N.<?,.4.]7i 



BlUaNOei — O.N t"UB>ill,«>. .i- 



239* 



X 



Genus Lion AS. 



IG. L. Bl'PEHnrs. — Tin- frontal loboof tliofjlaholla of this ox- 

 traoruin;irj trilohite lias ahiios^t cxacuy tlif form of an rjrir. cov- 

 erod witli tubercles, and plied on the aiiUrior hiilf of tliu head;. 

 its greater length corresj)oiidinjr, in direction, with the Icngtli or 

 tlie boJy. Behind this there arc two much smaller, sub-conical 

 elevations, separated from each other by a depressed space or 

 chauncl, the bottom of whifh is either flat or slightly convex. 

 Close behind these the occipital lurrow crosses the head : and 

 next ill order, the occipital ring or neck segment. The channel 

 betw(!eii the cones, pn j; '"'ig in a direction forwards, divides 

 into two branches, which diverging right and left, separate the 

 anterior sides of the cones from the posterior part of the large 

 frontal lobe. 'J'iie base of the frontal lobe has a concave constric- 

 tion all around, so that on a side, view, the lobe seems to stand 

 upon a low jiedicel, nearly as broad as itself. 



Judging fioii) the fragments 1 have examined, if a perfect spe- 

 cimen were placed flat on the ventral side, then the depressed 

 space or channel between the two posterior nodes of the head^ 

 would be horizontal, while the longer axis of the ovate frontal 

 lobe would slojte forwards and downwards, at an angle of between 

 GO and 80 degrees. In this position the length of the head of 

 one of our specimens is about 3 inches, divided as follows : width 

 of the neck segment 4 lines ; from the neck segment to the pos- 

 terior jiart of the median lobe 12 lines; thence to the most pro- 

 jecting point of the frontal lobe, forwards, 17 lines, in all 33- 

 lines. 



IMacing the base of the frontal lobe in a horizontnl position, 

 tht dimensions are as follows: greater length of the lobe (along 

 the median line) 21 lines; greatest width about the mid-length 

 17 1in<.s; greatest height above the constrietion that surrounds 

 the base 10 lines. 



The frontal l(d)e. althouiih 21 lines in length, owing to its 

 sloping condition, only contributes about 17 lines to the length 

 of the head. " ' •— •— ■ ♦ ■ '■ \ • : . ., ^ 



The width of the space, between the bases of the two cones 

 is six lines ; heiglit of the cones 5 lines. These cones perhaps 

 represent the anterior pair of the glabellar lobes of an ordinary 

 Lichas. 



We have one specimen in which the length of the frontal, 

 lobe is 3 inches and its width about 2 inches. 



