64 



rising from every second node, some times forked. Articulations half as 

 long as or subequal to the diameter in basal portion, little longer in the 

 median portion of branch, again becoming subequal in pinnulae, and 3 

 cells are seen in surface view. Stichidia lanceolate at first, linear- 

 lanceolate or oblong and apiculate when fully grown, compressed, with 

 an one-cell-long polysiphonous pedicel, coated with transversely arranged 

 rectangular cells. Cystocarps urn-shaped, sessile, sitting on the thick and 

 polysiphonous axis of pinnae. Colour pinkish red. Plant soft and flaccid 

 and closely adheres to paper in drying. 



Hub. : On several algae in the sublitoral zone. Kyushu to Hako- 

 date ; Japan Sea. Fruits: spring summer. 



Since the publication of the present plant and very closely related 

 species, H. tiotoensis, as new to science, I have collected many specimens 

 of both species from several localities and have found that there are 

 many forms which are not easy to distinguish one from the other. In 

 the typical form of H. pulchra upper and lower pinnae upon one and 

 the same branch are almost equal in length, while in H. notoeiisis 

 upper pinnae are decompounded and consequently branch assumes sub- 

 corymbose outline. But as those characters are not definite, there being 

 many irregularities in both species, I came to consider that H. iiotoensis 

 is nothing but a robust form of H. pulchni and better to unite the 

 both plants under one species. 



PL. CLXVI. Fig. 1 : frond of Hcterosiphonia pulchra (Okam.) Fkbg., 

 \. Fig. 2: growing apex, a ^. Fig. 3 : portion of branch showing the 

 disposition of pinnae, fi j* . Fig. 4: cross-section of branch, ^ . Fig. 

 5: portion of branch showing arrangement of pinnae which _bear 

 stichidia, ^ F'- 6: stichidium, ^ Fig. 7 : cystocarp, a little magd. 

 Fig. 8 : frond of the form hitherto taken as a different sp. H, tiotoensis. 



