38 



NILS HJ. ODHNER 



P- 



This is, as pointed out by the authors mentioned, very small, 

 with thin, membraneous jaws, making the impression of being 

 greatly reduced in comparison with the Aeolids, a fact that 

 Pelseneer (1894, p. 98) interprètes as a sign of higher speci- 

 alization of Doto compared with Aeolis. There are some further 

 characteristics in the bulbus which increase this difference and 



seem to speak in favour of the view 

 of Pelseneer, viz. the presence of 

 ptyaline glands of singular sti'ucture. 



Bergh (1888) i could not state the 

 occurrence of salivary glands, though 

 such have been found by Alder & 

 Hancock. On the other hand, he men- 

 'w tions the presence of ptyaline glands; in 

 D. fragilis he found one on each side 

 of the oral cavity. In D. coronata, as 

 well as in D. fragilis, I have found 

 many such glands all round the mouth; 

 they each consist of some spheroid acini 

 agglutinated on the proximal ends of 

 their ducts which join distally to stiff 

 and straight canals. Without doubt these 

 glands are the same as Alder & Hancock 



Fig. 15. Doto coronata ge- mention and figure as „accessory sali- 

 nital system (cf. p. 47). ^^^^ ^j^^^ . g^^jj^^ ^j^^^^ ^^^ ^^^^^ 



authors mention, and reproduce, a large simple „salivary gland" 

 imposed on the genital organs and opening by an elongated 

 duct into the oral cavity. Bergh (1888) recognizes this feature 

 in i). coronata an „eine grosse, weissliche, hinten so wie oben, 

 auf und an der (rechten) Seite des Schlundkopfes liegende und 

 sich etwas weiter gegen hinten erstreckende Drüsenmasse." I 

 have met vsMth the same gland in the two species of Doto exa- 



1 Beiträge zur Kenntnis der Aeolidiaden. Verhandl. d. k. k. Zool.-bot. 

 Ges. in Wien, IX. 



