Cryptomonadina.] infusobial animalcules. 145 



of a common enclosing envelope, had been found ; yet I cannot 

 doubt, but that they have the closest analogy ^^vith true Gonia, and 

 with what Ehi-enbcrg has called Syncrypta in his family Volvocina^ 

 One may suppose that the commencing self-fission observed in some 

 individuals would give rise to such groups, upon the destruction of 

 the lorica (integument) in these diiFcrent genera. This mode of 

 propagation occurs, undoubtedly, in most of those ha^'ing a soft gela- 

 tinous integ-ument, but in animals like Trachelomonas, whose lorica is 

 hard and brittle, we cannot imderstand how multiplication does 

 take place." 



In the addenda to his treatise, Dujardin has this remark, "I am 

 convinced that my Cryptomonas {Tetralmia), belongs rightly to 

 Gonium." 



Genus Ophedomonas. Tlie serpent Monads. The distinguishing 

 chai-acters of this genus are its filiform body, absence of the eye, its 

 smooth and obtuse lorica, and its transverse but complete self-division. 

 It was discovered by Ehrenberg in September, 1836. It is fui-- 

 nished with a filiform proboscis, as its organ of locomotion, which, 

 together with the tubular lorica, and the numerous digestive sacs, 

 form the whole of the organii^ation that has hitherto been de- 

 monstrated. Its extremely small ti-ansverse diameter is the gi'eat 

 impediment to a better acquaintance with this creature. A\Tiether 

 its brown colour is derived or not from the ova within it has not 

 been determined. (It has not been figured.) 



0. Jenesis. — Form very thin, cm'ved spii-ally, and equally obtuse 

 at both extremities ; colour oKve-brown ; motion brisk. Found only 

 at Jena, in well water. Size 1-5 70th. 



0. sanguinea. — ^Yery slender the interspaces between the stomach — 

 sacs filled with a red colour. Size 1-5 76th. inch. Found near 

 Cilonium, in brackish water. 



Genus Peognocejttetjm. The pointed-shell Monads. — The ani- 

 malcules of this genus are destitute of the eye, and have a smooth 

 lorica, resembling a little box {urceolus), pointed at the anterior ex- 

 tremity. They have a fiUfonn proboscis, and numerous large digestive 

 cells in the anterior of the body. Self-division has not been observed. 

 " It is worthy of remai'k," says Dr. Ehrenberg, " that the only spec' s 

 of this genus with which we are acquainted {^i.e. in 1838), belongs to 



