168 



DlATOMACEOUS DEPOSITS FROM JUTLAND. 



(Part 2.) 

 By F. Kitton. 



{Read January 21th, 1871.) 



In a previous communication, read before the Club on the 24th 

 June last, and published at page 99 of the present volume of the 

 Journal, I enumerated and gave descriptions of a series of forms 

 occurring in these deposits, chiefly those described, or referred to 

 by Heiberg. There remain other forms to be named and described, 

 some of them new, and all interesting, which form the subject of 

 the present paper. Some apology, perhaps, is needed for offering 

 so purely technical a communication to the Club, but the barren 

 facts of science are essentials, without which there could be no 

 generaliz ations . 



1. Stictodiscus angulatus (Grunow) — Frustules composed of two 

 dissimilar valves, one convex, the other slightly concave and um- 

 bonate ; valves disciform, the convex valve with two slight mar- 

 ginal projections at the opposite diameters ; markings cellulate and 

 costate; costae conspicuous near the margin, but disappearing as 

 they approach the centre cellules; radiant between the costa3 ; scat- 

 tered at the centre ; concave valve without marginal inflations ; 

 costae indistinct or wanting ; cellules more scattered ; centre with 

 distinct pore, or pseudo-nodule ; frequent in the Mors, Fuur and 

 Nykjobing deposits (pi. 13, figs. 1-2). 



This elegant little form resembles S. Kittonianus (Greville), but 

 differs from that species in the peculiar lip-like projections of the 

 convex valve. The concave valve resembles Porodiscus nitidus, of 

 Grev. Trans. Mic. Soc, vol. xi., p. 65, pi. 4, fig. 5, and it is 

 probable the two forms are identical. I have named this species, 

 on the authority of Moller's, " Typen Platte." 



2. Aulucodiscus Jutlandicus (n. sp., F.K.) — Valve hyaline; pro- 

 cesses sub-marginal ; furrows distinct ; granules radiant ; disc not 

 bullate, beneath the processes ; deposit Fuur (pi. 13, fig. 3). 



