230 Messrs. W. K. Parker and T. R. Jones on the 



In the 'Annals Nat. Hist/ 2nd ser. vol. xix. p. 285, we de- 

 scribed a small variety from the Norway coast, and made some 

 general observations * on the Operculina:. Since then, Dr. Car- 

 penter's Monograph on the genus has appeared in the c Phil. 

 Trans/ for 1859; and to this the student must refer for full 

 information as to the structure and relationship of the Oper- 

 culina. 



We may remark that Prof. Williamson, in his 'Monograph 

 on the Recent Foraminifera of Great Britain/ 1858, p. 35, re- 

 names the little northern Operculina " Nonionina elegans," ob- 

 jecting to its collocation with O. complanata, and grouping 

 Operculina, as well as Assilina, with Nonionina. That the com- 

 mon Nonionina pass into the Polystomellce we have shown when 

 critically examining Fichtel and Moll's Nautilus Faba and N. 

 stria topunctatus (Ann. Nat. Hist. 3rd ser. vol. v. pp. 102, 103) ; 

 and they thus diverge from the true Nummuline type, although 

 their plan of structure much resembles that of their more complex 

 and larger ally ; and although in some varieties (such as Nonionina 

 Limba, D'Orb.) this usually simple shell puts forth an extra 

 amount of exogenous growth and thickens its septa and edges 

 until it much resembles the small limbate Operculina complanata 

 in question, yet this condition does not prove the identity of the 

 two, any more than the like structure in Planulina Ariminensis 

 removes it from the group typified by Rotalia farcta and places 

 it with either Nonionina or Operculina. 



Nummulina. 



We are greatly indebted to MM. D'Archiac and J. Haime for 

 their conscientiously careful work on Nummulites f ; their in- 

 dustrious and clear collocation of synonyms is admirable, and 

 their hitherto unsurpassed illustrations of the Nummulites and 

 their structure supply (taken with those illustrating Dr. Car- 

 penter's paper in the Quart. Geol. Journ. vol. vi.) nearly all 

 that can be required in that direction. Without this work the 

 Nummulites would have remained in confusion ; with its help 

 we may hope to advance to the attainment of a more complete 

 classification than even the authors of that noble monograph 

 have given us. We have already expressed our views on this 

 point to some extent J, stating that we recognize three chief 

 groups (regarded provisionally as specific) of Nummulina, namely 



* In this paper we erroneously treated Planulina Ariminensis as a syno- 

 nym of the species under notice, misled by its great similarity of shape. 



t Description des Animaux fossiles du groupe Nummulitique de l'liide, 

 precedee d'un Resume Geologique et d'nn Monographie des Nummulites. 

 Par le Vicomte D'Archiac et Jules Haime. 4to, Paris, 1853. 



X Ann. Nat. Hist. ser. 3. vol. v. p. 102, &c. 



