GENUS CODOSIGA. 333 



pedicle rigid and very short, not exceeding half the length of the body. 

 Length of body 1-3000" to 1-2500". HAB. Fresh water. 



The zooids of this species have been encountered by the author abundantly 

 attached to the pedicles of the higher Infusorial types, Vorticella nebulifera, 

 V. campanula, Epistylis flavicans, and Carchesium polypinum. They not improbably 

 represent the so-called " squamulae adhaerentes " referred to at page 325, first met with 

 under similar conditions by O. F. Miiller. As in Monosiga ovata, the form of the 

 body is subject to considerable variations of contour. PI. II. Fig. 8 thus illustrates an 

 example in which the anterior extremity is so considerably prolonged as to impart 

 to the animalcule a flask- like or bottle-shaped outline, while on other occasions, as 

 at Fig. 9, the two apices may be so retracted as to produce an almost spheroidal 

 shape. The pedicle, though short, is always distinctly developed, a circumstance 

 which serves to distinguish this type from Monosiga Steinii. 



Monosiga longicollis, S. K. PL. IV. FIG. 18. 



Body flask-shaped, rounded and widest posteriorly, produced anteriorly 

 in an attenuate neck-like manner, rather over twice as long as broad ; pedicle 

 short, one-quarter the length of the body. Length of body 1-2500". 



HAB. Bog water, gregarious. 



This type, which exhibits persistently a flask-shaped contour closely correspond- 

 ing with that occasionally presented by Monosiga brevipes, was discovered by the 

 author in September 1879, attached in social groups to the branching zoothecium of 

 Rhipidodendron Huxleyi, previously described. 



GENUS II. CODOSIGA, James-Clark. 



Animalcules illoricate, spherical or ovate, attached socially to the ter- 

 minations of a simple or variously branching, fixed and rigid pedicle or 

 zoodendrium ; collar well developed, enclosing the single terminal flagellum ; 

 contractile vesicles conspicuous, two or more in number, posteriorly located ; 

 endoplast anterior or subcentral ; multiplying by longitudinal fission and by 

 encystment and subdivision into spores. Inhabiting salt and fresh water. 



To the single fresh-water representative of this genus, the Codosiga pulcherrima 

 of Professor H. James-Clark, since identified with the imperfectly observed Epistylis 

 botrytis of Ehrenberg, nine well-marked additional forms have been added by the 

 author. Some of these inhabit salt and some fresh water, while all are readily 

 distinguishable from each other by the form of growth of the supporting stem, 

 or by the varying contours of the individual zooids. The branching colony-stocks 

 of Codosiga, viewed with an insufficient amount of magnification, correspond so 

 closely in their general mode of growth with those of Epistylis, that many of 

 them encountered without a knowledge of their true nature, by both earlier and 

 comparatively recent investigators, have been regarded as either immature or 

 exceedingly minute species of that genus. Stein has preferred in his lately 

 published work to alter the designation of this generic group from Codosiga to 

 Codonosiga, upon the ground that the etymology of the first title as introduced 

 by Professor Clark is not perfectly correct. Adhering, however, to the recom- 

 mendations of the British Association,* to the effect that all scientific titles must 

 be regarded simply as proper names, without regard to their strict etymological 

 construction, and that when once conferred it is desirable that they should be 

 permanently retained, Stein's proposed alteration has not been adopted in this 

 manual. 



* ' Rules of Zoological Nomenclature,' ed. 1878. 



