830 General Notes. 
or represented by weak spines. 
RIACANTHIDA.—Scleroderms with the spinous dorsal very 
short and composed of a stout anterior spine and several approxi- 
mated weak ones behind it, the soft dorsal oblong, and with ven- 
trals represented by stout spines, and with or without weak axillar 
erable intervals, the soft dorsal short, and with ventrals atrophied 
L 
rays. 
ooi Scleroderms with the spinous dorsal very short, 
being represented (1) by a stout spine with which a weaker posterior 
spine interlocks in erection (and often a third spine exists), or (2) 
by only a single slender spine; the soft dorsal- long or oblong, 
and the ventrals wanting. : 
These characters are supplemented by important osteological ones 
for the last two at least. ` : 
The family Triacanthide was represented in the eocene seas of 
Europe by the genera Acanthoplewrus (Ag.) and Protacanthodes 
(Gill). The affinity of the former to Triacanthus was remar ed 
as long ago as 1859 by von Rath (Zeitschr. deutsch. Geol. Ges. 
V. ii., pp. 130-132). 
er genera referred to the sub-order of Scleroderms (e9. 
Blochius, Dercetis, Styracodus, Chilodus, Cælorhynchus, Ancistrodon 
are quite remote from it.— Theo. Gill. 
Seconp Nore upon Romanovsky’s MATERIALEN ZUR 
GEOLOGIE von TuRKESTAN.—In the Tertiary, as in the a0 
ceous, the absence of fossils renders it almost impossible to gois 
off stages, and even precludes the exact determination of post A 
of the group. It would appear that the continuity 1s compie™s 
and that Eocene, Oligocene, Miocene, and Pliocene are all me 
sented. The Nummilitic has been met with only upon the bo a 
of the Aral Sea, where it is overlaid by the sandstones, clays, an 
limestones belonging to the Oligocene, which are surmoun ste 
Miocene limestones, and by the argillaceous beds of the Sarm 
stage; these last form the upper layer of the plateau des 
Conglomerates, which form heavy beds in the mountains, are gra feat 
ally replaced by rocks of finer grain as the distance from Lage i 
increases. The Cretaceous strata of Turkestan contain anf et 
beds of phosphorite (mouth of the Syr-Daria), of gypsum the 
shan, Pamir), petroleum (Fergana), and sulphur (basin © úm 
ou-Daria) ; and the Tertiary has intercalations of salt and ey ae? 
(Sangar, Samarcand), the thickness of which diminishes gra 
towards the west. : iods has 
The history of Turan during the recent geological P Asia 
many features in common with that of the rest of Centra; ental 
and especially with that of Afghanistan. After the contin 
1 See de Zigno, p. 4; Am. Nat., 1888, p. 447, note. 
