No. 417.] MWORTH-AMERICAN INVERTEBRATES. 755 
&3. Lorica soft, much broader behind and tapering for- 
ward to the narrow head when extended ; broad ovate, 
truncate, when retracted. Toes short, with claw about 
one-third the length of the toe . 212, D. inermis Gosse 
d2. One rod-shaped toe . . Monostyla 
eZ. Lorica broad ovate, flat, Fuels apta d into two long 
sharp, outwardly curved spines, separated by a narrow rounded 
NBNER oso 213, M. quadridentata Ehr. (Fig. 150) 
€2. Lorica ovate, toe Manit fusiform 
214, M. closterocerca Schmarda (Fig. 151) 
e3. Lorica without spines ; toe rod-shaped or tapering to the tip 
Jr. Lorica broadly ovate, with a crescentic concavity in 
front when the head is retracted. Toe with parallel sides 
215, M. lunaris Ehr. (Fig. 152) 
J2. Lorica ovate, without a crescentic concavity in front 
when the head is retracted, but nearly truncate. Toe 
short, rod-like . . . 216, M. cornuta Ehr. (Fig. 153) 
J3. Dorsal plate high eres ventral somewhat convex ; 
anterior dorsal edge of lorica with a shallow, rounded or 
quadrate notch ; ventral plate with a much deeper, broader 
notch . . 217, M. bulla Gosse (Fig. 154) 
du. E. ovate ; two anterior lateral points when the head 
is retracted. Ventral plate flexible, with irregular longi- 
tudinal folds . . . 218, M. arcuata Bryce (Fig. 155) 
J5. Lorica subcircular, ae little longer than broad; two 
inwardly curved sharp points at the anterior edge when the 
head is retracted ; toe rod-like, ending in two short claws 
projecting from between two minute spines 
219, M. robusta Stokes (Fig. 156) 
Jó. Lorica subovate, with a straight anterior margin when 
contracted (insufficiently described) 
220, M. truncata Turner 
J7. Lorica broadly ovate, truncate, rounded dorsally. Dor- 
sal plate strengthened by two diverging longitudinal ribs 
about equidistant from each other and from the lateral 
edges of the plate, jig the anterior margin slightly 
angulate where they join it. . 221, M. ovata Forbes 
*4. Lorica a soft, flexible, destin skin, hardly deserving 
the name of lorica. Body oblong, samba se Toe rod- 
Shaped, with a short claw. . . . 222, M. mollis Gosse 
c9. Lorica of a single piece, like a coat, iios only the anterior 
half of the dorsal surface of the — or less ; foot long, jointed, 
with two minute toes . . . . . Cochleare 
dr. Lorica threesided . . . 225 C. indii Gosse (Fig. 157) 
