40 



J. H. ORTON. 



transportation of food-particles are effected by means of sets of cilia, but 

 in order to make out the actions of these different sets it is necessary 

 to examine separate living leaflets. 



THE CILIATION OF THE GILL OF SOLENOMYA. 



When two of the living leaflets (comprising a single pair) of Solenomya 

 are examined microscopically they are seen to resemble in general 

 characters those of Nucula (see Figs. 10 and 11). As in Nucula 

 the main current through the mantle cavity is produced by the 



I.e.- 



c i..^r'^f^§^$m^' 



U. Ifc fc 



\ ^ / '' < 



WK""'^. 



,,*y^' 



r 



CD. 



'•■0ilf'\^-^' 



Fig. 10. — View of a pair of living leaflets of Solenomya togata taken from about the middle 

 of the gill, to show the directions in which the different sets of cilia lash. ( x ca. 60.)' 

 The arrows marked A indicate the direction in which the lateral cilia lash to 

 produce the main current ; those marked C indicate the direction of lashing of the 

 latero-frontal cilia which act as food-strainers ; while those marked B show the 

 direction in which food-particles are lashed by the frontal ciha. 

 U.L. Upper lamella. 

 L.L. Lower lamella. 



I.e. Lateral cilia forming a broad band on the side of the gill, 

 l.f.c. Latero-frontal cilia, 

 f.c. Frontal cilia. 

 CD. Ciliated knobs. 

 I.e. Cilia interlocking with the mantle. 

 T.C. Cilia which transport food along the ventral edge of the gill towards the 



mouth. 

 C.v. Cilia interlocking with similar ones on the adjacent leaflet. 



lashings 



of the large lateral cilia on the anterior and posterior 

 faces of the leaflets (see Fig. 10, I.e. and the arrows marked A). 

 Food-particles are collected by the latero-frontal cilia (the presence of 

 which in this species has recently been doubted, see Kidewood, p. 193) 

 and frontal cilia, but transported solely by the latter (see Fig. 10, l.f.c. 

 and f.c). The latero-frontal cilia lash in a direction across the length 

 of the edges of the leaflets, i.e. away from the spaces between the leaflets 



