1902.] 



NUDIBRAXCHS FROM ZAXZIBAR. 



69 



anatomy to be coi-rect, paiticularly as regards the absence of jaws. 

 They say : " In Melibe the buccal organ is pi'ovided with neither 

 tongue, jaws, nor collar." Bergh, in his monogi-aph on the genus 

 (in Malac. Untersuch. in Semper's Reisen, Th. ii. Bd. i. p. 363), 

 thinks this statement will probably piove incoii-ect as other species 

 of Melibe are provided with jaws, and he gives as a generic 

 character: " Bulbus pharyngeus cum mandibulis aliquantulum ut 

 in Phylliroidis: margo masticatorius mandibular fortiter dentatus." 



Text-fig. 5. 



Mel He fimbria ta. 



a., anus. 

 din., diverticulum. 

 f.ce., folds of oBsophagus. 



h., hood. 



I., lip. 



pyhst., pyloric portion of stotnacli. 

 St., thin-walled stomach. 

 st.pl., belt of stomach-plates. 

 v., ventricle of heart. 



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

 of Melibe fimbriata, and in all failed to detect any trace of jaws. 

 Our drawing (text-fig. 5) will perhaps explain clearly the structure 

 of the digestive tract. In the centre and bottom of the hood is 

 a pi'otruding, circular, fleshy lip. This leads stiuight into the 



