474 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [JuilC 21. 



as mentioned in the foregoing paper. It consists of a considerable 

 portion of a skull, wanting chiefly the tympanic pedicles and the 

 lower jaw. It is embedded in a block of bright brick-red compact 

 stone, with its upper surface exposed. The skull is broad, depressed, 

 and of an almost equilateral triangular form. 



The breadth of the occiput is 4 inches 9 lines ; and the lateral bor- 

 der of the skull measures, in a right line, 4 inches 6 lines. The muz- 

 zle is rounded and obtuse. Most of the cranial bones are impressed with 

 radiating grooves, the intervening ridges being in some parts broken 

 up by communicating grooves into tubercles. The orbits are entire 

 and situated in the anterior half of the skull. Portions of small, 

 conical, pointed teeth form a single series aloiig the alveolar border 

 of the upper jaw. 



In investigating the structure of the occiput, the Professor suc- 

 ceeded in developing two well-defined occipital condyles, not so close 

 together as in the great Labyrinthodon salamandroides, but separated 

 as in Trematosanrus and Archeyosaurus. 



After a detailed description of the several parts, as far as the 

 abraded and otherwise mutilated condition of the fossil would allow. 

 Professor Owen states that it allows so many characters of the skull 

 of the labyrinthodont batrachians to be determined as can leave no 

 reasonable doubt of its true nature and affinities ; and he gives it the 

 appellation of Brachyops* breviceps, in reference to the shortness 

 of the facial part of the skull anterior to the orbits. 



6 Additional Observations on the occurrence of Pipes and Fur- 

 rows in CALCAREOUS and non-calcareous Strata. By 

 Joshua Trimmer, Esq., F.G.S. 



[Abstract.] 



The author considered that, for the full understanding of the views 

 he has taken on the origin of sand-pipes and furrows in and on the 

 surface of strata, some further remarks were required ; and offered 

 these additional observations in support of some positions he has 

 taken in former papers on the subject, and which, from their not 

 having been fully elucidated, appeared to require some explanatory 

 remarks in their defence. 



* From I3paxvs, short ; io\p, face. 



