174 University of Texas Bulletin 



Height of last whorl 9.7 mm 0.49 8.7 mm 0.50 7.8 mm 0.48 



Diameter of umbilicus ... . 3.8 mm 0.19 3.3 mm 0.18 3.1 mm 0.19 



(between the shoulders) 



VII VIII 



Diameter 14.5 mm (1) 11.6 mm (1) 



Width 12.5 mm 0.86 10.3 mm 0.89 



Height of last whorl 7.0 mm 0.48 5.7 mm 0.49 



Diameter of umbilicus.... 2.7 mm 0.19 2.2 mm 0.r8 

 (between the shoulders) 



Relation to other species: 



All the species of Waagenoceras described from Sicily are more or 

 less similar to our species, there being no varying sculpture to distin- 

 guish them by, and all of them being very globose forms. When we 

 compare the ratio of dimensions, W. Nikitini Gemm.-^ is certainly the 

 species which most resembles our Texan form. Its ratio seems to be ap- 

 proximately 1:0.82:0.45:0.17, against 1:0.87:0.43:0.18 in a specimen 

 of about the same size belonging to W. Dieneri n. sp. The principal 

 differences between our species and W. Nikitini are to be found in the 

 suture. Although the general character is very similar there are some 

 distinctive features in the detail. The median saddle of the siphonal 

 lobe is higher in the Sicilian species, the saddles in general are more 

 slender and probably higher, the external saddle shows a much more 

 triangular phyllum at its end, and in it as well as in all the rest of the 

 saddles this terminal phyllum is larger and the connection between it 

 and the lower part of the saddle is thinner. The siphonal lobe has in 

 each branch one point much longer than the other, while in our species 

 both points show very little difference in length. Similar differences 

 exist with respect to the other lobes. The antisiphonal lobe also shows 

 some dififerences ; the secondary saddles in our species lean farther 

 over toward the median line than in the Sicilian species, the median 

 branch is broader, the lateral branches are not bifid as in the Sicilian 

 form. The internal saddle leans more over toward the median line of 

 the antisiphonal lobe in our species than in the Sicilian one ; its highest 

 branches begin at different heights while in JV. Nikitini they branch 

 ofif from the same point. Taking everything together, the internal 

 suture of our species resembles more that of W. Mojsisovicsi Gemm.^ 



'Gemmellaro, Calc. c. Fusulina, App., p. 4, pi. A, fig. 1-4; pi. B., fig. 1. 

 ^Gemmellaro, Calc. c. Fusulina, p. 10, pi. 1, fig. 1-3; pi. 2, fig. 1-2; pi. 7, fig. 35; app., pi. 

 A, fig. 5, 7. 



