NOTE ON A ü IG ANTIC AURICULARIA. 



340 



they seem to be somewhat more numerously present than in his 

 specimens, a fact which may be in relation with the larger >i/,e of 

 the body. The diameter of the wheel varies within a range of 70- 

 IQ2iJ fi. The nave is solid and cup-shaped, facing the body surface 

 witli the convex side; the spokes number 11 -17. The ring seems to 

 be somewhat thinner in my specimens than in Chun's ; it shows no 

 transverse slits that should indicate its origin by fusion of lateral 

 outgrowths from the ou-er end of the spokes. The inner contour- 

 line of the ring is finely serrated, instead of being smooth as in 

 Chun's specimens ; there exist 4-6 teeth in the interval between the 

 outer ends of every two spokes. 



Fig. I. Wheel-shaped calcareous deposit, viewed obliquely from 

 side, x 300. 



Fig. 2. Siine seen from above, x 300. 



Fig- 3. Anterior parts of mid-gut and adjacent organs seen from 

 above ; drawn from a preserved specimen, x 22. ne anterior entero- 

 ccel ; l'y hydroccel ; Ipe left posterior enteroccel; oe oesophagus; pc pore- 

 canal ; rpe right posterior enteroccel ; $t mid-gut ; icp water-pore. 



As regards the alimentary canal, the oesophagus seems to be 

 relatively longer than is represented in Chun's figures. At its 

 junction with the mid-gut there is a short strong constriction. The 

 mid-gut is a large, elongate-cylindrical sac of a light brown colour ; 

 it usually contains no solid substance. As it lengthens with the 

 growth of the larva, the posterior part becomes broader than the; 



