imperfectly- defined Species of Jurassic Nautili. 273 



Sp>. char. Shell compressed, with deeply embracing whorls, 

 rapidly increasing- in diameter ; flattened upon the sides, with 

 a narrowly rounded periphery. Umbilicus deep, with rather 

 steeply sloping sides, the inner whorls exposed. Septa 

 somewhat distant from each other, being about three quarters 

 of an inch apart in the median line of the periphery, where 

 the thickness of the whorl is 2 inches. Sutures slightly 

 curved upon the sides and forming a very shallow sinus upon 

 the periphery. Test smooth, showing only irregular lines of 

 growth. Only a part of the body-chamber is preserved, so 

 that the proportion it bears to the septate part of the shell 

 cannot be ascertained. 



Remarks. The present form is so unlike any other fossil 

 Nautilus^ that no comparison can be made. 



A figure of the present species was submitted to Dr. Paul 

 Fischer (along with one of N. robustus), and he fails to iden- 

 tify it with any species known to him, but suggests the 

 possibility of its being represented in the private collection of 

 the late Eugene Eudes-Deslongchamps at Caen. However 

 this may be, we, like Dr. Fischer, can find no published 

 description or figure which can be identified with it. 



We have much pleasure in dedicating this beautiful species 

 to Dr. Paul Fischer, of Paris, who has laid us under many 

 obligations in connexion with the Jurassic Nautili. 



Horizon. Upper Lias. 



Locality. Fontaine-Etoupe-Four (Calvados), France. 



Lower Oolite. 



6. Nautilus ornatus, sp. nov. 



Fio\ 7. 



Nautilus ornatus. — a, lateral view of a young shell, showing the open 

 umbilicus and the ornamentation of the test; b, front view, showing 

 the position of the siphuncle. Drawn from a specimen in the British 

 Museum (no. 51952). About half natural size. 



