620 DESCRIPTION OF [Rotatoria. 



which latter is common to the ovarium and alimentary canal; 

 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 

 oesophagus is situated a nervous mass (analogous to brain), divided 

 into four or six lobes ; also (as in Megalotrochd) two ring-like 

 radiant processes with a row of ganglia, these lie beneath the 

 muscles of the cilia wreath ; the longest lobes (ganglia) are seen 

 from the ventral surface. 



Lacinulauia socialis {Vorticella socialis etjlosculosa, M.) — 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 it- 

 self. 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 loricse ; when only one is 

 born, it attaches itself at the side of the parent. In a recent paper 

 by Mr. Howard on this species, he states there are two kinds of 

 reproductive bodies, one the ordinary ova, the others twice their 

 size representing gemmae. Fig. 3/8 is an animalcule separated 

 from the mass ; it is highly magnified, and exhibits the organization 

 described under its genus. Found on Chara and other aquatic 

 plants near the margin of rivers. Length l-36th. 



Genus Melicerta. — The four-leaved Animalcules ; eyes two (at 

 least when young) ; cases solitary ; rotatory organ single, with four 

 lobes, when expanded. It has free longitudinal muscles for the 

 contraction of the body ; ahmentary canal broad and simple, with a 

 stomach-like division ; its oesophageal head has four muscles, two 

 jaws, with teeth in rows, and two pancreatic glands ; the mouth is 

 situated under the large leaves or lobes of the rotatory organ ; the 

 discharging orifice is at the base of the prehensile tail : in its propa- 

 gative system it resembles the preceding genus, but the male portion 

 is not satisfactorily known. A vascular system not observed, but 

 the two tubular processes beneath the mouth are probably sub- 

 servient to respiration ; the two frontal eyes in the ova and young 



