222 THE AMERICAN NATURALIST. | [Vor. XXXIV. 
&. Uropoda hardly surpassing the caudal segment; both 
branches equal in length. Epimera of last two segments 
of thorax surpassing the segments. Head narrowly 
rounded in front. . . Lévoneca ovalis (Say), NM.SG 
FAMILY X. LIMNORIIDA. 
Genus Limnoria Leach. . . . Limuoria lignorum (Rathke), AVMS 
FAMILY XI. SPHAROMIDZ. 
8 
Outer branch of the uropoda small, almost rudimentary. 
Cassidena Milne Edwards 
. Outer branch of the uropoda not rudimentary. 
6. Both external and internal branches of the uropoda projecting 
and exposed; outer branch capable of folding under inner. 
c. Terminal segment of the abdomen entire. 
d. Margins of the head not produced. Antenne conspic- 
uous. Legs normal. Mandibles with a. five-jointed 
palp. Spharoma Latreille 
d’, Anteater, d beni PEU M the head produced, con- 
crating. the antenna »Fropodts. of first and second 
pairs of tylus. Mandibles 
th a three-jointed palp. . Tecticeps Richardson 
c. Terminal segment of the abdomen excavated at its extremity. 
Dynamene Leach 
2. Only the external branch of the uropoda pitis and exposed ; 
outer branch incapable of folding under inn 
c. All the thoracic segments of equal wei Penultimate 
abdominal segment in male generally produced in spine. 
"Terminal segment excavated with or without median lobe. 
Cilicea Leach 
c. Sixth segment of the thorax much enlarged, and produced 
at the center far backwards, covering the shorter seventh 
segment for the most part. Terminal segment excavate. 
Nasa Leach 
Genus Cassidena Milne Edwards. . Cassidena lunifrons Richardson, M 
Genus Sphzroma Latreille. 
a. Body widening gradually from head backwards. Thorax transversely 
ridged and provided with three longitudinal rows of small tubercles. 
Branches of the uropoda very large, expanded. 
Spheroma amplicauda Stimpson, APD, surface 
a’. Body not increasing in width. Surface of thorax smooth. Branches 
of the PRS not Henn. 
6. Extremity inal duced in a rhomboid 
einai gy gk pp Rig Spharoma rhomburum Richardson, D 
& 
