TEXTULARIIDAE 113 



the proloculus encircled by 5-6 chambers ; a textularian series of 6-10 pairs of chambers 

 follows ; the chambers increase in size very gradually, so that the sides of the shell remain 

 almost parallel ; sutural hnes slightly depressed. 



Colour a dull rusty brown, with lighter patches; surface smooth but not highly 

 polished. Specimens mounted in balsam show that the wall is thin and largely com- 

 posed of cement, incorporating only a small proportion of minute sand grains. 



Length up to 0-5 mm. ; maximum breadth about 0-07 mm. 



This little species appears to be confined to the deep water of the Scotia Sea and 

 Drake Strait, the stations ranging between 2813 and 4259 m. It is frequent at Sts. 

 WS 471 and 472, rare or very rare elsewhere. The two specimens found at St. 362 were 

 very small and light coloured, but agree in structure with the type at the other stations. 



Genus Spiroplectella, gen.n. 



Test arenaceous, trimorphous, commencing with a spiral series of chambers, the 

 peripheral edge of which is in line with, and in the same plane as the edge of the suc- 

 ceeding series ; followed by a series of chambers arranged on a textularian plan, and 

 concluding growth with a third series arranged in a straight line. 



The organism figured and described by Brady under the incorrect name Spiroplecta 

 annectens (Parker and Jones) (B. 1884, FC, p. 376, pi. xlv, figs. 22, 23) should in future 

 be known as Spiroplectella annectens (Brady), as it has the trimorphous characters of my 

 genus. It has no resemblance to Textiilaria amiectens, Parker and Jones, a fossil from the 

 Gault. The original illustration of this species (P. and J. 1859, etc., NF, 1863, p. 92, 

 text-fig. i^ is not only crude but incorrect, as it shows the early spiral portion turned 

 as a crozier to one edge of the shell, which is also drawn much narrower than it is. 

 Brady may have been misled by this figure, as it does not appear from his text that he 

 was familiar with the fossil type. 



The types of Parker and Jones are in the Geological Department of the British 

 Museum (Natural History), Catalogue No. Parker Coll. VI, No. 34, trays 4, 5. The 

 uniserial portion is small, passing rapidly into the textularian series which widens 

 considerably before contracting at the junction with the uniserial portion. The aboral 

 extremity is trihedral, i.e. the initial spiral, if spiral it be, is turned over at right angles 

 to the edges of the test, and the observer, looking at the biserial chambers, sees only 

 the edge of the spiral portion. 



A better figure of Parker and Jones' species is to be found in Chapman's Gault of 

 Folkestone (C. 1891, etc., GF, 1892, p. 750, pi. xi, fig. 3 a, b) where the initial portion 

 is correctly represented in the drawing, and properly described as being " almost at right 

 angles to the succeeding biserial portion". The uniserial portion does not attain the 

 dimensions of the type, never exceeding a single chamber either in the Gault of Folke- 

 stone or of Reigate, Surrey, where I myself have found the species. 



Cushman selected Textiilaria annectens, Parker and Jones, as the genotype of Spiro- 

 plectinata, Cushman, 1927. He then (C. 1928, F, p. 235) described it as having the early 

 chambers planispiral, later biserial and finally uniserial, and placed it among the hyaline 



DX IS 



