BRITISH FOSSILS. 



reference to Galerltes umbrella of Lamarck would Lave been re- 

 tained, but that there is evidently a mistake altogether about that 

 species, which is a JS^ucleolites, and not a Pygaster ; and the 

 quoting of it at all by Agassiz was probably an accidental error, 

 which has been copied by himself and others without looking to 

 the original figure of Klein.* Lamarck's description indeed might 

 probably be mistaken for that of a Pygaster, as he distinctly says 

 " sulcis arahulacrorum angustis hiporosis'' but he adds, " suh- 

 striatis," and the figure shows broad avenues with the pores con- 

 nected by transverse furrows ; in fact, it is much like some forms 

 of the common Nucleoliies (Clypeus) patella, though probably a 

 distinct species. 



Prof Buckman's notice, in 1845, of Clypeus ornatus, from the 

 Oolite of Cheltenham, recalls the general form and markings of the 

 species, though his specimen, as usual, having lost the plates of the 

 disk, he makes a mistake in supposing the anal opening to have 

 been at the vertex, the broad sinus extending from it halfway 

 downwards being the aperture in question. 



" The figure given by Phillips in 1829 without a description is a 

 mere outline, two-thirds the natural size, without details of struc- 

 ture, but sufficiently like for identification. It is said, at p. 104, to 

 be common to the Coralline Oolite and Calc. Grit, in Yorkshire 

 and Oxfordshire." — (Forbes.) Phillips' species was admitted by 

 Desmoulins in his Catalogue of Echinoderms, and considered by 

 him a Niicleolites, Agassiz, in his Prodromus, placed it in the 

 genus Pygaster, under which name it has been included in the new 

 edition of Lamarck (1840), and in Desors ' Monograph of the 

 Galerites' (1842). The latter author considered it (p. 76, 77j as 

 probably the young state of the P. umbrella, not being aware that 

 Phillips' figures were so much reduced. But he, strangely enough, 

 quotes with it as synonyms of the P. umbrella, the old references 

 given by Lamarck to the figures in the Encyclopedie, and those 

 of Plott, Klein, and Leske, while he takes some pains in the text 

 to show how wrongly it has been arranged as a Nucleolites hj 

 the side of the N. patella. This confusion has only been partly 

 remedied by himself and Agassiz in the Cat. Eaissonne, the reference 



* It is remarkable that Agassiz should have repeated this mistake in rectifying the 

 synonyms of Pygaster in the Catal. Eaisonne. Klein's figure of Clypeus sinuatus, from, a 

 specimen in the Dresden Museum, is better than the copy in the Encyc. Method., and 

 shoTTS the broad avenues more plainly. Leske compares it with the common English 

 Nucleolites, ^hich he calls C. Flottii, and says it has a more depressed form. They are 

 apparently different species. 



