€0 , MESSES. W. WEST AND G. S. WEST ON 



nmbonatse, intra marginem anguli superioris emarginati uniuscujusque papilla 

 instructse ; a vertice yisse ellipticse, in medio umbone et polos triangulatos versus 

 papilla utrobique instmctse ; a latere visse subspbsericse in medio umbonato utrobique, 

 apicibus papillis tribus instructs. 

 Long. 14-15-5 ^u ; lat. 13-5 ^ ; lat. istbm. 5-5*2 /t; crass. 5*5-7'7 a*. 

 No. 0. (See note on p. 90.) 



This approaches C. Begnesii, Keinsch, but is larger and a little longer in proportion 

 to its breadth ; the isthmus is also comparatively narrower, but the lateral and vertical 

 views, with their protuberances, are markedly characteristic. This was seen in fair 

 abundance from lliccall Common, E. Yorks., but the protuberances in the vertical view 

 were less marked than in the examples from Madagascar. Pig. 43 is from a lliccall 

 specimen. C. Regnesii, E^einsch, is also figured for comparison (PL VI. fig. 44). 



81. CosMARiuM SUBLATERE-TJNDATUM, nov. sp. (PL VI. fig. 1.) C, submcdiocre, paullo 

 longius quam latius, rotundo-hexagonum, profunde constrictum, sinu angusto-lineari 

 extremo subampliato; semicellulse late truncato-pyramidata^, lateribus convexis 

 6-undulatis, apicibus truncatis et levissime 2-undulatis ; a vertice visa) ellipticse 

 polls leviter undulatis ; a latere visse circulares ; membrana irregulariter punctata. 



Long. 38-5-40/1; lat. 34-5-38-5 /x; lat. apic. 19-21 ju; lat. isthra. 115-15; crass. 19 ^. 



No. 0. 



This is nearest to C. latere-undatum, Eoy (in litt. cum icone) (see note on p. 90), but 

 differs in its larger size, its relatively broader cells, in the sides having more undulations, 

 in the faintly undulate apex, and in its punctate membrane ; in the lateral view 

 it is also more spherical, and the poles of the vertical view are slightly undulate. 

 Compare also with C. cyclicum, Lund., var. angulatum. West (Preshw. Alg. of N. Yorks. 

 in Journ. Bot., Oct. 1889, tab. 291. fig. 2 ; Preshw. Alg. of Eng. Lake District in Journ. 

 Roy. Micr. Soc, Dec. 1892, p. 728, pi. ix. fig. 19). 



82. CosMAEiUM BEATTJM, nov. sp. (PL VII. fig. 8.) C. parvum, paullo longius quam latum, 

 profunde constrictum, sinu aperto extremum versus lineari extremo subampliato ; 

 semicellulse late truncato-pyramidatoe, angulis inferioribus rotundatis, granulis 

 acutis tribus, lateribus verrucis emarginatis duabus, apicibus truncatis granulis 

 5-6 prceditis, in centro cum granulo magno et semicirculo granulorum 5 circa et 

 subter illud; a vertice visse elliptico-angulares, medio utrinque granulis tribus 

 ornatge, intra marginem lateralem utrumque serie granulorum polls truncatis tenus, 

 polls granulis tribus prseditis; a latere visse hexagono-circulares, apicibus sub- 

 truncatis, angulis superioribus cum papilla parva, utrinque granulis binis instructis. 



Long. 31'5 /t ; lat. 27 ^i ; lat. isthm. 8 /u ; crass. 19 ///. 



No. 3. 



This species and the two following are evidently allies of C. monomazum, Lund. 



83. CosMARiUM BELLTJM, nov. sp. (PL VII. fig. 9.) C parvum, paullo longius quam latum, 

 modice constrictum, sinu lineari extremo subampliato ; semicellulae late truncate- 



