ACTINIARIA 



felina coriacea with large warts occurs there, seems a little doubtful to me. Besides crassicornis, we probably 

 have to do with tuberculata or lofotensis). 



Exterior aspect: The exterior of this form has before been described by various authors, also by 

 myself (1893). It is not necessary to recapitulate the description here. 



Anatomical description. Several authors, also I myself (1893) have described the anatomy of 

 this form. As however several facts can be added, concerning the structure of various organs, it may be 

 practical to make these organs subject to a reexamination. 



Concerning the structure of the verrucae I have, after an examination of the maceration preparations, 

 been able to determine the nature of "the pyriform cells", which Me. Murrich (1889 p. 53) supposed to be 

 "nerve ganglion cells", and on which he later (1911 p. 76) pronounced the opinion that they "may possibly 

 be muscular in character." Already 1899 p. u 1 I have, however, pointed out that the pyriform cells are 

 granulous gland cells, "die in dem proximalen Theil des Ektoderms langgestreckt birnformig sind nach aussen 

 dagegen einen sehr feinen Ausfiihrungsgang haben." A comparison between the ectoderm in the middle 

 part of the verrucae, viz. the part, which in contraction is a little concave, and the ectoderm in the side-parts, 

 with which the other ectoderm of the column agrees, shows, that the middle part is constructed in another 

 way than the other parts of the column. The figures i, 2, PI. 4 show the cells occurring in the middle part 

 after a treatment with the maceration liquid of Hertwig (osmium & acetic acid. Hertwig 1879). In the 

 figure i PI. 4 the maceration is imperfect, in as much as the cells are still joined in the distal part, while 

 their basal parts are separated. Already here we can see that the ectoderm cells consist of elongated support- 

 ing cells and granulous gland cells, which is still more conspicuous as the cells are perfectly isolated (Fig. 2, 

 PI. 4). The granulous gland cells are thus the pyriform cells. They are namely swollen near the basal part 

 of the ectoderm, while the main part forms a long efferent duct, and recall in their appearance the gland 

 cells of the pedal disc, though the latter are more irregular (Fig. 3, PI. 4) than the former. There is thus no 

 doubt that the pyriform cells are gland cells. Macerative preparations of the ectoderm outside of the peculiar 

 verrucae, viz. on the rim of the concave part and between the verrucae, show the presence of supporting 

 cells, of nematocysts, of mucus-cells (Fig. 4 a, PI. 4), and of granulous gland cells. These last cells, however, 

 are of quite another structure than the gland cells of the verrucae. As we see from the figure 4b (PI. 4), they 

 are shorter and broader in the distal part than in the filiform proximal part, which is devoid of granules, 

 and a little coloured. The secretion of the pyriform cells probably is of small importance to the adhesion 

 of foreign bodies, neither do the gland cells of the pedal disc play any essential part by the adhesion of the 

 pedal disc. 



1 Wassilieff (1908 p. 99) has proclaimed that in ray papers of 1893 and of 1899 I have made myself guilty of an inconsequence, 

 concerning my statements of the structure of the verrucae. Concerning the nematocysts he seems to be right. In the main there are 

 no nematocysts in the ectoderm of the verrucae, but where they are adjacent to the other ectoderm of the column, which contains 

 nematocysts, glandcells etc., solitary nematocysts and also common gland cells may pass into the outermost part of the peculiar verruca, 

 while the main part of the verruca contains no nematocysts. Hence my different statement: sparse nematocysts and no such. Con- 

 cerning the gland cells in the verrucae I have in my paper 1893 not been able to decide the nature of the pyriform cells, wherefore 

 I also 1893 declared that there were no gland cells in the verrucae. The statement of Wassilieff, that the verrucae of Cribrina japo- 

 nica have the same structure as the other ectoderm of the column, is certainly due to the sections not having hit the middle part of 

 the verrucae. On the other hand, he describes the verrucae of Anthopleura me. murrichi in the same manner as I (1899 p. n) have 

 described them in Vrticina and Condylactis cruentata. The classification of the verrucae in "Saugwarzen" and "Klebwarzen" (Pax 

 1914 p. 360) does not hold good. Pax has evidently not observed my statement of 1899. 



