NO. 2286. THE NEW COPEPOD FAMILY SPHYRIIDAE— WILSON. 587 



the part behind it by a narrow constriction forming a sort of neck. 

 This head carries five nonarticulate, fleshy projections, arranged in 

 pairs with a single, unpaired one in tlie center. The anterior pair 

 are a little smaller and closer together, while the posterior pair are 

 larger and farther apart; the mouth is just behind the central, un- 

 paired projection. The rest of the cylinder is of the same diameter 

 as the head and without appendages. 



Behind this cylinder is the neck, 0.20 mm. in diameter, and join- 

 ing both the cylinder and the trunk abruptly. Just behind the 

 cylinder the neck is armed with four short, bluntly rounded processes, 

 extending out at right angles to the neck axis like four diagonals of 

 a square. 



The trunk is rectangular, a little longer than wide, with rounded 

 corners, and flattened dorsoventrally. The skin covering it is smooth, 

 chitirious, and rather thick, showing plainl}^ the attaclunent of the 

 four bundles of dorsoventral muscles, two anterior and two poster- 

 ior. From the center of the posterior margin of the trunk projects 

 the spherical abdomen, and on either side of this is a smaller genital 

 process, out of which opens the oviduct. To the abdomen are at- 

 tached the posterior processes, each composed of a central filiform 

 shaft, carrying, at short intervals, the respiratory cylinders, of 

 which the anterior two or three are shorter than the rest. There are 

 16 to 18 of these cylinders on each process, and they are all of the 

 same diameter, which is a little greater than that of the neck, and 

 have bluntly rounded ends, which are neither swollen nor divided. 



Color whitish, tending to yellow; darker on the neck and trunk. 



Total length, including the posterior processes, 29 mm. Cephalo- 



thorax, 4 mm. long, 1 mm. wide. Neck, 6 imn. long, 0.20 mm. wide. 



Trunk, 9 mm. long, 8 mm. wide. Posterior appendages, 10 m. long. 



(edwardsii, to H. Milne Edwards.) 



Remarks. — While Cornalia's description is in the main correct, 

 there are one or two points that require notice. Neither Cornalia 

 nor Claus, who had added ^ some important observations with 

 reference to ^'' Lop hour a,''^ knew how to interpret the four processes 

 on the neck. Claus even went so far as to say that they were nothing 

 but the chitinized ends of the ventral nmscle strands, which stood 

 out at this point as small ridges in consequence of an injur3'. 

 Cornalia criticized this interpretation, but offered nothing in its 

 place. 



In Cornalia's specimens the muscle fibers in the center of the 

 dorsoventral bundles in the trunk are strongly contracted, while 

 those around the margin of the bundles remain relaxed. This drew 

 in the body wall at the center of the bundle and formed a " deep 



^Wurzburger naturwlss. Zeltsch., vol. 1, 1860, p. 20. 



