708 



SYSTEMATIC HISTORY OF THE INFUSORIA. 



A. hiremis. — Linear and elongated, 

 with four horns anteriorly; back very 

 smooth, and having two lateral spines, 

 like oars. The oesophageal head has 

 three-toothed jaws. In phosphorescent 

 sea-water. 1-144". 



A, striata (Brachio?ius striatm, M.). — 

 Linear and elongated, with six horns in 

 front, and fom* on the abdominal surface 

 of the lorica; the back with twelve longi- 



tudinal flutings or rays, and obtuse at 

 the end. This species is very change- 

 able in form, owing to the membranous 

 lorica ;ydelding to the contraction of the 

 body : hence it is sometimes long, at 

 others short, sometimes urn-shaped, bell- 

 shaped, and even almost disc-shaped ; 

 the first, however, seems to be the normal 

 foi-m. Li fresh and salt water. 1-130". 



b. Spinous or attenuated ])osteriorly . 



A. inermis. — Lorica oblong, attenuated 

 and truncated posteriorly ; no spines an- 

 teriorly ; back furnished with faint longi- 

 tudinal rays. In peat-water. Length 

 when extended, 1-144". 



A. acuminata. — Lories oblong, attenu- 

 ated and truncated at the posterior extre- 

 mity, having anteriorly six sharp-pointed 

 horns or spines, twelve longitudinal rays 

 on the back. Amongst Confervas. 

 Length about 1-120". 



A. foliacea. — Lorica oblong, six spines 

 anteriorly, posteriorly terminating in a 

 spine ; dorsal and ventral surfaces longi- 

 tudinally striated ; frontal region rough. 

 It has four-toothed jaws, and a central 

 ganglion below the eye. 1-180". 



A. stipitata (Brachionus, M.). — Lorica 

 nearly square, or triangular; anteriorly 

 six spines ; posterior pointed like a 

 pedicle ; the back tessellated, (xxxv. 

 498 represents a dorsal view, with the 

 wheels extended.) Length about 1-200". 



A. Testudo. — Lorica square, having 

 anteriorly six straight spines, all of 

 nearly the same length, and posteriorly 

 a short one at each corner. The upper 

 and under surfaces are rough, the former 

 tessellated like Noteus, Length about 

 1-200". 



A. serndata. — Lorica ovate, square, 

 with six unequal spines anteriorly, the 

 two middle ones long and curved ; it has 

 two short spines at the posterior angles, 

 which are sometimes scarcely apparent. 

 The surfaces are rough, and the dorsal 

 also tessellated, like the preceding species. 

 Independently of the two wheels, the 

 brow has three cylindrical ciliated pro- 

 cesses, which are truncate at their extre- 

 mities. 1-216". 



A. aculeata (BracTiionus quadratus, 

 M.). — Lorica square, with six spines an- 

 teriorly, the two middle longest ; at the 

 posterior angles are two long and equal 

 spines ; back rough and tessellated, under 

 side smooth. At the brow, between the 

 two wheels, is a single ciliated frontal 

 process ; a little tactile organ is situated 

 in front of the eye. Length 1-144" ; 

 including the spines, 1-96". 



A. valga. — Lorica nearly square, with 

 six spines anteriorly, the two middle 

 ones the longest ; at each posterior angle 

 is a spine of unequal length ; dorsal and 

 ventral surfaces rough, the former tessel- 

 lated. The jaws are five- toothed, the 

 red eye oval, its longer axis transverse. 

 Length, without the spines, 1-210". 



The following species are given by Mr. Gosse (Ann. Nat. Hist. 1851, vol. viii.). 



A^Jlssa (Gosse). — Lorica smooth, hya- 

 line, swollen at the sides 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 

 doi-sal ; the ventral is also cleft through 

 its medial line j eye very large, pale. 

 1-220". 



A. tecfa nearly agrees in form with 

 A. eurvieornis; but the posterior extre- 

 mity is rather more pomted, and the 

 tessellations are difi'ereut, being larger, 

 and arranged on each side of a medial 

 dorsal ridge, which gives to the back 

 the form of a vaulted roof. 1-200". 



A. hrevispina nearly agrees with A. 

 aculeata ; but the posterior spines are very 

 shoi-t, the frontal spines are much less 

 curved forwards, the sm-face is not 

 punctated, and it is colourless. 1-146". 

 A. cochlearis. — Lorica spoon-shaped, 

 with six spines in front, the medial pair 

 curving strongly forwards ; posterior ex- 

 tremity attenuated into a long slender 

 spine, inclined forwards ; back ridged 

 and tessellated, as in A. tecta. 

 ! A. heptodo7i = Ascomo?pha Helvetica, 

 I Perty. — Lorica of equal width, con- 

 j tracted posteriorly, and terminated by an 

 j upturned tooth in the middle line. In 

 front are four teeth above and two below. 

 ' 1-12". This species, founded on one 



