MARINE INVERTEBRATA OF GRAND MANAN. 43 



dark brownish color above; the back with transverse ridges at the articulations, 

 very rugose and covered with marine sordes. Below, white. Last thoracic seg- 

 ment deeply emarginate behind for the reception of the abdomen. Maxilloe very 

 strong, crossing each other toward their extremities, and curving upward beyond 

 the anterior margin of the head. Eyes minute. Antennae two on each side, 

 close together, one above the other, at the corners of the head; the inferior 

 ones being a little the longest. Legs slender, with hard curved nails at their 

 extremities. Abdominal segments well denned, the anterior one narrowest, and the 

 terminal one becoming very narrow and tapering after the juncture of the caudal 

 appendages, which are highly developed, subequal, and extending considerably 

 beyond the extremity of the caudal segment. Length, 0.2 in. ; breadth of thorax, 

 0.08 in. ; length of abdomen, 0.085 in. Dredged on a sandy bottom in ten fathoms, 

 off Cheney's Head. It is very sluggish in its motions, which are ambulatory only. 

 It is more elongated than A. maxillaris of Europe, the head and jaws not so large, 

 and the caudal appendages much larger. 



ANTIIURA BRACHIATA, St., n. s. Body very slender, subcylindrical, tapering at 

 the head, broadest at the fifth thoracic segment, and greatly constricted at the 

 articulations of the second thoracic segment, which is narrower than any of the 

 others. The first three thoracic segments are sharply convex below ; the next three 

 concave along the middle, with a deep indentation on the back of each anteriorly ; 

 the last one very short, equalling in length a little more than one-third that of the 

 penultimate one. The antenna; are very minute, about equal in length, and all 

 arising close together at the anterior extremity of the head. The first three pairs 

 of legs are placed anteriorly on their respective segments; the last four on the 

 middle. Those of the first pair are a little shorter than the others, but very thick 

 throughout their length, the large ovate hand being set by the middle of its lower 

 side on the third and fourth articles, which are only rudimentary, while the first 

 and second are greatly developed. The finger or nail of this hand is very small. 

 The legs of the second and third pairs are shorter and not so slender as those of 

 the fourth, fifth, sixth, and seventh, but all terminate in small subcheliform hands. 

 The segments of the abdomen are with difficulty distinguished above. The caudal 

 appendages (last pair of abdominal feet), are much expanded, especially the exterior 

 laminse, which curve over above so as to inclose the terminal segment in a kind of 

 trumpet-shaped cavity. The outer laminae of the first or exterior pair of natatory 

 feet are hardened, and serve as opercula to the others, while the inner laminse of 

 this pair are minute, and articulated at about half the length of the outer ones on 

 their inner surfaces. The color is a uniform light brown when the animal is clean, 

 but it is usually covered with a reddish-brown muddy slime, owing to its sluggish 

 habits. Its length is 0.69 inch, of which the proportions of the other parts are : 

 length of the abdomen, .13 ; of the longest leg, .20; of the antennae, .10 ; and the 

 greatest breadth, .125. It was dredged on a shelly and somewhat muddy bottom, 

 in twenty fathoms, off the northern point of Duck Island. 



TANAIS FILUM, St., n. s. Very minute, slender, rounded on the back, white, 

 looking very much like a short piece of thread. Head small, and rather narrowed 

 in front ; first thoracic segment of great length ; the second half as long as the third, 



