BY G. I. PLA.YFAIR. 627 



(1) Var. australis Rac, Desm. Ciast. T.2, f. 15, the youngest; 

 (2) j3 variabile Nord , Frvv. Alg N. Z. T.4, £.17, angles slightly 

 mammillate and pointed; (3) a form of /S variabile observed by 

 me, with angles strongly inflated and produced, spines 3/x long; 

 and (4) var. pseud oconnatum raihi, the fully developed form. 



St. fontense, n.sp. (Plate xiii., fig. 18). 



St. minimum, corpore minuto clepsydriforme, vix constricto. 

 Semicellulse minutse, crateriformes vel subglobosae, sursum utrinque 

 in radios glabros, tenuissiraos, minute 4-fidos, singulos horizonta- 

 liter products; radiis cylindratis, sursum leviter curvatis. A 

 vertice corpus globosum, radiis tenuissimis 4(ut videtur)cruciatim 

 dispositis — semicellulis vero decussatim ordinatis. 



Long, c.rad. 19, s rad. 10; lat. corp. 5; lat. c.rad. 39; lat. rad. 

 ciic 2/tx. 



Sydney Water-supply (22). 



St. fontense naturally falls into line with St. tetracerum Ralfs, 

 T.23, f.7; and St. volans West & West, Alg. Madag. T.9, f 10, 11, 

 but is plainly distinct from both, even if the semicells were not 

 arranged crosswise. 



St. longispinum (Bail.) Arch. /3 depressum, n.var. (Plates xii., 

 fig.8, and xiii., fig. 19). 



Forma brevior, paullo magis constricta. Semicellulse latiores, 

 depressse, dorso planiores, lateribus magis convexis, aculeis hori- 

 zontaliter dispositis. 



Long. 59; lat. s ac. 64, c.ac. 90/>i. 



Botany (37). 



EXPLANATION OF PLATES XL -XIII. 



Plate xi. 



Fig. L— CI. lanceolatum Kiitz- (3 coloratum (Klebs) mihi( x 528). 



Fig. 2. — CI. lunula Ehr. /3 giganteum Bernard ( x 147). 



Fig. 3.-0^. praelongum var. strigosum Br6b.(?)( x 264). 



Fig. A.— CI. Delpontei Wolle var. elongatum West & West, f.( x 264). 



Fig. 5. — Pen. spirostriolatum Barker( x 528). 



