78 LEODICID^ OF THE WEST INDIAN REGION. 



Genus ONUPHIS Audouin et Milne Edwards. 



Audouin et Milne Edwards, 1834, p. 151, plate Ilia, figures 1-5. 



Prostomium with seven appendages arranged in three rows, the anterior row of 

 two "frontal tentacles" or "frontal palps," short and rounded at the ends. Other 

 appendages long, carried on ringed cirrophores, a pair of eyes between the bases of the 

 outer and inner paired tentacles. The anterior parapodia produced so as to extend in 

 front of the prostomium. Apparently only a single achsetous somite bearing nuchal 

 cirri (see p. 5). Gills pectinate or simple, extending through a greater or less portion of 

 the body. Anterior setse large and hooked, other regions with slender simple and pectinate 

 forms. Maxillfe and mandibles similar to Leodice in arrangement and structure. 



The classification of the Leodicidae with seven prostomial appendages has been 

 much confused. Audouin and Milne Edwards described Onuphis as having five tentacles 

 and two antennae, while in the same paper (1834, p. 155, plate Ilia, figures 6-8) they 

 described as Diopatra a genus with nine head appendages. Since it was clear that in the 

 latter case the nuchal cirri had been included in the nine, later writers have understood 

 that Onuphis has no nuchal cirri. (Quatrefages, 18656, p. 288; Ehlers, 1864-1868, 

 p. 281, and 1887, p. 73.) It is, however, perfectly evident from figures 1 and 2g of 

 Audouin and Milne Edwards and from their description "et de chaque cote du second" 

 [somite] "on voit un petit cirri tentaculaire g," that Onuphis has these cirri, and the 

 only distinction I can find between the two genera in their description is that Onuphis 

 has pectinate and Diopatra spirally twisted gills. Quatrefages (1865a, pp. 344, 345) 

 reexamined the type and stated that Onuphis has nuchal cirri. He transferred this speci- 

 men to Diopatra, retaining Onuphis for genera without these cirri. Kinberg (1864, p. 

 559) uses the gill structure as the distinction between the genera and he lists no genus 

 without nuchal cirri. Malmgren (1867, p. 181) described Hyalinoecia without nuchal 

 cirri, with oval antennae and five tentacles. Grube (18786, p. 83) remarked on the con- 

 fusion which exists in the usage of these three genera and evidently thought that the 

 composition of the tube and the position of the eyes are of importance in determining 

 genera. He stated that in Diopatra the eyes are between the unpaired and the inner 

 paired tentacles, though he admitted that in many cases the eyes are not to be seen. 



So far as I can determine, accurate usage requires that we recognize only three 

 genera in this group: * 



Gills pectinate or simple Onuphis 



With nuchal cirri ^ ^.j,,^ ^^.^^^^^ ^^^^^ Diopatra 



Without nuchal cirri Hyalinoecia 



My collections have included only Onuphis. A comparison with Diopatra shows that 

 the general appearance is very different in the two genera, the distinction being based 

 not merely on the gill structure. Northia, used as a generic name by some writers, seems 

 not to be a valid genus. Ehlers's (1887) species of Diopatra glutinatrix, D. pourtalesii, 

 and D. fragosa are all Onuphis, while his Onuphis {Par onuphis) gracilis is an Hyalinoecia. 



Onuphis magna Andrews. 



(Plate 7, figures 1 to 5; text-figures 279 to 287.) 



Diopatra magna Andrews 1891o, p. 286, plate 14, figures 14-20. 

 Diopatra magna Andrews, 18916, p. 121, plate viii, figures 1-7. 



The animals varied much in length, a medium-sized specimen being 300 mm. long, 

 width of prostomium 4 mm. The anterior region of the body has a pearly-gray appear- 

 ance and a marked iridescence, the darkest portion being a little back from the anterior 

 end. The frontal tentacles (seen below the median in figure 2, plate 7) have a length 

 about twice their diameter and are colorless or with yellowish-brown pigment on their 

 dorsal surface. The ceratophores of the other tentacles have about ten short basal 

 rings and a much longer terminal one. The terminal joint of the tentacles is very long 



