16 
PALAEONTOLOGY OF NEW YORK. 
We are not aware that any author has described or represented the form 
and size of the egg of the recent Lingula since the publication of Profes¬ 
sor Owen’s observations “ On the Anatomy of Terebratula,” in Davidson’s 
i; Introduction to the British Fossil Brachiopoda,” 1853. On plate i of this 
work, figures 7 , a, b, c, d and e, are given representations of the ova after 
impregnation has been effected, which indicate that their form in this condition 
is elongate-ovoid or sub-trihedral (7 c). According to Lacaze-Duthiers, the egg 
of Thecidium, in its earliest observed condition, is somewhat pyriform.* Morse 
describes the eggs of Terebratulina as “ generally kidney-shaped, though very 
irregular as to form and size.”f As to the actual size of the ova discussed by 
these authors, Owen’s figures, enlarged one hundred and twenty diameters, 
would indicate a length of .H mm. Morse has given no exact measurements 
of these bodies; the youngest embryo in which the shell is developed, is about .3 
mm. in length, and it is fair to assume that the ova are considerably smaller. 
On removing the shell from a specimen of Lingula lamellata ,, Hall, from the Niag¬ 
ara limestone at Hamilton, Ontario, in order to determine the character of the 
muscular scars, the interior filling, a compact, fine-grained calcareous mud, was 
found to be filled with minute ovoid bodies. The valves of the shell were in 
the normal apposition and in contact about the entire periphery. The bodies 
referred to {ova, as we believe them to be), vary somewhat in size and shape, 
their length being from .3 to .5 mm., their form elongate-ovoid or ellipsoidal. 
They are closely crowded together, but seldom in actual contact, the interspaces 
being filled, not with the mud of the sediment, but with a translucent crystalline 
calcite. They are most abundant wherever the pallial sinuses have extended, 
but in the marginal regions have been crowded inward by the intrusion of the 
sediment. A section of the interior of the filling shows that these bodies 
had evidently been set free into the perivisceral cavity, and have also found 
their way into the visceral region after the decomposition of the softer parts 
of the animal. That they are not of oolitic or foraminiferal nature is demon- 
* Annales des Sciences Naturelles, 4th Ser., vol. xv, p. 302. 1861. 
f On the Early Stages of Terebratulina Septentrionalis; Memoirs of the Boston Society of Natural 
History, vol. ii, page 31, pi. i, fig. 1. See, also, Embryology of Terebratulina, op. cit., pp. 251, 252, pi. viii, 
figs. 1-5. 
