1902} MICROSCOPICAL JOURNAL. 111 
g Posterior spines 3.000002... quadratus. Sup 
g Posterior spines 4, (1) 
h Anterior spines unequal, (i) 
h Anterior spines nearly equal ; dorsum tesselated.... leydigii. Sup 
h Anterior spines do. ; dorsum not tesselated i. costulatus 
i Hind border more or less concave, (j) 
i Eid er MONTY DIANO es cc longipes. Sup 
j Lorica widest behind, hind border rounded .......... latissimus. Sup 
j -Lorica not widest behind, hind border not rounded. 
SIMs ee salad ss) deed, bakeri var. rhenanus 
ik. Onter fromtal epimes Jongest 020i) secs eee, furculatus 
k Middle frontal spines longest ooo variabilis* 
1 Lateralspines 2; outer post’r spines longest...ancylognathus. Sup 
1 Lateral spines none; posterior spines equal ........... pustulatus. Sup 
1 Lateral spines none ; hind spines middle pair shorter 
. Se figd seeds Hered Wee lah ipa brevispinus. Sup 
m Posterior spines none, (n) 
m Posterior spines 5, outer 2 very long... polyacanthus, Sup 
n lLorica surface with minute spinules............ punctatus* 
m Trica teaselated, roti iii occ edesceessecees budapestinensis. Sup 
n Lorica smooth, frontal spines nearly straight... pala 
n Lorica smooth, frontal spines, middle 2incurved....... dorcas 
o Frontal spines none, (p) 
o Frontal spines merely tooth-like. Aquatic... 8. rubens 
o Frontal spines merely tooth-like. Marine... mulleri 
p Front margin straight, truncate _mollis* 
p Front mar. sli’tly undulate;2 blunt processes ebhind....angularis 
p Front margin slighly concave; lorica smooth... inermis. Sup 
p Front mar.with median cusp; hind spi. 4, curved...gleasonii. Sup 
61. Norgus. II., 121. 
Front with 2 curved strips, hind spines 2, long .... ........... quadricornis 
62. ANURAA. II., 122. Sup. 54. 
A lLorica with 6 or more frontal spines, (a) 
A Lorica with 4 frontal, no posterior spines, (i) 
A Lor. with no spines, formed of 2 plates; front truncate..hypelasma 
a Posterior spines none, (b) 
a Posterior spines one, (e) 
a Posterior spines two, (f) 
b Lorica smooth, often tesselated, (c) 
b Lorica punctate, stippled, often tesselated, (d) 
c Facets on each side of median ridge... tecta 
c Facets 5, median; lorica oblong, rounded behind... curvicornis 
c¢ Facets(?); lor, obtusely quad’te, rounded behind... squamula. Sup 
d Tesselated, the ridges serrate; lorica oblong-square....... serrulata 
* Hempel. Bul, Ill. State Lab. Nat. Hist., IV., 1896, 310. 
