Consequently, since Prof. v. Reuss' definition of this group has proved to be mis- 

 leading, the limitation of the »arenaceous» suborder laid down by the British natu- 

 ralists, particularly by Carpenter and Brady, must provisionally be adopted as 

 more or less consistent with nature. Still it should not be overlooked, that of 

 late some feAv evidences have been adduced, which tend to weaken the confidence 

 in the stability of those prominent characteristics, on which the tAvo sub-orders: »are- 

 7iaceous» and »vitreousyi have been established. Thus, when a whole assemblage of arena- 

 ceous species are met with, each assuming the identical shape Avith that of the corre- 

 sponding form in the vitreous group, the suggestion is easy, that in as much as a 

 species of Textularia or Bulimina is considered likely to appear in the two conditions, 

 the same sort of identity may also exist in other cases, where a similar kind of dimor- 

 phism has been met with. A.t present science is acquainted with not a fcAv forms 

 amongst the vitreous group, which have their corresponding isomorphs within the are- 

 naceous. Nodosarina, Globigerina, Rotalina, besides the forms just mentioned, afford 

 a fair illustration of this isomorphism. It would therefore be but just to give some 

 credit to the suggestions of several able observers, such as Dawson^), Wallich^) and 

 SoLLAs^), in regard to the near relation between and even the identity of many are- 

 naceous and vitreous forms, Avhich have been hitherto kept far asunder. 



Rash and unphilosophical differentiation of varieties, Avhich have specific unity, as 

 also generic distinctions based on trifling and not even constant characters, is an 

 evil long complained of to descriptive biology in general, and, as to this class in parti- 

 cular, the trespassing in this respect — begun by the founder of systematic Rhizopo- 

 dology and continued up to this very day — has passed beyond the boundaries of logic 

 and common sense. 



Those Avho have been engaged in the laborious task of throAving light upon the 

 nomenclature of this class, may in inany instances have been struck at finding their 

 lists of synonyms swelled to hundreds by different names having been conferred on 

 forms without even varietal distinctioii, founded upon quite accidental or individual 

 diversity or on no differentiating characters Avhatever. In this Avay names have been 

 heaped upon names for one and the same thing, rendering any attempt to arrange all 

 tliose synonyms the most unremunerative and time-Avasting kind of scientific labour. 

 Such proceedings, resulting from Avant of discernment and judiciousness, Avould, if not 

 checked by careful and philosophical researches, j^roduce perpetual confusion and ren- 

 der any view of the generic and specific atfinity betAveen the forms obscure. 



In the midst of this rudi.^^ indigestaque moles of descriptive biology the scru- 

 pulous and ingeuious investigations of the eminent and Avell-knoAvn British naturalists: 

 Professoi's W. C. Williamson, W. K. Parker, W. B. Carpenter and H. Brady have 

 established a good deal of clearness and systematic order, based on a thorough expe- 



^) Foramf. of St. Lawrence: Oanad. Naturalist (ti. s.) 5, p. 176; An. M. N. H. (4) 7, p. 86. 



^) IJeep-sea researches on the Biology of Globigerina; Lond. 1876, pp. 62 et seq. 



^) On the perforated character of the genus Webbiua; Geol. Mag. dec. 2, 4 p. 105. (Those uWebbinie» seem 

 to be irregular Planorbulinte). 



