GEAr ZU SOLMS-LAUBACH— MONOGRAPH OF THE ACETABULARlEiE. 27" 



and with it the character of Acetahuloides. I was then inclined to form from tliis species 

 a peculiar grouj), Polyphysoides, but was soon able to convince myself that as regards 

 the union of the rays all possible degrees were represented in the Acetahuloides scries, 

 so that A. Calycidus was merely an extreme case. The well-preserved specimens of 

 A. Calyculus permitted me to ascertain the distribution of the hair-tufts on the corona 

 superior. Each segment of the corona bears such a tuft almost regularly, and it arises 

 from the inner insertion, while the outer produces only a blunt, unicellular, hair-like knob. 

 We may here consider a doubtful Acetabular ia^ very hard to elucidate owing to the 

 dearth of material, which Harvey collected in the lagoon of Tongatabu (Friendly Islands) 

 and distributed as no. 18 in his ' Eriendly Island Algae.' I saw it in the London 

 collections and iii Hb. Thuret. Although its rays are connected they show a certain 

 independence, and in its habit the form approaclies our plant. However, it is possible 

 to believe that it is another member of the series of forms of A. caraibica so exceedingly 

 difficult to define. 



10. AcETABULARiA Parlowii, n. sp. Minor, brevipedunculata. Disci radii soluti, 

 ilexuosi, apice obtusi, emarginati. Coronte superioris processus pilis binis uni- 

 radiatis praediti. 



A very small and apparently short-stalked j)lant with white calcified stalk, and 

 completely free rays of cap curved upwards, and in ripe specimens appearing entangled 

 with each other; sporangial rays, about 30, slightly compressed towards the blunt 

 emarginate points ; corona inferior and superior more closely adpresscd than in 

 A. Caly cuius ; both with segments somewhat broadened externally and usually faintly 

 emarginate, those of the corona superior with two scars, one behind the other ; spores 

 large and round. 



Size : diam. of cap 6-7 mm. ; breadth of corona superior 0'15 mm. (Plate III. fig. 1.) 



Hah. Southern point of Florida, Key West {Farlow in Hb. Thuret). 



Unfortunately I have seen only three broken-ofl" specimens of this peculiar species^ 

 and they wanted the lower end of the stalk, that were sent by Farlow to Thuret. From 

 the structure of the corona it is nearer^, caraibica than A. Caly cuius, with which it has, 

 however, in common the completely free rays. It is to be hoped that this remarkable 

 plant will be found again soon. 



Section III. Polyphysa. 



Rays of the cap completely free, inserted on small projections of the central portion, 

 at most united by lime-incrustations ; corona inferior absent, superior composed of free 

 knobs bearing hair-tufts. 



A. Rays of the disc completely free, quite uncalcified, or with a very slight 

 lime-incrustation, evenly disposed. 



11. ACETABULARIA PeNICULUS. 



Plant long-stalked, disc with few rays (8-12), single rays completely free, with 

 narrow basal portion convex below and bearing the button-shaped coronal process above. 

 Sporangial ray inserted on the basal portion with a constricted base and closed against 

 it, vesicular, about twice as long as broad, not at all compressed, with blunt, rounded 



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