CAPULUS. 459 



Shell conical-depressed ; base oval, but slightly expanding anteriorly ; apex 

 posterior with a slender spiral curve. The strong radiating ribs are closely 

 arranged and decussated by encircling growth-lines, which are crowded on the 

 posterior side, wide apart anteriorly. The actual apex is smooth, and presents an 

 extremely small spiral knot, but the radiating ribs commence at a very early stage 

 (figs. 2a,2h). 



Relations and Distribution. — Whether Gapulus or Patella, this is by far the 

 most abundant limpet-like shell in the Jurassic rocks. P. Tessonii may be regarded 

 as a megalomorph from the " Oolithe ferrugineuse " of Moutiers, where the radial 

 costae are wide apart. 



Capulus rugosus is certainly rare in the Inferior Oolite of this country. 

 It is quoted from the "roestone " of Leckhampton Hill. I remember also to have 

 seen a specimen of considerable size from an inland locality of the Yorkshire 

 Dogger. Though by no means abundant, it is better represented in the Lincoln- 

 shire Limestone than in any other beds of Inferior Oolite age, e. g. Stoke Lodge, 

 Ponton, and Weldon. Varieties of this species may also be noted in beds of later 

 age than the Great Oolite. 



403. Capulus ancyloides, Sowerbij, 1824. Plate XLII, figs. 3 a, 3 h. 



182J;. Patella ancyloides, Soioerhy. Min. Couch., pi. cdlxxxiv, fig. 2. 

 1851. — EVGOSA, Sowerbi/, pars. Morris and Lycett, Gt. Ool. Moll., pt. 1, 



p. 89, pi. xii, figs. 1/, ly. 



Bihliographf, ^x. — Originally described from Ancliff. Sowerby noted the 

 decidedly spiral apex, " which being turned to one side makes it resemble the 

 Ancijliis fluviatilis." Morris and Lycett regarded it as the immature form of 

 " Patella " rugosa. There is only one specimen in the Sowerby type collection at 

 the British Museum, somewhat cracked, but otherwise in good condition. 



Description : 



Length . . . . . 6'5 mm. 



Width . . . . .5 mm. 



Height . . . . .2 mm. 



Shell conical-depressed, smooth ; base oval, apex spiral and posterior. The 

 spiral coil is relatively large, and is marked by fine strias (not sufficiently shown 

 in fig. 3 li) ; the rest of the shell is devoid of all ornament, except concentric lines 

 of growth, which become strong towards the margin. 



Relations and Distrihution. — The apical conditions of Capulus {Patella) 

 ancyloides are so different from those of Cajndus rugosus, that this alone would 



