Nomenclature of the Foraminifera. 343 



Walker's " umbilicatulus/^ " depressulus/' and " Isevigatulus '' 

 are species or varieties different from those so named by Mon- 

 tagu. The difficulty of recognizing essential differences in mi- 

 nute and very similar forms,, the mixing of specimens, or the 

 shifting of labels (numerals) may probably account for these 

 discrepancies. 



In criticising Montagu's nomenclature of the Foraminifera, as 

 well as in noticing Walker's figures, we frequently refer to Prof. 

 Williamson's Monograph of the Recent British Foraminifera, 

 the latest and best work on the subject. As the works of these 

 three authors comprise the main bulk of all the published ori- 

 ginal researches on British Rhizopods, it has been especially 

 necessary to keep Prof. Williamson's elaborate and well-illustrated 

 Monograph in view. Besides the occasions we have of noting 

 our agreement with many of his determinations, we have also 

 incidentally to notice points of disagreement between his views 

 and our own, without systematically corroborating or discussing 

 all the species which he has enumerated. We hope, however, at 

 some future time to compare notes with our highly valued 

 brother-naturalist ; and in the meantime we believe that he will 

 be as ready to take into consideration the points of difference 

 which we notice, as to recognize and be gratified by our general 

 concurrence with the results of his long-continued and important 

 researches. 



Occasional references are also made by us to the works of 

 Maton and Rackett, Turton, and others ; also to names adopted 

 by Lamarck and D'Orbigny. The two last-named authors will 

 supply us with matter for future papers ; and then we shall treat 

 of the generic names borrowed from them for the species figured 

 by Walker and Montagu. 



It may be well to observe in this place that we wish our 

 readers to remember that, although we protest against the adop- 

 tion of the numerous published binomial appellations of known 

 Foraminifera as specific names, yet we are quite cognizant of the 

 general convenience, and sometimes of the necessity, of retain- 

 ing the published names of varietal forms for use among zoolo- 

 gists, and still more especially among palaeontologists. 



(A. «.) PL 14. fig. 9, p. 522. " Vermiculum oblongum." This 

 is a common Triloculine form of Miliola, belonging to the typi- 

 cal species, M. Seminuluniy Linn., and has been conveniently 

 designated IViloculina oblonga by D'Orbigny (Tabl. Cephal., 

 Annales des Sc. Nat. vol. vii. p. 300, No. 16). Montagu collected 

 his specimens at Salcombe Bay, Devonshire. It is of frequent 

 occurrence on most shores. 



(A. b, c.) P. 519. " Vermiculum bicorne'^ and "V. perforatum.'' 

 See above, p. 341. 



