510 II. p. KJERSCHOW AGERSBORG 



deiii englisclien ^'erf. vorkommenden, von den untenstehenden 

 abweichenden anatomischen Angaben wahrscheinlich als 

 unrichtig erweisen . . , Besonders wird solches wohl der Fall 

 sein, wo Hancock den Anfang des Verdaiiungskanals bespricht : 

 " The buccal organ is provided with neither tongue, jaws nor 

 collar : it is not by any means very distinctly marked, formed 

 as it were by a mere enlargement of the oesophagus, and having 

 little or no increase of muscular power." ' 



P3ut Eliot (1902) verifies Hancock's claim when he writes : 

 ' I also found Alder and Hancock's description of the internal 

 anatomy correct, particularly as regards the absence of jaws. 

 . . . Mr. Crossland and I have . . . dissected several specimens 

 of Melibe fimbriata, and in all failed to detect any 

 trace of jaws.' 



Gould's Chioraera leonina (1852) corresponds very 

 closely in the general anatomy to that of Melibe fim- 

 briata Alder and Hancock, (1H64) ; this is also true in 

 regard to the species discovered by Rang (1829) and sub- 

 sequently described by Bergh (1863. 1871, 1875 &, 1879a 

 1884. 1888, 1890 6, 1902*^, 1904, and 1908). The only difference 

 is on the point in regard to mandibles. Some authors. Rang, 

 Gould, Pease, Cooper, and Fewkes, do not touch on this point, 

 and for that reason one cannot tell whether the particular speci- 

 mens with which they dealt actually had such organs. With 

 the exception of the mandibles, all the generic characteristics 

 as set forth by the earliest writers on this type of the molluscs 

 agree (Rang, 1829 ; Gould, 1852 ; Pease, 1860 ; Cooper, 1863; 

 Alder and Hancock, 1864; de Filippi, 1867; Tapparone- 

 Canefri, 1876 ; and Fewkes, 1889 ; as well as the numerous 

 descriptions of Bergh. 1863-1908). The discovery of the genus 

 Melibe by Rang (1829) seems to have been unknown to 

 Gould (1852), who created a new genus (Chioraera) for this 

 type. Cooper (1863) and Fewkes (1889) employed the nomen- 

 clature of Gould. The generic characteristics as enunciated 

 by the original author for Melibe, Rang (1 829), are practically 

 identical with those set forth by Gould twenty-three years 

 later for Chioraera. Tryon,' Jr. (1883: 328). without 



