Prof. H. Fol on the Family Tintinnodea. 245 



remain so characterized ; but we cannot place in it, as Stein 

 has tried to do, forms of which the peristome presents totally 

 different characters. 



It is true that Stein observed a marine form which he refers 

 to Tintinnus inquilinus^ with the body destitute of small 

 vibratile cilia, and, further, nearly the same organization as 

 his Tintinnus fluviatilis. As the peristome is not described 

 in detail, and in the complete absence of figures of any kind, 

 it is difficult to judge of the real position of this Tintinnus 

 inquilinus. Lastly, a third species, of which Stein proposes 

 to form a genus Tintinnojosis^ was ciliated over the whole 

 surface of the body, and presented at the peristome two rows 

 of vibratile cilia — an outer row composed of very long cilia, 

 and an inner row of cilia one half shorter; the test was 

 garnished with agglutinated grains. However, it is as well 

 to note that Stein only observed individuals deprived of their 

 tests ; he refers them, it is true, to some empty tests found in 

 the produce of the same gathering ; but the reader may enter- 

 tain some doubt as to the correctness of this collocation. 



Lastly, Hackel (IX.) describes and figures various forms 

 observed at Lanzarote and Messina. The author declares 

 that the vivacity of these animals prevented his ascertaining 

 all the features of their organization. Nevertheless he makes 

 known a series of very curious and interesting facts. All the 

 forms observed by our author are referred to two genera, 

 namely the genus Dictyocysta of Ehrenberg, with a perforated 

 test, and a new genus, Codonella. 



The Dictyocystce are represented as having a conical body, 

 contracting regularly to the point of attachment, which is at 

 the apex of the test, and with two rows of cilia on the peri- 

 stome — an outer row of stout and long cilia, and an inner row 

 of stout short cilia. Fortunately the description and the 

 figure precisely belong to one of the species {Dictyocysta 

 cassis) that I have had the opportunity of observing ; the 

 errors and deficiencies of Hackel's description cannot there- 

 fore serve to form a fictitious type, as so often happens. Dic- 

 tyocysta cassis is not gradually attenuated towards its point of 

 attachment, but presents a peduncle quite distinct from the 

 body. The cilia of the peristome are not in two rows, but 

 form a series of parallel spiroid lines, as I have described 

 above. The large cilia of the margin of the peristome are 

 much more numerous and shorter than Hackel figures them; 

 and, finally, the test is not ])erforated^ but only hollowed out 

 in pits on its outer surface. It is true that these pits are so 

 strongly marked and so deep that it seems at first sight like 

 an open trellis, and very particular attention is necessary to 



