126 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.53. 



the interspaces between the second and third and the third and fourth 

 pairs are comparatively large and siibequal. 



Color. — Head and horns light brown, trunk dark olive brown, the 

 grooves between the ribs lighter in color; egg strings gray white; 

 plumose appendages a deep black. 



Total length, exclusive of %gg strings, IGO to 180 mm. 



{orthagorisci^ the former generic name of the host.) 



Remarks. — This species differs from instructa, just described, in 

 the following particulars: The head in the present species is alwa3''s 

 wider than long, while in instructa it is always longer than wide; 

 the horns are usually three and are chitinous, while in iristructa there 

 are never but two, which are soft in texture; the trunk is compara- 

 tively three times the length and twice the diameter of that in 

 instructa; the first antennae are so close to the second pair that their 

 bases touch, while in instructa they are far removed ; Wright repre- 

 sents the second antennae as definitely three- jointed and slender, 

 while in inst^ructa they have but two joints and are fully as wide 

 as long. 



Genus PEGESIMALLUS Kr^yer. 



PegeshnaUiis KR0yEB, Bidrag til Kundskab om Suyltekiebsene, 1863, p. 332, 

 pi. 18, fig. 7. 



Generic characters of female. — Body made up of five distinct 

 parts : First, an elongate-ovate head, destitute of antennae and mouth 

 parts, but with a small proboscis; second, a short and slender neck; 

 third, a thicker posterior neck covered with excrescences resembling 

 bunches of grapes; fourth, a vermiform anterior trunk, transversely 

 ridged, with a ventral row of soft processes along either side of the 

 midline; fifth, a posterior trunk, in three coils, and covered with 

 villous processes. 



Remarks. — The above is adapted from Kr0yer's generic diagnosis 

 and gives the principal characters of this parasite. He had but a 

 single specimen which was found amongst some Greenland crabs that 

 were sent to him. 



There is nothing in the description or in the figures to show that 

 this is a copepod and not a worm, as there were no egg strings. 



It may be a copepod not fully developed and covered with Gymna- 

 blastic Hydroids like those described by Jungersen.^ But we must 

 have many more details of its structure before we can decide where 

 to place it; meanwhile it may be left here among the Lernaeans 

 where Kr0yer located it, with the understanding that its presence 

 is very questionable. 



1 Vidensk. Meddel. fra natnrh. Foren., vol. G4, 1911, p. 21. 



