16 PALMONTOLOGY 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 

 '■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. 



t On the Early; Stages of Terebratulina Septentrionalis ; Memoirs of the Boston Society of Natural 

 History, vol. ii, pafi-e 31, pi. i, fig'. 1. See, also, Embryology of Terebratulina, op. cit, pp. 251, -252, pi. viii, 

 figs. 1-5. 



