16 Marine Investigations in South Africa. Vol. V. 



Dolabella Hasseltii, Per. Eliot, Notes on Tectibr. and Naked Moll. 



from Samoa. Proc. Ac. Philadelphia, 1899, p. 515, pi. xix., 



fig. 3. 

 (Dolabella callosa, Lam. Syst. des Anim., s. v. 1801, p. 62.) 

 Dolabella BumiMi, Cuv., Rang. Bgh., I.e., 1905, pp. 13-20; 



taf. vii., figs. 22-40; taf. viii., figs. 1-7 (9). 



PI. XIV., figs. 10-20. 



One specimen was procured at East London and preserved in 

 formalin. 



The length of the individual was 12 cm. by a breadth of 9 and a 

 height up to 6"3 ; the length of the posterior disk was 7'5 cm. by a 

 breadth of 8-5 (the breadth of its brim 1-2) ; the length of the 

 branchial slit 7 cm. by a breadth at both ends of 1 ; the height of 

 the sipho 9 mm., that of the parapodia 13, of the (contracted) 

 rhinophoria 6 mm. ; the length of the curved gill in a straight line 

 3-5 cm. by a breadth of 2-3 and a thickness of 1-8 cm. The animal 

 was one-coloured, yellowish white, the gill less bright. 



The shell of typical form (figs. 12, 13), 4-3 cm. long by a breadth 

 of 3-3 ; the crest on the hinder end not strong ; the calcareous layer 

 on the under side of the strong yellowish cuticula broken in pieces in 

 front, the upper as well as the under side of the shell chalk-white. 



The form of the animal was typical, the branchial fissure reaching 

 to about the middle of the hinder disk. The back with rather 

 numerous (fig. 11) small pointed cones of a height of 2-4 mm., as 

 also the hinder disk, as well as its somewhat laciniated brim 

 (fig. 10). The seminal furrow in its first part running in the 

 depth between the parapodia for a length of 2 cm., then continued 

 forwards to the male genital opening under the right tentacle. The 

 mouth, the sipho, the anus, and the pallial gland as usual. Nearly 

 the posterior half of the gill projects freely ; on either side it showed 

 about ten strong compound chief lamellae ; at the base of the 

 frenulum of the gill the reno-branchial aperture. The common 

 genital opening as usual. 



The central nervous system agrees with that of the true AplysiiE, 

 and is quite different from that of the Notarchidae, with which group 

 the Dolabellae otherwise show affinities ; the visceral ganglia thus 

 situated far backwards (on the side of the spermatotheca). The 

 nearly coalescent cerebral ganglia measure in breadth nearly 4 mm. ; 

 the cerebro-pleuro-pedal connectives about 13 mm. long ; the pleuro- 

 pedal ganglionic mass 8 mm. broad ; the pleural ganglia scarcely 

 half as large as the pedal.* 



* Cf. Amaudrut, Bull. Soc. Philom., x., 1886, pp. 68-74. 



