194 



whom Mr. Ball has in many instances received valuable aid 

 in zoological pursuits. The fins of both these species of Ros- 

 si£e are like in form and position to those of Sepiola Ronde- 

 letii. 



16, Spirula australis. Shell found at Youghal, 1820. 



The following are the Measurements of the Rossice in Inches : 



Length of body, 



Breadth over fins, 



Length of fin, 



Extreme breadth, 



Breadth between eyes 



Extreme breadth of head, . . . 



Length of head, 



Length of tentaculae, .... 

 Portion of tentaculae occupied by Aceta- 



bula, 



Length of first pair of arms, counting 



from top of head, 



Ditto, second ditto, ditto, 



Ditto, third ditto, ditto. 



Ditto, fourth ditto, ditto. 



Depth of fin between first pair of arms. 



Ditto, first and second do. 



Ditto, second and third do. 



Ditto, third and fourth do. 



Ditto, fourth do. 



Kossia 

 Owenii. 



1-7 



2-0 



0-7 



0-45 



0-9 



M 

 0-5 



4-0 



0-9 



2-1 



2-4 



2-7 



2-3 



0-2 



0-3 



0-42 



0-4 



0-04 



Rossia 

 Jacobii. 



2-1 

 2-7 

 1-5 

 0-7 

 1-2 

 1-4 

 0-7 

 5-7 



1-5 



2-2 

 2-3 

 2-6 

 2-4 

 0-4 

 0-5 

 0-6 

 0-8 

 0-03 



William Roberts, Esq., F.T. CD., read a paper on a class 

 of spherical curves, the arcs of which represent the three 

 species of elhptic transcendents. 



A cone of the second order, whose vertex is upon the 

 surface of a sphere, and one of whose pi'incipal axes is a 

 diameter, will intersect the sphere along a curve which ad- 



