408 ONUPHIS BREVIBKACHIATA. 



their places being taken by two powerful yellowish hooks with bifid, winged tips. The 

 brush-shaped bristles offer no peculiarity;, 



Synonyms. 



1875. Diopatra brevibrachiata, Elilers. Zeitschr. f. wiss. Zool., Bd. xxv, pp. 21 and 49, Taf. hi, figs. 



11—21. 

 1903. Onuphis {Diopatra) brevibrachiata, Mcintosh. Ann. Nat. Hist., ser. 7, vol. xii, p. 133, pi. x, 



figs. 5 — 10. 



Habitat, — Dredged in the ' Porcupine' Expedition of 1869 at Station 36, 21st June, 

 48° 50' N., 11° 7' W., and therefore in the British area, at a depth of 725 fathoms on a 

 bottom of sandy mud. 



Also procured in the ' Porcupine ' Expedition of 1 870, probably between Stations 46 

 and 47, in 358 fathoms, and east of Cape cle Gatte, six miles from shore, in 60 to 160 

 fathoms, and west of the Strait of Gibraltar, on a bottom of fine grey mud, and in water 

 varying from 286 to 322 fathoms in depth. 



Head (Plate LXIII, figs. 10 and 10 a [after Ehlers] ) with two frontal tentacles 

 (Stummelfiihler) arising close together in the median line, and forming two rounded and 

 somewhat flattened lamella in spirit. The five tentacles have the normal position, but they 

 are short — much shorter than in Diopatra neapolitana — though they also have an enlarged, 

 ringed cirrophore. The tentacular cirri arise from the anterior border of the first 

 segment, are wide apart, and have a slightly fusiform outline due to a constriction at the 

 base. The palpi form two flattened bosses on the ventral surface. 



Body somewhat resembling that in Hyalinoecia, but readily distinguished by the 

 presence of the tentacular cirri and the condition of the branchiae, which lean to the type 

 seen in Eunice, The length is uncertain, as no complete example occurs. Ehlers gives 

 24 mm. and forty-four segments, with a breadth 3-4 mm. The first segment of the body 

 is about the breadth of the succeeding. The dental apparatus (Plate LXIII, fig. 8) is 

 pale, a dark brown touch occurring at the tip of the posterior appendages of the maxillae, 

 whilst at the junction of the several parts is a triradiate band. The tips of the maxillae 

 and the teeth of the great dental plates are slightly brownish. The maxillae are strongly 

 curved, sharp-pointed, and rather abruptly swollen a little behind the middle. The 

 posterior appendages are half-spoon-shaped, with a constriction at the base. Each of the 

 great dental plates has about ten teeth, and the azygos plate the same number. The 

 right anterior curved plate has five ; the left appears to have a larger number, but is 

 broken. The mandibles (Plate LXIII, fig. 8 a) have an oblique smooth edge anteriorly, 

 and at the junction of this with the shaft, externally, is a projection. 



The branchiae commence on the twelfth foot as simple filaments attached to the 

 dorsal cirrus a little above its base. As far as the sixteenth foot they remain simple, long 

 filaments. The seventeenth foot has a branched branchial process, and at the twentieth 

 it has a single stalk above the cirrus, and the terminal part is clichotomously divided — a 

 feature of the species. At the thirtieth foot three divisions occur above the cirrus, which 

 they considerably exceed in length, and then the tip is clichotomously divided into two 

 still longer processes. The specimen terminated at the thirty-fifth foot, and on this, so 

 far as could be seen in the injured preparation, the number of gill-filaments was not less. 



