﻿PRESERVATION AND EXTERNAL CHARACTERS. 



39 



of the work it became quite obvious that not a few of the cycad trunks had been 

 broken up by persons casually wandering about the great Minnekahta locality before 



it had been brought to scientific notice. 

 These trunks had been mostly eroded out 

 and lay exposed within a mile of a rail- 

 way siding, which had been in use for ten 

 years before the first specimens were se- 

 cured by the United States National 

 Museum and the State University of 

 Iowa. It also became evident that, in 

 addition to the ordinary vicissitudes of 

 erosion and time, not only had different 

 collectors taken away parts of groups, 

 but handsome and solid trunks had in 

 a few instances been broken apart to se- 

 cure the best-preserved branches. The 

 writer accordingly made, with not a little 

 success, the most strenuous efforts to 

 bring together again, so far as possible, 

 the branches and parts of truuks thus 

 unfortunately separated. He spent two 

 months after the collections had been 

 made fairly extensive, studying isolated 

 branches and fragments of trunks, fitting 

 together such as he could and noting the 

 character of the missing parts. This work 

 completed, at the very earliest opportunity 

 he resumed the exploration of the several 

 Black Hills cycad-bearing horizons, ex- 

 amining them with great care, discover- 

 ing several new localities and securing 

 from localities already known a large 

 amount of additional material, mainly 

 belonging to groups of trunks or branch- 

 ing trunks already in the Yale collection. 

 Some of the more striking of these new 

 or reconstructed (?) specimens, exhibit- 

 ing various stages of branching, may be 

 described here at some length. 



Various truuks from Minnekahta 

 show a late development of branches in 

 which there is a well-marked central or 

 main trunk, with various minor branches. A very fine example of this kind is 

 afforded by Yale specimen 129, the largest central stem of which bears five well- 

 marked lateral branches. 



Fig. 10 — Cycas revoluta. 



As grown by Japanese horticulturists. The " hoso" above 

 affords a suggestive comparison with the yet more freely 

 branching Triassic Anomozamites. (Cf. figure 13.) 



