336 



THE GEOLOGIST. 



ing strata overlying the pipes both in the chalk and magnesian lime- 

 stone, for it assists in corroborating the views of Mr. Prestwich. 



For a full exposition of the theory I have adopted, I would refer 

 to Mr, Prestwich's most able paper " On the Origin of the Sand- 

 and Gravel-pipes in the Chalk of the London Tertiary District," 

 " Quart. Jour. Greol. Soc," vol xi., p. 64, 



OjS" the old red sandstone and its fossil fish 

 in forfarshiee. 



By W. PowEiE, Esq. 



As anything calculated to throw light on the peculiar fauna of the 

 Old Red Sandstone period must be interesting to geologists, I send 

 you a short notice of some fossils lately found in the flagstones of 

 Forfarshu-e, which may aid in adding to our knowledge of the pecu- 

 liarities of the creatures found in these rocks. 



Some six v/eeks ago, by far the finest specimen of Pterygotus 

 miglicus yet 'found was discovered in the " pavement" quarries of 

 Cannyllin : this superb specimen is now in the Arbroath Museum. 

 This fossil, coming clean out from the matrix in which it was 

 imbedded, consists of all the body-segments, a part of the caudal 

 plate being also preserved and well seen in the cast from which the 

 fossil had been lifted. It shows no features absolutely new or 

 liitherto unknown, but it is nevertheless very interesting, as exhibit- 

 ing the manner in which both the dorsal and ventral portions of this 

 creature had been covered and protected by strong sculptured plates. 

 It also proves that Mr. D. Page was quite correct in the place which 

 he latterly assigned to the curious duck-bill like plate ^vith its 

 wing- like appendages, which, as noticed in Hugh Miller's " Old Red 

 Sandstone," occasioned the name of " Seraphim" to be applied to 

 this fossil. It is found in situ, covering the under portions of the 

 segment next the head. In all probability, as suggested by Mr. 

 Page, it formed part of the sexual organs of this creatm^e, and also a 

 covering for the vent or anal opening, there being no vestige of any 

 such opening in either the sub-caudal segment, in the portion of the 

 caudal plate, or telson, preserved, or on the junction of these seg- 

 ments. It gives some idea of the manner in which the different 

 plates forming the body-segment joined into one another, the joinings 

 being seemingly of such a nature as to allow the creature consider- 

 ablo powers of curvature. It also shows its comparative length and 

 breadth, although in this respect it seems to differ from other speci- 

 mens, showing a rather gTeater proportional length ; but this might 

 have been occasioned b}^ these belonging to different sexes, the one 

 being probably of a more slender form than the other. The head 

 with all its appendages is wanting. The entire length of the fossil, 



