614 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxviii. 



men a brownish yellow, considerably darker than the genital segment; 

 of the egg strings a dark brown. 



{tyjHcns, typical, that is. th(^ type of the genus.) 



The National Museum collection includes three unnumbered lots 

 collected b}" Dr. H, M. Smith from the inside of the operculum of the 

 conmion channel bass {Sc!;eitoj>>i ocelldtii-s Lannteus) in the lisli markets 

 in Washington city. 



In 1803 Kroyer pu])lished the description of some speciinens of 

 female copepods which he had obttdned from this same diannel bass 

 at New Orleans. He called the tish C(>rvlnaunlinac\ilata. in his manu- 

 script, lie states frankly that the parasites had no head and only a 

 portion of the long and slender neck. But they seemed to him so dif- 

 ferent from any of the others he had examined that he established for 

 them a new genus EcJtetus^ and a new species, tt/jjicus. From his fig- 

 ures and description there is no doubt tliat his specimens were the 

 same as those here described, especially as they were obtained from 

 the same species of tish. The names Avhich he gave have accordingly 

 been adopted, and the genus designation, which has already been 

 explained (p. Oil) seems peculiarl}^ appropriate for a creature which 

 burrows into the Hesh of its host the entire length of the carapace and 

 louii' fi"ef' segment, leavino- nothing but the genital segment and abdo- 

 men exposed. 



So tirni is the hold which the creature thus obtains that it is impos- 

 sible to remove one entire without cutting away the flesh from around 

 its neck and cara[)ace. Those which Kroyer obtained were probably 

 pulled out without cutting the flesh, with the result that the free seg- 

 ment broke somewhere near the center, to judge by the measurements 

 which he gives. For the obtaining of the head intact upon several of 

 the present specimens the author is deeply indebted to the persistent 

 and careful efl'orts of Doctor Smith. And the result fully justifies the 

 efi'orts, for the addition of the head changes entirely the s3'Stematic 

 position of the genus and its relationships. Kroyer considered that 

 the portion which he obtained indicated considerable degeneration. 

 He states that "'the large knobs on the dorsal surface are, as it were, 

 the beginning of a monstrosity of the genital parts observed in Leruce 

 hrancJnad.s and L. vydopterlna., and indicates an approximation to those 

 forms.'' And in accordance with this view he places the species in a 

 group which ho designates as Lernteocerina (Lernicidte), including the 

 most degenerate forms known. But the general arrangement of the 

 various body regions, together with the details of the carapace and the 

 appendages, show at once that it belongs to the subfamily Caliginte 

 now under consideration. It thus takes its place among the least rather 

 than the most degenerate forms. 



It is most closely related to the genus Calk/odes^ founded by Heller 

 iu 1805. On comparing it carefully with the three species alread}' 



