90 TBEEBBLLID^). 



bristles, there is nothing distinctive in either figure or description. It differs from 

 M. elisabetlise. 



Fauvel (1909) thinks Marenzeller's form (1874) closely allied to Grube's M. palmata, 

 from which it differs by its smaller size, its coloration, and the hooks with only four 

 teeth. He found Grube's M. palmata at the Isles of Chausey near St. Malo, where 

 Grube procured his specimen, and he thus was able to compare it minutely with M. 

 adriatica. He found uncini with four teeth amongst the others with five in the thorax, 

 and so with the Neapolitan examples. 



Family XXIX. — Terebellid^, Malmgren, 1867. 



Amphitrite, 0. F. Muller, Brugui&re ; Nereis, Pallas ; Terebella, Linnaeus, Grube, 

 Cuvier, etc. ; Terebellacea, Grube, Carus, etc. 



Cephalic lobe (upper lip) more or less reduced, semicircular, usually an oval lobe 

 above the mouth. Numerous grooved and ciliated tentacles (generally devoid of blood- 

 vessels), usually collected in two fascicles and springing from the buccal segment, thus 

 approaching the Amphictenidas and the Ampharetida?. A tentacular membrane is repre- 

 sented by a thick roll behind the tentacles. The free border of the buccal segment 

 forms a lower lip. Byes simple, with cup-shaped pigment-cells and a ganglion-cell; 

 only two eye-spots on ganglion. Nuchal organs small. Body vermiform, more tumid 

 anteriorly, tapering posteriorly ; skin smooth ; glandular scutes ventrally ; anterior region 

 differing from the posterior. The buccal segment is probably the second (Hessle). Upper 

 lip best developed. Branchias in pairs on the second or following segment, ramose, 

 rarely filiform, with or without pedicles ; rarely confluent, or only one. Blood either in 

 a system of vessels or in the coelom. Anterior dissepiment between the fourth and fifth 

 segments. Anterior heart and heart-body. Anterior bristles in two rows from the 

 eleventh segment, the anterior stouter, borne on tubercles, capillary, and generally with 

 wings; usually on the anterior region, though they may go to the posterior end. 

 Anterior hooks on transverse tori or pinnules, arranged alternately and reversed, in a 

 single or double row with long chitinous threads, pectiniform or avicular. In general 

 the nephridia consist of a large funnel and a U-shaped tube ending in a nephridiopore. 

 The posterior nephridia have large funnels ending in a kidney-chamber. They inosculate 

 in Lanice and Loimia, whilst in Terebella punctata there is a long tube into which the 

 nephridia open. In Amphitrite the posterior nephridia communicate with each other. 

 Tube membranous, strengthened with mud, pebbles, sand, fragments of shells, and 

 adherent to rocks, stones, shells, etc. 



In Polymnia nebulosa (Fig. 146) the cuticle covers a highly glandular hypoderm, 

 which in the preparations presents in various parts many circular granular cells toward 

 the surface. Within the foregoing is a powerful circular muscular coat, from which the 

 oblique comes off on each side at the lower edge of the dorsal longitudinal and passes to 

 be inserted into the circular coat over the outer border of each nerve-trunk. The dorsal 

 longitudinal muscles extend on each side from the mid-dorsal line, where the raphe for 

 the mesentery of the alimentary canal separates them, to the origin of the oblique, where 



