STARFISHES. 105 



only a few species have been found, and they did not form reefs. 

 Among the Polyzoa are the Cellepora, which constitute bark-like 

 incrustations on the shells and stones (such as Cellepora pumi- 

 cosa, Lam., from Corban), and round-celled Milleporce (M. trun- 

 cata, Lam.). 



The sea-urchins, which were numerous in the Nummulitic 

 ga, are much less frequently met with in the Molasse period. 

 Only about half a dozen species are known ; all of them are 

 extinct, but they belong to living genera. Two species (Psam- 

 mechinus mirabilis, Nic., sp., and Spatangus ocellatus, Desf.) have 

 been discovered at La Chaux-de-Fonds ; two others (Brissopsis 

 Nicoleti, Des., and Echinolampus scutiformis, Dum.) have been 

 found near Verrieres in the Canton of Neuchatel; a Scutetta 

 occurs near Kilwangen ; and Echinocardium Deikei, Des., near 

 St. Gall. The existence of starfishes in the Molassic sea is 

 proved by slabs of sandstone covered with them which have 

 been found near Reiden. 



It is remarkable that few Crustacea remain in the marine 

 Molassic strata. Only a small number of cirripedes (Balani) 

 have been discovered, which doubtless had been attached to the 

 rocks of the shore. One species, identical with the common 

 European Balanus (B. tintinnabulum, Linn.), is abundant in the 

 marine Molasse, as in the quarry of Stockeren at the foot of the 

 Bantigerhubel, near Berne, and near St. Gall ; smaller species 

 are found at the Belpberg, at Imi, and near Lucerne. When 

 they are still attached to rocks they enable us to ascertain the 

 limits of the sea and the height of its surface, as these animals 

 always live on the border of the sea in the zone of breakers. 



Scanty traces remain of worms of the Molassic sea ; but here 

 and there great quantities of the calcareous tubes of Serpulce are 

 found adhering to shells ; and in some places the tortuous galle- 

 ries of the Nemerteans occur, which have produced in the Mo- 

 lasse worm-stones of the same kind as in the Flysch. At least 

 it seems very probable that to animals of this kind the fossil 

 remains on the fragment of Shell-sandstone from Reiden, in the 

 Canton of Lucerne, are to be ascribed. The specimen was com- 

 municated to Prof. Heer by M. Bachmann, and is represented 

 in fig. 327, p. 103. 



Of the remains of reptiles in the Molassic sea only a few large 



