

1G7 



2. Aplysiella unguifera (Rang)? 



Aplysia unguifera, Rang. I.e. 182S. p. 52, pi. V, fig. 4 — 7. 

 Dolabrifera unguifera, Gray, 1. c. 



PI. I, Figs, li)— 30. 



One specimen of the form examined here was taken on Febr. 17th, 1900, at 

 Koh Kahdat. 



The animal, preserved in spirit, had a length of 12 mm , by a breadth of up to 6 mm , 

 and a height of up to 4 mm ; the length of the gill-slit was 4*5 mm . — The colour was 

 whitish; on the back a few scattered black spots were seen, and here and there small 

 whitish tufts with brown-gray, roundish bases; on the fore part of the back three such 

 tufts were found in a longitudinal series. The marginal part of the foot-sole was finely 

 dotted with gray. The gill was whitish. 



The form was as usual. The left parapodium joined the shell closely, covering one 

 half of it, while the right one lay almost exposed in the gill-slit, scarcely covered by the 

 right foot-lobe which had a height of '2™™. The tufts of the back (fig. 19) had tubercles 

 and short branches. 



The shall (figs. 20, 21) had a length of 5 mm , by a breadth of 3-75 mm ; it was flat- 

 tened, only posteriorly at the nucleus a little hollowed (fig. 21), rather thin, but highly 

 calcinated and firm; its contour was ovate, narrowing posteriorly, the right margin was 

 posteriorly somewhat notched ; the nucleal part projected upward in a knob ; the lines of 

 growth were rather strong. 



The relations of the central nervous system were not to be determined. The 

 otocysts had a diameter of 0"075 mm , they were crammed with otoconia. 



The bulbus pharyngeus was whitish, of a length of l'ö™ 11 , the radula-sheath 

 projected a little on the lower side posteriorly. The palatal hooks were as usual, of a 

 length of up to 0'04 mm , rising more or less obliquely (fig. 23). . The yellowish mandible 

 plates had a length of O'öö 111111 , by a breadth of up to O - ^"" 11 ; their hinder edge was a 

 little convex, while the fore edge was a little concave, above and below they were rounded. 

 The elements of the plates were closely set; their hook mostly bent upwards, forked, now 

 and then somewhat irregular, of a height of O^IO 111111 (fig. 22). The tongue was as usual; 

 in the slightly yellowish radula 17 series of tooth-plates occurred, in the sheath 12 devel- 

 oped series and 3 undeveloped ones; thus the total number of series was 32. In the 

 series up to 30 lateral plates were found on either side of the median ones. The breadth 

 of the median plates was - 08 mm ; the height of the hook of the second lateral plate was 

 0-055 mm , the heights of the 4 outermost plates were 0*04— 0-06— 0-08— 0M0 mm , and the 

 height rose to (H2 mm ; the colour of the plates was yellowish, the outermost ones were 



