454 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxni. 



DINEMATURA HAMILTONI (Nogaus male) Thomson. 



Dinematura hainiltoni Thomson, 1889, p. 357, pi. xxv, figs. 1 a to j. 



This species described by Thomson in 1889 incKided both sexes, and 

 their anatomy conforms so closely as to leave no doubt of their iden- 

 tity. The male also corresponds in every detail given with the t3^pe 

 here established for the genus Dinematura, and it may therefore be 

 accepted as originally published. 



NOGAUS LATREILLII Leach. 



N'ogajis lalrciUU Leach, 1819, p. 53(5. 



The male of Pandarus cranchii (see p. 405). For the form which 

 Kroyer claims to be the female of this species see page 442. 



NOGAGUS LUETKENI Norman. 



Nogagus luetkeni Norman, 1869, p. 300. 



This species was described briefly in the Shetland Final Dredging 

 Report, in 1869, by the Rev. Canon A. M. Norman, and was appar- 

 ently based upon a single specimen obtained from a skate. 



Its carapace was orbicular with large and incurved posterior lobes; 

 the genital segment enlarged, longer than broad, and without rudi- 

 mentar^r legs; abdomen two-jointed, the joints unequal; anal laminae 

 large and armed with large setae. But as absolutely nothing is said 

 with reference to the size of the creature, or to the structure of the 

 swimming legs, it is impossible to locate it definitely. 



NOGAGUS LUNATUS Steenstrup and Liitken. 



Nogagus liinatus Steenstrup and Lutken, 1861, p. 389, pi. ix, fig. 17. 



The above-named authors give the following for this species: 

 "Two specimens were taken by Captain Hygom on the same voyage 

 and in the same latitade and longitude as Eclithrogaleus coleoptratus, 

 and so probably together with them. Whether they are possibly the 

 males of that species we do not venture even a conjecture." In this 

 respect they are wiser than Claus, who, in describing his new genus 

 Luetkenia in 1864, says there is the same difference between the sexes 

 in the posterior part of the body as there is between Echthrogaleus 

 coleoptratus, Guerin and Nogagus lunatus, Steenstrup and Lutken, and 

 ventures the conjecture that these latter are the two sexes of the same 

 species. 



Two things are very evident here, first, that the host of this Nogagus 

 lunatus is not known, and it is therefore conjectural whether it came 

 from the same fish as the Echthrogaleus or from a different one. In 

 the second place there was evidently not enough agreement in the 

 anatomy of the two forms to warrant even a conjecture on the part of 

 the original describers as to their relationship. This indicates that 



