F. KITTON ON DIOTOMACEOUS DEPOSITS FROM JUTLAND. 101 



processes, of which the larger occurs at the broadest part of the 

 frustule ; both are armed with two spines. 



Hemiaulus Proteus (Heiberg). — Frustules in series, cohering at 

 the produced angles, each of which are armed with a stout curved 

 spine ; space between the angles with a large central inflation, and 

 one or more smaller inflations on each side, decreasing as they 

 approach the angles. Side view elliptic, lanceolate centre widely 

 constricted, and four or more costee (the costee correspond with the 

 depressions seen in front view) ; cellules scattered, distinct. 

 (Cementstein Mors, brown deposit, Fuur. PI. xi., fig. 1-6.) 



Hemiaulus hostilis (Heiberg). — Frustules in series cohering at 

 the angles ; processes elongated, terminating in a slender, straight 

 spine ; one large central inflation between the angles ; side view 

 oval, with two costee ; cellules scattered, distinct, smaller, and closer 

 in centre (between the costee) ; Cementstein Mors, brown de- 

 posit, Fuur, rare in Nykjobing deposit (pi. xi., fig. 7-11.) 



Hemiaulus februatus (Heiberg). — Frustules in series ; processes 

 terminating in a stout, curved spine ; space between the processes, 

 with a single inflation ; bases of processes suddenly inclining to- 

 wards the inflation ; side view ovate ; costee, two ; cellules large, 

 moniliform, very conspicuous in the centre (between the costal), in 

 all the preceding deposits (pi. xi., fig. 12-16.) 



Trinacria Regina (Heiberg). — Frustules in series cohering at 

 the processes ; processes produced hornlike at right angles to valve, 

 tipped with two incurved spines ; valves with three or more sides, 

 slightly concave ; outline slightly undulate ; marking consisting of 

 conspicuous pearl-like granules, distant and scattered near the 

 smooth centre, but distinctly radiant as they approach the margin ; 

 common in the Cementstein Mors and Fuur deposit, scarce in the 

 Nykjobing deposit (pi. ii., fig. 1 to 7). 



Trinacria excavata (Heiberg). — Frustules in series ; processes 

 long, at right angles to valve, armed with two incurved spines ; 

 valves, with margins, deeply concave ; granules distinct, radiating 

 from the centre ; Cementstein Mors brown deposit, Fuur ; the small 

 variety occurs in the Nykjobing deposit (pi. hi., fig. 6 to 9). 



The small form (fig. 7) is probably identical with Triceratium 

 ligulatum of Dr. Greville (Trans. Mic. Soc, vol. xii., pi. 13, fig. 9.) 

 The larger form I have no hesitation in referring to T. Solenoceros* 



* Dr. Heiberg says in his Danske Diatomeer, "Kan jeg ikke antage Andet 

 end at Brightwell har hav enfra neervserende Art faskjellig Form for sig " (page 

 51). 



