PICTURESQUE SKETCHES 



its name is taken. This has been compared* to the 

 Fig. 22 crescent- shaped blade of a 



saddler's cutting-knife, the 

 body forming the handle. 

 It is extremely broad and 

 flat, extending on each side 

 considerably beyond the 

 body, and the bones appear 

 to have been firmly sol- 

 dered together, so as to 

 form one shield, the whole 

 head thus being apparently 

 covered by a single plate 

 of enamelled bone, and when 

 seen detached from the 

 body hardly to be distin- 

 guished from the head of a 

 trilobite. The body com- 

 pared with this singular head 

 appears extremely diminu- 

 tive ; the back is arched, 

 and gradually recedes in elevation towards the tail, 

 which is of moderate length ; the fins are few in num- 

 ber, and not very powerful, but appear to have posses- 

 sed a bony ray in front, the rest of the fin being more 

 fibrous. The whole body was covered with scales, 

 which varied in shape in different parts, and seem to 

 have been disposed in series. This fish never seems 

 to have attained a large size ; the best preserved spe- 

 cimen having a length of only seven inches, with a 

 breadth of three inches between the points of the 



* The Old Red Sandstone ; or, New Walks in an Old Field, by Hugh 

 Miller, p. 138. 



BUCKLER-HEADED FISH. 

 ( Cephalaspis.) 



