BRITISH FOSSILS. 



s 



History, — Described by Dr. Wriglit in the paper above quoted, 

 and admitted into Morris's Catalogue, 2nd edit, by Prof. E. Forbes. 

 He left no notes upon the species. 



Locality and Geographical Position. — Inf. Oolite, in the pea- 

 grit of Crickley Hill, north of Cheltenham. Mr. Lycett's specimen 

 came from the Inf. Oolite, near Stroud. (Dr. Wright.) 



J. W. Salter. 



Explanation of Plate VIII. 



Fig. 1. Dr. Wright's specimen from Crickley Hill. Upper side ; the disk plates lost, 



and the space occupied by them confused with the anal opening. 

 Fig. 2. Under side of do. only partly relieved from the stone. 

 Fig. 3. Posterior view, showing the height of the test. 

 Fig. 4. Lateral view, left side. 



Fig. 5. Plates and avenues, with tubercles and granules . 



Fig. 6. A tubercle from the interambulacral area, upper surface. 



I'ig. 7. Do. from the under side. 



Other British Species of Pygaster. 



As Dr. Wright will give a full description of this genus in his volume on the EcJiino- 

 dermata (Palseont. Soc. Trans.), it will be only necessary to notice the other British 

 species very briefly. He has furnished us with the following memoranda:— 



2. " Pygaster Jibrrt'si/, Wright, Annals and Mag. of Nat. Hist. vol. 9. 2nd series, pi. iv. fig 1. 



" Test pentagonal depressed; marginal fold very tumid; single interanibulacrum much 

 truncated; ambulacral areas wide, com^ex, and prominent, with six rows of tubercles; 

 interambulacra wide, with the tubercles in regular rows, from 20 to 22 rows at the 

 equator ; base depressed towards the mouth opening, which is small ; anal opening large, 

 occupying two-thirds of the dorsal portion of the single interambulacrum. 



" Locality. — Cornbrash, near Stanton, Wilts. (Dr. Wright.) 



"3. Pygaster umbrella, Agassiz, Descript. Echinoderm. Foss. de la Suisse, part 1. p. S3, 

 tab. xiii. fig. 4. 



" Test large, very pentagonal, more or less elevated ; ambulacral areas narrow, M'itii two 

 marginal rows of tubercles throughout, and [two inner rows which commence at some 

 distance from the peristome and extend only a short way above the marginal fold ; 

 interambulacral areas wide, with from 16 — 18 rows of tubercles at the equator; the 

 tubercles are arranged in threes obliquely across the plates, and thus produce irregular 

 rows ; the anal opening is distinctly pyriform, occupying rather more than one-half the 

 length of the dorsal surface of the single interambulacrum ; base concave ; mouth opening- 

 small ; peristome decagonal, equal-lobed ; tubercles on the base, larger, and more regularly 

 arranged, than those on the upper surface. 



Localities. — Coraline Oolite, Calne, Farringdon, Malton; specimens from each 

 of these localities are in the collection of Dr. Wright. 



