60 MATTHEW ON OEGANISMS 



the head and additional joints to the limbs, beyond what has been preserved on the 

 stone. The slate is also flaked off at the posterior end of the fossil, which may have had 

 other joints beside those preserved. 



Among living insects the caddis-worm is one which appears to come near to this 

 larva in form. Several examples of rather thick organisms, which are short, curved or 

 bent, have been found in the plant bed at St. John ; these are similar in size and appear- 

 ance to the object herein described, but they have rough surface and do not show any 

 trace of segmentation ; these may possibly have been cases for larva similar to the caddis- 

 worm. A larva thus protected, however, would not require the strong chiteuous covering 

 which this species possessed. On the whole, therefore, it seems most probable that it 

 belonged to an insect similar to those known to have be(^n living at the time by the 

 detached wings already discovered in these plant beds. 



EURYPTEBELLA ORNATA, n. gen. et sp. (PI. IV, fig. 12.) 



Minute. Body ovate-elongate, obscurely divided into three regions, and also faintly 

 trilobed longitudinally by impressed lines near the margin. Apparently furnished with 

 a pair of large limbs. 



Head triangular, rounded at the outer corners, and emarginate behind on the median 

 line. Seemingly comj)osed of three anchylosed segments, of which the first is qixite 

 narrow, the second double the width of the first and emarginate behind ; as is also the 

 third, which is much wider than the second. 



Thorax subqiiadrate, compose of four segments, of which the first is a double segment 

 produced by the union of two rings, the elements of which are nearly obliterated ; this 

 segment has an elevated ridge on the mesian line. The three posterior segments are 

 progressively narrower and shorter, and the ends are rounded forward. 



The abdomen is elongately triangular, and consists of several segments ; of these the 

 first three have a firmer texture than the others, which form a long flexible tail, and are 

 but faintly indicated on the stone. 



At the side of the body there appear a few joints of a limb, which apparently was 

 attached to the last segment of the head. The extremity of this limb, which is bvxt poorly 

 preserved, was broad and flattened. 



Ornamentation. — This consists of rows of tubercles arranged along the posterior 

 margin of the segments, on each side of the median line. The tubercles of the first 

 segment of the head are quite obscure, and those of the second not distinct ; on the suc- 

 ceeding segments there are in order 4, 5, 5, 4, 4, 3, 2 and 1 tubercles on each side of the 

 mesian line respectively, as far as the third segment of the abdomen. 



The crust is very thin, and not so distinctly chitenous as in the preceding species. 



Size. — Length, 8 mm. ; width, 4 mm. Length of the limb, 4 mm. 



Horizon and Locality. — From Plant Bed No. 2, Lancaster, N.B. Found by "W. J. 

 "Wilson. 



This is one of the most puzzling forms met with in the Devonian plant beds. It is 

 here referred to the Crustacea, but no known crustacean of similar antiquity has such a 

 head as is here represented ; the front, however, is poorly preserved, and there is doubt 



