of T. Burnupi. The jaws are 

 covered with short hooked rods very similar to those of T. Burnupi. 



The buccal mass, salivary glands, crop, and stomach are quite 

 normal but for a dilatation of the oesophagus, about its middle. This 

 may, however, be an individual peculiarity, or possibly a pathological 

 condition. The intestine is remarkably short and very simply coiled 

 (Fig. 9). The point of the csecum projects from the hepato-pancreas 



Fig. 9. 



further and more abruptly than in the other species examined, 

 although in the usual place, where the intestine begins to run forward 

 upon the left side of the hepato-pancreas. 



Organs of circulation : The intra-pericardial part of the aorta has 

 no expansion {crista aorta). 



Reproductive organs : These have the usual characters, but (in this 

 specimen) are of large size. The complex of organs that lies between 

 the hermaphrodite duct and the external opening measure 7 mm. in 

 length. The seminal vesicle and spermatheca are also very conspicuous. 

 The albumen gland is nearly circular. 



The opaline gland is small (3 by 2 mm.), and consists of an 

 aggregation of separate follicles. 



Tethts elongata (Pease). 



Of this species there were two specimens fi'om Port Shepstone. 

 They had the following dimensions: total length, 21 mm. ; height, 

 (through the visceral sac) 1 1 mm., (in front of the parapodia) 7 mm. ; 

 distance from the mouth to the anterioi: end of the parapodia, 7 mm., 

 the rhinophores being situated about midway between these two 

 points. The parapodia are united behind, 2 mm. in front of the 

 extremity of the foot, to a depth of 4 mm., and are separated in front 

 by a distance of 6 mm. Their greatest depth is 4 mm. 



The rhinophores and tentacles have the same shape as in T. nigro- 

 einda. The mantle orifice measures 8 by 6 mm. The siphon is 

 small and broad. The external openings are as in T. nigrocinda. 



The colour of the animal is dullish olive green, tending to yellowish 

 brown. The concavities of the rhinophores and tentacles are black. 



The eyes lie external to the bases of the rhinophores. 



