SALPINA. 159 



transparent spots, which before were opake. The 

 three-sided rather rough lorica is of very curious 

 form ; the under side is flatly rounded, the back 

 crested, the sides also project, and the space 

 between is hollowed out ; at the end, where the 

 head is placed, it has four points, or horns, and 

 at the base only three, where the two-forked tail 

 projects. It has a compound rotatory organ, 

 which it withdraws completely into the lorica 

 when alarmed. The red eye and toothed jaws 

 are easily discerned, the latter moving very ra- 

 pidly when the creature is feeding. The eggs 

 are large, frequently found attached to weeds, and 

 so transparent that the young are visible within ; 

 these, when nearly arrived at maturity, produce a 

 vibratory motion, easily seen. This animalcule 



