10 
PALEONTOLOGY OF NEW YORK. 
of Wisconsin* Upon the first plate of this volume are given, in addition to 
copies of the figures named, a number of illustrations representing these impres¬ 
sions in different degrees of completeness; especial attention may be directed 
to the figures of L. punctata, L. Procteri, L. densa, and to those of L. lamellata, 
upon Plate IYk. (See, also, the figures of L. Lewisi, Sow., given by Davidson,! 
and the accompanying text illustrations of extremely well preserved internal 
casts of L. Melie [brachial valve], and L. paracletus, sp nov. [pedicle-valve].) 
There has been a considerable diversity of opinion among authors, in regard 
to the special functions of the various muscular bands in Lingula. Few in¬ 
vestigators have brought to the study of this subject the clear insight and 
incisive judgment of Professor William King, whose nomenclature of the mus¬ 
cles, we have preferred to adopt. 
The first strong impression arising from the comparison of these ancient forms 
with the type-species is that in the former, the dorsal scars of the central muscles ( h ) 
are relatively much the larger, and 
are situated somewhat posteriorly, 
apparently encroaching upon that 
portion of the visceral chamber 
which, in L. anatina, is occupied 
by the essential organs of the 
animal. This apparently great 
size, however, is somewhat illusory, = 
as undoubtedly a portion of these 
large scars is due to their contin¬ 
ued advance as the shell increases 
in age, and probably at no time in 
the mature life of the animal did 
these muscular bands, at their or¬ 
igin and insertion, cover the entire & > middtesTlS^® 
Lingula anatina, after Davidson. 
Fig. 6. Pedicle-valve. Fig. 7. t Brachial valve. 
Lonal muscle; i, transmedians, ft, centrals; 
* Vol. iv, p. 345, pi. xxvii, tigs. 3-5. 1882. 
f Monogr. British Silurian Brach., pi. iii, figs. 5, 6. 
J Davidson’s figures are diagrammatic copies of the more elaborate illustrations given by King. In the 
process of copying it is evident that fig. 7 has been reversed, and the position of the double and single 
muscular bands of ( i ) inverted. 
