ORDER ISOPODA — STENOSOMA. 43 
(EXTRA-LIMITAL.) 
I, triloba. (Say, l.c. Vol. 1, p. 425.) Body oval, somewhat oblong; its segments with the lateral 
processes very convex, lobated. Eyes very prominent. Middle lobe of the tail the largest; the last 
longer than all the others together, subtriangular. Feet armed with very strong acute incurved 
nails, Length, 0:25. Egg harbor. 
GENUS STENOSOMA. Leach. 
With the general characters of the preceding. Body sublinear. External antenne nearly as 
long as the body, not comprising the tail ; internal antenne very short. Feet robust. 
Ozss. This genus has been united by recent authors with the preceding. 
STENOSOMA IRRORATA. 
PLATE X. FIG. 42. 
(STATE COLLECTION.) 
Stenosoma irrorata. Say, Jour. Acad. Nat. Sciences, Vol. 1, p. 423. 
Ss. td. Goutp, Invertebrata of Mass. p. 338, 
Description. Body oblong, somewhat tapering at each extremity, and composed of seven 
segments ; those in the midde of the body largest ; no appearance of articulation on the sides 
of the second or following segments. Eyes prominent, brilliant, black and lateral. Tail of 
four segments ; the three first small, subequal; the third ebsolete above. ‘The fourth or ter- 
minal segment is nearly as long as four of the body segments, obsoletely carinate on the 
dorsal surface ; tip with an elongated central point, and an obtuse tooth on each side. Lateral 
appendices oblong, rounded, with a transverse articulation near the posterior tip. Feet multi- 
articulate, hispid at the joints with acute incurved claws. External antennz scarcely exceed- 
ing in length the ultimate segment of the tail, with a minute spine on the inner side of the 
tip of the first joint; but this is not observable except in the largest specimens, Internal 
antenne very short, scarcely reaching the tip of the third joint of the outer antenne. The 
last joint of the exterior antenne is composed of more than twenty articulations. 
Color, varies from deep purple to sea-green and even reddish. Some are of a uniform 
color, whilst others are varied with light sea-green and cinereous brown. The specimen 
figured in the plate, represents one with two longitudinal sea-green bands. Scarcely any two 
individuals are alike in their markings. 
Length, 0°2-1°0. Width, 0°03 - 0°05. 
6* 
