THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[THIRD SEKIES.] 



«* perlitora spargite museum. 



Naiades, et circiJin vitreos considite fontes : 

 PoUice virgineo teneros hlc carpite flores : 

 Floribus et pictum, divje, replete canistrum. 

 At vos, o Nymphae Craterides, ite sub undas ; 

 Ite, recurvato variata corallia trunco 

 Vellite muscosis e rupibus, et tnihi conchas 

 Ferte, Deje pelagi, et pingui conchylia succo." 



N. Partkenii Giantiettasii Eel. 1 . 



No. 91. JULY 1865. 



I. — Descriptions of new Genera and Species of Diatoms from 

 Hmgkong. By R. K. Greville, LL.D., F.R.S.E. &c. 



[Plate v.] 



Palmeria, nov. gen., Grev. 



Frustules free, hemispherical, having an axis on the plane, 

 and longitudinal lines, indicative of fissiparous division, on the 

 convex surface; structure an exceedingly minute hexagonal 

 cellulation, appearing (except under a high magnifying power) 

 like a fine close moniliform striation, radiating from a subcentral 

 nucleus to the margin of the valve, along with a more distant 

 series of fine costae terminating in intramarginal punctiform 

 nodules. 



This very singular Diatom cannot be satisfactorily referred to 

 any of the families defined in the most recent general arrange- 

 ment—that of Mr. Ralfs in the last edition (1861) of Pritchard's 

 ' History of Infusoria.' With two of them, however (the Cym- 

 hellea and the Coscinodiscea) , there appear to be some points 

 in common. The form of the valve agrees with the first of these 

 families, and the frustule, as in Amphora, presents a ventral and 

 a dorsal aspect j but there are no transverse striae, no longitudinal 

 line, no nodules. With regard to the second family named, it is 

 excluded at once by the absence of the requisite disciform struc- 



Ann. Sf Mag. N. Hist. Ser. 3. Vol. xvi. 1 



