1893.] NEW YORK ACADEMY OF SCIENCES. 239 



Columbia College, and Prof. Kemp very kindly lias given me 

 the privilege of describing them. 



The trilobites are found in a soft, tine, black shale, and are 

 very perfectly preserved. The most noticeable character about 

 them is the presence of long, many-jointed, rod-like attach- 

 ments to the front of the head, which resemble exactly the 

 antenure of other crustaceans. These come out close together 

 from just under the centre of the anterior border of the head- 

 shield, and diverge generally at an angle of 30° or 40°. In one 

 specimen (Fig. 1), a length considerably exceeding that of the 

 glabella is shown* ; in the rest, the}- are more broken, but a 

 considerable length is jjreserved in three or four, and the 

 stumps are distinctly seen in upwards of twenty others. They 

 curve slightly outward and taper gradually down towards the 

 end ; the tip itself is not preserved. These antenuie are com- 

 posed of a great number of joints, each of which is conical, 

 about half as long as wide, and smallest at the base of the joint. 

 (See Fig. l'^.) As preserved, they are calcareous, but ap- 

 parently of a structure less lirm and thick than the substance of 

 the carapace- Their point of origin appears to be under the 

 front of the glabella, as they can be traced a little way under 

 the head-shield, where they almost coalesce, then diverge and 

 disappear ; no joints are distinguishable in this part. (See 

 Fig. 2.) Just over where they come out, the anterior rim is 

 arched slightly upward, seemingly to give room for their play 

 to and fro. 



These organs must certainly belong to the trilobite ; when 

 attached, they are in all cases in exactly the same position, 

 and are but rax'el}' to be seen separate ; moreover, in a number 

 of sjoecimens in which they were not shown, they were developed 

 b.y cutting away the matrix in the proper place. Their character 

 seems also tolerably certain, as both in position and structure 

 they are like the antennae of modern crustaceans. The appear- 

 ance of the right hand antenna in Fig. 3, may indicate that 

 these organs could be bent back under the sides of the shield — 

 but this point needs more evidence. 



Besides these, there are shown in several of the specimens, 

 other appendages, some of which may be branchial in their 

 character, and others, walking or swimming legs. In Fig. 1, the 

 side of the head shield has been broken away, exposing the 

 appendages, apparently of three cephalic segments. These are 

 of two kinds, one of which seems to be a narrow, jointed, 



* I\Ir. Yiiliant has since shown me a specimen which has antenna' one ami a 

 half times as long as the glabella. He informs me that there aro rmw aixnit 

 sixty specimens showing antenna-.— June, I89:i. 



