IOWA ACADEMY OF SCIENCES. 



81 



No. of Nodes. axial segments occupied. 



1. 1st. 2d. (?) 3d. 



2. 3d. 4th. 5th. 6th. 

 •6. 7th. 8th. 9th. ]Oth. 



4. 10th. 11th. 12th. 13th. 14th. 



5. 14th. 15th. 16th 17th. 18lh. (?) 19th. 



The following table sets forth the facts observed graphically 

 and in detail. It will be noted that not a single segmental 

 line of the first twenty- three is unoccupied by a tubercle. No 

 law obtains as to the successive number of the intervening 

 segments. For comparison the sequences of nodes on two 

 described species are inserted. Of the distinct trends observable 

 in the grouping of the nodes that toward the formula of E. 

 ornatus is most largely represented in the specimens at hand. 



Geological Laboratory, Cornell College, December 31, 1895. 



NUMBER OP AXIAL ANNUL ATIONS. 



'No. 17. E. ornatus, H. & W. 

 . 31, E. thre>ihei i, Foerste. 



E. punctatus, Murch SJuria. PI. Ill, fig. 6 



