165 



Vayssière, rech. — sur les moll, opislhobr. I. Tectibr anches. 1885. (Ann. du mus. d'hist. nat. de Marseille, 



II, 3). p. 71 (—75). pi. 3, flg. 70— 76). 

 Pelseneers, rech, sur divers OpisthobrancJies. 1894. p. 26. pi. 10, flg. SO — 81. 



Forma corporis fere ut in Aplysiis propriis, attamen nonnihil elongata, postice 

 nonnihil latior, antice (capite et collo) angustior. Senium palliale cum testa non desunt. 

 Podarium non angustum. 



Ganglia visceralia antice inter pleuralia sita. 



1. Aplysiella incerta, Bgh. n. sp. 

 PI. I, Figs. 9—18. 



One specimen of this form was taken together with Dolabrifera unguifera (see 

 hereafter) on Febr. 17 th, 1900, at Koh Kahdat. 



Preserved in spirit the specimen had a length of 25 mm , by a breadth of 13 mm , 

 and a height of 6 mm ; the length of the gill-slit was 7 mm . The colour was dirtily yellow, 

 on the back scattered black spots were seen; the short and thick gill, of a length of a" 

 was yellowish white; on the sole of the foot scattered yellow gray spots and numerous 

 white dots were seen. 



The form was as usual, in the general outline longish-oval; the foot-lobes were 

 small, the right one overlapped the other, and the shell was quite covered; the gill was 

 rather large. On the back small, rather thick cones of a height of up to O'SO 111111 were 

 found sparingly scattered (flg. 9). 



The shell (fig. 10) was horn-like, yellowish, not quite thin, of a length of 9\5 mm , 

 by a breadth of up to 8"5 mm , only little bent, of the common form; the nucleal part was 

 exceedingly small, the lines of growth were rather distinct. 



The yellowish central nervous system (fig. 11) was upon the whole very 

 similar to that of Notarchus. The cerebral ganglia which adjoin each other, were roundish, 

 almost twice the size of the pleural ones ; between the latter the two visceral ganglia 

 were found, the right one closely adjoining the right pleural one, the left one connected 

 with the left pleural one by a short connective; close behind the arch formed by the 

 pleural and the visceral ganglia, the large, transverse-oval pedal ganglia are found, some- 

 what notched in the hinder end, and connected by a short commissure. The rather large 

 buccal ganglia were connected by a short commissure; the short-stalked gastro-oesophagal 

 ganglia were small (of a diameter of 0'08 mm ), roundish. The nerve cells had a diameter 

 of at least up to 0-1 2 mm . 



The otocysts had a diameter of 0'10 mm ; they were closely filled with otoconia 

 of a diameter of up to OOIG 111311 . 



The buccal tube had a length of 2 mm . The short-pyriform bulbus pharyngeus 



