30 Colorado College Studies. 

 Var. CLAVATUS. 



Plate II, fles. 1-3. 



Suture considerably les.s comi^lex than in similarly sized 

 specimens of mons-comanchcdims, the leaves beinjij capitate- 

 clavate, the summits of the larger leaves departing less (or 

 at most, not more) from a simple outline, in a specimen ex- 

 ceeding 100 mm. in height, than do those of the little (27 mm.) 

 specimen of S^yhenodisciis bclvidereiisis figured in Vol. XI ^' 

 of the American Geologist, Plate I, figs. 4, 5. In a smaller 

 specimen (which, if the missing portion of the body-chamber 

 were restored, would have a height of about forty-seven or 

 forty-eight mm.), the first four (all that the specimen shows) 

 of those saddles that succeed the secondary, are not emarg- 

 inate, the first and third of them being narrower (the first 

 narrower than the third), and of rounded outline, the second 

 and fourth being broader and truncate. The two type speci- 

 mens were obtained, with the type of mons-comfincJieanits, 

 from the Comanche Peak limestone of Tarrant County, Texas. 



Var. UDDENi. 



riate I, figs. 3 aud 4. 



Suture relatively complex, the primary lateral and the 

 larger secondary lateral and auxilliary leaves little different 

 from those of var. mons-comancheamis, the leaves and saddles 

 interior to the secondary ones being as follows: First and 

 second lateral leaves irregularly and obtusely dentate, inclos- 

 ing a large, simple, subrotund saddle; these followed in suc- 

 cession by a deej)ly emarginate saddle: an intermediate-sized, 

 asymmetrical, feebly denticulate leaf; three simple, subro- 

 tund, subequal saddles, parted by two small, narrow, simple, 

 clavate leaves; a small emarginate leaf; a small deeply emargi- 

 nate saddle; a narrow emarginate leaf; a broad emarginate 

 saddle (this in the line of the series of circum-umbilical 

 tubercles); and finally, a small leaf and saddle,. both emargi- 

 nate. The type-specimen of this variety is in the museum of 

 Augustana College, and was kindly loaned me for study by 

 Prof. J. A. Udden, who collected it in the Kiowa shale, a 

 few miles west of Lindsborg, Kansas, and for whom it is 

 named. 



