86 BEITISH PARASITIC COPKPODA. 



rami of the first and fourth pairs composed of two 

 joints, and those of the second and third pairs of 

 three joints ; the rami of the first three pairs are 

 furnished with tolerably long plumose setae while those 

 of the fourth pair are armed with spines. 

 The only British species is that described below. 



1. Dinemoura producta (0. F. Miiller). 



(Plate XXII, fig. 3 ; Plate XXVI, figs. 1-3 ; Plate 

 XXVII, figs. 1-8.) 



1785. Caligus productus O. F. Miiller. (86) p. 132, pi. 21, fig. 3. 



1829. Dinemoura producta Latr. (38) Cuv. Regne Anim., vol. iv, p. 127. 



1835. Pandarus lamnx Johnston. (65) p. 203. 



1850. Dinemoura lamnse Baird. (4) p. 286, pi. xxxiii. fig. 7. 



1853. Nogagus productus Gerst. (48) Wiegmann's Archiv fur Natur- 

 gescli., vol. xix, p. 63, pi. iv, figs. 1-10. 



1857. Dinematura elongata P. J. van Beneden. (14a) Bull. Acad. 

 Roy. Belg., p. 231, pi. xxiv. 



1861. Dinematura producta Stp. & Liitk. (127) p. 34, pi. vii, fig. 13. 



1900. Dinematura producta T. Scott. (112) p. 156, pi. vi, figs. 27-31. 



1907. Dinematura producta C. B. Wilson. (148) p. 380, pi. xxiii. 



Female. Carapace suborbicular and equal to about 

 a third of the entire length of the animal ; width 

 slightly exceeding the length ; lateral margins boldly 

 rounded ; frontal plates narrow ; eyes small, but quite 

 distinct, not quite close together and distant from the 

 front margin about a tenth part of the total length. 

 The first free thoracic segment furnished with small 

 lateral plates which inclose the next segment between 

 them, these two segments together filling the entire 

 space between the produced postero-lateral lobes of 

 the carapace. The third segment of the thorax carry- 

 ing a dorsal plate which is equal to about one-sixth of 

 the entire length of the animal and is as wide as the 

 genital segment the anterior part of which it overlaps ; 

 the antero-lateral corners of the plate subangular, 

 and also divided from behind forward into two lobes 

 by a narrow median fissure which extends to near its 

 base, each lobe being boldly rounded at the posterior 

 end. Genital segment oblong, considerably longer 



