NO. 5 HARTMAN : POLYCHAETOUS ANNELIDS 485 



speculation as to their long historical development. The species differ 

 so abruptly among themselves that any attempt at relationship is difficult. 

 Furthermore, the known species have not only widely spaced geographic 

 distribution but great bathymetric ranges. In addition, they inhabit pre- 

 sumably all gradations of temperatures from warm tropical, to cold, 

 arctic degrees. These features suggest that the group is very old, allow- 

 ing adequate time for divergence among species and dissemination of 

 populations, with subsequent extinction in intervening areas. The dis- 

 junct distribution of some species, notably Ancistrosyllis rigida is espe- 

 cially interesting. 



Acknowledgements. — I am indebted to the Allan Hancock Founda- 

 tion for permission and facilities to examine these interesting collections. 

 Grateful acknowledgement is due the Director, Dr. Allan Hancock and 

 the Chancellor of The University of Southern California, Dr. Rufus B. 

 von KleinSmid. The illustrations are the result of the skill and patience 

 of the staff artist, Mr. Anker Petersen. 



The family Pilargiidae is here considered to include 5 genera with 17 

 (or 18) species but one of these genera (Talehsapia) is incompletely 

 known and another (Cabira) is too poorly known to identify beyond 

 family. Each of these genera is represented by species numbering only 

 1 to 8 (or 9). They are listed immediately below. Those in heavy face 

 type are represented in the collections of the Allan Hancock Foundation. 



1. Pilgaris St. Joseph, with 4 species of which one is new: 



P. verrucosa St. Joseph, P. tardigrada (Webster), P. berkeleyi 

 Monro and P. maculata, new species. 



2. Ancistrosyllis Mcintosh, with 8 (or 9) species including those in 

 which 



a. tentacular cirri are short, with 4 (or 5) species: 



A. groenlandica Mcintosh, A. cingulata (Korschelt), A. 



gracilis Hessle, A. rigida Fauvel and possibly A. albini 



Langerhans which may be identical with A. cingulata. 



b. tentacular cirri are long, with 4 species of which one is new : 

 A. constricta Southern, A. robusta Ehlers, A. tentaculata 



Tread well and A. bassi, new species. 



3. Loandalia Monro, with 3 species of which one is new: 



L. aberrans Monro, L. fauveli Berkeley and L. americana, 

 new species. 



4. Talehsapia Fauvel, with one species : T. annandalei Fauvel. 



5. Cabira Webster, with one species : C. incerta Webster. 



