246 DESCRIPTION OF [Pohjcjastrica. 



eyed Animalcules have a siliceous lorica, striped or co- 

 vered with spines or stiff hairs, and an eye; they are 

 destitute of a transverse zone or furrow. The organ of 

 locomotion is a simple flabilliform proboscis. The interior 

 has scattered transparent vesicles, probably stomach-cells. 

 The ova cluster is a brownish green granular mass ; a large 

 bright spot or spermatic gland is also visible. Self- division 

 has not been observed. 



369. Chaetoglena volvocina. The rolling Chaetoylena 

 has an ovate body, with brownish -green ova, and a red 

 eye ; between the lorica and the soft body a beautiful red 

 ring is visible in the live specimens. (See jig. 216, 217, 

 and 218.) Found, amongst conferva, at Hampstead and 

 Hackney. Length l-1150th. 



Genus LXXXV. Peridinium. The wreath Animal- 

 cules. — Characters : membranous lorica, with a transverse 

 cilated zone; no eye. The locomotive organs are a fihform 

 proboscis, and the zone or wreath of cilii. In P. pulvisculus 

 and cinctum the digestive apparatus can be demonstrated, 

 by employing indigo and carmine as food ; but in 

 P. acuminatum, fulvum, and cornutum, it is visible, M'ith- 

 out having recourse to artificial means. The oral aperture 

 is found in a hollow near the centre, as in Bursaria. The 

 ova cluster is generally of a brown or yellowish -brown 

 colour, though sometimes it is green, or even almost 

 colourless. In P. tripos and fusus an oval seminal gland 

 is visible. The self-division is longitudinal in P, pulvis- 

 culus and fuscum ; and, according to some observers, trans- 

 verse in P. fusus and tripos. 



