ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
703 
Dr. Patten’s Classification of Animals. 
Vertebra ta. 
Urochorda. 
Cephalochorda. 
Siphoneura. 
Central nervous system tubular. 
Eyes on neural surface. Retinas to both median 
and lateral eyes inverted. 
Ichthvoida f Cephalaspis, Ptericlithyt 
icntnyoiaa J PleraspiSt Botlmolepis. 
Arachnida. 
Merostomata. 
( Limulus. 
\ Eurypterus . 
Trilobites. 
Peltacephala. 
Head shield -shaped. Eyes on haemal surface. 
s .✓ 
SYNCEPHALA. 
Divided into Head, Body, and Tail. 
Head-segments 9-13; in four groups; first three head-segments 
devoid of appendages. Terminal segments more or less fused to form 
a urostyle. Eyes median and lateral. Median eyes 2-4, in a common 
sac or tube ; retinas inverted. 
Insecta. 
' 
Myriopoda. 
Crustacea. 
y 
PSEUDOCEPHALA. 
Brain segmented, originally post-oral. 
Annelida. 
ENCEPHALA. 
Brain unsegmented, pre-oral, 
v / 
SEGMENTATA. 
CCELENTERATA. 
ECHINODERMATA ? 
PROTOZOA. 
3 d 2 
