GEAF ZU SOLMS-LAUBACH— MONOaRAPH OF THE ACETABULAIUE^. 20 



A. Penicuhis by the quite aberrant form of its sporangial rays. I was able to study the 

 disposition of the liair-tufts in a youni^ sterile specimen, thanks to its having been 

 preserved in spirits. On each coronal segment one of these is produced, which springs 

 from one of the two outer insertions. The other two hair-processes are stunted and 

 appear as simple unicellular knobs. 



B. Rays of tlie disc united by strong calcification of tlic side-walls. 

 (i. Coronal segments roundish knobs with three hair-insertions. 



13. AcETABULAiiiA PAiivuLA, n. sp. Minima, brevipedunculata, disco piano rotate. 

 Radii ad septa tan turn incrustati, inde subcohserentes, vesiculiformes, clavati, obtusi, 

 apiculo perpusillo instructi. Coronse superioris processus subtriangulari-rotundati, 

 pilis ternis ad angulos dispositis instructi. 



Small, short-stalked, with a terminal, flat expanded, wheel-like disc; mys few in 

 number (about 16), very little calcified on upper and under sides, but strongly on the side- 

 walls and thereby connected ; lime layers between the rays at the outer margin 

 projecting in the form of emarginate buttons. Sporangial rays thick, vesicular, clavate, 

 obtusely rounded, with minute apiculum, seated on a basal portion constricted on both 

 sides, which bears the knob-shaped coronal process with the three roundish triangular 

 hair-scars. 



Size : diam. of cap 2-12 mm. ; breadth of coronal process measured radially 0'042 mm. 

 (Plate II. figs. 3, 5.) 



Sab. Tropical India; collected at Macassar (Celebes) witli A. dentata by Mrs. Weber 

 van Bosse. 



/S. Upper surface of coronal segments radially elongated, and with an elliptical 

 group of numerous hair-insertions. 



14. AcETABULARiA POLTPHYSOIDES, Crouan, in Maze et Schramm, Essai de Classification 

 des Algues de la Guadeloupe, 2nd ed. p. 84. Minime brevipedunculata, disco rotate 

 parce incrustato. Radii pauci, vesiculosi, obtuso-rotundati, subliberi. Coronae 

 superioris processus pilorum octonorum vel novenorum seriem verticem ellipticum 

 circumdantem gerentes. 



Diminutive plants with short stalk and circular expanded disc, and the side-walls 

 slightly calcified. Sporangial rays few in number (12-15), seated on the small constricted 

 basal portion, vesicular and swollen, obtuse and rounded, with rudimentary or absent 

 apiculum. Segments of the corona knob-shaped, radially elongated upwards, with 

 oval, apical surface, on which there are 8-9 hair-insertions, forming an elliptical figure. 

 Hair-tufts short and copiously branched. 



Size : radius of the disc 1-75 mm. ; breadth of the coronal knobs measured radially 

 0-15 mm. (Plate IV. figs. 2, G.) 



Bah. Guadeloupe, Pointe-a-Pitre. (" I16t a Cochons, sous la batterie O ; nicli' a des 

 Centroceras en tapis sur des roches ensablees qui ne restent a decouvert qu'aux plus l)assos 

 marees. Vert brillant a I'etat de vie. En Eevrier 1861 tres rare." — 3Iaze, ser. i. no. 223.) 

 Specimen in British Museum, Hb. Thuret. 



