154 ABSTRACT OF THE INFUSIONSTHIERCHEN OF EHRKNBERG. 



The following is a Synoptical Table of the Genera : 



Organ of 



sight 

 not present 



/Form short; self-division longitudinal ( c 

 Lorica or wanting 



obtuse and -I 



smooth Form elongated, tortuous ; self-divi- ( QPHIDOMONAS, 

 sion transverse 1 



Lorica acuminated anteriorly PROROCENTRUM. 



f Lorica, with a neck or narrowed orifice LAGENELLA. 



sieht (L oricaw itfi- Lorica an open shield, or scutellate ... CRYPTOGLENA. 



\ out a neck 

 P resent ! or narrowed! 



orifice ( Lorica a closed case, or urceolate TRACHELOMONAS. 



Genus CRYPTOMONAS. 



Eye not present ; anterior extremity obtuse ; form short, not fili- 

 form or elongated ; spontaneous self-division longitudinal, or none. 



The species of this genus are like those of CHILOMONAS ; but the 

 latter are destitute of a lorica. 



Seven species are known : five are of a green colour, the remaining 

 one is brown. 



Genus OPHIDOMONAS. 



Eye not present ; lorica obtuse glabrous ; form elongated, or filiform ; 

 spontaneous self-division transverse. 



One species is alone described : this is of a brown colour. 



Genus PROROCENTRUM. 



Eye not present ; lorica glabrous, terminating anteriorly in a point. 

 One species is known : this is of a yellow, waxy hue, and is one of 

 the phosphorescent Infusoria met with in luminous sea- water. 



Genus LAGENELLA. 



Eye present ; lorica rostrate, or with a neck, or narrowed orifice. 

 One species is known : this is of a beautiful green colour. 



Genus CRYPTOGLENA. 



Eye present ; lorica open like a buckler, and rolled in at the edges 

 (scutellate); not rostrate or necked. 



Three species are known : these are of a green colour. One is found 

 in water when of a temperature near the freezing point. 



