ON THE REPRODUCTION OF CERTAIN SPECIES OF ICHTHTOSAPRCS. 71 



foar Ichthyosanrs are referred to, whicli each contained a foetus. One 

 of these is the specimen originally figured by himself ; ' the second is at 

 Tiibingen ; and the third from Zell, near Kirchheim, was exhibited at 

 Munich in 1864. He remarks that these are all entirely enclosed between 

 the ribs of the parent, are all fully developed, and were ready to be born, 

 or in the act of being born, as the animals sank to the bottom. ' In these 

 three cases the head, though still in the body of the old animal, is directed 

 backward. On the other hand, one specimen of Ichthyosaurus from 

 Ohm den, now at Madrid, has the head of the young one directed forward, 

 and in sequence with a connected series of vertebras.' Jaeger argues 

 that the young do not exhibit any trace of having been eaten, since no 

 digested matter is found with them, while the vei'tebrte are in sequence, 

 and the bones hold the exact position they should have if the Ichthyo- 

 saui'us were viviparous. And he further remarks, that though these 

 yoting examples are rare, yet they really exist, while we find no traces of 

 any eggs, though numerous coprolites are preserved ; and from the cir- 

 cumstance that the skull in the young of these German specimens belongs 

 to the same species as the old aaimals, concludes that, at least, the 

 species which he names Ichthyosaurus tenuirostris was vi\4parous. 



Other important and beautiful specimens have been acquired for the 

 University Museum at Tubingen, by Professor F. A. von Quenstedt^ 

 F.M.Gr.S., and admirably developed by him. They are briefly noticed in 

 his well-known works, ' Der Jura ' and ' Epochen der Natur,' but they 

 led the learned and accomplished author to the conclusion that the young- 

 specimens had been devoured. In the former work (1858, p. 219), after 

 describing the species, which he names J. quadriscissus, it is observed, 

 * this specimen contains a young one between the ribs, in a position which 

 indicates that it was eaten. The splendidly preserved skull of the young 

 one measures 10 inches in length, with its point towards the hinder extre- 

 mity, while its tail still remains in the throat. Hence we may infer that 

 the intestinal canal was as simple as in sharks.' And in the later work,, 

 published in 1861, p. 549, these statements are repeated, except that two 

 specimens are mentioned as being in the Tubingen collection. Though no 

 argument is offered upon the subject, the large size of the young, and 

 extent to which its tail reaches forward in one of his specimens, has 

 evidently weighed with the Tiibingen professor in the printed expression 

 of his judgment. He, however, called my attention to a small specimen in 

 the University Museum, with the tail coiled up, which he thought might 

 have been foetal, but it is not contained in the body of another animal. 



In 1876, Arnold R. 0. Wurstemberger printed in the ' Jahreshefte 

 Ver. Nat. Wiirtemburg,' a memoir entitled ' Ueber Lias Epsilon,' which 

 concludes with some account of the species of Ichthyosaurus, giving 

 an interesting description of I. quadriscissus (Q). After describing a 

 large parent animal, in which the head is said to be 50 cm. long, and 

 the vertebral column 240 cm. in length, Wurstemberger observes that 

 the stomach lies unusually far forward, being only 20 cm, behind the- 

 head, and is defined by containing fish-bones and the dark-coloured 

 remains of cuttle-fish. A small Ichthyosaur lies entirely behind this 

 region, and is so contained between the ribs, that the author is convinced 

 that it could not have got there after the death of the large animal, hence 

 it can only have been eaten or be an embryo. Many bones of the young 



■ Be Ichthyosauri swe Pi'ateoti fossilu spccim. in a^ro Bolletmg repeitis. 1824 

 fol. Tab. I. fig. 4a. 



