Reviews—Prof. K. v. Zittel’s Palichthyology. LZ 
Vols. i.—iii. of Signor Jervis’s “‘Subterranean Treasures of Italy” 
treat of the ‘“Topovraphical Mineralogy” of that kingdom, under 
the three same geographical headings as are used in vol. iv. These 
three earlier parts (1873, 1874, 1881) constitute a work complete in 
itself (price 40 lire); and so does vol. iv. (price 15 lire). We have 
already’ recommended with pleasure some of Signor Jervis’s books 
on the fossil fuel, mineral waters, etc., of Italy; and now we again 
can only praise his long-continued efforts for thirty years (we 
believe), in gathering together and publishing in convenient form 
so many well-considered facts and so much information valuable for 
thinkers, workers, and capitalists, not only in his adopted country, 
but throughout the civilized world. This too is the more creditable 
to him, as he has not spared his private means, any more than his 
_ arduous and continuous exertions in travel and research. We hope 
and trust his labours will be rewarded with the honour and profit so 
well deserved. Jide 
IJ.—Pror. Dr. von Zitten on PaicHTuyoLoey. 
Kart A. von Zitrren, HanpBucH peek PatmontToLocizr. PaLmo- 
zootoctgE. Band III. Lief. J. Il. (R. Oldenbourg, Munich, 
1887-88. 
(Continued from page 130.) 
Drpnotr. 
HE chapter on Drpnot commences with a list of the more im- 
portant works relating to its recent representatives, and an 
interesting brief discussion of the systematic relationships of the 
group. ‘To the Ctenodipterini are referred Dipterus, Ctenodus, 
Paledaphus, Holodus, and other more fragmentarily-known fossil 
forms; and a supplementary section includes Megapleuron, Concho- 
poma, and the problematical Tarrasius. Ceratodus is the only fossil 
genus of Sirenoidei; and Dr. Fritsch has recently suggested that 
this is wrongly thus placed, exhibiting no characters by which it 
can be separated from the Ctenodipterini.” 
GANOIDEI. 
A long introductory section to the important group of Ganoids 
comprises, in addition to the usual general topics, a number of 
valuable, and, to a large extent, novel remarks upon the various 
stages of development met with in the vertebral column of these 
fishes, illustrated by several woodcuts. Commencing with the 
notochordal forms, and then referring to the false appearance of 
vertebree in the Pycnodonts, Dr. v. Zittel proceeds as follows: ‘As 
a rule there first appears on the underside of the notochord an 
arched bony plate (hypocentrum), which in the caudal region is 
clasped by the inferior arches and sends upwards shorter or longer 
1 Grou. Mac. Dec. II. Vol. VII. June, 1880. 
* Fauna der Gaskohle, vol. ii. pt. 3 (1888), p. 68. 
DECADE III.—VOL. VI.—NO. IV. 12 
