GRAF ZU SOLMS-LAUBACH — MONOGRAPH OF THE ACETABULARIE.*:. 33' 



Clavts Specierum. 



a. Forma unica viva 1 . A. Schenckii, 



b. Formse fossiles. 



1. Disci fragmenta scptis crassissimis cavitatis sporarum subtus et supra 



biseriatae 2. A. Andrussowi. 



2. Spicule sporigera^ tantnm rota? aciculares. 



a. Spicula extus rotundato convexa 3. A. viioccnica. 



y9. Spicula extus profunde emarginata... 4. A. pavantina. 



Fertile whorl terminal, consisting of wedge-shaped rays united laterally with each 

 other ; corona inferior and superior developed, approximately of the same shape ; spores 

 adhering in a cluster from the strong calcification of the outer memhranes and filling the 

 whole sporangial ray, through the upper surface of which the spores appear. The c^ilci- 

 fied suhstance is a homogeneous slime, in which, after decalcification, no trace can he 

 demonstrated of a cuticuloid layer. In the cavities of this slime-mass are situated the 

 easily detachable spores enclosed within a thin, sharply- contoured membrane with a lid. 



a. Living Forms. 

 1. AcicuLARiA Schenckii, Solms. Unica species adhuc viva, char. gen. 



Stalk thin-walled, somewhat stout as if inflated, flabby, witb scars of hair-whorls and 

 terminal fertile disc flat or infundibuliform ; rays 30-50, foirly closely united, wedge- 

 shaped, as if cut off straight at the margin, with sharp, somewhat projecting angles, and 

 seated on well-developed vestibules ; segments of the corona superior crowded together, 

 deeply scolloped externally, irregularly Inlobed, and with much thickened membrane, 

 bearing two hair-scars, one behind the other ; corona inferior of the same shape ; the 

 lime-spiculae enclosing the spores obtusely quadrangular in section, pointed inwards, 

 enlarged outwards, and ending in an obtuse arch, on all sides revealing the spores ; 

 incrustation distinctly composed of the lime-layers of the spores, so that each spore- 

 cavity appears to be surrounded by its peculiar ring of lime ; tliese rings united with 

 each other at the surfaces of contact, and, between them, here and there in the angles, 

 gusset-shaped cavities. 



Size: diam. of the disc about 6 mm.; breadth of corona 0'13 mm.; spore diam. 

 0-06 mm. (Plate III. figs. 4, 9, 11, 12, 14, 15.) 



Acetabiilaria Schenckii, Mobius in ' Hedwigia,' vol. xxviii. 1889, p. 318. 



Mab. Martinique (misit Ze/w?rmcf;^c?, Herb. Berol.) ; Guadeloupe ( F«»»>r i^omarf/, I860,. 

 Herb. Thuret) ; Brazil, Cabo Frio, Prov. Rio de Janeiro. In shallow lagoons. May 1887 

 (H. Schenck, Hb. Schenck). Goebel has recently collected magnificent specimens at 

 Cura9ao (Mus. Bot. Monac). 



The specimens I have seen of this interesting species agree in the main in all respects. 

 The specimens from Martinique are distinguished by the great delicacy and fragility 

 of the sporangium-walls, not noticciible to the same degree in the otlicrs. This may have 

 arisen from their being collected when over-ripe and beginning to decay, so tliat it was 

 difficult to obtain for examination a cap that continued to hold together. Frai;inents of 

 such, and especially beautiful, intact lime-spiculae, are to be found ahundantly inthe mass 



SECOND SERIES. — BOTANY, VOL. V. *" 



