REPORT ON THE FORAMINIFERA. 
377 
spiral commencement, tlie later chambers subquaclrate and arranged alternately. 55 They 
further state that it “ may be regarded as an arrested form of Textularia armectens. 
Spiroplecta biformis is distinguished from its allies by its small size and invariably 
arenaceous test, its nearly uniform width and rounded lateral edges. In the recent con- 
dition, at any rate, it is far removed from Spiroplecta annectens, and there seems nc 
reason to regard it as an arrested form in any ordinary sense of the term. 
Under the name Spiroplecta rosula} Ehrenberg has figured a Cretaceous species 
closely resembling that under notice in general contour, but with a hyaline and perforate 
shell ; and this also is occasionally met with in the living condition. 2 
Amongst the Challenger gatherings Spiroplecta biformis is exceedingly scarce, having 
only been observed at two localities, namely : — Station 323, South Atlantic, east of 
Buenos Ayres, 1900 fathoms ; and Station 285, South Pacific, mid-ocean, 2375 fathoms. 
It has been found by Wright and Balkwill in shallow water on the coast of Ireland. But 
it is as an arctic species that it is best known, indeed until recently its distribution was 
supposed to be confined to high latitudes. The following are some of the northern 
localities from which specimens have been obtained -Franz- Josef Land, lat. 79° to 80° N., 
113 to 145 fathoms ; west coast of Novaya Zemyla, 55 to 70 fathoms ; Baffin’s Bay and 
Smith Sound, 27 to 80 fathoms ; and the Hunde Islands, Davis Strait, 60 to 70 fathoms. 
As a fossil it occurs in the Gault and Chalk (Parker and Jones), and in the Post- 
tertiary beds of the north-east of Ireland (Wright). 
Gaudryina, d’Orbigny. 
Gaudryina, d’Orbigny [1840], Reuss, Parker and Jones, Karrer, Staehe, Schwager, Giimbel, 
Hantken, Brady, Wright, Norman, Marsson, Martonli, &c. 
Sagrinci, pars, d’Orbigny [1840]. 
Heterostumella, Reuss [1865]. 
Plectina, Marsson [1878]. 
The genus Gaudryina embraces a group of dimorphous Textularince which have the 
earlier segments arranged in a more or less regular triserial spire, and the later ones in 
two alternating series ; in other words, those forms which are Yerneuiline at the 
commencement, and subsequently Textularian in their mode of growth. 
Yon Reuss has attempted to confine the use of the term to the species that preserve 
the typical Textularian or marginal aperture, and places such as have a terminal orifice 
in a separate genus, Heterostomella. In dimorphous forms, generally speaking, the 
pseudopodial orifice is an even more variable feature than in the types from which they 
are derived, and that the genus Gaudryina is no exception to this rule may be seen by 
1 Mikrogeologie, pi. xxxii. II. fig. 26. 
2 Found on the north-east coast of England, and described under the name Textularia complexa, Brady, Nat. Hist. 
Trans. Northd. and Durham, 1865, vol. i. p. 101, pi. xii. .fig. 6, a.b. A similar form from the Philippine Seas was 
subsequently figured by Ehrenberg, with the name Spiroplecta demersa ( Abhandl . d. k. Ak. Berlin, for 1872, pi. vii. fig. 26)- 
