262 
DEVONIAN FAUNA. 
specimen shows tlie shell as distinctly sinistral, with the upper surface of the 
whorls lying almost in one plane. 
In some of the foreign species of this genus, while the apical whorls are closely 
coiled or even contiguous, the coiling becomes looser with the increase in size.^ 
Hence, whether all the present fossils are full-sized specimens, or whether some 
are only the apical whorls of a larger species, cannot be decided until more 
numerous specimens are found. At present there is no reason against regarding 
them as full-grown shells. From the accompanying species they appear to be 
distinct, as in the former the coiling is very much looser even to the apex. In 
Ph. militaris, moreover, the rate of increase of the whorls is very much greater. 
At first sight this species seems identical with Su. retrorsus, F. A. Romer," as 
given by Sandberger f but his enlarged figure is only that of a cast, and a refer- 
ence to Homer's original description shows that his species is very different, and 
that its whorls are contiguous instead of being free. 
One of the examples of Eu. seiyida figured by d' Archiac and de Verneuil* is 
so similar that it may belong to the same species, though it appears to differ in 
having the central whorls in contact. 
Both de Koninck^ and d' Archiac and de Verneuil quote each other in their 
original description of their species. It would seem probable that that of the 
latter authors was published first ; but, as they ascribe the species to de Koninck, 
and he claims it as his own, his must be regarded as the authoritative description. 
Moreover, in his later work,^ de Koninck states that the French authors were 
incorrect in their identification of their shell with his. He considers that Euom- 
phalus serpula, var. gracilis, of Ooldfuss, is one of the Devonian species described 
by them under his name, and says that it should bear the name of Ph. gracilis. 
Although, as he first described it, there is no appreciable difference in Ph. serpula 
from our shell, his latter description shows that it differs by bearing one or two 
spiral strige. 
E-uomphalus approximatus, de Koninck,'' is so similar that I was at first 
inclined to regard it as identical. It differs, however, in having a very decidedly 
elevated spire, and therefore, remembering the difference of the formation, it is 
best to regard it as distinct. 
As given by Goldfuss, Eu. serpula, de Kon., var. gracilis, probably differs from 
1 The figure of our small Lummaton specimen (fig. 13) seems to show this character. This 
appearance is deceptive, and is due to the light in which this specimen was drawn. The outer whorl 
should have been represented as wider, and closer to the next within. 
2 1850, F. A. Eomer, ' Beitr.,' pt. 2, p. 15, pi. iii, fig. 15. 
^ 1853, Sandberger, ' Verst. Rhein. Nassau,' p. 213, pi. xxv, figs. 8, 8 «, 8 b. 
^ 1842-4, de Koninck, ' Desc. Anim. Foss.,' p. 425, pi. xxiii bis, figs. 8 a, b. 
^ 1883, de Koninck, 'Ann. Mus. Eoyal H. N. Belg.,' vol. viii, pt. 4, p. 4, pi. xxii, figs. 1 — 3. 
^ Ibid., p. 6, pi. xxii, figs. 14 a, b. 
