no PROCEEDINGS OF THE ACADEMY OF [1880 



The oral tube whitish, of about 1.0 mm. length, wide. The bulbus 

 pharyngeus clear brownish-yellow, somewhat pyriform, with oblique 

 flattened posterior end, in length about 1.6, by a height of nearly 1.3, 

 and a breadth of 1.5 mm. ; the sheath of the radula a little prominent 

 downwards, and to the left from the hindermost part of the under side of 

 the bulbus. The lip-disk clothed with a brownish-yellow cuticula, that 

 is continued into the two mandibular plates behind the lip-disk at the 

 entrance of the oral cavity, the form of the mandible could not be 

 determined with certainty ; a yellowish cuticula clothes the rest of the 

 cavity. The tongue with ten rows of plates, further backwards six 

 developed and two younger rows ; the total number eighteen.^ The 

 rhachis (fig. 2) not very narrow. The plates yellow. The length of 

 the first plate about 0.11, of the second 0.20, of the inmost of the ex- 

 ternal plates 0.14, of the following 0.12, 0.10, 08 and 0.06 mm. (all 

 from the hinder part of the sheath). The first lateral plate (fig. '■laa^ 

 5, 6) formed somewhat as in the P. Lessouii, the hook still smaller ; 

 the second of the same form, but larger (fig. 2&i, 3), the hooks much 

 larger, especially the anterior, which is broader and excavated (fig. T). 

 More outwards five external plates (fig. 2cc), all with a crest, which is 

 larger in the two innermost ; adjoining the outermost of these plates 

 several longitudinal folds of the lingual cuticula, which sometimes 

 simulate one to two plates more (fig. 2). 



The salivary glands whitish, elongate. The oesophagus rather wide, 

 the stomach inclosed in the liver. The intestine appearing at the 

 middle of the length of the liver a little to the left, at the bottom of a 

 deep and large cavity in the upper side of the liver ; the pyloric part 



' According to Alder and Hancock (Monog. Part VII, 1855, PI, 41 sup- 

 plement, fig. 20, 21), the number of rows was fifteen in the Polycera qnad- 

 rilineata, sixteen in tlie P. ocellata. thirteen in the P. Lessonii ; Alder and 

 Hancock saw (1. c.) four external plates in the Pol. quadrilineata, five in 

 P. ocellata, and six in P. Lessonii. Meyer and Moebius saw five to seven 

 external plates in their Polycera ocellata, whilst the number of rows (1. c. 

 PI. 50) is noted as thirteen to fifteen ; in the P. quadrilineata they found 

 four to five external plates and twelve to thii-teen rows. In four specimens 

 of Pol. quadrilineata I saw six to eight rows on the tongue, more back- 

 wards six to seven developed, and one not quite developed row ; the total 

 number of rows was fourteen to fifteen. In all specimens there were but 

 four external plates. In four specimens of Pol. Lessonii I saw nine to ten 

 rows on the tongue, more backwards eight to seven or five developed, 

 and a single not developed row; the total number of rows was sixteen to 

 eighteen. In all the specimens there were eight external plates. 



