258 Part III.— Tenth Annual Report 



ing from the base, bat the terminal claw of the same appendage in Th. 

 harpactoides is provided with only a single delicate seta. From Th. 

 mysis this species is at once distinguished by the form of the fifth feet in 

 both $ and S specimens. 



Scutilidium fasciatum (Boeck). 



1864. Porcilidium fasciatum, Boeck, ' Oversigt Gorges Copepoder,' 



p. 56. 

 1868. Aspidiscus fasciatus, Norman, 'Brit. Assoc. Keport,' p. 298. 

 1880. Scutilidium fasciatum, Brady, 'Monog. Brit. Copep.,' ii. p. 

 178, pi. lxviii. fig. 11 ; pi. lxix. figs. 1-9. 

 Habitat — In a shore-gathering from Dunbar, collected by Mr Peter 

 Jamieson, assistant naturalist. This and S. tisboides may be distin- 

 guished from most other British Copepoda by the peculiar form of the 

 first pair of feet. 



Cylindropsyllus Icevis, Brady (PL XIII. figs. 1-18.) 



1880. Cylindropsyllus Icevis, Brady, 'Monog. Brit. Copep./ vol. 



in. 



Female. — Length 1 *4 mm. Animal elongate, cylindrical, cephalo-thorax 

 five-jointed, not distinctly separated from the abdomen, which is four- 

 jointed ; the first body segment about as long as the ne :t two together ; 

 forehead produced into a sharp rostrum. Anterior antennas short, scarcely 

 longer than the first body segment, seven-jointed, the proportional length 

 of the joints as in the formula 



10 • 22 ' 9 ' 6 ■ 5 " 4 ' 8 



1 • 2 ■ 8 '4 • 5 • 6--7 



Sparingly setiferous, a long slender olfactory appendage springs from the 

 end of the fifth joint. Posterior antennas two-jointed, basal joint long 

 and moderately stout, bearing near the proximal end a very small one- 

 jointed secondary branch which is furnished with one long terminal setae ; 

 the last joint of the primary branch is armed with several spiniform hairs. 

 Three of those which spring from the extremity of the joint are long and 

 bent near the middle, where, on the outer one of the three, is a produced 

 spine-like process, which looks to be a continuation of the straight proximal 

 half of the hair. Mandibles well developed, consisting of a stout biting part 

 furnished with several small teeth, and a small one-branched palp bearing 

 three moderately long terminal hairs. There is anterior to the mandibles 

 a peculiar organ possessing at its anterior edge two subtriangular append- 

 ages which are crenate on the outer margin and measure in breadth very 

 nearly *01 mm. These subtriangular appendages resemble somewhat the 

 sucking disks on the forehead of Caligus and may function as such, 

 but this is very doubtful. Our dissection shows a slender muscle 

 extending upwards and, terminating between the two appendages where 

 it becomes dilated, and seems to connect the two. 



The maxillae (fig. 7) consist of flattened plates, ciliate on the inner 

 margin, the cilia being bounded externally by a small spine. Anterior 

 foot-jaws one-jointed, small, and furnished with one or two marginal pro- 

 cesses ; posterior foot-jaws stout, bearing a prominent, somewhat clawed 

 terminal spine, and two marginal setiferous processes. Outer branches of 

 first four pairs of swimming feet three-, inner branches two-jointed ; fifth 

 pair one-branched, foliaceous. (For description of swimming feet, caudal 

 stylets, and setae see ' British Copepoda,' iii. p. 30.) Ovisacs two, each con- 

 taining three large ova arranged as shown in the figure. The integument 



