278 Part III. — Twenty -fourth Annual Report 



Idya minor, T. Scott. 

 Laophonte curticauda, Boeck. 



„ gracilis, T. Scott. 



„ hispida, B. & R. 



,, inopinata, T. Scott. 



,, intermedia, T. Scott. 



,, littorale, T. and A. Scott. 



„ longiremis, T. Scott. 



„ thoracica, Boeck. 

 Longipedia Scotti, G. 0. Sars. 

 Nannopus palustris, G. S. Brady. 

 Parathalestris liibernica (Brady & Robertson) 

 Platychelipus littoralis, G. S. Brady. 

 Pontopolites typicus, T. Scott. 

 * Pseudothalestris major, T. and A. Scott. 

 Stephos Scotti. G. O. Sars. 

 *4 Tachidius djkipes, Giesb. 

 / ,, littoralis, Poppe. 



Zaus spinatus, Goodsir. 



Genus Pseudodiosaccus, T. Scott (1906). 



Pseudodiosaccus propinquus (T. and A. Scott). PI. xiv., figs. 19-29. 



1893. Diosaccas propinquus, T. and A. Scott. Ann. and .Mag. 

 Nat. Hist., sev. 6, vol. xii. (Oct., 1893), p. 237, pi. xi., 

 figs. 1-6. 



1906. Pseudodiosaccus propinquus, T. Scott. Ann. and Mag., 

 May, 1906, p. 465. 



This species was obtained in the Moray Firth, a few miles to the 

 northward of Kinnaird Head, where the water is very deep ; the parti- 

 cular part where this species was obtained gave a sounding of 130 

 fathoms (240 metres), the dredge line hanging free, and straight up and 

 down. As the species appears to be rare, and as the number of drawings 

 used to illustrate the description were only sufficient for its identification, 

 I propose to supplement the original description with some additional 

 remarks and drawings, especially as it has been considered necessary to 

 remove the species from the genus to which it was first ascribed. 



* Professor G. O. Sars. in Vol. V. of his great work on the Crustacea of Norway, at 

 present in course of publication, deals with what is probably the most difficult as well as 

 the most interesting group of the Copepoda, viz. : — the Harpacticoida. In this volume, 

 at p. 142, the learned author is inclined to regard Pseuclothalestris major, T. and A. Scott, 

 as identical with Westwoodia minuta, Claus. The description and figures of this form 

 given by Dr. Claus are meagre — they are not only limited and indefinite, but it is only 

 the male that he describes. On the other hand, Professor Sars' description and figures 

 of what he believes to be the female of Claus' species are full and clear, like all that 

 author's work, and they no doubt show a certain close resemblance to the female of 

 Pseudothalestris major. But there is at least one point where an important difference 

 occurs. The author describes the antennules of the female as composed of six joints, 

 whereas those of the female of Pseudothalestris major are eight-jointed, the first four 

 being moderately elongated and the other four shorter. There appears also to be some 

 difference in the structure of the posterior antennas. 



It may also be noted that the same author makes Pseudothale&tris Brady, a synonym 

 of Westwoodia, Baird, but as the small group of species that have been arranged under 

 the genus name Pseudotlmlestris are clearly distinguishable from Westwoodia by the 

 difference in the structure of the first pair of thoracic feet, I prefer to keep them separate 

 under the genus instituted by Dr. Brady. The fact that all the species belonging to the 

 group hitherto arranged together under Pseudothalestris are similarly characterised by 

 the peculiarity in the structure of the first pair of feet that distinguishes them from the 

 typical Westwoodia is, I think, a valid reason for keeping them separate from that genus. 



