588 



SYSTEMATIC HISTORY OF THE INFrSORIA. 



This well-known animalcule is usually I out its length with red dots. 1-1150" to 

 found attached to extraneous bodies in ! 1-570" j stalk foiu" to five times as long, 

 water ; such as the leaves of duck-weed, j Perty treats V. lunaris, V. faseiculata, 

 small aquatic shells, clusters of the ova, j and V. cirrata of Miiller as distinct 

 or the larv£e of insects ; an example of j species, instead of accepting them as 

 the latter is shown in the Microscopic varieties of others named by Ehrenberg- ; 

 lUmtrations, fig. .30, where it may be 

 considered as a parasite, or rather an 

 epiphyte. As, when fully developed, 

 it is mostly attached to some sta- 

 tionary object, it affords many facilities 

 to the microscopist for observation, and 

 forms a good object also for ascertaining 

 the defining power of his instrument, 

 and his expertness in its management; 

 for much of the clearness in structure 

 will depend on the manner in which he 

 manages the illumination. If this be not 

 attended to, and the instrument has not 

 sufficient power and penetration, it will 

 exhibit only two cilia instead of a cir- 

 cular row; indeed this animalcule is 

 described and draA\Ti in this manner by 

 the old authors, — an error which recent 

 improvements in the microscope have 

 demonstrated. 



\.picta. — Ovate, conical, campanulate ; 

 frontal portion dilated, and its margin 

 slightly expanded. The pedicle is veiy 

 slender, and cmiously marked through- 

 Genus CAECHESIUM (XXX. 9) 

 genus by the spirally flexible branched pedicle. The bodies (zooids) upon 

 the pedicle are all of the same form. The organization of this genus is not 

 so well known as that of VorticeUa and Ejjistylis. There is a simple wreath 

 of cilia, which duiing quick vibration appears double ; and, as in VorticeUa^ 

 a posterior circlet is produced at certain periods ; within the pedicle a trans- 

 versely folded contractile band is observed during contraction. The mouth 

 is lateral. Internally are whitish granules, and a contractile bladder ; but 

 the nucleus is indistinct. The gTo^i;h of gemmae has been observed ; and 

 the zooids can detach themselves from the stalk, as in the case of VorticeUa. 

 One of the best distinctive features between Carchesium and Zoothamnium, 

 is that the contractile band of the former is not continuous throughout the 

 pedicle and its branches as it is in the latter (see p. 293). This is noticed 

 both by Stein and Dr. Wright : the latter adds, " The division of the zooids 

 is more complete in Carchesium than in Zooihamnium. In the former, at 

 each division, one of the zooids produces a new muscle not connected with 

 that of the zooid from which it has separated." 



Carchesium pohjpinum (Leeuwen- I C. pygmxBum {Zoothamnium Parasita, 

 hoek) {V. poly])ina, M. and Duj.) (xxx. | Steiu). — Very small, ovate, white, rather 

 9). — Conical, campanulate, white ; the i dilated in front ; pedicle branched in a 

 frontal portion broad, trmicate, and its I bifid, rarely in a trifid manner. 1-2400''. 

 margin expanded ; pedicle branched in a | Berlin. On Cyclops quadricornis. 

 sub-umbellate manner. The axis matter C. spectahile. — Conical, campanidate, 

 or supposed muscle of the pedicle, first dilated in front ; branching in an oblique 

 observed bv Mr. Varley, is very distinct. | conical poh^ary, attaining two lines in 

 1-570" to i-430". 1 height. Berlin. 



Genus EPISTYLIS (XXVII. 16, 22, 23 ; XXX. 11).— Pedicle rigid, either 

 simple or branched ; all the zooids of the same figure ; or, in other words. 



but he fails to give the characteristics 

 necessary to their establishment as such. 

 It is to be remarked, however, that V. 

 hmaris and V. faseiculata are, he is in- 

 clined to believe, merely varieties of the 

 same species. 



VorticeUa Ampulla (MiiUer) is treated 

 by Lachmann as the representative of a 

 new genus, as yet unnamed, belonging 

 to the Stentorinae (A. N. H. 1857, xix. 

 p. 128). 



V. infusionmn (Duj.) is not equivalent 

 to V. microstoma and V. Convallaria, as he 

 represented it to be. He describes it as 

 commonly ovoid or nearly globular, trmi- 

 cated at the head, wdth a slightly pro- 

 jecting border. The pedicle is very 

 flexible, its surface striated obliquely. 



V. ramosissima (Duj.) = Carchesium 

 polypinum (Ehr.). 



V. Arhuscula (Duj.) = Zoothamnium 

 Arhuscula (Ehr,). 



V. lunaris (Duj.)= V. Campanula and 

 V. patellina (Ehr.), 



Distinguished from the preceding 



