GASTEROPODA. 83 



Margarita Groenlandica, Chemnitz. Supplement, Tab. V, figs. 11, a, b. 



Trochus Groenlandicus, Chemn. Conch. Cab., vol. v, p. 108, t. clxxi, fig. 1671. 

 Margarita undulata, Gould. Invert. Massach., p. 254, fig. 172.* 



— — S. P. Woodward. Norwich Crag Shells, p. 5, 1864. 



Diameter, \ of an inch. 



Locality. Fluvio-marine Crag ?, near Norwich. Middle Glacial, Hopton. 



A specimen of this species has been obligingly forwarded to me by Mr. Bayfield, of 

 Norwich, and he thinks it was found either at Thorpe or Postwick, but he is not able to 

 say whether it is from the upper or lower bed. The present specimen is not a 

 full-grown individual, as it possesses little more than three volutions. G. B. Sowerby 

 describes this shell (M. undulata) as having four, Messrs. Forbes and Hanley describe 

 it as having five, and Mr. Jeffreys as having six, volutions. 



Three varieties of this species are given by Mr. Jeffreys, and our present shell seems 

 to correspond with the one he has named Icevior, which is said to be smooth. The Crag 

 shell has visible lines of growth with one or two nearly obsolete spiral ridges, but there 

 are no nndulations upon the upper part of the volution. 



The pullus of this species, as well as those of M. maculata and M. trochoidea, are free 

 from strise or ornament of any kind. 



Several small specimens, more or less imperfect, of a Margarita have occurred in the 

 Middle Glacial sand of Hopton. Their rubbed condition will not allow one to say posi- 

 tively that they belong to this species, but there can be little doubt of their belonging to 

 one of the varieties of it. 



Margarita maculata, S. Wood. Crag. Moll., vol. i, p. 185, Tab. XV, fig. 3. 



Localities. As in ' Crag. Moll.' 



This elegant species would be a shell of some importance if the one found fossil in 

 America and also recent upon the Coast of California should be identical with it. I have 

 not been able to see the fossil from Williamsburg, spoken of by Sir Charles Lyell 

 "Solarium, nearly allied to Solariella maculata," 'Proc. Geol. Soc./ 1845, p. 555, but I 

 have compared a recent shell from the Cataline Islands Solariella per amabilis, Carpenter, 

 "Rep. Moll., West Coast of N. America," 'Brit. Assoc.,' p. G53, 1864, with the Crag 

 species. The recent shell has a more elevated spire, and in consequence a more 

 contracted umbilicus, while the striae in the Crag shell are rather more distinct. 



The shell from the Cataline Islands is of a rufous brown, and possibly the spots 

 remaining upon the Crag fossil may be some of its original colour. 



