of the Fishery Board for Scotland. 114 



Sphyrion Iwnpi, T. Scott, 19th F.B. Rept., Pt. III., p. 128, vol. 

 vii., fig. 13. 



A fine specimen, the most perfect I have seen of this curious species, 

 was presented to me by Mr. Irvine of Aberdeen ; it was obtained by him 

 on one of a number of catfishes, Anarrhicas lupus, landed at Aberdeen 

 Fish Market from a Norwegian trawler. The fishes were captured in 

 about 200 fathoms, and therefore beyond the limits of the Scottish area. 

 An imperfect specimen was taken from a Lumpsucker captured in April 

 1900 in the nets of the salmon fishers near the Laboratory at Bay of 

 Nigg, Aberdeen, and is described and figured in Part III. of the 

 Nineteenth Annual Report of the Fishery Board for Scotland. 



Genus Chondracanthus, De la Roche (1811). 

 Chondracanthus depressus, sp. n. PI. vi., figs. 7-13. 



Description of the Female. — This species resembles in its general 

 appearance the Chondracanthus flurce of the Long Rough Dab, Drepanop- 

 setta platessoides, but it is more depressed. The cephalon, which is sub- 

 quadrangular, is scarcely as long as broad, the next two segments are also 

 wide and very short, while the last thoracic segment is distinctly con- 

 stricted in the middle and very depressed ; it is broader in proportion to 

 its length than the same segment in Chondracanthus flurw, being about 

 as broad as it is long. The postero-lateral processes are somewhat narrow, 

 cylindrical, and sigmoid, and curved inward so as to approach close to each 

 other, and sometimes overlap (fig. 8). The abdomen is very short. 



The specimen represented by the drawing (fig. 7) measures about 5 mm. 

 (4- of an inch), exclusive of the ovisacs, which are tolerably short and 

 thick. 



The antennules are short and very robust ; they are simple in structure ; 

 and the distal extremity, which appears to be obscurely jointed, bears 

 scattered apical spinules (fig. 9). 



The antennae are somewhat similar to those of Chondracanthus cornutus. 



The mandibles, which are stout, moderately elongated, and strongly 

 curved, taper gradually to the attenuated distal extremity ; they are each 

 armed with a row of small but moderately stout denticles along each 

 margin, as shown in the drawing (fig. 10). 



The first maxillipeds are greatly dilated at the base, and the terminal 

 joint, which is also stout, tapers to a blunted apex, the internal margin 

 is coarsely toothed on the distal half (fig. 11). 



Thoracic feet two pairs, short, stout, and bifid, or with two rudi- 

 mentary branches ; both branches are stout, but the outer is shorter and 

 scarcely so much dilated as the inner. Though the first pair are as robust 

 as the second they are scarcely so long ; the two branches in both pairs are 

 covered more or less with minute prickles, as shown in the drawings (figs. 

 12 and 13). 



Habitat. — On the gills of the Flounder, Pleuronectes flesus, captured in 

 the Firth of Forth and St. Andrews Bay. 



This form differs from any of the species previously described by the 

 very short anterior thoracic segments and by the last segment being 

 depressed and of a broadly quadriform outline, as well as by the structure 

 of the thoracic legs. 



A form which appears to be a variety of the species just described, and 

 which has also been observed on the same kind of fish, differs in being 

 rather more elongated and less depressed. The antennules are larger, 

 with a slightly different armature ; the two pairs of thoracic legs are also 

 larger and more robust, and the inner branches more distinctly triangular 



