394 ORGANIC REMAINS. 



harder kinds of algce, and other marine plants, such as those repre- 

 sented in Plate IV, Fig. 9. 



The corals are divided into various genera, as ttcbipores, madre- 

 pores, cellepores, &c. ; differing from one another in their internal 

 structure or organization. Several varieties of them are found in the 

 regular strata of the district, but a much greater number in the 

 alluvium. 



Tubiporites, or petrified tubipores, occur in the alluvial beds, 

 chiefly in nodules of limestone, which are washed down by the rains, 

 and found among the gravel on the beach. The Scarborough 

 Catalogue of Fossils enumerates four different species as occurring on 

 the coast; one of which is the tuhipora musica, resembling organ 

 pipes, and another the chain coral. A few others have been noticed 

 by the authors on the Whitby shores, and moi*e may yet be discover- 

 ed, as there is an almost endless variety of fossils in the alluvium. 

 We have not observed any specimens in the regular strata. This 

 kind of coral is composed of erect hollow cylindrical parallel tubes, 

 commonly joined together by small cross tubes. 



Madreporites, or star-stones, distinguished by their stellular con- 

 formation, are a beautiful class of corals, frequently met with in this 

 district. Numbers occur in the regular strata, and many more are 

 found on the beach, in limestone nodules that have fallen from the 

 alluvial cliffs. They display great vai'iety and beauty, particularly in 

 their polished cross sections. 



The madrepores are distinguished into simple and compound, 

 the former shewing only one star, the latter an assemblage of stars. 

 Both are found in our strata, particularly in the oolite and the 

 chalk. 



Many of the simple madrepores bear a great resemblance to 

 some kinds of mushrooms; while others resemble pears, and other 

 fruits; rising up from a stalk, by which they appear to have been 



