BY G. I. PLAYFAIR. 529 



In size and shape very like Cox. suhtumidum Nord., for 

 which see W. & G. S. West, Monog. Br. Desm., ii., PL 63, 

 f. 18-20. 



Var. suBELLiPTicuM, n.var. (PI. liv., f.l4). 



Seraicellulae subellipticse vel subtriangulares, ad apices levis- 

 sime acuniinatae, superne valde arciiatae, inferne basi con- 

 vexa ; lateribus utraque parte curvatis ; angulis lateralibus 

 latissime-rotundatis ; nienibrana tractu incrassata infra apices 

 instructa. 



Long. 40; lat. 33; isth. 6 //.. Cum priori. 



Cos. ANisocHONDRUM var. coNFUSUM, n.var. (PL liv., f.l5). 



Semicellulae subtriangulares ; apicibus angustis truncatis ; 

 angulis lateralibus latissime-rotundatis ; lateribus sursum 

 levissime arcuatis ad apices convergentibus ; puncta-granulis 

 in seriebus radiantibus, granulis 2-3 infra marginem, ad 

 isthmum granulis 4, media semicellula paucis obscuris irregu- 

 lariter dispositis ornatae. 



Long. 28-30; lat. 27-30; isth. 7; ap. 12/t. 



Cos. Meneghinii var. Regnellii (Wille) mihi, formae. 



(PL liv., f. 16). 



Una semicellula formae typicae consimilis sed apice crenis 

 obscuris 4 instructa ; altera lateribus arcuatis ad apicem trun- 

 catum convergentibus, lateribus crenis 3 ornatis, apice crenis 

 obscuris 4. 



Long. 17; lat. 15; isth. 4; ap.8/x. 



Syn., Cos. UvgnelUl Wille, Sydamer. T. i., f.34. These 

 forms show Cos. Regnellii passing over into Cos. Meneghinii. 

 Two intermediate crenae form on the apex, and one on each 

 side at the base ; with growth of the semicells, the crenation 

 gradually becomes regular. 



Cos. TURGiDUM var. Ai.PESTRE (Roy & Bisset) mihi. 

 Endochroma in taenias parietales 8 ordinata. 

 Long. 75-86; lat. 68-80 ii. 



Syn., C. (ilpcsfre Roy & Bisset, Scottish Desm., p. 29, PL i., 

 f.6. The specimen was surrounded by a mucous investment 



