434 SAMUEL H. SCUDDER ON NEW 



the body. No spines are presei'ved anywhere, and only slight indications of their in- 

 sertion are apparent. The segments are obscure throughout, excepting near tlie head, 

 and therefore coukl not be enumerated, but for the legs. As in the previous specimen, 

 they appear to be generally of about equal length and breadth, but next the head they 

 are broader than long. The division into tAVO parts, as shown in the other specimen, is 

 obscured here, exce[)ting next the head Avhere it is identical. The legs are as in the 

 other specimen, except in being possibly a little longer and in showing some basal ex- 

 pansion. 



Length of body (if straightened), 40 nun.; middle width of same, 1.5 mm.; length of 

 legs, 2.8 mm.; their basal width, 0.3 mm. 



The sjjecimen comes from the same place, and bears the number 1838cd, in Mr. 

 Lacoe's collection. 



A third specimen (fig. 4) seen, together with the following, after the pi-eceding de- 

 scriptions had been written, shows a lateral view of a slightly arcuate aniuial, nearly 

 the whole of which is pi-eserved, although almost wholly destitute of appendages. The 

 body is thus seen to be of nearly equal size thoughout, scarcely tapering on the first 

 three or four segments and in the posterior fourth, composed of forty-two subquadrate 

 segments, besides the head; the latter is a little broader and larger than the segment 

 behind, well rounded but shows no appendages. The segments are everyAvhere simi- 

 lar, about a third or a fourth broader than long and show a division into two subseg- 

 ments by a median or antemedian tranverse sulcation and a slight difference in eleva- 

 tion of the two subsegments, the anterior being slightly the higher; the signs of spines 

 are slight, but occasionally a simple, arcuate, very short spinule rises above the dorsal 

 outline. The legs are almost entirely obliterated, but a few at either extremity show 

 that they are as long as the width of the body or even longer, and very slender. 



Length of body (if straightened), 45 mm.; middle width of same, 1.6 mm.; anterior 

 width, 1.2 mm.; length of anterior legs, 1.5 mm. 



The specimen comes from Mazon Creek, 111., and was received from Mr. E. D. 

 Lacoe, in whose collection it bears the number 1838gh. 



A fourth specimen (fig. 6) shows a scarcely arcuate body of a specimen slightly 

 larger than the last but not so fully preserved, both ends being lost. About thiity- 

 six segments are seen, slightly broader than long, but in general they show very little 

 structure; it would seem, however, as if besides the median sulcation between the sub- 

 segments, each of the latter had its own submedian transverse sulcation much sharper 

 and slighter than the other; the surface was apparently smooth; no signs of spines ap- 

 pear except a latei-al series indicated at one extremity by very deep circular pits at one 

 margin, presumably the antei'ior, of each segment. Legs are seen all along the lower 

 margin of the body, though by no means always jierfect; when complete they are some- 

 what longer than the width of the body, very slender, and delicately tapering. 

 Length of the fragment, 52 mm. ; breadth in middle, 2 mm. 



This specimen also comes from Mazon Creek, 111., and from Mr. Lacoe, and bears 

 the number 1838ef. 



A fifth specimen is a curious one; it represents apparently a single specimen, but it is 

 bent abruptly ui^on itself twice, so as to be broken or apparently broken into three 



