22() I'ROCElCDiyc.S OF TlIK y.lTJONJL MUSI'WM. vol.xxi. 



section, with or witliout bnict scars, tlic larger ones lyinjif in iiiter- 

 rni)toil lows riinninji;' in tlie same direction as tliose of the scars which 

 they crowd and distort, elliptical in section, the longer diameter being 

 along the line ot the rows, 2.1 mm. by .'5S mm. in diameter, usually solid 

 except their roughened extremities, sometimes open or crater-like at 

 the summit, a few solid and cylindrical (one of which has been detached 

 and will be sliced for mici'(>S('opic sections); armor \ to 7 C/m. thick, 

 soj)iirated IVom the axis by an even line; i)arenchymatoiis zone 2 cm. 

 thick; lihrous zone W cm., divided into three rings, one of which exhib- 

 its a. somewhat open structure in places crossed by thin medullary rays 

 and inclosed between walls or sheaths of harder material; medulla 13 

 cm. in diameter ami nearly circular, solid, tine grained, and homogeneous 

 in structure. 



The line specimen upon which tlui above description is wholly based 

 was ])urchased by me from Mr. Homer Moore in Hot Si)rings, (South 

 Dakota, on August liii, 181)."), together with the two fragments above 

 described, belonging to C.jennvyann. It consists of four i)ieces which 

 belong together and tbrm a very remarkable trunk, dilVering greatly 

 from any other from the lilack Hills or from any other section. 



1 iu(piired carefully into the history of these specimens and learned 

 that some years before they had been found by a railroad employee 

 named A. B. Noble, who was no longer in that region, soiiu'. two miles 

 below Hot Springs in a canyon or ravine which makes into Fall liiver 

 from the northeast. No further details (;ould bo gathered, but as it 

 is A miles to l^^vans's <puirry, where the true Dakota^ group is exposed, 

 it is certain that the horizon nuist be in the Lower Cretaceous, and it 

 is probably substantially the same as that of all the other trunks. 



The four ])ieces or sections which have bi^en luunbered from 1 to 4, 

 beginning with the basal one, may be brielly described as follows: 



1. No. 1, which is considerably the largest in all respects, represents 

 the true base, and swells out below to a diameter of over 40 cm. and 

 a girth of nearly 11- cm. It is slightly elliptical, the minor axis of a 

 cross section being only '6\\ cm., but part of this dilference is duo to the 

 erosion of the armor on the broader sides. 



2. No. li is a shorter an<l smaller piece, but tits i)erfectly upon the 

 upper fracture of No. 1, which is somewhatobli(|ue. On one side alarge 

 elliptical area has decayed, forming a depression which reaches to the 

 bottom of the leaf stalks. This depression is about equally divided 

 between Nos. 1 and 2. 



li. No. 3 is a nuu;h shorter i)iect^, the upper fracture of which is very 

 obli(pie, so as to nuike it almost wedge sliai)ed. The ui)per surface of 

 No. 2 and the lower surface of No. 3 do not form a. i)erfoct Joint. A 

 thin slice, or a number of such i)i(Hies, have a|)parently scaled off and 

 are wanting. There is, however, abundant evidence of the general 

 agreement of the two sections, and one decayed area extends across 

 the break and reappears on No. ;». 



4, No. 4, which is the uppermost section, tits perfectly upon No. 3. 



