SCIENTIFIC SUMMARY. 
205 
exhibit widely different spectra, inasmuch as these absorption bands vary in 
position and in intensity. This widely different behaviour of the benzene and 
alcoholic compounds is a point likely to prove of service, as, for example, in 
the study of the constitution of the terpenes. 
GEOLOGY AND PALAEONTOLOGY 
Toothless Ichthyosaurus. — Those wonderful regions of the western terri- 
tories of North America from which so many remarkable fossil forms have 
been derived show no signs of approaching exhaustion. Soon after the dis- 
covery of birds with true teeth had startled naturalists, remains of Ptero- 
dactyles were for the first time found in America, and these, following the 
example of the birds, reversed the accepted order of nature by exhibiting 
toothless jaws. Following up this remarkable series of discoveries, Pro- 
fessor Marsh now announces ( Amer . Journ. Science and Arts, January, 1879) 
the occurrence in Jurassic deposits immediately below what have been des- 
cribed as the Atlantosaurus- beds, of the remains of a Saurian, presenting in 
most parts of its skeleton the characteristics of Ichthyosaurus , but entirely 
ivithout teeth. He says “the vertebrae, ribs, and other portions of the 
skeleton preserved cannot be distinguished from the corresponding parts of 
Ichthyosaurus ; and many features of the skull show a strong resemblance. 
The general form of the skull is the same. The great development of the 
premaxillaries, the reduced maxillaries, the huge orbit, defended by a ring 
of bony plates, are all present ; but the jaws appear entirely edentulous and 
destitute even of a dentary groove.” 
The remains of this Saurian, which Professor Marsh names Sauranodon 
natans, preserved in the museum of Yale College, indicate an animal eight or 
nine feet long, of which the skull, which has the facial portion much pro- 
duced, makes up about two feet. The orbits are very large, but the sclerotic 
ring consists only of eight plates, which are not arranged in a nearly flat 
ring, as in ordinary Ichthyosaurus, but form the basal segment of an elongated 
cone, as in the eyes of many birds. 
Professor Marsh regards this curious creature as representing a special 
order of reptiles which he proposes to name Sauranodonta. It seems doubt- 
ful, however, whether the mere absence of teeth, either in this form, or in 
the toothless Pterodactyles, is a character of sufficient importance to justify 
the establishment of a new ordinal group. 
Holer ophyllece, a new order of ^Carboniferous Plants. — In April last Count 
Gaston de Saporta established a new genus of fossil Gymnosperms, under the 
name of Dolerophyllum, upon certain large conical buds formerly referred by 
Professor Goppert to the Musacese, and upon some leaves which were pre- 
viously regarded as leaflets of Nceggerathiee or of ferns. These leaves were 
allied to M. Grand-Eury’s genus Doleropteris, which, in his opinion consti- 
tuted, with Rhacophyllum and Aphlebia, a group of plants wavering between 
Nceggerathice and ferns. 
M. de Saporta and M. Penault have investigated these plant-remains, and 
according to the statements of the former ( Comptes rendus , September 9, 
