236 THE TWO FORMS OF THE SEA-ASTER. 



the other two species occurring but very rarely. In this con- 

 nection it is of interest to note that in the case of Ilford the 

 remains of the prevalent species of Rhinoceros exhibit a tendency 

 to vary towards the prevalent species occurring at Grays 

 Thurrock in the greater complication of the transverse valley of 

 the molars by combing plates — a character much more common 

 in B. leptovhinits (the Grays form) than in R. hemitoechns. A 

 precisely analogous instance is presented in the relationship 

 between the Elephant remains found in the deposits of the 

 two localities. At Ilford Elephas primigenins is the common 

 form, while at Grays Thurrock this position is held by 

 E. aniiqnns. But many of the molars from Ilford of the 

 Mammoth depart from the typical form of that species and by 

 having plates of thicker enamel, more or less complicated by 

 crimping, they approach in appearance what is seen in 

 E. antiqmis. 



In the present state of our knowledge, no conclusions can 

 be with safety drawn from these facts of distribution. They, in 

 common with many other ascertained facts of Pleistocene 

 Geology and Palaeontology, indicate important portions of the 

 history of the Thames Valley, but these portions we cannot read 

 until we have been able to appreciate many factors which as yet 

 are but little understood. 



In conclusion I have to express my best thanks to the 

 gentlemen mentioned in this paper for the loan of their speci- 

 mens and my warmest gratitude to Mr. F, W. Reader for his 

 kindness in preparing the admirable figures in the accompanying 

 plate. 



THE TWO FORMS OF THE SEA-ASTER 

 (ASTER TRIPOLIUMj. 



By PERCY CLARK, B.A. 



As I now write (September 6th, 1901) the Essex Salt- 

 marshes, bordering the sea, which are overflowed by the water 

 at springtides, present a beautiful appearance. The tall up- 

 standing masses of the Sea-Aster growing there in wild and 

 unchecked profusion, are all in flower, and their small golden 

 heads massed together in thousands shed a glow of soft yellow 

 colour over the Saltings. But a few paces inland v/here the 



