138 . DEVONIAN FAUNA. 



Torquay Museum as the type, it will be seen that it differs from that shell in 

 several particulars. The rings are closer, steeper, and half as numerous again 

 (i. e. 3 to 2), and the section is circular. Hence, in the opinion of Mr. Foord and 

 myself, it has to be regarded either as a distinct species or variety. 



I have coupled the specimen in the Museum of Practical Geology with it with 

 some doubt, as while it presents a great resemblance there are some points of 

 difference. These are probably due, however, to its being in a different state 

 of preservation and belonging to a different part of the shell. It appears to 

 contain part of the body-chamber and the upper portion of the septal chambers. 

 Its rings are less elevated, and in the upper part the tube is cylindrical and the 

 rays more distant, with minor lineations between. This last feature reminds us 

 of the ornamentation in 0. eutrichum, but its markings are much coarser than 

 those of that species. Towards the lower part of the specimen the characters 

 grow much more like those of the upper part of the Torquay specimen, which 

 is, I imagine, a portion of the tube considerably nearer to the apex ; and there- 

 fore there seems every reason for presuming that they are specifically identical. 



Affinities . — From 0. calamitaceum, Portlock^ (not Miinster), it differs in the 

 coarseness and closeness of its rays, and in the absence of the finer radiations in 

 its lower part, as well as in its circular section. The section of the Irish shell, 

 which Blake treats as a variety of 0. gracile, Portlock*^ (not Blumenbach),^ is very 

 elliptic, but Portlock seems to consider that this might have been due to pressure. 

 0. Nicholianum, Blake,* a still nearer form, differs from our type in having sharp 

 ribs and less prominent and fewer rays, and in the septa being apparently closer. 



10. Orthoceeas subannulaee, Miinster. Plate XIV, figs. 7, 7 a, 8, 8 o, 8 h. 



1840. Oethocebatites strBANNULAEis, Munst. Beitr., pt. 3, p. 99, pi. xix, fig. 3. 

 1850. Oethocebas Wissembachii, F. A. Rdmer (not d'Areh. and de Vern.). 



Beitr., pt. 1, p. 17, pi. iii, fig. 22. 

 1SG8. — DISCKETXJM, Barrande. Syst. Sil. Boheme, vol. ii, p. 276, 



pi. cclxxix, figs. 38—43, Et. F. 

 ? 1868. — SUBANNULAEE, Barrande. Sjst. Sil. Boheme, vol. ii, pt. 3, 



p. 343, pi. ccx, figs. 8—10 ; pi. 

 ccxii, figs. 14 — 18 ; pi. ccliii, 

 figs. 11 — 14; pi. cclxxxiii, figs. 

 1 — 19 ; pi. cccxxiii, figs. 15 — 19, 

 &c., :Gt. E and G. 



1 1843, Portlock, ' Eep. Greol. Londonderry,' p. 365, pi. xxv, figs. 1 a, I. 



2 Ibid., p. 366, pi. xxv, fig. 2. 



•' 1803, Blumenbach, ' Specimen Arcliaeologiae Telluris,' p. 21, pi. ii, fig. 6. 

 * 1882, Blake, ' Mon. Brit. Toss. Ceph.,' pt. 1, p. 89, pi. iii, figs. 7, 8, 15. 



