ZOOPHYTES. 195 



fixed, generally swelling out, or spreading, either suddenly or grad- 

 ually, and having a depression or cavity in the upper surface. 



A few specimens of simple madrepores, partly from the oolite, 

 and partly from the chalk, are figured in Plate IV, No. 1, 3, 4, 5, 

 6, 7, 8. — No. 8 is a large and beautiful star, resembling a flower; and 

 is supported by a short stalk. It is from the oolite at Malton; and, 

 like most other madrepores in the oolite, consists partly of lime, and 

 partly of flint or chert. The stalk, as in the other specimens, shews 

 the longitudinal edges of the septa, or internal lamellated partitions 

 in the madrepore. The upper edges of the same septa, diverging 

 from the centre, give the fossil its stellated aspect. 



No. 5, which is from the chalk, bears a considerable resemblance 

 to No. 8 in the upper surface; but it has no stalk, except a small 

 protuberance below, from whence the septa diverge to the circumfe- 

 rence, as on the upper surface ; Avhich last has a slight depression in 

 the centre. The edges of the lamellae are less conspicuous than in 

 No. 8, their interstices being more filled up with calcareous matter. 

 It resembles in shape the madrepora porpita, or shirt-button mad- 

 repore. 



No. 4 is an elongated turbinated madreporite, from the Malton 

 oolite. The upper part terminates in a kind of cup, and the whole 

 fossil resembles a collection of cups, placed one within another, the 

 lowest ending in the stalk. A section of the same fossil is given in 

 Parkinson's Organic Remains, Vol. II, Plate IV, Fig. 8. The edges 

 of the lamellae are visible in the stalk, but not prominent. 



Nos. 1, 3, 6, and 7, are specimens of what are usually called 

 alcyonites, being regarded as petrified alcyonia. Numbers of these 

 fossils are found both in the oolite and the chalk; appearing in 

 various forms; some being like mushrooms, as No. 7; others resem- 

 bling pears or figs, as No. 3; and others as No. 1, and 6, partly 

 fungiform, partly in the shape of a trumpet, being furnished with a 



