33 
Subclass II]. ASIPHONOPHORA. 
Mantle lobes mostly free, bearded behind, or on the whole edge, 
sometimes with a separate siphonal opening for the vent. 
Order IIT. Lastacea. 
Mantle lobes united, with an anal siphonal aperture under the 
hinder adductor muscle, and a large pedal opening. 
Fam. 1. Solenomyade. 
Pedal opening anterior. Foot large, oblong, clavate, truncated 
at the end. Siphonal opening in a disk surrounded with long 
beards. Gills pinnate, appearing only one on each side, broad, of 
separate threads. Palpi small, slender. Shell gaping, thin. Peri- 
ostraca hard, polished, dilated beyond the shell. Cartilage linear, 
internal. Animal leaps and swims about by suddenly drawing in 
the umbrella-shaped foot ; at the same time the water is expressed 
from the hinder opening by the closing of the valves. 
1. SOLENOMYA. 
1. S. mediterranea, t. 352. f. 1, 2, 3, 3a, 4, 4a. 
Fam. 2. Lasiade. 
Pedal opening inferior, moderate ; front edge sometimes produced 
into a hood (or united and forming an anterior aperture for an in- 
halent siphon?). Gulls two on each side, laminar, dependent, un- 
equal, oblong. T.ips cylindrical ; outer pair small, inner very broad. 
Foot compressed, with a central, inferior, byssiferous groove. Mantle 
double-edged ; inner dilatable. 
1. KELuIA. 
1: K. rubra, t. 334. f. 2. 
2. K. suborbicularis, t. 334. f. 1, 4. 
2 
1. T. purpurea, t. 351. f. 9. 
3 
1. B. seminulum, t. 334. f. 8. 
| 
1. L. squamosum, t. 334. f. 6. 
Fam. 3.° Montacutide. 
Mantle extending beyond the edge of the shell, free beneath, with a 
single posterior anal siphon. Foot very large, broad, subtriangular, 
slightly geniculated, and with a distinct byssal groove. Gills (one 
on each side?). Hinge with a distinct shelly plate over the carti- 
lage, as in Anatinide. 
1. Montacuta. 
1. M. substriata, t. 334. f. 3. 
VOL. WV. D 
