250 MESSES. W. WEST AND G. S. WEST OX 



in lineis 11 ordinatorum, in centro granulis reductis, ad medinm utrobique granulis 

 paucis ornate (in margine circ. 5) ; a latere visge ovatse, apicibus subtmncatis, cum 

 zona lata verticali granulornm in lineis 11 (in seriebus borizontalibus 15) ordi- 

 natorum, ad basin utrobique granulate marginibus superioribus glabris ; membrana 

 punctata ; pyrenoidibus binis. 

 Long. 88-5-103 i^i. ; lat. 61-5-69 a* ; lat. apic. circ. 22-27 /* ; lat. istbm. 19-20 fi ; 

 crass. 44 /u. 



Compare witb C. JSichleri, Eacib. (in E.ozi)r. Akad. Krak. ser. II. ii. (1892) p. 384, t. 1. 

 fig. 7), and C. siipraspeciosum, WoUe (Desni. U.S. p. 88, pi. 50. figs. 5, 0). 



81. CosMARiUM Favum, uov. sp. (PI. XV. tigs. 5, 6.) 6'. mediocre, H-plo longius quam 



latins, profunde constrictum, sinu angusto-lineari extremo valde ampliato; semi- 

 celluljje transverse oblongo-ellipticoe, granulis in seriebus obliquis et sub verticali bus 

 ornatae, cum sulculo rotundo-liexagono circa granulum unumquemque (cum punctulo 

 ad angulum unumquemque), in centro cellulae circa istbnium membrana glabra ; a 

 vertice visge oblongo-ellipticae. 

 Long. 69 jU ; lat. 55-5-57-5 /u; lat. istlmi. 19 ^ ; crass. 35 /u. 



This species is nearest to C. margaritatum, Roy et Biss. in Journ. Bot. xxiv. (1886) 

 p. 194 : et in Ann. Scot. Nat. Hist. (1894) p. 167, pL 2. fig. 12, but differs in its more 

 rounded semicclls and different ornamentation. 



82. C. suBPULCHELLUJi, nov. sp. (PL XV. fig. 12.) C submediocre, paulo longius 



quam latins, modice constrictum, sinu angusto-lineari extremo ampliato ; semicellulse 

 transverse oblongse lateribus rotundatis, apicibus late truncatis et levissime concavis, 

 dense et minute granulatse, granulis ivregulariter ordinatis, in centro glabrae ; a 

 vertice visse anguste oblougae, polis rotundatis; a latere visse ellipticae. 

 Long. 47 A*; lat. 44 ^u ; lat. isthm. 15 ^i; crass. 16 fx. 



Tbis differs from 0. pulchellwyi, "W. B. Turn. (Fresliw. x\lg. of E. India, p. GQ, t. 9. 

 fig. 46), in the depressed subconcave apices, in the irregular arrangement of the more 

 numerous granules, ^\bicli are absent at the centre of the semicells, and in the much 

 narrower vertical and lateral views. 



83. C. BiAURiTUM, Nordst. in Vidensk. Meddel. 1869 (1870) p. 212, t. 3. tig. 30. Forma 



granulis in medio semicellularum paulo reductis. 

 Long. 20 |u ; lat. 15-5 ^t ; lat. isthm. 4-5 fx ; crass. 10 fx. 



84. C. ABRUPTUM, Lund. Desm. Suec. p. 43, t. 2. fig. 22. 



Var. GRANiJLATUM, Wcst & G. S. West, in Trans. Linn. Soc. ser. XL, Bot. v. (1895) ]). 65, 



pi. 7. fig. 32. Forma paulo major et cellulis subquadratis. 

 Long. 17-19 m; hit. 135-16^; lat. isthm. 4-5-5-5 ft; crass, llo m. 

 Sab. Orono, Maine. 



S5. C. cosMETUM, nov. sp. (Pi. XV. fig. 4.) C. mediocre, paulo longius quam latius, 

 profunde constrictum sinu angusto-lineari extremo ampliato; semiceUulue oblongo- 

 trapeziformes, angulis inferioribus superioribusque rotundatis, lateribus convexis 



