﻿CIRRUS. 



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the figured specimen, though unusually fine, is thoroughly representative (I have 

 one even larger). The French specimen, according to the figure in the ' Terrains 

 Jurassiques,' has the whorls somewhat more angular than the Coker variety, but 

 there does not seem anything in the author's description to bear out this feature. 

 Some of the Coker specimens show the laminated structure due to the oblique 

 growth-lines, which is also very conspicuous in the types of Cirrus pyramidalis. 



Smaller specimens of Cirrus Calisto, crushed and badly preserved, occur in the 

 Pea-grit at Longfords and at Crickley. 



246. Cirrus varicosus, sp. nov. Plate XXV, fig. 2. 



Description .- 



Length . . . . .20 mm. 



Height of body- whorl to total length . . 44 : 100. 



Spiral angle (mean) .... 62°. 

 Shell sinistral, turbinate, moderately umbilicated ; spiral angle concave. 

 Number of whorls probably ten ; apical ones unknown. The whorls are convex, 

 widely separated by the suture, and ornamented by numerous rugose spiral lines, 

 whilst the traces of axial costse are slight and confined to the posterior half of 

 each whorl. About three stout varices are developed in each whorl, but not in 

 regular sequence, and this kind of ornamentation is continued throughout the 

 base to the margin of the umbilicus. 



The body- whorl is moderately ventricose and without keel ; aperture circular, 

 adherent, and probably expanding. 



Relations mid Distribution. — There can be no doubt that this form is closely 

 related to Cirrus Calisto, i. e. to the Coker variety of that species. But it cannot 

 be regarded as merely the local representative of the Coker fossils, for we 

 find exact micromorphs of these on the Pea-grit horizon. There is every reason 

 to believe that Cirrus varicosus occurs in the Oolite-Marl, and thus represents the 

 calisto-grou]) on a somewhat higher horizon. Extremely rare. 



247. Cirrus nodosus, Soiverby, 1818. Plate XXV, fig. 6. 



1818. Cirrus nodosus, Soiv. Min. Conch., pi. ccxix, tigs. 2 aud 4. 

 1879. — — sp., J. Bzickma?i. Proe. Dorset N. H. Field Club, p. 137, 



pi., figs. 3, 3 a. 



Non Cirrus nodosus, Sotv. Min. Conch., pi. cxli, fig. 2. 



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