AMPHARETE. 65 



Recently Hessle (1917) has given a classification of the Ampharetidaa in which he has 

 used the nephridia along with the older features in all but Melinna and Isolda as aids in 

 the arrangement. Thus the groups Ampharete, Sabellides, Glyphanostomum,, Neosabellides, 

 Anobothrus, Sosane, Lysippe, Lysippides and Samytha fall under the division in which the 

 anterior nephridia (in the fourth segment) are larger than the posterior ; whilst Amphi- 

 samytha, Amphicteis, Amage and Phyllocomus are placed under the second division in which 

 the anterior nephridia are absent or smaller than the posterior. It would not appear, 

 however, that this system does much more than corroborate the former classifications of 

 Malmgren and others. It is doubtful, indeed, if this classification has any advantage 

 over that of Malmgren, founded on the presence or absence of palmulaa and the condition 

 of the tentacles and branchiae. It further has the disadvantage of requiring dissection. 

 It must be kept in mind, however, as a feature of importance. 



Genus CXXXVIII. — Ampharete, Malmgren, 1865. 



Amphitrite, Sars ; Crossostoma, Grosse ; Amphicteis, Grube & Schmarda ; Ampharete, 

 Malmgren ; Isolda, Fritz Miiller ; Branchiosabella, Claparede. 



Cephalic lobe subquadrangular, smooth, without bands ; anterior margin truncate or 

 a little arcuate ; frontal part separated by grooves as a trapezoidal or subrectangular 

 area; no median sulcus. Nuchal organs in the form of grooves. Buccal segment a little 

 shorter than the cephalic lobe. Tentacles not numerous, short, filiform ciliated. Second 

 segment short, smooth ; third segment under a transverse sulcus, bipartite ("transversely), 

 short and narrow. Rows of golden palea? more or less expanded anteriorly on each side 

 of the third segment. Branchiae subulate or filiform, forming a transverse row on each 

 side of the third and part of the fourth segment. Fourteen cylindrical setigerous 

 tubercles, commencing at the fourth segment. Rows of hooks beginning at the sixth 

 segment (third setigerous) continued to the anteanal segment. Capillary bristles with 

 curved, winged apex. Hooks subquadrangular, in two rows, multidentate, five to ten 

 long acute teeth. No abdominal cirri. Stomach with two anterior diverticula ; ventral 

 glands; two pairs of dissimilar nephridia (Fauvel). Diaphragm between the third and 

 the fourth segments. Tube composed of mud, thick, with a membranous lining. 



In the Ampharetidas J. T. Cunningham 1 (1888) found large neural canals; in 

 Melinna one on the inner side of each nerve-cord in the thoracic region. These canals 

 also occur in the anterior region of Ampharete. Cunningham supposed these canals 

 were for the support of the nerve-cords— an idea combated by Fauvel, who points out that 

 they are present only anteriorly in Ampharete, where the cords are sunk most deeply in 

 the tissues, but are absent posteriorly when the cords are near the surface. 



1 c 



Quart. Journ. Micr. Sci./ vol. xxviii, p. 274. 



178 



