Tendo: CORALLINE VERJE. 717 



6a) so that we could not suppose it to belong to this species, 

 had it not been provided with some normal branches in a portion 

 of the frond (PL LIL, Fig. 4). 



Although I distinguish these four formae, intermediate forms 

 between them are naturally met with. Especially f. intermedia 

 and f . -polymorpha are likely to be confounded with the abnormal 

 forms of Cheil. planiusculum. In this case the external thick 

 margin of the apical articuli and the robust stipes are the impor- 

 tant characters of this species to separate it from the latter. The 

 apical articuli of Chcil. -planiusculum are mostly thin and com- 

 pressed, and the stipes are delicate filiform. Nevertheless, it 

 would not be an unreasonable supposition that the hybrid between 

 Chcil. frondcsccns and Chcil. planiusculum ma) 7 occur in nature. 



Common : between tide marks, also in pools. 



5. Cheilosporum planiusculum (Kiitz.). PL LIIL, Figs. 1-3; 



PL LVI., Figs. 9 and 10. 



Fronde dense ca^spitosa suberecta, 3-7 cm. alta, superne com- 

 planata, bi-tripinnata ; articulis axium inferioribus tenuioribus 

 cylindraceis mediis superioribusque compressis late triangulari- 

 bus subcostatis, pinnarum sagittatis lobis acutis saspe cordatis, 

 pinnularum ancipitibus lanceolatis vel linearibus, ultimis obo- 

 vatis compressis ; geniculus brevissimis ; conceptaculis hemi- 

 sphaericalibus, 2-5 in articulo instructio. 



Corallina planiuscula Kiitz., Tab. Phyc., VIII., p. 3i,taf. 

 63> Fig. 3. 



The present plant is extremely variable in the shape of its 

 articuli, and sharp definition is hard to give. Kiitzing counted 

 four formae in the original description (/. c.) though I could not 

 find any form referable to f. laciniata. The other three formae 

 may be found mixed together in one bunch of the plant, often 

 branches of different forms occurring in one individual. In an 

 extreme instance, especially in a plant growing at high-tide 

 mark, the frond becomes a moniliform filament with a few 

 articuli of the normal shape (Plate LIL, Fig. 3). Generally 

 speaking, the articuli of the upper and middle portions are 

 sagittate, with lobes thin, delicate and sharp at the upper angles, 

 and with evident ribs at the middle ; the pinnules are thin, 

 spatulate or lanceolate. As the consequence, an articulus is 

 not approximate with its adjacent ones as in Cheil. frondescens 

 f. typtca(comp. PL LVI., Fig. 4, and PL LVI., Fig. 10). 



