1002.] 



ON KTSENTA AND ECKLONTA. 205 



wave?. Sucli a one miglit give rise to other forked branches from each 

 old ones by the similar process as the latter have been formed : cf. the 

 accompanied fiiiure. The writer has met with two individuals of this 

 form on the coast of th(! province of Boshn. The blades have been 

 almost entirely torn away, ami tlie stem was full of scratches which must 

 be the effect of tlie fi-i;-ti'jn witli the rocks during its long travel or life. 

 This form, linwcver, seems to be rather rare; the writer was not able to 

 find it in the other parts of Japan for several years collection. 



In Fch. cava the sori appear as the large patches on the both 

 surfaces of the pinu;e. In IJck. hicydis, they first appear as the narrow, 

 linear patches running in the direction of longer axes of the pinnre, situat- 

 ed, as it were, in the grooves of the wrinkles, A groove on one side is 

 the ridge on the oth.-r. So the patches occur alternately on the both 

 surfaces. The similar ex:vmples are to be seen in Costaria and Pastelsia. 

 These linear patches, in the case of Eclc. lioyclis, become broader and 

 broader toward the ridges til! finally they fuse together at the anticlinal 

 lines to f.rm a Lirge continuous patch. 



About the shortening of the primary lamina in Eisenia, Setchell has 

 already noticed the similar phenomenon in Eck. hicydis, Eclc. huccinahs 

 &c.i> But he stopped to go further, saying that " the process of erosion 

 in all species stops far sliort of the transition place, and a considerable 

 ])art of the central portion of blade remains." And areschong, also, in 

 remarking the generic character of Ecldonia says: "quo factum est, ut 

 speciraina {Ecldonue huccincdis ex. gr.) non raro iuveniantur, in quibus 

 lamina me^lia vix pollicem longa est et fuliorum seu pinnarum numerus 

 vix 2-3."-^ And KjeHman, again, thinks the primary lamina in all species 

 of Ecldonia " fast immer ungespalten bleibt."-'> In full grown form of 

 Ecldonia hicydis, h(jwevcr, as is given in the PI. XIX and XX, 1. c. by 

 Suringar, no one can imagine that it had been provided with the middle 

 bnxad lamina at the point where now is smooth, thiclc, round edged sinus. 

 In Eck. cava, as fcir as the writer could observe, the middle blade was 

 permanent — the genuine character of Ecldonia. 



One more difference between Eck. hicydis and Eis. arhoria lies in 

 the point that tlie liold fast in the former is always conical, with its 

 height sul)equal to the diameter of the base, while it seems to expand 

 broader in the latter. 



1). 1. c. y.. l.J8. 



•2). Clserv. Thycol. V. p. V2. 



3). Englei- u. Piantl. rilunzeufam. I. abt. II. algre. p. 357. 



