^ MESSES. W. AVEST A'ND G. S. WEST ON 



93. CosMARiUM PULViNATUM, HOY. sp. (PI. VI. fig. 24.) C. parvum, paullo latins quam 

 longum, profunde constrictum, sinu linear! extreme subampliato ; semicellulse oblongo- 

 ellipticce, apicibns truncatis subtruncatisve ; a vertice visse angusto-ellipticse, in 

 medio utrobique multo inflatse ; a latere visce depresso-cllipticoe, apicibus subtrun- 

 catis ; membrana minute et irregnlaritcr granulata. 

 Long. 17-18'5 /u ; lat. 21-5-22-5 ^ ; lat. istbm. 7-7-8 /a ; crass. 14 ^u. 

 No. 36. 



This species dififers from C. pnnctulatum, Breb., in its depressed cells, smaller grannies, 

 and in the large inflation on each side of the semicells, as seen in vertical view. 



94. CosMARiUM TEACHYDEKMUM, nov. sp. (PI. YI. fig. 26.) C, mcdiocrc, panllo longing 



quam latum, modice constrictum, sinu aperto extremo obtuso ; semicellulae elliptico- 

 •; oblongae, lateribus rotundatis, apicibus s ub truncatis ; a vertice visae ellipticse; 

 a latere visae subcirculares ; membrana granulata, granulis parvis et irregulariter 

 ordinatis ; pyrenoidibus binis. 

 Long. 40*5 ^i ; lat. 36 n ; lat. isthm. 16 n ; crass. 21 fi» 

 No. 1. 



Compare with C. scahratiilum, n. sp., and 6'. Holmii, Wille, f. depmiperatay Boldt. 

 (Desmidieer fran Gronland, p. 27, tab. ii. fig. 29). 



95. CosMARigM sCABRATrLiTM, nov. sp, (PL VI. fig. 27.) C. mediocre, paullo longius quam 



latum, submodice constrictum, sinu multo aperto extremo obtuso ; semicellulse 

 ellipticse ; a vertice visae late ellipticae, ad polum unumquemque leviter productae ; a 

 latere visae depresso-globosse : membrana granulata, granulis parvis et irregulariter 

 ordinatis. 

 Long. 42 ^t ; lat. 35-38-5 fx ; lat. isthm. 16-19/4 ; crass. 21-27 ju. 

 Nos. and 1. 



In some specimens the apices and the rounded sides of the vertical view appear to be 

 less granulate than the rest of the membrane. Its nearest ally is C. trachydermum, 

 supra, from which it differs in its elliptical semicells, more open sinus, and different 

 vertical view. 



96. CosMARiUM Blyttii, Wille, Bidrag til Kundsk. om Norges Perskv. Alg. p. 25, tab. i. 



fig." 7. 

 Long. 15-5 /*; lat. 13 /t; lat. isthm. 4/i; crass. 8*5 ju. 

 Nos. 0, 1, and 3. 



97. CosMAiiiuM SPYRIDION, nov. sp. (PI. VIII. fig. 26.) C. minutum, paullo latius quam 



longuni, modice constrictum, sinu aperto et obtuso ; semiccllulae hexagono-ellipticse, 

 angulis lateralibus rotundatis granulis parvis tribus prteditis, infra apicem utrobique 

 concavis, apicibus truncatis minutissime 4-granulato-undulatis, intra angulos laterales 

 granulis minutis 3-4, in centro papilla instructis ; a vertice visa? ellipticae, minute 



