110 BRITISH COPEPODA. 



to the youngest stages of growth. . . . Many- 

 species may, no doubt, have been founded on characters 

 no more distinct than these, and on mere deviation 

 of character in the joints, which a critical investigation 

 would prove to be worthless."* It maybe noted that 

 many of the peculiarities here pointed out by Dr. Glaus 

 especially the strong, doubly-curved claws of the 

 first feet in the stronger, and the very slender simply- 

 curved claws in the weaker form have their exact 

 counterparts in the two varieties of D. tisboides here 

 described. 



2. DACTYLOPUS SIMILIS, Glaus. PL LY, figs. 14 16. 



Dactylopus similis, Glaus. Die Copepoden-Fauna von Nizza, 

 p. 25, taf. ii, figs. 29, 30 (1866). 



This species differs little from D. Stromii except in 

 the proportionate lengths of the various antennal 

 joints, the length of the rostrum, and some other 

 minor points. The rostrum is very long and curved, 

 and the relative lengths of the joints of the anterior 

 antenna (fig. 14) may be expressed (allowing some 

 latitude for individual variation) as follows : 



1, 2, 3, 4, 5, 6, 7, 8. 



20 12 883527 



The lower foot- jaw, the first and all the following 

 pairs of feet differ scarcely at all from the same organs 



* Die Copepoden-Fauna von Nizza, Ein Beitrag zur Charakteristik 

 der Formen und deren Abanderungen, " im Sinne Darwin's," von Dr. 

 C. Glaus, Marburg und Leipzig, 1866. 



