IL'U "TERRA NOVA" EXPEDITION. 



a fine superficial layer of cement composed of the finest )uud, and apparently 

 liiglily perforate. Tliis thin superficial layer is, in nearly all instances, produced 

 out at the edge into fistulose extensions. In the most typical examples this 

 fistulosity extends the entire length of the shell ; in others it is confined to the 

 initial half. In a few instances it extends backwards from the fistulose tubes 

 as a ridge along the middle of each chamber towards the median line, and when 

 broken away leaves a very characteristic scar across the chamber, hardly dis- 

 tinguishable from the limbation of T. rugosa, though due to quite another 

 cause. 



These N.Z. specimens appear to link up two widely dift'erentiated species, T. sagittula 

 and T. agglutinans. In their compressed cuneiform outline, spiroplectine initial chambers, 

 and fistulosity, they closely indicate a relationship to T. sagittula, Defr., whereas the 

 inflated later chambers and the oval, or nearly circular, cross-section of the later plan 

 are characteristic of T. agglutinans. Brady's Fig. 19, T. sagittula-, var. fistulosa, differs 

 from the other three figures in the swollen character of the later chambers and pro- 

 bably represents the N.Z. form. Chapman, in his Batesford Limestone paper, assigns 

 Brady's form to Spiroplecta, and, in his Barrier Island paper, describes both the 

 plain and the fistulose types under S. sagittula. We have already published our 

 views on this question of the separation of the spiroplectine forms (H.-A. & E., 1913, 

 CI, p. 57). Cushman's T. stricta appears without question to be the same as our form. 

 No mention is made l)y him of the nature of the initial chambers, but the 

 rounded extremity of his figure strongly suggests a spiroplectine beginning. 

 Under the name Textularioides infiata (gen. nov., sp. nov.) he figures a single 

 attached specimen which appears to be inseparable from this form. Incidentally 

 it may be noted that at both the '" Terra Nova " Stations specimens occur which 

 have been attached to Polyzoa, and sessile individuals are recorded in many 

 species of Textularia. 



186. Textularia fungiforinis, Fornasini. 



Textularia fumiifonitis, Fornasini, 1887, ITl. ^j. 396, pi. x, figs. 1, 1 a, h ; 1896. TC. ]). 2, ct mj. 

 pi. 0, figs. 1-5. 



Stations 1, 3. 



The tendency to variation V)y expansion of the later-formed chambers in T. 

 aqglutinans reaches its extreme development at Stations 1 and 3, resulting in typical 

 specimens of this species. 



187. Textularia abbreviata, d'Orbigny. 



Textularia abbreviata. d'Orbigny, 1846, FFV. p. 249, pi. xv, figs. 7 (not 9)-12. 

 Cushman, 1910, etc , FNP, 1911, p. 14, fig. 20. 



Station 6. 



A few good specimens at this single Station. 



