No. 417.| MORTH-AMERICAN INVERTEBRATES. 745 
ór. Lorica oval, compressed, without teeth or spines, formed of two 
subequal convex plates ; one tse 
, Anapus ovalis Bergendal (Fig. 96) 
ġ2. Lorica truncate in front pei: behind, formed of a convex dorsal 
and a concave ventral plate ; no teeth nor spines 
132, Anuræa hypelasma Gosse (Fi ig. 97) 
43. Lorica with six teeth or spines at the anterior edge (usually box- 
like in form, open at the anterior and posterior ends ; frequently 
with spines at the posterior end also o) 
cI. Lorica oblong, convex above, flattened beneath ; dorsal surface 
marked off into polygonal areas 
dr. Lorica subconical in dorsal view, prolonged at the posterior 
end into a long, strong spine which is slightly narrowed at its 
base ; polygonal areas of the dorsal surface divided into right 
and left sets by a median longitudinal line 
3, Anurea cochlearis Gosse (Fig. 98) 
42. Lorica as in dz, but porci spine lacking 
Anurea cochlearis, var. tecta 
4j. Like Zr, but there is a median dorsal row of polygonal areas 
on the lorica . . . Anuræa cochlearis, var. stipitata 
44. Lorica subquadtangular with a spine at each of the two 
posterior lateral angles 134, Anuræa aculeata Ehr. (Fig. 99) 
eI. As in d4, but the Mor separating the polygonal areas 
Strongly serrate . nurea aculeata, var. serrulata 
e2. Asin ZZ, but the two posistidt omm unequal 
urca aculeata, var. valga 
c2. Dorsal surface of the lorica area with Do mene furrows 
or striations . . . Notholca 
dr. Loricaa inne te narrow, ebur ey prolonged at the 
posterior end into a long spine, equal in length to the body. 
Anterior spines large, the right one of the two median spines 
immensely developed, so as y be as long as the bo 
135, JV. longispina Kellicott (Fig. 100) 
d2.. Ovoid, truncated in front, the anterior spines rather short ; 
body rounded and without spines posteriorly ; longitudinal 
striations of dorsal plate strongly marked; dorsal plate of 
lorica much wider than the ventral plate 136, JV. striata Ehr. 
dj. Much like JV. striata, but with a subquadrangular projection 
from the posterior orifice . striata, var. labis 
44. Cylindro-conical in form ; duni plate ixteedal posteriorly 
to form a tooth or spine; ventral plate elevated posteriorly to 
form a high angular projection . . . 137, N. foliacea Ehr. 
42. Foot present 
br. Foot transversely wrinkled or ringed (as in Figs. 101-102) ; very 
retractile 
