BRITISH FOSSILS. 



5 



Fig. 3. Under side, with the small ten-notched mouth. 

 Fig. Sa. A part of the same magnified. 



Fig. 4. A few plates from the upper side of the test, magnified. (Dr. "Wright's 

 specimen.) 



Fig. 5, 6. A primary tubercle, with its small smooth-edged boss, surrounded by 



miliary granules. G, the same seen edgeways. 

 Fig. 7. The apical disk surrounding the anal space, a, perforated genital plate. 



by that one which bears the madreporiform tubercle, c, ocular plate. 



J. W. Salter, 



March 1856. 



Notes on other British Species. 



Prof. E. Forbes has left in MS. the following account of a large species of this genus 

 in William Smith's collection, preserved in the British Museum: — 



1. Ech. Smithii. Forbes, sp. nov. \_Cidaris, sp. 2. of William Smith's Strat. System, 

 p. 109.] 



E. hiuncialis pentagona depressa, superne gi^antdosa tuherculisque magnis hifariis late 

 divaricatis instructa : subtus tuberculis quadrifariis, magnis, omnibus etiam ambulacralibus 

 primaria fere cequantibus : ore profunde inciso. 



" ' Pentangular depressed, with projecting and rather distant small mamillse ; two con- 

 tiguous rows in each areola, and four converging rows in each area, the two* 

 middle rows short, and only on the side or widest part of the area: rough, with 

 small points encircling the mamillffi ; rays obliquely triporous. 

 " ' The areolae form the angles of the pentagon. The two larger rows of mamillae in 

 each area are parallel to the rays, and converge to the aperture, and the space 

 between them on the side is occupied by two shorter converging rows. 

 " ' Locality. — Tucking Mill.' 

 " The above is the description given by William Smith of a fossil from the under Oolite, 

 to the original of which, preserved in the British Museum, my attention has been kindly 

 directed by Mr. Woodward. Tucking Mill is in Moreton Combe, S.E. of Bath, and the 

 beds from which this urchin came probably belong to the Coral Rag. 



" The specimen is a fine fragment, exhibiting two interambulacral and an ambulacral 

 area. The disk is broken away, but the notches of one angle of the mouth are exposed ; 

 they are deep, and have reflected edges. The tubercles on the ambulacral area, which is 

 very narrow, closely alternate, and are smaller* than those on the interambulacrals. The 

 inferior interambulacral plates bear, towards the periphery (and below it), two tubercles 

 each : the superior ones bear only one each, and that towards their outer margin. The 

 tubercles are deeply perforated. The boss is elevated and smooth-edged, with a deeply 

 channeled summit, and with a distinct flattened areola at its base. The intermediate spaces 

 between the two rows of primaries above, and among the large tubercles on the under 

 surface, are occupied by very small perforated secondary tubercles with areola), and with 

 granules round them. The diameter of the test was nearly two inches, and the height 

 about one inch. The pores are arranged in three ranks, and become close and crowded 

 below." 



E. F. 



* They are so, but on the under surface are unusually large, and to the eye appear 

 equally conspicuous with the primaries. This appearance has therefore been adverted to 

 in the diaguosis. On the upper half of the superior face they abruptly cease. — J. W. S. 



