Messrs. Hancock & Attliey on Archiclitliys sulcidens. 79 



the stumps of the teeth attached. The right ramus is ahnost 

 perfect ; the alveolar border is quite so, and exhibits the teeth 

 in a beautiful state of preservation ; a great portion of the 

 dentary bone is present, and is covered with the usual reticu- 

 lated sculpture ; the anterior extremity is quite perfect, as well 

 as the articular bone — at the posterior end with the glenoid 

 sm-face, which is transversely elongated, deep, and consider- 

 ably elevated. 



This large and perfect ramus is nearly 14^ inches in length, 

 and at the widest part, which is about 4 inches from the pos- 

 terior extremity, is 2| inches broad. From this point it tapers 

 gradually to the anterior end, where it is little more than an inch 

 wide. The inferior margin is slightly convex ; and the alveolar 

 border is somewhat concave, with a slight eminence in front 

 giving support to the first large tusk-like tooth. 



There are upwards of twenty teeth, seventeen or eighteetr 

 of which are well preserved ; a dozen are entire. They vary 

 much in size, and in some places are arranged almost in con- 

 tact; in other places they are considerably apart. Three are 

 much larger than the rest, and seem to correspond to the 

 vomerine and palatal tusks of the skull. These large teeth 

 are 1^ inch long, and are upwards of ^ an inch wide at the 

 base. The first of these is placed an inch from the anterior 

 extremity, upon the eminence of the alveolar border already 

 noticed ; a single small tooth is situated in front of this. The 

 second large tooth is 2 inches further back, and the third is 

 Ig- inch behind the second; the last is therefore 3f inches be- 

 hind the first ; but the space between the apices of the first 

 and last large teeth is 4^ inches — a distance corresponding- 

 very nearly to that between the depressions behind the vome- 

 rine and last palatal teeth. The smaller teeth vary from f to 

 about I of an inch in length ; they are all considerably com- 

 pressed towards the apex, and have wide cutting-margins ; 

 the lower portion is rounded and grooved, the grooves extend- 

 ing for a considerable way up the crown. 



Archichthys sulcidens^ Hancock & Atthey. 



Some additional remains of this large and powerful fish 

 have recently occun-ed at Newsham, where the original speci- 

 mens were obtained that were described some time ago in the 

 ' Annals ' (April 1870). The most important of these recent 

 acquisitions is a considerable portion of a crushed head, which, 

 though in a bad and much disturbed condition, shows in a 

 very satisfactory manner the thick, massive character of the 

 bones ; moreover many of the parts are very well displayed. 

 A large portion of a mandible, measuring upwards of 10 inches 



