108 THE FOSSIL CORALS AND 



ALCYONARIA. 



Family GORQOmDM. 



Suhfamily ISIDIN^. 



Genus ISIS. 



1. Isis Dan^, Duncan. Plate XXVIII, Figs. 1-3. 



Fragments of a huge Isis abound in the collection from Naigh-Nai valley, south- 

 west of Manchhar, and also in the Gaj series ; and they appear to be characterized by 

 very numerous flexuous grooves and corresponding ridges on their surface, and by 

 numerous, alternately large and small, lamellae passing into the midst of the sclerobasic 

 axis. The ridges are moderately distinct, project slightly, and are often alternately 

 large and small ; they are most distinct in the smaller joints. The joints are irregu- 

 larly cylindrical, long, stout, branch at the ends, and present the appearance here and 

 there of abortive interjoints. The upper and lower surfaces, nearly circular in outline, 

 are slightly concave or plane. 



The great size of the joints distinguishes the form to a certain extent; they are 

 much longer than broad, and it appears that the interjoints must have been small. 



Length of joint 2 J inches, 1^^ inch, and 1-^ inch; breadth 1^ inch and ^^inch. 



Locality. Naigh-Nai valley, in the Gaj series (Survey-number G ■^^), and five 

 miles north-west of Tong, in the same series (Survey-number G -t^-) ; and at Tandra 

 Eahim Khan (Survey-number G ^^). 



Illustrations of the Species in Plate XXVIII. 

 Fig. 1. Large joint: natural size. 



2. End of a joint, part of: magnified. 



Isis Daj^^e, Duncan. Variety. 



This form has many abortive branchlets or projections on opposite sides of the 

 joints, along their length. 



Locality. Naigh-Nai valley. Survey-number G -^q^- 



Illustration of the Variety in Plate XXVIII. 

 Fig. 3. Joints : natural size. 



2. Isis ELONGATA, Duncan. Plate XXVIII, figs. 6, 7. 



The joints are long in relation to their breadth ; the interjoints were very thin ; 

 the ridges are very distinct, and the fluting regular. The ridges are.subequal, except 

 when they bifurcate. The cylindrical reed-like joint is marked with the traces of 

 aborted interjoints, and the ends of it are nearly flat. 



