FEESHWATEK LIFE. 127 



The fi-ont and hinder extremities differ in different species. S. mucronata 

 has a lorica fiu-nished -with four spines in front and three behind; 

 S. ventralis has two in front only, and its lorica is spotted. On the back 

 of 'the neck of the former will be found a feeler, armed with a bristle. 

 The body of a full-grown Salpina is about the 100th of an inch or more 

 long. A young one has just the reehng side-to-side motion of its parent, 

 but has a soft lorica, which becomes hai-d and firm with age. Our next 

 example is one which occun-ed to me in a gathering from the small 

 Arboretum pond before mentioned. Dinocharis pocilhim has the basal 

 portion of its tail-foot fi-eely jointed, the joints having spinous processes. 

 There are also two spines near the origin of this organ, and a minute 

 bristle marks where the fork begins. The lorica is rather loose, and 

 stippled all over with open dots. The actions of the a nim al arequeerly 

 angular and vigorous. One of the most beautiful of the loricated 

 Eotifera is StephanojJS lamellaris, in which the body-shield undergoes 

 a pecuhar expansion on its anterior margin, so as to form a very elegant 

 crown over the animal's head. Behind the lorica is armed with thi'ee 

 spines, and there are three bristles at the end of the tail-foot. 

 On each side of the head is a Uttle horn, and the neck has a 

 collar-like thickening. The entire length of the lorica, including 

 spines and hood, is about the 200th of an inch. A famihar friend to the 

 microscopist is SqiiameUa ohlonga. Its favourite occupation is to climb 

 about the stems or roots of water-plants, feeding as it goes like a minute 

 species of cattle. It has four crimson eye-spots, and a lorica ai'med in 

 front with four small spines. 



One of the most interesting of all the free swimming Eotifera 

 is, undoubtedly, the httle creatiu'e which has given its name to 

 the order, and is known as Eotifer vulgaris. When the wheel-Like 

 apparatus is drawn in, the shape of the animal reminds one of a 

 spindle, the forward extremity tapeiing, as it were, into a blunt- 

 pointed snout. Its movements are then much like those of a leech. 

 The body is alternately wi-inkled up telescopic-fashion, and stretched 

 out over the ground intended to be covered. The cihary wreath is 

 double, and seiwes both for swimming and feeding. On the back, near 

 the head, is a small feeler. There are two eyes, placed much in advance 

 of the masticatoiy organ, and, apparently near the tip of the snout, in 

 the retracted state of the cHiary wreath. I was very much puzzled, 

 some years ago, when, having caught a full-gi-own female specimen, I 

 observed a young one, about half her length, freely disporting itself in 

 the interior of its parent. Omitting the parent's taU-foot, about two- 

 thu-ds of her body was occupied by the young one, with eyes, and 

 chami^ing gizzard all complete. Even the ciliary wreath of the latter 

 played at intervals. And all this must have taken place iu the maternal 

 ovary, which had been stretched to accommodate the offspring for some- 

 time before actual birth. In fact the common Rotifer is occasionally ovo- 

 viviparous ; that is to say, the young, though produced from eggs, may be 

 retained within the ovaiy for a ceriain time after they are hatched. 



In Brachionus urceolaris the lorica is closed at the sides and open at 

 the ends Uke the shell of a tortoise. Into this the animal can entirely 



