510 



SYSTEMATIC HISTOEY OF THE INFUSORIA 



Crypto GLENA conica (x-\tji. 32). — 

 Conical, anteriorly dilated and trun- 

 cated ; filaments two, half the length of 

 the body ; posterior end acutely attenu- 

 ated. Colour bluish-green. Abundant 

 in river water, in company with Orypto- 

 monas glmica, from which they are 

 readily distinguished by their form, 

 larger size, and red eye. They move 

 briskly in the direction of the longitudi- 

 nal axis of their bodies, but when ob- 



structed spring or leap out of their direct 

 course. 1-1100". 



C. pigra. — Oval, approaching to glo- 

 bular, and emarginate anteriorly ; colour 

 a beautiful green ; movement slow. In 

 water when covered with ice. 1-3000''. 



C. cesrulescens. — Depressed, elliptical 

 and emarginate anteriorly ; colour bluish 

 green; motion quick, 

 fervte. 1-6000". 



Amongst Con- 



Mr. Carter has added and figured some new species, viz. — 



C. lenticularis (A. N. H. 1858, p. 253). 

 — Spherical, compressed ; lorica distinct 

 and stout; endochrome separated from 

 it by a distinct clear zone ; contrac- 

 tile vesicle seated at the point of in- 

 sertion of the two filaments, where 

 there also seems to be an interruption 

 in the continuity of the lorica (emar- 

 ginate) ; eye-speck on one side, nucleus 

 visible. The horizontal view is ovate, 

 and acuminate at both ends. Fission 

 takes place in the power of two, just 

 as in Chlamydococcus, from which in- 

 deed no satisfactory distinctive fea- 

 tures are perceptible in the engravings 

 furnished. 



C. corcliformis. — Distinguished by its 

 cordiform" lorica. The contents are orbi- 

 cidar, and do not nearly fill the lorica ; 

 filaments four ; a resting-stage perceived, 

 wherein the contents are covered by a 



into 



thick envelope, and are divided 

 numerous cells (microgonidia.) 



C. angulosa {A. N. H. 1859, iii. 18).— 

 Lorica compressed, oblong, angular, 

 shield-shaped, transparent, round poste- 

 riorly, square anteriorly, where it pre- 

 sents a short neck in the median line for 

 the passage of the cilia; border thin, 

 cm-led up posteriorly and anteriorly on 

 opposite sides. Internal or gTeen cell at 

 some distance from the lorica, angidar, 

 lined with chlorophyll, provided with 

 two cilia, which issue through the neck 

 of the lorica ; two contractile vesicles at 

 their base; an eye-spot median and 

 peripheral, and one to four starch-cells 

 of a circidar form. Swimming with its 

 cilia forwards in an extremely irregidar 

 line. Length of lorica 1-1080", and 

 breadth 1-1800". Freshwater tanks in 

 the island of Bombay. 



Genus TRACHELOMONAS (XYIII. 33, 34 ; XIX. 9-11).— Have a single 

 long filament, an ej^e-speck, and a closed elongated or spherical lorica, with- 

 out a projecting neck. Yery minute transparent vesicles have been discerned 

 in T. nigncans and T. volvocina. It is probable that some of the highly inter- 

 esting animalcules which enter so abundantly into the silicified substances in 

 certain chalk formations belong to this genus. The genus Trypemonas 

 (Perty) is equivalent to this, the characters of which are hereafter given at 

 large in Perty's words (p. 513). 



Trachelomonas nigricans. — Oval, 

 approaching to globular; colour rarely 

 green, mostly of a reddish or blackish 

 brown. Eye-speck brown. 1-1700". 



T. volvocina (x^^n. 33, 34 ; xix. 9, 10). 

 — Spherical, with a delicate filament; 

 colour mostly green, sometimes of a 

 bro-^mish hue, with a distinctive red 

 ring around the body : between the in- 

 ternal vesicles is a very fine granulated 

 substance, to which the colour of the 

 body is due. The red circle, so re- 

 markable a featm-e in this species, 

 always appears in the same horizontal 

 position, how quickly soever the creature 

 may be revolving on its long axis. The 

 uppermost figure represents the flabellum 



extended ; in the next it is retracted ; the 

 lowest of the three is a very young spe- 

 cimen; and 34, a full-groTvn one that 

 has been forcibly pressed and the lorica 

 broken. Amongst Confervas. 1-860". 



T. cylinclrica (xix. 11). — Oblong, ap- 

 proaching to cylindrical ; filament almost 

 as long as the body. Colour a beautiful 

 green ; eye-speck red ; ring purple. 

 1-1000". Perty points out the fact that 

 T. nigricans is nothing more than an 

 old specimen of this species, brown and 

 opake by age. 



T. areolata, — Globose, surface areo- 

 lated. 



T. aspera. — Similar to preceding, but 

 its surface covered with rough points. 



