122 DEVONIAN FAUNA. 



Museum is by far the finest, although its ornamentation is destroyed. That in 

 the Godwin- Austen Collection adds something to our knowledge, as some signs of 

 its surface ornament are to be discerned, although they are not very distinct. 



I have referred these fossils to 0. rapiforme, Sandberger,^ as they appear to 

 agree exactly with it both in the highly conical shape, and, if I interpret the 

 God win- Austen specimen aright, in the narrowness of the chambers. The shell 

 which F. A. Romer figures as 0. rajpxforme, Sandberger, is slightly elliptic, and 

 perhaps tapers rather more rapidly. 



Affinities. — This species difi'ers from 0. conoideum, Miinster,^ in being much 

 more conical. 0. arcuatellum, Sandberger,' is distinguished by having much 

 deeper chambers ; it would be interesting to know if the surface ornamentation 

 on the body-chamber were of the character of those of that species. 



0. transiens, Barrande,* appears somewhat less conical and is slightly recurved ; 

 its markings were probably similar. 0. deludens, Barrande,^ tapers less rapidly, 

 and appears to have a more complicated ornament. 



2. Orthoceras eutrichum, WMdborne. PI. XIII, figs. 1, 1 a, and PI. XIV, fig. 10 ? 



Cf. 1853 ? Oethoceeas ttjbicinella, Sandb. (not Sow. nor PJiil.). Verst. Khein. 



Nassau, p. 169, pi. xix, fig. 6. 

 1889. — COMATUM, Whidh. Geol. Mag., dec. 3, vol. vi, p. 29. 



Description. — Shell elongate, slightly conical, moderate in size. Section appa- 

 rently circular. Septa and siphuncle unknown. Surface covered with numerous 

 distant, raised, thread-like, longitudinal lines, between which are one or two series 

 of much finer similar lines, and crossed by very fine and numerous, irregular, 

 rugose marks, and very indistinct and broad, transversely oblique bulges, the 

 major series of longitudinal lines being alone visible on the cast. 



8ize about 23 mm. in width. 



Locality. — A finely preserved specimen from Lummaton is in Mr. Champer- 

 nowne's Collection, which shows the surface ornamentation very minutely. 

 Another doubtful specimen from the same locality is in my Collection, which 



^ 1852 ? Sandberger, ' Verst. Ebein. Nassau,' p. 167, pi. xi.x, figs. 4, 4 a. 

 2 1840, Miinster, 'Beitr.,' pt. 8, p. 96, pi. xviii, figs. 3, 4. 

 2 1852 ? Sandberger, ' Verst. Ebein. Nassau,' p. 166, pi. xix, figs. 2 a—g. 



* 1868, Barrande, ' Syst. Sil. Bobetn.,' vol. i, pt. 3, p. 88, pi. ccxviii, figs. 8 — 11 ; pi. ccxxiv, figs. 

 17—23 ; pi. ccxcii, figs. 1—21 ; pi. ccxciii, figs. 1—12 ; and pi. ccccii, figs. 12—15, Et. E. 

 5 1870, Ibid., p. 47, pi. cccxcvii, figs. 5—9, Et. E. 



