Cope.] loo [Aprils, 



It would not be surprising if this genus should prove to be related to 

 Anoplonassa Cope, which has the long symph3^sis mandibuli of the Ph}^- 

 seter, with the nearly edentulous character of the Choneziphiidte. 



Cfiar. specif. — The species is founded on a rostrum similar in its mode 

 of preservation to Ziphioids in general. Nothing is preserved posterior to 

 the nares, and the edge of the left maxillary, with the end of the muzzle, 

 is broken off. All the parts are coossified. 



The anteroposterior diameter of the basin exceeds by a little the trans- 

 verse. The bottom is nearly regularly concave, with a few shallow foss« 

 at the right side. The part of the median vomerine ridge which forms 

 the anterior half of tlie left border of the basin is thicker than that which 

 bounds the posterior half of the same, and it presents an angular tuber- 

 osity horizontally to the left. The fractured edge of the left maxillary 

 shows that it was thin at this point, and at no point had it when perfect 

 any considerable horizontal extension to the left side. It is separated 

 from the vomerine ridge by a groove, which extends from the left maxil- 

 lary basin to a foramen, which is situated at a point in advance of the great- 

 est width of the vomerine rostrum. A corresponding foramen exists on 

 the right side, which is opposite the anterior border of the central basin. 

 The vomerine rostrum contracts rapidl}' forwards, forming a prominent 

 rounded ridge, and the premaxillaries rise to it on each side. The maxil- 

 laries are little expanded, and their superior surface is subhorizontal and 

 is moderately rugose. It is much thicker on the right side than on the 

 left, and is probably also wider on the right side. On the left side it is 

 bounded below by a deep groove from opposite the anterior part of the 

 left maxillary basin to a point in front of and below the supramaxillary 

 foramen of the same side already described. On the right side there is a 

 similar foramen which bears the same relation to the supramaxillaiy fora- 

 men of the same side. In front of the foramen on the left side the groove 

 continues. On the right side the groove does not continue, but is suc- 

 ceeded forwards by a narrow vertical wall to the anterior extremity of the 

 specimen. 



On the inferior side the middle line is deeply grooved to a point oppo- 

 site the middle of the superior median basin. On each side of the groove 

 the palatal aspect of tlie maxillary slopes slightly upwards, and on the 

 left side rolls up to a thickened inferior border of the inferior or submax- 

 illary groove. On the right side the palatal face of the maxillary turns 

 up more obliquely to the border of the superior median basin. 



Measurements. mm. 



Total length of specimen 330 



Length from front of median basin 150 



T -1 J- I F A- ^ • f anteroposterior 160 



Inside diameters of median basin. .J ' 



( transverse loO 



Depth of basin 64 



Width of rostrum in front of basin 80 



