THE FRESHWATER ALG^ OE M.U3AGASCAR. 69 



the sides and with no granules within the poles; tlie side view also has the gran u](^s 

 distant from each other. 



The stated magnifications of Bocrgesen's figures (/. c.) in his (lescrii)ti()iis of the plates 

 must certainly he wrong according to his own measurements in the text ! 



109. CosMARiTJM ELABORATLM, nov. sp. (PL VII. fig. 15.) C. mediocrc, l-}-plo longius 

 quam latum, profunde constrictum, sinu angusto-lineari extremo suhampliato ; semi- 

 cellulse subsemicirculares apicibus levissime depressis, angulis inferioribus sub- 

 recta ngularibus, lateribus undulato-crenatis 5-6 majoribus sursum, apicilnis verrucis 

 rotundo-quadratis magnis i, intra apicem serie vcrrucarum magnarum 5 (vel C), 

 intra angulos inferiores granulis 1-3, in centro granulis 5-8 varie ordinatis ; a 

 vertice visse ellipticse, polls truncatis tripapillatis, verrucis magnis 5 (vel G) utro- 

 bique, intra marginem lateralem utrumque serie verrucarum magnarum (circ.) 8, in 

 medio de polo ad polum papillis binis 5 ordinata^ ; a latere visa? subcyathiformcs* 

 marginibus superioribus verrucis magnis duabus, marginibus inferioribus verrucis 

 minoribus duabus instructis, serie verrucarum magnarum intra marginem verticale 

 lateralem utrumque et in medio serie singula vertical! granulorura ; membraui\ 

 delicatissime punctata. 



Long. 53-54 fx ; lat. 10-5-42 ^u; lat. isthm. 15o-l7 /u ; crass. 28 ^, 

 No.O. 



110. CosMARiUM suBSPECiosuM, Nordst. Desm. Arct. p. 22, tab. vi. fig. 13. 



Var. TRTJNCATUM, nov. var. (PL VII. fig. 22.) Var. semicellulis apicibus magis truncatis 

 crenis 5, crenis laterahbus 6, crenis granulatis ut in forma typic^, supra isthmum 

 tumore granulate, granulis in seriebus verticalibus 6 ; a vertice visis tumore majore ; 

 a latere visis tumore basali prominentiore, apicibus truncatis. 



Long. 42-5 jn ; lat. 34 fi ; lat. isthm. 15 /n ; crass. 20 /«. 



No. 0. 



Yar. EFFiGiATUM, nov. var. (PL VII. fig. 16.) Var. major, semicellulis crenis later- 

 alibus 8, subemarginatis (non granulatis), supra isthmum tumore granulato, 

 granulis in seriebus verticalibus confertis 7, a vertice et a latere visis tumore 

 majore. 

 Long. 74 /n ; lat. 51 /u ; lat. isthm. 17*5 ^ ; crass. 34 /x, 



111. CosMARiUM GLYPTODERMTJM, nov. sp. * (PL VII. fig. 23.) C. submaguum, circitcr 

 IJ-plo longius quam latum, subraodice constrictum, sinu rotundo-excavato ; sonii- 

 cellula? subsphairico-depressse, apicibus levitcr subtruncatis ; a vertice visa? circu- 

 lares; membrana depressionibus magnitudinum duarum quincuncialiter ordinatis 

 ornata, inter 2 depressiones majores binis depressionibus minoribus, circa unara- 



* This was described in the MSS. and referred to in letters as C. sculptum ; but this name has since been occupied 

 by Eichler and Gutwinski, De nonn. Alg. nov., Krakow, 1894, p. 1G9, tab. iv. fig. 22. 



