658 DESCRIPTION OF [Botatoria. 



sent full-grown specimens, with the head withdrawn ; the latter 

 figure is a bade view, the former an under one. Fig. 449 is a side 

 view, head extended. Fig. 451 is an egg, just deposited on Lemna ; 

 fig. 452 an egg, with the young vibrating ; and fig. 450 shows the 

 young one just escaped from the shell ; fig. 453 represents the teeth 

 separately. Length of lorica 1- 144th. 



Salpina spinigera. — Lorica horned,four frontal, three posterior horns ; 

 the posterior dorsal one longest, and a little recurved. Glands on the 

 alimentary canal not observed. Found amongst Ceratophyllum. 

 Length of lorica 1 -140th. 



S. ventralis. — Lorica stippled, horns two in front, three behind, the 

 dorsal one short and decurved. Found amongst Conferva, &c. 

 Length 1 -120th. 



S. redunca. — Lorica smooth, horns two in front, three behind, two 

 of the latter (the under ones) hooked, the dorsal crest bifid and 

 gaping ; teeth four to each jaw. Found amongst Conferva. Length 

 l-200th. 



S. brevispina. — Lorica scabrous, horns two (small) in front, and 

 three behind, short dorsal crest not gaping ; lorica milky and tui-bid, 

 but appearing bright ; respirator}^ tube unknown. Found amongst 

 Ceratophyllum. Length 1 -144111. 



S. hicarinata. — Lorica smooth, horns four in front, three behind, 

 short ; neither lateral muscles nor respii-atory tubes known. Length 

 1-2 1 6th. 



Salpina spinigera, S. ventralis, S. redunea, and S. hicarinata, are 

 considered as slightly variable forms of one and the same animal. 



Genus DiNocHAEis. — 2'he gohlet Rotatoria. — Eye single, cervical ; 

 foot furcate, and lorica closed below, and unanned at both ends. 

 The compound rotatory organ has five or six muscles, and the foot 

 two in two species. An oesoijhageal head, with single-toothed jaws, 

 is found, except in D. tetractis, which Dr. E. thinks has four teeth ; 

 oesophagus very short, alimentary canal constricted, except in D. 

 pocillum {gasterodelaj, which is constricted : two oval glands exist in 

 D. pocillum and D. tetractis. Glandular portions of ovarium are seen 

 in all, and a contractile vesicle at the base of the foot in D. pocillum. 

 Traces of a vascular system are perhaps to be seen in D. pocillum, 

 though even here it is doubtful, for the apparent tremulous organ, 



