2 20 Introduction to Animal Morphology. 



head-lobes developed, with a single tentacle and lateral 

 antennae and palpi ; eyes sessile or stalked (Pontogenia, 

 Hermione) ; gills small, simple ; epipharynx mostly with tsvo 

 upper and two lower teeth and jaws ; vascular system often 

 rudimental ; one central tentaculum and lateral antenna?, and 

 sometimes palpi. Polynoe has no prostomial tubercle ; 

 eyes 4 ; 12-35 P^i^" of elytrae. Gastrolepidia has ventral as 

 well as dorsal scales. Aphrodite, the sea-mouse, has an 

 oblong body, iridescent elytrse on the 2-4, 5-7 ^''^''*'' 23-25-28, 

 &c., segments ; eyes sessile, facial tubercle under the single 

 frontal tentacle. Iphione is oblong, with two lateral head- 

 lobes and two frontal tentacles ; noto- and neuropodia united. 

 Acoetes has two eyes, and no facial tubercle. 7. Palmyridse — 

 elytrae none : each segment covered by a fan-like group of 

 paleaceous scales ; dorsal cirri alternating with tubercles ; 

 segments many '(Bhawania), or few ; eyes i (Palmyra) or 4 

 (Paleanotus). 8. Amphinomidas — angular or flat ; segments 

 equal, not many ; head small, usually with five tentacles ; 

 toothless ; gills dorsal, comb- or tree-like ; bristles hair-like, 

 serrate, not acicular ; head-lobes often compressed ; pro- 

 stomial caruncle may be long, each segment carrying several 

 branched gills (Euphrosyne) ; the caruncle is absent, and the 

 head-lobes small in Hipponoe, or there may be round head- 

 lobes with frontal feelers, and two bipinnate gills on each 

 segment remote from the feet (Chloeia), or at the point of 

 the feet (Notopygus). The head caruncle may be heart- 

 shaped (Amphinome), or with leaf-like lateral lobes (Her- 

 modice). g. Euniceidae — rounded, long, with many meta- 

 meres, flattened ventrally, living in sand-burrows ; head- 

 lobes notched in front, with 1-5 tentacles; several separate 

 upper, and two, often united, lower jaws ; parapodia simple, 

 with acicula ; gills either beside the dorsal cirri, simple, 

 comb-shaped (Eunice, Onuphis), or spiral (Diopatria), or 

 else absent (Lumbriconereis, Lysidice), or replaced by leaf- 

 like dorsal cirri (^none, Aglaura). 10. Nereidae — body 

 long, with two anal cirri ; head flat, small, with four eyes, 

 two small middle and two large outer feelers ; peristome with 

 eight feelers ; epipharynx protrusible, with two large hori- 

 zontally movable jaws, armed with denticles ; parapodia 



