70 MESSES. W. WEST AND G. S. WEST ON 



Forma tetragona. 



Long. 19 fx ; lat. 20 ^i ; lat. istlim. 6 jx. 



No. 1. 



140. Statirastrum incurvatum, nov. sp. (PL YIII. fig. 33.) S. parvum, IJ-plo latius 

 quam longum (cum processibus), profunde constrictum. ; semicellulse urniformes, 

 in basi inflatoe cum annulo granulorum acutorum, apicibus valde convexis 

 granulatis, angulis superioribus in processus incurvatos undulatos et punctato- 

 granulatos productis, apicibus tridenticulatis ; a yertice yisse triangulares, lateribus 

 concavis, in medio lateris uniuscujusque retusae et intra marginem (in medio 

 retusum) serie singula granulorum 6, angulis in processus undulatos et transverse 

 punctato-granulatos productis ; membrana punctata. 



Long. 23 jit ; lat. cum proc. 36 |t ; lat. isthm. 5'5 ^u. 



No. 3. 



141. Staurastrum basidentatum, Borge, Chlorophyllopb. fran Norska Finmarken, 

 p. 8, fig. 5. 



Var. SIMPLEX, Borge, 1. c. fig. 6. (PL YIII. fig. 45.) 

 Long. 21 ju ; lat. cum proc. 31 jtt ; lat. isthm. 9 ju. 

 No. 0. 



142. Staurastrijm subgemmulatum, nov. sp. (PL YIII. fig. 34.) S. parvum, pauUo 

 latius quam longum (cum processibus), modice constrictum ; semicellulse late 

 cuneatse, apicibus convexis glabris, angulis superioribus in processus breves validos 

 granulates liorizontales productis, apicibus truncatis; a vertice visas sexradiatse, 

 processibus conicis granulatis truncatis, angulis inter processus subrectangu- 

 laribus, in centre glabrae. 



Long. 33 |u ; lat. cum proc. 38 ju ; lat. isthm. 10 fx. 



No. 0. 



This is nearest to >S'. gemmulatum, W. B. Turn. (Ereshw. Alg. of E. India, p. 114, 

 tab. xiii. fig. 26), but differs in the absence of the apical gemmules, in its smaller size, 

 and in having the processes in front view horizontal and sparsely granulate (not striolate). 

 Compare also with S. polymorphum, Breb. 



Yar. GRACiLius, nov. var. (PL YIII. fig. 35.) Yar. semicellulis granulis paucioribus, 

 processibus minus validis apicibus minute tridenticulatis. 

 Long. 27 fi ; lat. cum proc. 38 ^ ; lat. istlim. lOjit. 

 No. 0. 



143. Stalrastrum Baronii, nov. sp. (PL YIII. fig. 36.) S. parvum, paullo latius 

 quam longum (cum processibus), profunde constrictum ; semiceUulse late campanu- 



