534 H. p. KJBRSCHOW AGf^KSBORG 



a. Mandibles and E a d u 1 u . 



Bergh (1902: 207) reports the presence of mandibles for the 

 species M. bucephala, saying: 'The mandibles joining 

 above are of a form like that of other Melibes. . . . The masti- 

 catory edge is finely dentate in the upper part, in the lower 

 part provided with coarser, rounded teeth.' For the species 

 M, pellucid a (1904: 13) he reports : ' ... die gelblichgrauen 

 Mandibel ganz zerbrockelt.' And for M. rosea (1908 : 94^9) 

 he writes : ' . . . through the walls the outlines of the mandibles 

 were very distinctly visible (hg. 36). The clear yellow mandibles 

 (fig. 5) resembling those of/, ex., the T r i t o n i a d a e or P 1 e u r o - 

 phyllidiae ; . . . very plump denticulated masticatory edge, 

 the denticles reaching a height (fig. 5) up to 0-08 mm. (The 

 bulbus pharyngeus with its mandibles agree very likely in other 

 species of Melibes ; in general with that of the typical species.) ' 

 It is thus seen that Bergh finds mandibles in many of his 

 Melibes, in fact, in all species of Melibe which he described, 

 or nearly so. He even took issue with Hancock's description. 

 It really seems strange that Bergh should be so insistent on 

 this point. I have m^ doubt as to the correctness of his 

 description of one of the species (M. pellucida), collected 

 from the mouth of Columbia Eiver in the State of Washington, 

 as no other authors (Gould, 1852 ; Cooper, 1863 ; Fewkes, 

 1889; Heath, 1917; Agersborg, 1916, 1919, 1921, 1921 «, 

 1922, 1922 a, 1923 ; and O'Donoghue, 1921, 1922, 1922 a) who 

 have collected the species from the same coast, i.e. off the 

 coast of Santa Barbara, at Monterey, South-eastern Alaska, 

 Puget Sound, and the VancouA^er Island region, have recorded 

 mandibles for the types with which they dealt. A number of 

 other authors who have described several species from different 

 parts of the world also, do not record mandibles for this genus : 

 Rang (1829), M. rosea; Pease (1860), M. pilosa, 'mouth 

 proboscidiform, and the orifice vertical ' ; de Filippi (1867), 

 Jacunia papillosa (s. Melibe papillosa de Filippi) ; 

 Tapparone-Canefri (1876), M. papillosa '. . . nel suo 

 intenio ha ne lingua, ne radula, ne mascelle.' On the 



