656 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 47. 



as siirely dorsal. The discovery of this species in the nostrils of the 

 barndoor skate upon our own coast makes it necessary to include it 

 in the North American fauna. 



CHAROPINUS BICAUDATUS (Kr^yer). 

 Plate 41, figs. 114 to 118; plate 42, figs. 119 and 120. 

 Lernaeopoda bicaudata Kr0yer, 1837, p. 275, pi. 3, fig. 11. 

 Brachiella pastinacae P.J. van Beneden, 1851, p. 118, pi. 4, figs. 8, 9.— Kurz, 1877, p. 



389, pi. 25, figs. 2, 3. 

 Brachiella pastinaca Bainbridge, 1909, p. 50, pi. 8, figs. 6, 7; pi. 9, fig. 8. — T. and A. 

 Scott, 1913, p. 211, pi. 64, fig. 8. 



Host and record of si)edmens. — Eight females with Qgg strings were 

 obtained from the spiracles of the common dogfish, Squalus acantJiias, 

 by Dr. F. D. Lambert at South Harpswell, Maine, July, 1912. They 

 have received Cat. No. 43536, U.S.N.M. 



Specific cTiaracters of female. — Cephalothorax short and wide, and 

 inclined at an angle of 45° to the trunk axis; a narrow dorsal cara- 

 pace divided longitudinally through the center, the two halves 

 resembhng closely the elytra of beetles, and diagonally truncated 

 anteriorly; trunk somewhat pear-shaped, narrowed into a long and 

 slender neck anteriorly, swollen into a sphere posteriorly, and flat- 

 tened dorso-ventrally; posterior processes cylindrical, plump, dorsal 

 to the egg strings and haK the length of the latter, and inclined back- 

 ward; egg strings stout, cylindrical, and about the same length as 

 the trunk; eggs in 8 longitudinal rows, about 18 eggs in the longest 

 row. 



First antennae two-jointed, the basal joint considerably swollen 

 and armed on the anterior margin with a long and stout spine, the 

 terminal joint narrower and tipped with two oKactory cylinders and 

 a small spine ; second antennae biramose, both rami unsegmented, 

 the endopod considerably larger than the exopod, and both of them 

 covered with small spines and bristles. Mandibles long and narrow, 

 with four large principal teeth, two smaller secondary teeth, and two 

 intermediary teeth. First maxiUae tripartite, the outer ramus 

 smaller than the other two, palp large and tipped wdth two setae. 

 Second maxiUae slender and cylindrical, two-fifths as long as the 

 trimk and enlarged at the tip into a crescent or semicncle, at right 

 angles to the axis of the maxilla. Maxillipeds \vith a stout basal 

 joint, armed on the inner margin with two knobs covered with 

 spines and a large solitary jomted spine; terminal claw slender, with 

 an accessory claw at the tip on the inner margin. 



Color (preserved material), a uniform yellowish white. 



Cephalothorax, 2.20 mm. long, 1.25 mm. wide. Trunk, 3.75 mm. 

 long, 2 mm. wide, 1.60 mm. thick. Egg strings, 2.75 mm. long. 

 Posterior processes, 1.10 mm. long. 



{bicaudatus, his, two, and caudatus, tailed, alluding to the pair of 

 small posterior processes, looking hke two tails.) 



