ASCOCEEATID^. 
255 
septal chambers in adult individuals is six, not counting those 
which have been lost by truncation in the earlier stages of the shell’s 
growth. The ornaments of the test consist of faint longitudinal 
ridges crossed by very fine and close-set transverse lines, which can 
only be seen by means of a lens. Just below the aperture in some 
specimens the surface characters undergo a complete change, the 
horizontal lines predominating over the longitudinal ones. Another 
specimen exhibits an equality in the strength of the two series of 
lines. The cast is marked by very fine, irregular, impressed lines 
produced by the mantle of the animal ; these are more distinct in 
the young than in the adult shells. 
RemavTcs. The variety curta (fig. 44) is distinguished from the 
species by its shorter and more inflated form. It is not represented 
in the Collection. 
Horizon. Etage E, bande e 2 ( = Salopian). 
Locality. Dlauha Hora, Bohemia. 
Eepresented in the Collection by a very imperfect specimen. 
[In the memoir upon Ascoceras, published in the BuU. Soc. Geol. 
de France, 1855, vol. xii. p. 157, and in Leonh. u. Bronn, Jahrb. 
1855, Heft iii. p. 277, Barrande drew attention to certain species 
of that genus in which the septal chambers, bordering the body- 
chamber, were absent. In 1865 these species were constituted a 
subgenus — Aphragmites — Ascoceras Buchi being taken as the type. 
In 1867 Aphragmites was erected by its author into a distinct genus, 
containing two species, viz. Aphrag. Buchi and Aphrag. Salteri. 
Finally, in 1877 (Syst. Sil. de la Boheme, vol. ii. Suppl. p. 94) 
Barrande came to the conclusion that the absence of the arched 
septa at the side of the body-chamber was due to absorption, and 
the genus Aphragmites was then abandoned, and the two species 
representing it relegated, the one {Apjhr. Buchi) to Ascoceras Beshayesi, 
the other {Aphr. Salteri) to Ascoceras Bronni. This disposal of them 
shows that the absence of septa was regarded by Barrande as an 
individual variation. Professor Hyatt has re-established the genus h 
It is not represented in the National Collection.] 
Proc. Boston Soc. Nat. Hist. vol. xxii. 1883, p. 279. 
