MB. W. JOSHUA ON BURMESE BESMIDIEjE. 641 



S. leptocladum, Nordst., var. /3. cujstatum, Wolle. 

 S. gracile, Half's. Several forms. 

 S. gracile, (3. curtum, Nordst. 



S. VESTITUM, Balfs. 



S. Avicula, Br eh. 



S. BRASILIENSE, Not'dst . 



S. leptocladum, Nordst. (9-gona.) 



S. saltans, 11. sp. (Plate XXIII. fig. 21.) 



S. majus ; semicellulis quadrangularibus dorso late curvatis, 

 lateribus apicis spino maguo expanso utrinque instructis, basi 

 truncatis, profunde incisis, apud margineni granulis globosis 

 minutis instructis : angulis superioribus brachii valde incurvis, 

 apicibus bifurcatis ; spinis valde robustis, superiori duplo et 

 ultra majore ; brachio granulis rotundatis serie regulari dispo- 

 sitis, instructo. Longit. 45 ft, latit. 93 ft, cum spina 150 ft. 



Rather large ; semicells quadrangular ; the back widely curved, 

 furnished at each side of apex with a large spreading spine; base 

 truncate, with deep incision, furnished at edge with small globular 

 granules; upper angles of arm much incurved, aud with bifurcate 

 apices ; spines very strong, that on the upper side more than 

 double the length of the other ; arm having a regular series of 

 circular granules. It differs from S. leptocladum, Nordst., in the 

 absence of the lateral crenation and subglobose inflation of basal 

 lobe. Length 45 ft ; width to end of spine 93 ft, with spine 

 150/x. 



S. horrescens, n. sp. (Plate XXIV. fig. 3.) 



S. magnum, fere tarn longum quam latum, subovatum, pro- 

 funde constrictum, isthmo latitudine, spinis exclusis, aequanti } 

 partem diametris transversi: membrano toto spinis robustis, 

 truncatis, in serie regulari dispositis, obtecto. Longit. sine 

 spinis 73 ft, cum spinis 85 ft, latit. sine spinis 70 ft, cum spinis 

 80 ft: isthmi latit. 14 ft. 



Large, about as long as broad, subovate, deeply constricted ; 

 breadth of isthmus one fifth part of transverse diameter, exclusive 

 of spines ; the whole membrane covered in regular disposition 

 with strong truncated spines. Differing from S. Pringtheimii, 

 Beinsch, the semicell of which forms nearly a perfect ellipse, and 

 has no inflation, of angle at point of juncture. Length without 

 spines 73 m, with spines 85 ft; width without spines 70 /i, with 

 spines 80 ft ; width of isthmus 14: ft. 



