102 F. KITTON ON DIATOMACEOUS DEPOSITS FROM JUTLAND. 



Eh., and T. Kittonianum Grev. (see Trans. Mic. Soc, vol xiii., page 

 1, pi. 2, fig. 18) ; a careful examination of the deposits in which 

 Ehrenberg found his specimens has afforded me an opportunity of 

 observing many valves perfect and fragmentary ; and I find the 

 "pseudo-nodules" are more or less distinct in all of them. The 

 differences between T. Solenoceros and T. Kittonianum, which Dr. 

 Greville says are so very decided, are really of no specific value ; 

 the pseudo-nodules (processes as seen in side view) are not absent 

 in T. Solenoceros, excepting in the figures in the Microgeologie and 

 Mr. Brightwell's monograph of the Triceratia. I have examined 

 Mr. Brightwell's slides, and although the processes are not very 

 distinct, they may be detected. In the same paper Dr. Greville re- 

 marks that the pseudo-nodule is very conspicuous in T. Kittonianum, 

 and he quotes my sketch of the front view, in which he says it 

 11 projects above and below the connecting zone like a hammer:" 

 this character further identifies it with Trinacria excavata. 



Solium exsculptum (Herberg). — Frustulesin series cohering at the 

 angles ; processes at right angles to surface of valve tipped with 

 two curved spines ; space between the processes inflated ; valves 

 with four or more sides ; angles produced mammiform ; costate at 

 base ; cellules small, slightly radiant ; Cementstein Mors, brown 

 deposit, Fuur, Nykjobing deposit (pi. iii., fig. 10 to 15). 



This remarkable form seems to bear the same relation to Amphi- 

 tetras as Trinacria does to Triceratium ; in the Fuur deposit valves 

 with five angles are not uncommon. 



Corinna elegans (Heiberg). — Frustules wedge-shaped in series co- 

 hering at the angles ; processes two, unequally produced, armed 

 with a short spine ; inner margin of process slightly undulated ; 

 centre conspicuously inflated ; valve ovate, apiculate ; cellules 

 small, radiant. Common in the Cementstein Mors, brown deposit, 

 Fuur, Nykjobing deposit. 



A very curious form, closely allied to Hemiaulus, from which, 

 however, it is separated by the two unequal processes. The long 

 process of one frustule is attached to the long process of the next 

 frustule, and thus forming a curved filament. The Hemiaulus pul- 

 vinatus of Greville greatly resembles this species. 



In a future paper I hope to describe some of the discoid and 

 other forms occurring in these deposits. 



