NEREIDIFORMIA. 



477 



short, with only "a few segments; prestomium with 4 eyes, 2 or 3 tentacles, 



and generally with jointed palps ; peristomium and 2 or 3 following segments 

 achaetous, with long tentacular cirri. Parapodium usually uniramous, or, if 



biramous, notopodium small, dorsal cirri long and multi-articulate. Eversible 



region short, pharynx long, unarmed ; two diverticula behind pharynx often 



containing air (air-bladders*). 

 Anal segment with two cirri, 

 and often with reduced para- 

 podia. Hesione Sav. (Fig. 

 385) ; H. sicula, D. Ch., 

 Med. ; Psamathe Johnst. : 

 Tyrrhena Clp. ; Telamonc 

 Clp. ; Stephania Clp. (Ophio- 

 FIG. 385. Hesionc splendida Sav. (Regne Animal). dromus Sars) ; Dalhousia 



M'Int. ; Salvatoria M'Int. ; 



Magalia Mar. and Bob.; Oxydromus Gr. ; Kefersteinia Qtf. 



Fam. 4. Aphroditidae. With broad scales (elytra, i.e., flattened dorsal 



cirri) on the notopodia ; these are usually placed on alternate segments, often 



only on the anterior part of the 



body. Prestomium with eyes, with 



one unpaired and usually two lateral 



tentacles, to which may be added 



two palps. Facial tubercle in front 



of month. Pharynx thick-walled, 



with two upper and two lower jaws. 



The intestine is provided with a 



number of paired caeca. Very com- 

 monly as epiparasites on other 



animals, e.g. , Malmgrcnia castanea 



M'Int, in the mouth of Spatangus 



purpureus ; Hermadion, assimile 



M'Int., round the peristome of 



Echinus esculcntus, Halosydna 



Bairdi between the mantle and foot 



of Fissurella cratitia ; Acholoe asteri- 



cola Clp. in the amubulacra of Astro- 



pccten, Polynoe cirrata in those of 



Spatangus spinosissimus, Hermadion 



echini in those of Echinus sphaera ; 



Evarne pentactes Giard on the body 



of Cucumaria pentactes ; or as com- 

 mensals with other Annelids, e.g., 



Lagisca extcnuata in the tube of 



Scrpula vermiciilaris, Harmothoe 



maclcodi in the tube of Tcrebella 



conchilega, Polynoc scolopendrina in 



the tubes of Terebellids, Harmothoe 



Malmgrcni, and Nychia cirrosa in 



the tubes of Chaetopterus insignis 



(Ivar iopcdatus). 



* H. Eisig, Hit. a. d. Zool. Stat. Neapel, 2, p. 255. 



Fia. 386. Aphrodite aculeata Baster (Regne 

 Animal). 



