644 ME. W. JOSHUA ON BURMESE DESMIDIE.S. 



bearing a long subulate spine at each point. Breadth without 

 spines 48 /u ; breadth with spines 98 xx ; width of isthm us 10 /x. 



10. Artheodesmus, Ehrenb. 



A. GIBBEEULUS. 



A. Incus, Sags. Forms. (Plate XXIV. figs. 10, 11, & 12.) 



A. octocoenis, Ehrenb. 



A. subulatus, Nordst., n. var. guacilis. (Plate XXIV. 

 % 13.) 



A. mediocris, profuude constrictus, angulo lineari ; semicellulis 

 utriusque anguli polaris spinis longis convergentibus ornatis, 

 nonnihil longioribus quam latis, apicibus spinarum fere conni- 

 ventibus : dorso leviter curvato, cum spinis uniformiter arcuato. 

 Longit. 27 /i, latit. sine spinis 35 ju, cum spinis 65 /i: constrictio 

 6-7 ii. . 



Medium size ; deeply constricted, with linear angle ; semi- 

 cells at each polar angle furnished with long converging spines ; 

 the two apices of opposite spines nearly meeting ; rather longer 

 than wide ; back slightly bent, forming a uniform curve with the 

 spines. Length 27 xx ; breadth without spines 35 fi, with spines 

 65 ft ; constriction 67 xx. 



A. aecuatus, n. sp. (Plate XXIV. fig. 14.) 



A. mediocris, profunde constrictus, angulo late hianti, non 

 spinosus, fere tarn longus quam latus : membrano lsevi aut leviter 

 punctato : cellulis subovatis, dorso late rotundato : angulo utrius- 

 que poli spinoso, spina valida, divergenti. Longit. 40 p, latit. sine 

 spina 36 /x, cum spina 70 xx : constrictio 10 /x. 



Medium size ; deeply constricted, with wide gaping angle ; 

 without spines ; about as long as broad ; membrane smooth or 

 slightly punctate ; cells subovate ; back widely rounded, with a 

 strong divergent spine at each polar angle. Length 40 xx ; breadth 

 without spine 36 xx, with spine 70/* ; constriction 10 /x. 



A. apiculatus, n. sp. (Plate XXIV. fig. 15.) 

 A. parvus, subtrapezoideus : profunde constrictus, angulo 

 latiore : semicellulis lateribus rotundatis, dorso curvato, inflato : 

 angulis polaribus Bpinis apiculatis verticalibus ornatis. 



Small, subtrapezoidal, rather longer than wide ; semicells with 

 rounded sides and curved inflated back ; polar angles furnished 

 with apiculate spines, set vertically ; constriction deep, with 

 rather wide angle. Not common. No measurements made. 



