130 Part III. — Twenty-first Annual Report 



moderately rare species, but it has so much the appearance of a 

 Scutellidium or a Zaus that it may have been frequently overlooked. 

 Thalestris rufocincta, Norm., and Thalestris clausii, Norm., were taken 

 in the same gathering with T. peltata. 



Genus Westwoodia, Dana (1855). 



Westwoodia nobilis, Baird. 



1845. Arpacticus nobilis, Baird, Trans. Barw. Nat. Club, vol. ii., 



p. 155. 

 1880. Westiooodia nobilis, Brady, British Copepoda, vol, ii., 



p. 141, pi. lxiii., figs. 1-13. 



This prettily-coloured Harpactid was observed in the same gathering 

 with the Thalestris just mentioned. It seems to be a littoral form, and 

 its habitat here agrees with what is stated by Prof. G. S. Brady and Kev. 

 A. M. Norman, but it has also been obtained in water of moderate depth, 

 as off Portincross, Pirth of Clyde, where it occurred at depths ranging 

 from ten to thirty fathoms.* 



LlCHOMOLGID^E. 



Genus Paranthessius } T. Scott, gen. nov. 



Antennules short and seven-jointed. Antennae four-jointed, armed with 

 a stout terminal claw. Mandibles and m axillae somewhat like those of 

 Lichomolgus fucicolus. Anterior maxillipeds small, furnished with 

 strongly curved and elongated terminal claws. The first three pairs of 

 thoracic feet are similar to those of Lichomolgus, but in the fourth pair the 

 inner branches appear to be entirely wanting. Fifth pair rudimentary or 

 very small. 



Paranthessius dubius, T. Scott, sp. nov. PI. vi., figs. 16-24. 



A single male specimen of a somewhat curious Lichomolgus-like 

 copepod was obtained in some dredged material sent from the Clyde, and 

 collected on June 13, 1899. It has been left unrecorded hitherto in 

 expectation that other specimens, especially females, might be found, and 

 a more exact knowledge obtained of its structure and affinities. It differs 

 in several particulars from any described genus or species at present known 

 to me, and I therefore submit the following description of it under the 

 name of Paranthessius dubius. 



The male in its general outline somewhat resembles Pseudopsyllus 

 elongatus, a copepod described in my paper in Part III. of the Twentieth 

 Annual Eeport. The body is elongated and narrow ; the cephalo-thorax 

 is composed of five segments, the first is rather broader than the others 

 and is considerably longer than the combined lengths of the remaining 

 four segments ; these four segments, which are sub-equal in length, 

 become gradually narrower, so that the last is narrower than the first 

 segment of the abdomen. The first abdominal segment is considerably 

 dilated, but the remaining segments are short and narrow ; the furcal 

 plates, which are moderately broad, are about as long as the last two segments 

 of the abdomen (fig. 16). The length of the specimen is fully 2 mm. 

 (about J-g- of an inch). 



The antennules (fig. 17) are short and moderately stout and composed 

 of seven joints, the second joint is the largest, the third and fourth are 



* British Copepoda, vol. ii., p. 142 (1880). 



