ONUPHIS QUADEICUSPIS. 413 



at an angle and winged, as well as finely tapered (Plate LXXXIV, fig. 5 6). Brush-shaped 

 bristles occur amongst them. A single bifid hook (Plate LXXXIV, fig. 5 c) is present. 



A trace of a branchial process appears in some on the eleventh foot, but as a rule 

 only on the twelfth foot. It is continued backward, as in the former species, almost to 

 the tip of the tail. It is a simple process throughout; only occasionally is an accessory 

 filament found on it. On the whole it is a considerably smaller process than in Onuphis 

 britannica. The dorsal cirrus diminishes from before backward. 



The tube (Plate LXIII, fig. 9) generally consists of coarse gravel and minute stones 

 fixed to a lining of the secretion. More rarely it is formed of fragments of shells and 

 stones. Dr. Johnston found the glairy secretion so tenacious that the threads could be 

 drawn out a foot without breaking. 



Several forms, though differing in certain features, approach this species, such as 

 Onuphis abranchiata, 0. pycnobranchiata, and 0. macrobranohiata of the ' Challenger.' 



Hansen (1879) gave a description of this form as a new species in the account of 

 the Annelids of the Norwegian North Atlantic Expedition in 1876, and mentioned it sub- 

 sequently in the next year's Expedition. His figures are somewhat indefinite in detail, 

 but, like the description, give no new feature. 



Horst's figure 1 of the jaws of the species is good, though his example has asymmetrical 

 posterior processes to the maxillse. 



Ehlers (1887), in his ' Florida Anneliden,' adopts (Ersted's title under the genus 

 Diopatra as D. Eschrlchtii, yet admits that it is identical with the unpins coiichylega of 

 Sars. 



Hornel (1891) mentions this species as common off the Liverpool bar, but whether 

 his form pertains to 0. britannica or 0. coiichylega is uncertain, though in all probability it 

 is the former. 



The Nothvia opalina of Verrill 2 is probably a closely allied form, if not one of the 

 foregoing species. 



4. Onuphis quadricuspis, M. Sars, 1871. Plate LXIV, figs. 2 and 2a — teeth; Plate 



LXXV, fig. 8— foot. 



Specific Characters. — Read nearly typical, but the median is considerably shorter and 

 somewhat more slender than the adjoining tentacles. Frontal processes (antennas, Sars ; 

 palpi, Ehlers) ovate, small. No eyes. Tentacular cirri two, at the anterior border of the 

 buccal segment. Body elongate, minute, pale bluish iridescent, with two adjacent 

 brownish bands in the mid-dorsal region. Segments about 150 (Sars), flattened, with the 

 exception of the first five. It is little tapered anteriorly, but more distinctly so posteriorly, 

 where, it ends in four cirri — two longer dorsal and two shorter ventral. Branchige begin as 

 simple processes on the ninth foot, by-ancl-by become bifid, then in three to five divisions 

 or pectinate, and finally in the posterior part of the body again simple (Sars). Proboscis 

 with the maxillge much curved with a marked constriction behind the point of junction, 



1 'Niederl. Arch. Zool./ Suppl. Bd. i, 1881. 



3 « Proc. Amer. Assoc. Sc./ 1873, p. 381, pi. 4, f. 4, 1874. 



