FROM TflE CARBONIFEROUS FORMATION. 173 



sometimes wanting. The legs are also preserved in the same part of the body and not 

 elsewhere and are considerably shorter than the width of the body, being only from 2.25 

 to 2.5 mm. long, where the body is considerably broader. It should also be noted that the 

 segment behind the head bears not only a spine but apparently at least one pair of legs, 

 while on the second and each of the succeeding segments two pairs of legs are preserved. 

 But the greatest interest in this specimen is found in the head and its appendages. It 

 is very short, with a well rounded front, and extends downward, as in the preceding speci- 

 men, considerably beyond the general lower line of the body. At its upper outer limit one 

 sees a rounded oval space covered with a cluster of about a dozen large prominent hemis- 

 pherical wartlets, each separated from the others by nearly its own diameter, and which 

 together represent, apparently, the eye. It will be noticed that it appears on the upper 

 part of the head and not, as in a specimen of Acantherpestes major, on the lower part. 

 Projecting beyond the lower edge of the front is seen a long and slender jointed organ, 

 which seems to be an antenna, agreeing in a general way with that found in E. granosa. 

 It is about as long as the legs, nearly equal, perhaps a little larger in the middle than at 

 the two ends, moniliform, composed of five subequal, broad, obpyriform joints, a little 

 longer than broad, besides a much smaller, roundish oval, apical joint. The whole length 

 of the antenna is 2.6 mm. and its middle width 0.3 mm. (PL 13, fig. 18.) 



This specimen differs from all the others in the greater length and slenderness of the 

 subdorsal spines, but agrees so well in its other characteristics that there are hardly valid 

 grounds for its separation from them. 



The fourth specimen is the largest of all though not very perfect ; apparently the whole 

 creature from head to tail is represented. It is 75 mm. long and appears to have about 

 33 or 34 segments besides the head, but some of the posterior segments are very obscure, 

 making the exact number uncertain ; the body tapers forward from about the fifth seg- 

 ment, but only slightly ; back of this as far as the sixteenth segment or thereabouts, they are 

 of nearly equal size, and then taper again a little more rapidly ; but not so much so as usual 

 in this species, although the hinder half of the body as a whole is only just half the breadth 

 of the front part, the breadth in the front portion being 5.8 mm., in the middle of the hin- 

 der half 2.9 mm., at the hinder extremity 2.5 mm., and on the first segment behind the 

 head 4.2 mm. ' The body is preserved on a dorsal view and the segments of the broader 

 portion are a little more than twice as broad as long. The spines are very small, shaped 

 as in the first specimen described, and not more than one-fourth as long as the width of 

 the body in its broadest part. The legs are only to be seen in a few places ; on the seg- 

 ments directly behind the head they are about three-fourths as long as the width of the 

 segments, while near the middle and a little behind the middle of the bocty they are nearly 

 as long as the width of the segment bearing them. 



The head is about as long as the segments next it but much broader ; indeed nearly 

 twice as broad, being 7.5 mm. broad, with a w r ell rounded front. No traces of any appen- 

 dages can be seen. The second and third segments behind the head bear each two pair 

 of legs, and the first segment a spine. This and all the specimens hitherto mentioned 

 were received from Mr. Carr. 



The last specimen to be mentioned (PI. 13, fig 17), and which belongs to Mr. Armstrong, 

 is a mere fragment of the head end of the body, showing about seven segments besides the 



