lOO SPECIES OF DESMIDS. 



c. Semi-cells 5-lobed (111). 



c. Semi-cells 3 or obscurely 5-lobed; lateral sinus shallow, obtuse; 



lateral angles mucronate decemdentata, 1 1 3 



d. Basal lobes with 3 linear processes on each side . muricata, 118 



d. " without linear processes, but (e). 



e. Forked once only, margins finely serrate, Mahabuleshwarensis, 112 

 e. " " " margins and surface spinous . . spinosa.** 

 e. " " " margins smooth . . . Nordstedtiana, 113 

 e. Forked twice (lobules forked); cytioderm spinous . . spinosa* 

 e. " cytioderm smooth; margins serrate, ^ifrOTfl;z;^za;z(3:, 112 



e. " " " margins not serrate, ^;«^w3«a, 112 

 /. End lobe nearly as wide as the basal, apices deeply notched i^g). 



f. ' " ■' " " " apices not deeply notched (A). 



f. End lobe much narrower than the basal, end convex, oscitans, 116 

 /. " " " " " " end deeply emarginate, 



foliacea, 118 

 /. " " " " " " end slightly concave, 



Rabenhorstii*'^ 



g. Basal lobes furcate (with lobules), (/). 

 g. " not furcate {J). 



h. End lobe convex, without prominences . . . taticeps, 115 



h. " truncate, with 2 small prominences . . . recta, 112 



h. " retuse, basal lobe furcate ... . Baileyt, 118 



i. " with 2 slender, transverse, bidentate projections, 



quadrata, 117 

 /. End lobe without projections, convex; sinuses broadly rounded, 



Kitchellii, 1 1 6 

 /. " without projections, concave; neck short; sinuses acut- 



ish Rabeiihorstii, 118 



i. " " " ■' neck long; basal lobes 



curved upwards simplex* 



j. Basal lobes horizontal, not curved . ... pinnatifida, 116 



/ " curved upward, narrow, 



expansa, 117; arcttata, 117; simplex. * 

 k. Basal and lateral lobes deeply furcate (with lobules), furcata, iii 

 k. " " " shallowly furcate, surface smooth, (^) 



k. " " " " " surface spinous; diam., 



175-200/^ apiculata.** 



h. " " " not furcate . . . pseudofurcata, iii 



* Journ. R. Micr. Soc, Dec. 1885. 

 ** F.-w. AlgEe, p. 36 et se.j. 



