54 THE NAUTILUS. 



the species of the American west coast which falls within this 

 description must be of the same genus Melibe. The effort, 

 therefore, to build further 011 the nomenclature of Gould, asi 

 has been done by Cooper (1863), Fewkes (1889) and more 

 recently by Dr. O'Donoghue (1921) seems to me to be inde- 

 fensible, and, owing to the fact, that the genus Melibe may 

 either possess mandibles (Bergh, 1875) or not, (Alder and 

 Hancock 1864, De Filippi 1867, Tapparone-Conefri 1876, 

 Eliot 1902), the generic description may be modified to read 

 in part: 



Bulbus pharyngeus aut cum mandibiUs aut sine mandibilisj 

 radula et lingua destitutus. 



In point, of fact, Bergh (1908) pp. 94, 95, for the family; 

 Tethymelibidae Bergh (1892) pp. 1039-1043, after consis- 

 tently having reported mandibles for each species of Melibe 

 he described during a number of years (1875, 1880, 1884, 

 1888, 1890, 1892, 1902, 1904) finally admits of the following: 



" Forma corporis quasi ut in /Eolitliidis. Caput perma- 

 gnum et cuculliforme ; rhinophoria vagina magna retractilia, 

 clavo perfoliato; tentaeula nulla. Epinotidia (papillae dor- 

 sales) colosseas sine bursis cnidogenis. Bulbus pharyngeusi 

 rudimentarius, lingua et interdum quoque mandibulis desti- 

 tutus. ' ' 



In the family Tethymelibidae there are only two genera, 

 Tethys and Melibe. In the genus Melibe he includes eleven 

 species, but he thinks that continued examination will likely 1 

 reduce this number. Among the species mentioned he in- 

 cludes Chioraera leonina (Gould) and now, (1908) emphasizes 

 the following as Melibeau characteristics: 



" Corpus nomiihil compressum. Branchiae (proprias) 

 nullfe. Podarium angustius. Bulbus pharyngeus soluin 

 lingua destitutus." , 



It is thus seen that he admits, in spite of his controversy 

 with Hancock, that: the tongue and sometimes also the man- 

 dibles are entirely lacking. 



None of the authors, (Gould, Cooper and Fewkes) who have 

 not employed the nomenclature of Rang for this type, have 

 described mandibles, and O'Donoghue, (1921) states defini- 



