CRINOIDEA. 59 



Remarks — Specimens from the Mineola are abundant but are never well preserved. 

 None of them retains the surface markings, and identifications must be made largely 

 on the basis of shape. Even in this there is considerable variation but the smaller speci- 

 mens are all elongate, nearly symmetrical, and flat to convex between the ambulacra. 

 The only large specimen collected is much less elongate compared with the width and 

 is somewhat larger near the ventral end as is common with N. verneuili (Troost). 



Occurrence — Mineola limestone of Montgomery County. 



Class CRINOIDEA 



Order Camerata 



Family Melocrinidae 



Genus Melocrinus Goldfuss 



Melocrinus gregeri Rowley 

 Plate 7, figures 11 and 12. 



1893. Melocrinus gregeri Rowley, Am. Geologist, XII, pp. 303-304, pi. 14, fig. 1. 

 1897. Melocrinus calvini W. and Sp., Harv. Mus. Comp. Zool. Mem., XX, p. 300, 



pi. 22, fig. 6. 

 1909. Melocrinus gregeri Greger, Am. Jour. Sci., XXVII, p. 376. 



Description — Calyx subpyriform; sides nearly straight from the top of the basals 

 to near the bases of the arms; top of the tegmen nearly flat, with a small, short eccentric 

 anal tube. Each of the radials, fixed brachials, and interbrachials to the third row, 

 usually crowned by a pointed node. The lowest distichals in some cases bear nodes. 



Basals projecting downward around the column and often forming nodes at the 

 lowest part of the plates; in large specimens the radials and costals are wider than long 

 but in small specimens they may be nearly equidimensional or longer than wide. Inter- 

 brachial spaces large, somewhat irregular, the plates arranged 1, 2, 3, 3, or 1, 2, 2, 2, 

 or 1, 2, 3, 4. Four distichals are present but no interdistichals. The lower distichals 

 are much smaller than the axillary. Anal area widest, with plates arranged 1, 3, 4, 5, 

 or 4. Plates on the ventral disk small and subequal in size. 



Occurrence — Snyder Creek shale of Callaway County, location 1. The writer knows 

 of only six specimens of the species from the Snyder Creek shale. 



Melocrinus lylii Rowley 

 Plate 6, figures 7 and 8 



1894. Melocrinus lylii Rowley, Am. Geologist, XIII, p. 152, fig. 2. 

 1909. Melocrinus lylii Greger, Am. Jour. Sci., XXVII, p. 376. 



Rowley's description — "This is the smallest crinoid yet discovered at the Callaway 

 locality. Three of the basal plates are quadrangular and the fourth pentagonal, slightly 

 projecting outward. Three of the first radials are heptagonal and two hexagonal; 

 width and length about equal. Second radials hexagonal. Third radials heptagonal, 

 supporting above two series of two small plates each. Interradial series twelve to 

 thirteen, arranged as usual in this genus. First interradial about as large as the second 

 radial piece and hexagonal. Anal interradius composed of twelve pieces, all being 

 small with the exception of the lowest piece. 



All the plates of the calyx of this little crinoid bear a central short spine and strong 

 radiating ridges connecting the centers of all the plates, giving the specimen a very 

 handsome appearance. 



Vault plates numerous, almost spinose and having the radiating ridges. Proboscis 

 slender, excentric. Free rays, arms and column unknown." 



