28 Mr. W. H. Baily on a new Species of Solarium. 



with the remains of this and other individuals of the same 

 species. 



EXPLANATION OF PLATE I., Figs. 1 a-\ I 



Fig. 1 a. Pentacrinus Fisheri, natural size : 1 b, detached head of a 

 larger specimen ; 1 c, plan of arrangement of plates composing 

 the calyx of a larger specimen (natural size), showing articulating 

 surface of ramules ; 1 a, joints from the upper part of the column ; 

 1 e, part of ditto, enlarged ; 1 /, articulating surface of ditto ; 

 1 g, portion of column, of still larger diameter, nat. size ; 1 h, part 

 of ditto, enlarged ; 1 i, articulating surface of ditto ; 1 j, portion 

 of the column, enlarged, showing fragments of the ramules arti- 

 culated to one of the joints ; 1 k. two plates from the upper part 

 of the rays, showing a double ridge ; 1 I, one of the pinnules. 



VII. — On a new Species of Solarium from the Upper Greensand, 

 near Dorchester. By W. H. Baily, F.G.S. 



Class MOLLUSCA. Order Gasteropoda. 



Fam. Littorinidae. 



Solarium Binghami, Baily, n. sp. PL I. fig. 2 «, 



S. testa parva discoidea-depressa ; spira prope plana ; anfractibus (6) 



clathratis, marginibus bicarinatis tuberculatis, umbilico magno 



profundo margine tuberculosa ornato ; apertura angulosa. 



Diagnosis. — Shell small, discoidal ; spire nearly flat, consist- 

 ing of six whorls, their margins bicarinated and ornamented 

 with varices or tubercles ; whorls decussated with longitudinal 

 and transverse lines ; umbilicus large and deep, its margin being 

 ornamented with a row of tubercles gradually decreasing in size ; 

 mouth angular. 



Dimensions. — Elevation T % inch ; diameter T ^. 



Affinities and Differences. — This pretty little Solarium differs 

 specifically from all other described forms, being distinguished 

 from S. moniliferum, Michelin, by its very depressed spire and 

 large, deep umbilicus ; and from S. albensis, LVOrbigny, by its 

 depressed spire and reticulated sculpturing. Its nearest affinity, 

 however, is with these, and more remotely with S. ornatum, 

 Fitton, — all species from the Gault, the two former being from 

 foreign localities, the latter a British species. 



Locality and Stratigraphical Range, — This beautifully pre- 

 served specimen was collected from the Upper Greensand at 

 Bingham's Melcombe, near Dorchester, by the Rev. C. W. 

 Bingham, a gentleman who has enriched the Museum of that 

 town with many contributions, and to whom I have much plea- 

 sure in dedicating it. 



EXPLANATION OF PLATE I., Figs. 2 a-2 c. 

 Fig. 2 a. Side view of Solarium Binghami, natural size ; 2 b, the same, 

 magnified 3 diameters ; 2 c, upper surface of the same ; 2 c?, under 

 surface of the same. 



