678 DESCRIPTION or [Rotatoria- 



and at the back ; flattish on the belly, truncate in front, without any 

 spines, attenuated and truncate posteriorly. There is a deep fold 

 running down each side, or else the ventral plate is distinct from the 

 dorsal ; the ventral is also cleft through its medial line ; eye veiy 

 large, pale. Length 1 -220th. 



Aniteaea tecta nearly agrees in form with A. curvicornis, but the 

 posterior extremity is rather more pointed, and the tesselations are 

 different ; being larger and arranged on each side of a menial dorsal 

 ridge, which gives to the back the form of a vaulted roof. Length 

 1 -200th. 



A. hrevisinna nearly agrees with A. aculeata, hut the posterior 

 spines are very short ; the frontal spines are much less curved 

 forAvards ; the surface is not punctated ; and it is colourless. Length 

 l-146th. 



A. cochlearis. — Lorica spoon-shaped, with six spines in front ; 

 the medial pair curving sti'ongly forwards ; posterior exti'emity 

 attenuated into a long slender spine, inclined forwards ; back ridged 

 and tesselatcd, as in A. tecta. 



Genus BRAcnioNUS. — Bracliionaca which have a single cervical eye 

 and a furcate foot. In all the species the lorica is a closed shell, 

 with two openings like a tortoise-shell {testula), the margin of the 

 anterior opening dentate, as is also, sometimes, that of the posterior. 

 In B. Bakeri and B. militaris, the lorica is rough, and in the former 

 tesselated ; in all the other species it is smooth ; the animalcule can 

 completely withdraw itself within its lorica. The locomotive organs 

 consist of a double rotatory apparatus, and a wrinkled and very 

 flexible furcate foot. Between the rotatoiy organs are from one to 

 three frontal processes, which are provided with long cilia or feeler- 

 like hairs ; between these processes, in six species, are from two to 

 four long styles or bristles. The rotatory organs, when not com- 

 pletely extended, sometimes appear as if two or thrcc-lobed. In 

 all the species, from two to eight internal muscles, for moving the 

 vibratory organs, are observed ; also two foot muscles ; and in six 

 species from two to eight internal longitudinal ones. The digestive 

 system comprises a large muscular oesophageal head, with two many- 

 toothed jaws, (mostly five, but in B. pohjacaiitkus four-toothed) ; a 

 slitjrt oesophagus, and a constricted alimentary canal (gmterodela) ; 



