142 
NAUTILOIDEA. 
Endoceras complanatum, Eichwald. 
1732. Orthoceratites siplione ad peripheriam, Breynius, Dissert, phys. 
de Polythalamiis, p. 36, § 68, tab. v. fF. 1-4 (not f, 5). 
? 1835. Orthoceratites gigantei (?), Kutorga, Beitrag zur Geoguosie und 
False ontologie Dorpati’s, i. p. 32, Taf. vi. f. 6. 
1849. Orthoceratites duplex^ Quenstedt, Die Cephalopoden, p. 41, tab. i. 
ff. 2, «, h. 
1855. Orthoceras duplex^ Barrande in Leonhard and Bronn’s Neues 
Jahrb. fiir Min. &c. p. 264, Taf. iii. ff. 12, 12*. 
1857. Orthoceras duplex, Boll, Beitrag zur Kenntniss der Silur. Ceph., 
in Archiv fiir die Naturkunde von Mecklenburg, p. 10, Taf. i. 
f. 2. 
1860. Endoceras complanatum, Eichwald, Lethaea Rossica, Seconde 
Section de I’ancienne Periode, vol. i. p. 1242, pi. xlix. ft'. 12, a, h, c. 
1866. Orthoceras duplex, Barrande, Syst. Sil. de la Boheme, vol. ii. 
Texte iii. 1874, p. 709 (pars), pi. ccxxxviii. f. 31. “ Espece in- 
connue.” 
1880. Endoceras Eamesii, Dewitz, Zeitschr. der deutsch. geol. Gesell. 
Band xxxii. Heft i. p. 390, Taf. xvi. ft*. 1, 1 a, 1 b, 1 c. 
? 1880. Orthoceras duplex, Angelin-Lindstrom, Fragmenta Silurica, p. i 
(pars), tab. iii. ft; 1-4. 
1881. Endoceras Damesii, Schroder, Schriften der physikalisch-okono- 
mischen Gesell. zu Konigsberg, Jahrg. xxii. Abtli. i. p. 90, Taf. 
iii. ft'. 2 a, 2 b. 
? 1881. Endoceras rectestrigatum, Schroder, ibid. p. 92, Taf. iv. f . 3 & 
ft*. 4, A, B, c. 
Ep. Char. Shell straight ; very slowly tapering at the rate of 
about 1 in 32, and even less than this in some individuals. Section 
elliptical, the ratio of the two diameters being roughly as 20 : 17 ; the 
specimens are, however, too imperfect to admit of strictly accurate 
measurements. Septa strongly undulating, so as to have a consider- 
able obliquity when viewed in some aspects ; distant about the dia- 
meter. Siphuncle marginal, very large, being about |- the diameter 
of the shell. The test is described by Eichwald as consisting of 
“]3lusieurs membranes tres-minces et strides transversalement, a 
stries tres-fines et tres-serrees, qui sont souvent confluentes so that 
the surface is very finely rugose, which is regarded as the principal 
character of the species. From the extreme fineness of these mark- 
ings I should, however, be disposed to deem them to belong, not to 
the surface of the test, but to its inner layers ; and if this be the 
case, they would have little or no specific importance, because 
minute sculpturing of this character occurs in other species of En- 
doceras, and has been figured by Barrande in Orthoceras, in his 
‘ Systeme Silurien de la Boheme,’ in numerous instances. 
