192 University of Texas Bulletin 



steep than the one nearer to the venter; its form, therefore, is rather 

 obliquely tongue-shaped. The first auxiliary saddle is broad, trian- 

 gular, rounded at the end, at the base as broad- as the lateral saddles. 

 The second auxiliary saddle is only visible in two-thirds of its form; 

 it is similar to the first one but much lower and narrower. 



We have described this form under the generic name of Stacheoce- 

 ras. It certainly belongs to this gen^is, which probably should be con- 

 sidered a family, as it includes a great number of very different 

 forms. It is very possible and even probable that this species belongs 

 to Marathonites, but this question can only be decided when the in- 

 ternal suture will be known, or when the study of more material and 

 of different species shows that all those Stacheoceras with very few 

 lobes and saddles possess the characteristic internal suture of Maratho- 

 nites. 



The only species which can be compared to our form is Stacheoceras 

 Romanozvskyi Karp.^ It has a very similar simple suture and shows 

 also the bifid branches of the siphonal lobe and the trifid lateral lobes 

 with a middle point much longer than the lateral ones. There are 

 small differences in the suture, especially in the 'form and the number 

 of the saddles, no second auxiliary saddle showing on the flank of the 

 Asiatic species; this is enough to demonstrate that the two forms are 

 specifically different, although they probably belong to the same group. 



With Stacheoceras Walcotti White, our species has nothing in com- 

 mon. The species of White belongs to a much more highly developed 

 section of the genus, and resembles rather those described by Gem- 

 mellaro from the Sicilian Sosio beds. 



This species also indicates the relationship between our strata and 

 the cephalopod-bearing sandstone of the Artinsk, or at least with the 

 nearly synchronous strata of Darwas in Bokhara, Central Asia. No 

 similar form has as yet been found in higher strata. Only Stacheoce- 

 ras pygmacum Gemm.^ could possibly be compared with it, but the 

 branches of the siphonal lobe are not bifid. 



The species does not seem to be very rare at the locality four miles 

 south of Dundee, our collection containing four specimens. 



'Karpinsky, Amm. d. Artinsk, p. 77, pi. V, fig. 6. 

 'Gemmellaro, Calc. c. Fusulina, p. 39, pi. VIII, fig. 15-17. 



