ASCOCEEATID^. 
253 
body- chamber occupies about | of the total length of the fossil. 
The test covers the 'whole of the truncated extremity, as in other 
species, but the truncated part is as usual quite smooth. The 
remainder of the test is ornamented 'with fine imbricating lines, of 
which about six are contained in the space of one line. The iuternal 
cast shows a series of very fine interrupted, irregular, impressed 
lines produced by the mantle of the animal ^ ; these can only be seen 
with the aid of a lens. 
Remarlcs. The characters which distinguish Ascoceras Bohemicum 
from all other allied species are : — its great size (the largest known 
measures 5| inches in length, and 2 inches in its greatest diameter ; 
the ornaments of the test ; and the relatively great development of 
the septal chambers, which considerably reduce the width of the 
body-chamber, as seen laterally upon a cast. 
This species is identified by Blake (Joe. cit.) from the Upper Ludlow 
of Whitecliffe, Ludlow ; but he observes that “ it may well be 
doubted if our British specimen is indeed A. Bohemicum, its section 
is different, and the septal convexity is greater ; but as these differ- 
ences may arise from compression, there are no ample grounds for 
their separation.” 
Horizon. Ltage E (= Salopian). 
Locality. Karlstein, Bohemia. 
Genus GLOSSOCSRAS, Barrande^ 
Gen. Char. Glossoceras differs from Ascoceras in its more slender and 
less infiated form, and in having a lobed, instead of a simple aperture. 
Remarlcs. Barrande has compared the lobated aperture in Glos- 
soceras with that of Hercoceras mirnm, Barr. (pi. cii. ff. 4, 6, 8), 
Ophidioceras simplex, Barr. (pi. xcvii. ff. 1, 2, 6, 7), and 0. rudens, 
Barr. (pi. xlv. ff. 13, 18, 20) : he also compares it with certain 
species of Gomphoceras, such as G. pavidum, Barr. (pi. li.), G. pu- 
sillum, Barr. (pi. lii.), G. incola, Barr. (pi. Ixviii.), &c. 
Barrande supposes the constricted aperture in this genus to have 
been removed by absorption, and renewed during the successive 
stages of growth of the animal, just as in Hercoceras (see ante, 
p. 214). 
^ The specimen sho'wing the ornamentation just described is numbered 8088 f 
in the Collection. 
^ Barrande, pi. xciii. f. 1. 
^ Sjst. Sil. de la Boheme, 1867, vol. ii. pt. i. p. 372. 
