DESCKIPTION OF AN EXTINCT PALEOZOIC INSECT. 



55 



Geracus tubifer. n. sp. 



Apterous. Body obscurely divided into three regions of head, 

 thorax and abdomen ; somites of the head cemented and fused (?) 

 with the prothorax, all the others separate, and 

 approximately of equal width. 



Head conical, prolonged into a tube or pro- 

 boscis, which is thrice as long as the rest of the 

 head (and of separable parts 1). No eyes or 

 antennfe are recognizable. 



The rest of the thorax consists of two separate 

 rings of subequal length ; of these the mesothorax 

 is wider than the other laterally. The meta- 

 thorax narrows backward at the sides, and at its 

 posterior edge the body of the insect is narrowest. 

 Under this interpretation of the thorax, we 

 suppose the prothorax fused with the head, or 

 suppressed. The legs are unknown, except that 

 there is an obscure impression of the second one 

 on the right side. 



The abdomen is ovate and somewhat pointed 

 behind, and consists of six joints. The first ring 

 of the abdomen has the posterior margin pushed forward in the 

 middle. The three next have directly transverse margins, but 

 the line dividing the fourth and fifth joints is slightly arched 

 foaward in the middle, and these two joints may be anchylosed. 

 At the back of the last joint is a narrow obscure slope, slightly 

 emarginate. No appendages are visible. 



Size. Length 13 mm. Length of head, including the tube, 

 4 mm.; width 2 mm. Length of thorax 3 mm.; width 3 mm. 

 Length of abdomen 6 mm.; width 4 mm. 



Horizon and Locality. Dai'k shales of Plant Bed No. 2, 

 Lower Cordaite shales of the Little River Group. Lancaster, 

 St. John County, N. B. Rare. 



Condition of Preservation. This fossil presents the brownish- 

 black, shining surface, characteristic of the insects and myriapods 



Fig. 3. 



Gracus tubtpbr. 



n. gen. and sp. 



mag. 4. 



