apparently new Copepods from the Clyde. 189 



The antennae are stout and ap[)arently four-jointed, and are 

 provided with several terminal setfB ; two of these setas are 

 elongate and slightly hooked, while other two terminate in 

 what appear to be rounded disks, as shown by the figure 

 (PI. XL fig. 7) ; the antenna3 do not appear to be furnished 

 with secondary branches. Tlie mandibles are elongate 

 slender appendages that terminate in hook-like extremities 

 and are furnished interiorly near the middle with two long 

 marginal setaj (PI. XI. fig. 8). The maxillee are very rudi- 

 mentary, each being little more than a short stbut tubercle 

 bearing two small hairs (PI. XI. fig. 9). The anterior foot- 

 jaws, which are also rudimentary, are short, stout, and some- 

 what triangular in outline, and are one-jointed and provided 

 with two terminal setge (PI. XI. fig. 10). The posterior foot- 

 jaws are apparently two-jointed, the first joint being compara- 

 tively large and dilated interiorly, so as to assume a gibbous 

 form and having a considerable portion of the interior surface 

 clothed with minute spines ; the second joint is very small 

 and armed with three unequal setifi, as shown by the figure 

 (PI. XI. fig. 11). So far as can be made out there aj)pear 

 to be only three pairs of thoracic feet ; the first and second 

 pairs are somewhat similar in structure; the basal joints of 

 each foot are two in number and very stout, the second of the 

 two basal joints carries two branches, which are compara- 

 tively wide apart ; the inner branches are composed of two 

 and the outer of three joints, and both are moderately slender; 

 the armature of the inner branches consists of three terminal 

 setge, the exterior one being short, while the other two are 

 elongate and plumose ; four elongate setae spring from the 

 inner margin of the outer branches, one from the second joint 

 and three from tlie last; the exterior marginal sette are 

 short (PI. XI. fig. 12). The third pair of feet are apparently 

 only one-branched, the outer branches being developed, while 

 the inner are obsolete ; these outer brandies are two-jointed 

 and articulated to the U[)per part of the distal extremity of 

 the stout second basal joints (PI. XI. fig. 13). There appear 

 to be no fourth or fifth pairs. The ovisacs form elongate 

 cylinders and appear to contain a single series of large ova. 

 Situated between and a little in front of the mandibles is a 

 large circular appendage, which from its peculiar structure is 

 probably a sucking-disk for enabling the Copepod to adhere 

 more securely to the creature that forms its host ; but whether 

 that is its only function we are unable to say. This ap- 

 pendage is represented by figure 17, Pi. X. 

 Male unknown. 



