234 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. [Apr. 2, 



As the following descriptions only refer to the features of the 

 plates discovered, which can only give but imperfect ideas of the 

 species to which they belong, I have thought it better to leave two 

 unnamed, so that those who follow in helping to work out the 

 characters of the species may have their share of the honour (if 

 there be any) of giving them names. 



1. Chiton Bubeowiantjs, spec. nov. Figs. 1 & 2. 



A nearly perfect posterior plate and a fragment of an intermediate 

 one represent the present species. 



Posterior plate rather more than semi- Figs. 1 & 2. — Posterior 

 circular marginally, depressed posteriorly Plate of Chiton Bur- 

 and laterally ; median elevation moderate, rowianus. 

 angulation obtuse; dorsal area compara- (Enlarged one-third.) 

 tively long, flatly rounded, terminating pos- 

 teriorly in a blunt, depressed apex ; shell 

 thick, surface apparently worn, lines of 

 growth faint; length j inch, breadth f inch. 



The fragment of the intermediate plate 

 is on the same piece of limestone as the 

 one described. It shows the apex, most of 

 the dorsal and small portions of the lateral 

 areas. The apex is acute and depressed ; 

 dorsal area rounded and arched longi- 

 tudinally; lateral areas slope rapidly, al- 

 most at a right angle; shell thick, surface j TJpp£_ 

 similar to that of the posterior plate, and 2. Lateral view, 

 size proportionally the same. 



The near position of these plates, and their similarity of size, sur- 

 face, and shell-thickness lead me to consider them to belong to one 

 individual, hence to the same species. 



As a slight acknowledgment of the value of Mr. Burrow's re- 

 searches in palaeontology, particularly of his discovery of four 

 Chitons new to science, I gladly adopt his name for the present 

 species. 



2. Chiton coloratus, spec. nov. Figs. 3-6. 



Under this name I include an intermediate and a posterior plate, 

 which, from their size and general character, appear to belong to 

 one species. 



The intermediate plate is one-fourth wider than long, and much 

 longer medianally than at the extremity of the lateral areas, as both 

 anterior and posterior margins trend inwards as they proceed from the 

 median line to the lateral extremities ; angulation of the plate more 

 obtuse than a right angle, though more acute centrally than laterally ; 

 dorsal area (?) raised a little above the general surface ; lateral areas 

 obscure ; later lines of growth well marked ; anterior portion of the 

 plate and dorsal area coloured black, the colour following the con- 

 tour of the margin and the raised dorsal area ; shell strong, length 

 ■^ inch, breadth | inch. 



)er view. 



