ORDER LCEMIPODA CAPRELLA. 41 



GENUS CAPRELLA. Lamarck. 



Body linear or filiform, composed of unequal segments. The upper antennae with the last 

 segment many-jointed, and as long as the three others. Two sessile compound eyes. 

 Feet ten, elongated, arranged by pairs in an interrupted series, unguiculated ; the second 

 and third segments furnished with branchial vesicles. Marine. 



Caprella geometrica. 



C. geometrica. Say, Journ. Acad. Nat. Sciences, Vol. 1, p. 390. 



Description. Body smooth above. Head obtuse, with a short spine in front ; three last 

 segments of the body shorter, convex above ; terminal one smallest, and truncate at the 

 tip. Second pair of feet with dilated oval compressed hands armed with teeth ; one of 

 which is near the base, linear, and almost parallel with the palm ; the other large, obtuse, 

 little elevated, placed near the base of the claw : thumb curved, attenuated at the tip, where 

 it closes on the posterior tooth. Branchial vesicles short, oval. Terminal pair of feet 

 longest. 



Color. Body with a few scattering reddish brown spots ; eyes red ; antennae and feet 

 annulate with reddish brown. 



Length, 3. 



This species is found among sponges and seaweed along the coast, on which it walks after 

 the manner of some caterpillars called Measuring worms. It swims by alternate curvatures 

 of the body. Dr. Gould has indicated two species on the coast of Massachusetts, which are 

 very probably distinct from any hitherto described. 



(EXTRA-LIMITAL.) 



C. . (Godld, Mass. Rep. p. 335.) Delicate, without any spines on any part. Color, thickly 



dotted on the back with dark green. Length, 0-5. Massachusetts. 



C. sanguinea. (Id. lb. p. 335.) Head blunt. Lower antennae ciliated, and extending to the second 

 segment, and the upper ones to the third segment : a spine on the middle of the first segment. Two 

 last segments short and heart-shaped. Color, bright crimson. Length, 1-0. Coast of Massa- 

 chusetts. 



C. equilibra. (Say, 1. c. Vol. 1, p. 391.) First and second segments of the body equal to one half of 

 the whole length. Second pair of feet placed in the middle of the body. Hand toothless : nail 

 closing without an interval. Second pair very large; the hand oblong-oval; palm rectilinear, 

 bidentate. Length, 1-0. Sjuth-Carolina. 



Fauna — Part 6*. 6 



