46 :Mr. R. Vallentin on the 



Lacinularia soeiil/'s^ I at: last succeeded in obtaining" one 

 series of sections that left no doubt on my own mind as to 

 the final termination of the lateral canals. On reference to 

 fig. 13 the thin membranous-like termination of the united 

 lateral canals will at once be seen. The slightly dilated 

 junction rapidly narrows and opens to the exterior immedi- 

 ately beneath tlie anal aperture (tig. 18, e). I think tlie 

 extreme ditliculty one experiences in viewing in a satisfactory 

 manner the termination of these lateral canals is mainly 

 owing to the extreme delicacy of the walls of the lateral 

 canals in the region of the posterior third to their junction. 

 This statement receives confirmation from the fact that the 

 termination of the lateral canals in all my other sections has 

 eluded my most careful scrutiny. 



Literature referred to. 



(1) Hudson, C, T., and Gosse, P. II. Tlio Rotifera or Wheel- 

 animalcules. 188(3. 



(2) JOLIET. " Monographie (los i^e/iceries," Arch, de Zool. exper. et 



gen. vol. i. 188-5. 



(3) Huxley, T. II. " Lacimdnn'a socialis: a Contriljution to the 

 Anatomy and Physiology of the Kotifera," Trans. Micr. Soc. Lond. 

 vol. i. i8o3. 



(4) Leydig, F. " Ziir Anatomie und Eutwic]ilung?geschiclite der 

 Lacinularia socialis " Zeitsclir. f. wiss. Zool. iii. 1851. 



(-5) Williamson, W. 0. " On the Anatomy of MeliceHa rhiffem,'" 

 Quart. Journ. Micr. S^i. vol. i. 185.3. 



(G) GossE, P. H. " On the Structure, Functions, Habits, and Deve- 

 lopment of MeliceHa ri7ii/ens" Quart. Journ. Micr. Sci. vol. i. 

 1853. 



(7) . " On the Structure, Functions, and Homologies of the 



Manducatory Organs in the Class Rotifera," Phil. Trans. 1855. 



EXPLANATION OF THE PLATES. 



List of Reference Letters. 



I.e. Lateral canals. ST., st. Stomach. 



o. Ovary. i. Intestine. 



s.ff. Salivary glands. c. Cuticle. 



S.R. Salivary receptacles. gg. Gastric glands. 



a. Opening of salivary receptacles x. Opening of gastric glands into 



into pharynx. oesophagus. 



//. Ganglia (brain), ce. (Esophagus. 



m. Muscles. h.c. Body-cavity. 



m.c. Mucous cells. f.c. Flame-cell. 



