346 DESCRIPTION OF [Rotatoria. 



transverse circular canals, vascular network at the base 

 of the rotatory organs,, and tremulous gill-like bodies, are 

 observable. The system of sensation is indicated by the 

 visual organs, which rest on ganglia ; they are red in the 

 developed ovum and young animalcule, but become blackish 

 or disappear with age. Near the resophagus is situated a 

 nervous mass (analogous to brain), divided into four to 

 six lobes, also (as in Megalotrocha) two ring-like radiant 

 processes with a row of ganglia, these lie beneath the 

 muscles of the cilii wreath; the longest lobes (ganglia) are 

 seen from the ventral surface. 



577. LACINULARIA socialis ( Vorticella socialis etjloscu- 

 losa, M.) The social Lacinularia. Lorica gelatinous, of a 

 yellowish colour, and conglomerate, several (from ten to 

 sixty) uniting to form a spherical mass. Each animalcule 

 is fixed by its tail to a separate cell, within which it can 

 entirely withdraw itself. It has a large horseshoe-shaped 

 rotatory organ ; seven or eight eggs are deposited, free, 

 within each cell ; the young, when hatched, form a new 

 cluster, swim away, and form loricae; when only one is born, 

 it attaches itself at the side of the parent. Fig. 378 is an 

 animalcule separated from the mass ; it is highly magni- 

 fied, and exhibits the organization described under its 

 genus. Found on chara and other aquatic plants. Length 

 l-36th. 



Genus CXLVII. MELICERTA. The four-leaved Ani- 

 malcules have two eyes (at least when young), solitary 

 cases, and a single rotatory organ, with four lobes, when 

 expanded. It has free longitudinal muscles for the con- 

 traction of the body ; the alimentary canal is broad and 

 simple, with a stomach-like division ; its oesophagal head 



