ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 355 



to him through the literature of the subject, according to their mode 

 of occurrence. Thus the forms hitherto found in the different seas 

 are enumerated, after which a catalogue is given of those belonging to 

 fresh water, according to the manner of their occurrence in lakes, 

 marshes, streams, ditches, &c. ; and finally a list of those forms which 

 have been hitherto found in both sea and fresh water. These last 

 include four forms, viz. Ceratium tripos Wavh,, furca Ehrb., Peridinmm 

 spiniferum Clap, and Lachm. (according to Maggi's observations), and 

 Prorocentrum micans Ehi'b. The paper concludes with an enume- 

 ration of the known fresh-water forms, arranged according to the 

 different countries in which they occur, and going so far as to give 

 for each form the particular locality in which observers had met 

 with it. From this section may be specially selected the fact that 

 the author records Peridinium pulvisculus, Ehrb., spiniferum Clap, 

 and Lachm., tahulatum Schm., as well as Ceratium longicorne Perty, 

 as found by him in Upper Italy. It is unnecessary to go more fully 

 into Maggi's results, as he has made no attempt to examine closely 

 and compare the forms described by various writers, in order to 

 decide their claims, but contents himself with simply enumerating 

 them. 



Infusorial! with Spicular Skeleton.* — E. S. Bergh has obtained 

 large quantities of the Infusorian described by Claparede and Lach- 

 mann under the name Coleps fiisus, in the open sea off' the Small 

 Belt (Denmark). The peculiarities which he has observed in this 

 species appear to him sufficient to raise it to the rank of a new 

 genus, whose principal character, distinguishing it from Coleps, is 

 that the skeletal sheath is not a continuous fenestrated test, but con- 

 sists of single disconnected spicules. These are parallel to the long 

 axis of the animal, which has a considerable longitudinal extension 

 and is pointed at the aboral pole ; they are arranged in five 

 transverse series, showing considerable differences between their 

 heights. The spicules are provided with short lateral cross-branches, 

 differing (but not constantly so) in number in the different series ; they 

 constitute an indication of reticulate structure, but, as already stated, 

 they are not so much developed as to unite the spicules together. 

 The spicule-elements of the skeleton consist of an organic sub- 

 stance, and lie imbedded in the peripheral protoplasmic layer. The 

 cilia are placed above, not between them. A compact crown of cilia 

 is found at the oral pole. The simple, roundish nucleus lies within 

 the middle series of spicules. 



Contractile Vacuole of Vorticella.f — After an historical intro- 

 duction relating to the controversy about the presence of a membrane to 

 the contractile chamber, J. Limbach describes his own observations 

 on the subject as follows : — In pathologically altered specimens of 

 Vorticellce, in which their characteristic ciliated organ is swollen up 

 and the body is detached from the pedicel, the contractile vacuole 



♦ Vidensk. Meddel. Naturh. Foren. Copenhagen, 1879-80, pp. 265-70, wood- 

 cuts. Cf. Zool. .Jahresber. Neapel for 1880, i. p. 170. 



t Kosmos, (Zeitschr. poln. Naturf. Ges. Kopernicus), 1880, pp. 213-21. Cf. 

 Zool. Jahresber. Neapel for 18S0, i. p. 169. 



