MELINNA CRISTATA. 83 



cephalic lobe. Two groups of simple eyes ; imchal organs ciliated grooves. Tentacles 

 smooth, filiform. Four rather long, subulate branchiae on each side. A single large 

 curved hook on each side with two basal glands behind the branchiae on the dorsum of 

 the third segment (fourth, Hessle), three anterior bristled segments coalesced in the form 

 of a vagina, free anteriorly, fixed posteriorly, partly ensheathing the mouth and the 

 sides of the branchiae. The fourth setigerous segment (sixth of body) has dorsally a free 

 membranous edge regularly denticulated. The lateral borders of the first five segments 

 elevated (Hessle). Eighteen fascicles of bristles commencing on the fifth segment, the 

 three anterior sunk in the tissues, the following fifteen having subcylindrical setigerous 

 processes. Bristles with slightly curved and winged tips. Feet with rudimentary cirri. 

 The second, third, fifth and sixth segments have simple bristles ventrally. The anterior 

 feet have dorsally no cirri, whereas the posterior have rudimentary cirri. Uncinigerous 

 processes commence on the seventh segment and continue to the posterior end. Hooks 

 sub triangular with few teeth (four) and in a single row. Minute subcorneal papillae 

 bearing capillary bristles above the uncinigerous pinnae posteriorly. 



Stomach without a diverticulum. Four pairs of long, tubular nephridia in segments 

 5 — 8. Diaphragm between the third and fourth segments with muscular sacs, Ventral 

 glands. Branchial vessels arise from the heart by two ramified branches. Tube composed 

 of mud lined by tough secretion. 



1. Melinna oristata, Sars, 1851. Plate OXVIII, fig. 9— body ; Plate OXXV, figs. 1— 



1 c — bristle and hooks. 



Specific Characters. — Head a short, bluntly rounded process, but in extrusion of the 

 tentacles a flattened lamella. An eye-speck on each side. Body long (50 mm., Hessle), 

 somewhat clavate, tapering to the slender tail with a terminal anus, which has two lateral 

 flaps and a few short papillae. Branchiae four on each side, arising from a basal process 

 on the third segment, and each process gives rise to an anterior and a posterior pair. 

 Dorsal collar with regular conical processes on its edge — ten to twenty in number. A 

 single large curved hook on each side behind the branchiae, with a broad base and a 

 terminal canal. Eighteen setigerous processes anteriorly, the first three less developed. 

 Bristles with striated shafts and slightly curved and winged tips, and in a longer and a 

 shorter series. They commence on the fifth segment (Hessle). Hooks appear on the 

 fourth bristled segment, have a rounded crown, four teeth on the anterior edge, increasing 

 in size from the first to the fourth. From fifty to fifty-five lamellae for the hooks in the 

 posterior region. Nephridia in the fifth, sixth, seventh and eighth segments. Tube of 

 secretion coated with mud, cylindrical, and three times longer than the animal. 



Synonyms. 



1851. Sabellides cristata, Sars. Nyt Mag., vi, pp. 132 and 206. 



idem. Fauna Lit. Norweg., vol. ii, p. 19, Tab. ii, figs. 1 — 7. 

 Danielssen. Nyt Mag., xi, p. 55. 

 Sars. Forhandl. Yidensk.-selsk. Christ., p. 57. 

 Malmgren. Nord. Hafs.-Annul., p. 371, Tab. xx, fig. 50. 

 De Quatrefages. Annel., ii, p. 377. 



J.OOU. 



a 



a 



1861. 



a 



,, 



1864. 



a 



a 



1865. 



Melinna 



a 



a 



Phenacia 



a 



