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



12. Desmiditjm Baileyi, De Bary, Conj. p. 76 ; Nordst. Alg. et Char. i. p. 4. Aptogomim 

 Balley% Ralfs, Brit. Desm. p. 208, tab. xxxv. fig. 1.) 



a. GENTJINA, Nordst. Preshw. Alg. of New Zeal. & Austr. p. 27, tab. ii. figs. 4, 5. 



Long. cell. 18-5 lu; lat. 19-24 ^u. (PL IX. fig. 36.) 



No. 0. 



Tbis is a tetragonal form and approaches var. indicim, W. B. Turn. (Fresbw. Alg. of 



E. India, p. 149, tab. xix. fig. 5). 



Genns Bocidium, Breb. 



13. DociDiTJM Bacultjm, Breb. in Balfs, Brit. Desm. p. 158, tab. xxxiii. fig. 5. 



Long. 238 fx ; lat. ad bas. semicell. 10 )u ; lat. med. semicell. 9-5 ^ ; lat. apic 6 ^. 

 (PI. V. fig. 30.) 

 Nos. and 1. 



14. DociDiTTM MANUBRIUM, nov. sp. (PI. V. fig. 31.) D. modiocre, circiter diametro 



13-plo longius ; semicellulae attenuatse, undulis duabus parvis prope basin, granulis 

 16 in circumferentia baseos (visis 9), lateribns recti s, apicibus truncatis ; membran^ 

 irregnlariter punctata. 



Long. 384 /u ; lat. ad bas. semicell. 31 ju ; lat. ad apic. 19 /*. 



No. 0. 



This species bas the characteristic basal plications present in other members of this 

 genus, viz. : — D. Baculum, Breb., D, dilatatum^ Lund., and D. nohile, Lund. 



Genus Pleurot^nium, Nag. 



15. PLEUROTiENiUM subcoro:nulatum. (DocicUuM suhcoronulatum, W. B. Turn. Preshw. 



Alg. of E. India, p. 29, tab. iii. fig. 1.) 

 Long. 407-453 ^ ; lat. ad bas. semicell. 29-37 /a ; lat. apic. 25-29 )u. (PL V. fig. 33.) 

 No. 0. 



16. PLEUROTIENIUM LiGATUM, nov. sp. (PL V. fig. 42.) P. maguum, diametro circiter 



14-plo longius, in medio modice constrictum (lat. constrict. 33 fi) ; semicellulse sine 

 inflatione basali, lateribus parallelis apices versus subattenuatse et constrictse, 

 apicibus truncatis, tuberculis oblongo-ellii^ticis parvis 34 (visis 18) instructis; 

 membrana irregulariter et minute punctatli. 



Long. 614 ^ ; lat. ad med. semicell. 44 ^ ; lat. juxta apicem 32 fi. 



No. 0. 



17. Pleurot^nium moniliferum, nov. sp. (PL V. fig. 32.) P. magnum, diametro 

 circiter 15-plo longius; semicellulge levissime attenuatae, sine inflatione basali, 



