2 PKOCEEDINGS OF THE NATIONAL MUSEUM vol.77 



which terminates in an anchorlike head of four teeth; by means of 

 these teeth, which are sunk into the body of the host, the animal 

 is fastened to the latter. On the body are various lines of thick- 

 ened chitin, but whether or not these have anything to do with 

 the original segmentation can not be determined. The two known 

 species of this genus are parasitic on Alpheidae [Crangonidae] and 

 Hippolytidae. 



The systematic position of the genus Faba is somewhat doubtful. 

 The embryos of F. glabra certainly are those of copepods; and no 

 doubt Fdba belongs to the Epicaridea. Absolute certainty must, 

 however, wait until the development of the male is known. Accept- 

 ing Faha for the present as an Epicarid, there can be little doubt that 

 this " simple sac filled with eggs " (Richardson, p. 497) belongs to 

 the Tribe Cryptoniscinae. But great difficulties arise in assigning 

 it to any particular family. The greater part of the families sug- 

 gested by Bonnier contain often very few species, sometimes only 

 one species, and these are not always thoroughly known. Hence a 

 clear analysis of the families is often lacking. In one respect, how- 

 even. Bonnier was very positive ; each family is related to a different 

 group of hosts. 



Faba has very few characters; they are of no value in placing it 

 in any of the families now known. Nor can this problem be solved 

 by means of the host, for no family of the Cryptoniscinae is known 

 to prey directly upon decapods, although some forms of Danalia 

 (Liriopsidae) are often found associated with the former. But in 

 these cases a rhizocephalid is the true host, the Danalia perforating 

 the body-wall of the decapod in order to attach itself to the " root " 

 of the rhizocephalid, though this is not always the case. It seems 

 that some of these forms have ultimately become parasites of dec- 

 apods. It is possible that Fal)a represents such a case, and it is 

 true that the mode of attachment of the latter bears a striking re- 

 semblance to Danalia. As we have no other reason to suppose that 

 Faha is, or has been, a parasite of Rhizocephala, we do not feel 

 justified in regarding it as such. Nor do we set enough value upon 

 the resemblance of the trunk of both forms to regard Danalia and 

 Faba as allied. Only the study of the evolution of the female will 

 enable us to decide the correct systematic position of Faba. 



FABA SETOSA, new species 



Holotype. — Cat. No. 62732, U.S.N.M. One female on Spirontocaris 

 hispinosa Holmes. 



Type locality. — Albatross Station 3170, off Central California, 38° 

 17' N. ; 123° 29' W. ; March 28, 1890 ; 167 fathoms, mud bottom. 



Description. — Length, 8 mm. The body, especially the ventral 

 side, is sparsely set with long setae. They are irregularly scattered. 



