44 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 10 



complete posteriorly. Autotomy is frequent, and regeneration of lost 

 parts, including tail and anterior ends with parapodial parts, not un- 

 usual; abnormal structures such as bifurcated dorsal and ventral cirri 

 are occasionally observed, indicating a notable potentiality for replace- 

 ment of lost parts. Many species have been described with accent only 

 on macroscopic parts, such that their uniqueness is indeterminable; con- 

 sequently much confusion exists in the literature. 



Eight genera are usually recognized in the family Onuphidae. These 

 are: 



1. Diopatra Audouin and Edwards, p. 49. 



2. E pidio pair a Augtntr (1918), p. 45. 



3. Hyalinoecia Malmgren, p. 46. 



4. Leptoecia Chamberlin (1919), p. 45. 



5. Nothria Malmgren, p. 83. 



6. Onuphis Audouin and Edwards, p. 66. 



7. Paranorthia Moore (1903), p. 45. 



8. Rhamphobrachiutn Ehlers, p. 47. 



Key TO Genera of Onuphidae 



1. Peristomium with tentacular cirri 2 



1. Peristomium without tentacular cirri 6 



2. Branchiae spiraled in part Diopatra, p. 49 



2. Branchiae absent, cirriform, simply branched or pectiniform 3 



3. First 2 or 3 parapodia greatly enlarged, prolonged forward. . 4 



3. First few parapodia only slightly enlarged, if at all ... . 5 



4. These enlarged parapodia provided with numerous, slender, 

 recurved hooks capable of being projected far forward . . . 

 Rhamphobrachiurn, p. 47 



4. These enlarged pai'apodia provided with coarser hooks, resem- 

 bling those in Onuphis Paranorthia Moore 



5. Branchiae unbranched, if present .... Nothria, p. 83 



5. Branchiae branched on some segments . . . Onuphis, p. 66 



6. Branchiae spiraled on some segments . Epidiopatra Augener 



6. Branchiae not spiraled, if present 7 



7. Without branchiae Leptoecia Chamberlin 



7. With cirriform branchiae Hyalinoecia, p. 46 



It should be noted that Nothria and Onuphis are frequently united, 

 since their separation (branchiae simple filaments, or more or less 

 branched) is based on an artificial character; their separation is here 

 maintained for convenience. Similarly, Leptoecia and Hyalinoecia might 

 be regarded congenerically. 



