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otolith in connection with the macula acustica recessus 
utriculi, and another with the papilla acustica lagen, but 
none were observed in relation to the three criste acustice, 
although it is possible that small concretions of chalk 
were there also. There is a very large sense organ on the 
inner wall of the sacculus in front, known as the macula 
acustica sacculi (m. a. s.), and behind, the sacculus is pro- 
longed upwards and backwards into the digitiform lagena 
(lag.), otherwise known as the recessus sacculi or cochlea, 
the inner wall of which, at about the roof, contains another 
sense organ, the papilla acustica lagene (p. a. .). A 
constriction or definite sacculo-cochlear canal is not 
differentiated. 
The sense organ on the floor of the utriculus known 
as the macula acustica neglecta is entirely wanting in the 
Plaice. 
The ear and auditery nerve of Plewronectes flesus have 
been described by G. Retzius,t who, with other authors, 
refers to the utricular, saccular and lagenar otoliths 
respectively as the lapillus, sagitta, and asteriscus. His 
description agrees very closely with ours of the Plaice, so 
that it is only necessary to point out that he did not 
succeed in finding either a reduced ductus endolymphati- 
cus or a utriculo-saccular connection. With regard to the 
latter he says:—‘‘ An der unteren Wand des Utriculus, 
ungefahr gerade unter dem Sinus superior, findet sich eine 
kleine, trichterférmige, hohle Verlingerung des Utriculus, 
welche nach hinten geht und sich zu einer feinen Diite 
verschmalernd an die Wand des Utriculus legt; ob aber 
dieser Canal blind endigt, was ich am meisten glaube, 
oder ob er vielleicht in den Sacculus (als ein Canalis 
communicans) ausmiindet, kann ich nicht mit Bestimmt- 
heit angeben.”’ 
t Anat. Unters., 1872, p. 52, Taf. v., figs. 10—18. 
