PACILOPODA. 271 



tu-o multifid feet ? on each side plarrd on an eminence ; 4, four pre- 

 hensile feet, the two lirt of which r< i tliifh and leg termi- 

 niited by various unequal and dentatcd hooks, and the others of 

 an enlarged thi^li terminated l>y a small hut stout nail. The second 

 and third segments are almost lunulated, each bearing a pair of feet 

 formed of a single joint, terminated by two kinds of toes, dentatcd at 

 the end. To thr fourth Moment is attached another pair of feet, the 

 fifth and last, but having the form of simple, oval, divergent, and 

 immoveable vesicles, which Hermann presumes are rather ovaries than 

 feet. This segment, as wrll us the next, is nearly square. The sixth 

 is much longer, and cylindrical. The seventh and last is three times 

 shorter, almost orbicular, flattened, and terminated by two small 

 .-Irs. The eyes are not distinct. 



Dichelestium sturionis, Herm., Jun. Mem. Apter. p. 125, V, 

 7, 8 ; Desmar., Consid. L, v. About seven lines long and one 

 broad. The second segment is prolonged on each side into an 

 obtuse papilla, and the four following are red in the middle, 

 with whitish-yellow along the lateral margins. When viewed 

 from above, the feet are not visible. This animal penetrates 

 deeply into the skin and places itself on the osseous arches of 

 thr branchiae, but without, as it appears, intruding upon their 

 combs. Twelve of them were taken by Hermann from a sirigle 

 fish. Of this number, two or three, perhaps males, were one 

 third shorter than the others, and had a curved body ; one of 

 the tweive lived three days. They are constantly whirling about 

 and with considerable vivacity. By means of their frontal 

 claws they are enabled to cling with great tenacity. 



NICOTHOE, Aud. and Edw. 



These animals terminate the Crustacea, and are distinguished from 

 all others of that class by their heteroclitical form. To the naked 

 eye they seem nothing more than two lobes united in the form of a 

 horse-shoe, which inclose two others. By the aid of glasses, how- 

 ever, we discover that the two large lobes are formed by the great 

 expansion of the sides of the thorax, which resemble wings, are 

 almost oval and thrown behind; that the two others are external 

 ovaries or clusters of eggs, analogous to those of a female Cyclops, 

 and inserted, one on each side, into the base of the abdomen by 

 means of a short pedicle ; and that the body of the animal is com- 

 posed of the following parts : 1 , a distinct head furnished with two 

 separate eyes ; two short, setaceous, lateral antennae formed of eleven 

 joints, each with a hair on the inner side ; a mouth forming a circular 

 aperture which acts as a cup, and accompanied on each side with 

 anterior feet maxilliform appendages : 2, a thorax of four seg- 

 ments, with five pairs of feet beneath, the two anterior of which 

 are terminated by a stout hook, and are bidentated on the inner side; 

 the remaininir rijrht being formed of one large joint, terminated by 

 two nearly equal and cylindrical stems, each composed of three joints. 

 and furnished with setae : 3, a pointed abdomen of five annulli. thr 

 first and largest of which gives origin to thr oviferous sacs ; the last 



