STENTOR. 



[ 736 ] STEPHANOSPH^RA. 



line resembling a rib, up tbe centre of each 

 fertile lobe. Tetraspores and antheridia 

 unknown. 



BiBL. Harvej', Marine Alg. 123, pi. 15 D. 



STENTOR, Oken.— A genus of Hetero- 

 trichous Infusoria, of the family Bursarina. 



Char. Body conical or trumpet-shaped, 

 fi'ee, or sessUe and attached by the narrow 

 base, covered with cilia; anterior portion 

 widened and fringed with a marginal row 

 of longer cilia, with a spiral row of ciha 

 extending from it to the mouth. Fresh- 

 water. 



These Infusoria are among the largest 

 and the most beautiful of the class. The 

 body is very contractile and liable to varia- 

 tion in form, often becoming ovate, oblong, 

 or globular; the nucleus is moniliform or 

 strap-shaped. Reproduction by oblique fis- 

 sion, and by germs arising from the nucleus. 

 The enc^'sting process has been noticed in 

 some of the species. 



According to Lachmann, in S. Miilleri, 

 jjoli/morphus, and Rwselii, near the plane of 

 the ciliary disk is a large contractile vesicle, 

 from which a longitudinal vessel with 

 several dilatations runs to the posterior ex- 

 tremity of the body"; also an annular vessel 

 round the cUiary disk, close under its row 

 of cilia. 



S. Miilleri (PL 32. fig. 3). Body colour- 

 less imless from containing foreign coloured 

 particles, with a fringe of cilia or a ciliated 

 crest extending from the mouth to near the 

 middle of the body ; nucleus monUiform. 

 Length 1-24" 



Several other species. 



Dajardin places this genus in the family 

 Urceolarina. 



BiBL. Ehr. Inf. 261 ; Stein, Infus.., pas- 

 sim ; Pritchard, Inf. 581 ; Clap, et Lach. 

 Inf. 222 ; Kent, Inf. 588 ; Laukester, Qu. 

 M. J. 1873 (col. matter). 



STEPHANOC'EROS, Ehr.— A genus of 

 Rotatoria, of the family Floscularifea. 



Char. Eyes single ; rotatory organ di\aded 

 into five tentacle-like lobes, furnished with 

 whorls of vibratile cilia ; body attached 

 by the base to a cyhudrical hyaline ca- 

 rapace. 



*S'. Eichhornii (PI. 44. fig. 25). The only 

 species. Freshwater; length 1-36". This 

 beautiful animal uses the lobes of the ro- 

 tating organ to catch its prey, in the manner 

 of Hydra. At a (tig. 25) are seen the tre- 

 mulous bodies, above Avhich is a row of 

 roundish globules, called by Ehrenberg ner- 

 vous ganglia. 



BiBL. Ehr. Inf. 400; Pritchard, Inf. 

 668 ; Oubitt, Mn. Mic. Jn. iii. 240. 



STEPHANODIS'CUS, Ehr.— A genus 

 of Diatomacefe. 



Char. Frustules discoidal, single ; valves 

 circular, alike, not areolar (under ordinary 

 illumination), and with a fringe of minute 

 marginal teeth ; freshwater. 



»S'. berolinensis has the valves finely ra- 

 diate, with mostly thirty-two teeth, and is 

 1-1 LoO" in diameter. S. Niagarce (PL 18. 

 fig. 26) ; »S'. lineatus (fig. 27) ; S. sinensis 

 (fig. 28) ; S. Mgijptiacus (fig. 29) ; S. Bra- 

 maputrcB (fig. 29*). 



Blbl. Ehrenb. Ber. Berl. Ak. 1845, Ixxii. ; 

 Klitz, Sp. Al(/. 21 ; Rabenht. Alg. i. 36. 



STEPHANOGO'NLl, Ehr.— An obscure 

 genus of fossil Diatomacese. 



Char. Frustules resembling those of ilfas- 

 togonia, but with the apices of the valves 

 truncate, angidar, and spinous. 



Two species found in Bermuda and North 

 America. S. poh/gona (PI. 18. fig. 30). 



BiBL. Ehrenb.' ^e;-. Berl. Ak. 1844, 264; 

 Kiitz. Sp. Alq. 26; Pritch. /;//. 814. 



STEPHANO'MA=Pandorixa. 



STEPfLlNOM'ONAS, K.— A genus of 

 Cilio-Flagellate Infusoria. Free, ovate, 

 with an anterior circle of cilia, and a single 

 flagellum. S.locellus; freshwater. (Kent, 

 Inf. 466.) 



STEPH'ANOPS, Ehr.— A genus of Ro- 

 tatoria, of the family Euchlanidota. 



Char. Eyes two, frontal, foot forked; 

 carapace depressed- or prismatic ; anterior 

 part of body expanded so as to form a fron- 

 tal hood ; jaws each with a single tooth. 



S. cirratus (PL 44, fig. 28). Carapace 

 with two posterior spines j freshwater; 

 length 1-240". 



!S. muticus has the carapace without spines 

 posteriorly, and the eyes have not been 

 recognized ; whilst <S'. lamellatm has three 

 posterior spines. 



BiBL. Ehr. Inf 478 ; Pritch. Inf. 600. 



STEPHANOPYX'IS, Ein-.-A genus of 

 Dintomaceed = Fi/xiclicula in part. 



STEPHANOSI'RA, Ehr.— A genus of 

 Diatomaceae. 



Char. Frustules united into a short fila- 

 ment, disk with radiating series of minute 

 puncta and a marginal crown of teeth. 

 Allied to Stephanodisms and Melosira. On 

 trees. (Pritchard, Infus. 823.) 



STEPIL\NOSPIE^'RA, Cohu.— A ge- 

 nus of Volvocinese (Confervoid Algse). 

 S. pluvialis (PL 48. fig. 22) is neai-ly related 

 to Pandorina, consisting of a large hyaline 



