Polystomidae. — Aphanostomidae. 139' 



A. Tribus Acoela Ulj. 



Tiibus intestinalis nullus , substantia medullaiis digestionem performansy 

 systema nervosum nulluni, organa excretoria nulla; orgaua genitalia hermaplirodita, 

 testiculorum folliculi parenchymate inclusi, ovaria paria; pharynx plerumque nullus: 

 otolithus singulus. 



1. Fam. PEOPOKIDAE v. Gkaff. Orificium genitale unicum, bursa semi- 

 nalis 1$) nulhi, penis mollis. 



Proporus (0. Schm.) Gkaff. {Schizoprora 0. Schm. p., Ul.i., Otocdis Celidoti» 

 DiES. p.). PharijHX mdJus; os tcrmimdc ante otoJithnm, occJJi dno; corpus aiifjustHin, 

 tercs, utraqnc cxtrcmitate oT)tuse rotuiidcda. 



m 1. Pr. rubropunctatus 0. Schm. (OtoccJis ruhropunctcda Dies.). Corpus 

 long. 1,5 mni, niedio crassius, tiavido-album ; cutis acervulis bacillorum pyrifor- 

 mibus et bacillis singulis acuminatis munita; ocelli coccinei, otolitlius gibbus; ori- 

 licium genitale trilaterale ventrale. 



Habit. : Xapoli (Gkaff); Adria: Trieste (Graff), Lesiua (0. Schmidt). 



2. Pr. venenosus v. Gkaff. {Scliizoprora vcncnosa 0. Schm., Cclidotis vcncnosa 

 DiES.). Corpus gracile angustum, long. 1 mm, aeque latum, viridi-flavum ; cutis 

 bacillis in utraque extremitate acuminatis, acervulis pyriformibus talium et corpus- 

 culis lageniformibus granulatis munita; os paullum post extremitatem anteriorum, 

 ventrale; ocelli magni nigri; otolithus magnus gibbus, radiatim striatus; orilicium 

 genitale in extremitate posteriore corporis. — Var. : Fr. vcncnosus violaccus Graff. 



D i s t r i b. : Pontus Euxinus. 



Habit. : Napoli, Messina (v. Graff); Adria: Trieste (Gkaff), Lesina 

 (0. Schmidt). 



2. Fani. APHANOSTOMIDAE v. Graff. Orilicia genitalia duo, femineum 

 ante masculum ; bursa seminalis ; penis mollis. 



Aphanostoma Oerst. {Proporus 0. Schm. p.). PJuiri/nx nulJus; os anticum 

 antc otoJifhum, ocelJi nuJJi ; hursa alisque partiJjus duris; corpus teres aut paulJo depressum. 



1. A. diversicolor Oekst. Corpus long. 1,13, latissimum in dimidio po- 

 steriore ((),27 mm); otolitlius gibbosus, ^/s — ^/o longitudinis corporis post extre- 

 mitatem anteriorem; penis obtuse conicus aut pyriformis; corpus medio violaceum, 

 antice flavum. 



Distrib. : Mare europaeum septentrionale (Norvegia, Britannia magua). 



Habit. : Napoli (v. Gkaff); Adria: Trieste, rarum (Graff). 



Cyrtomorpha v. Graff. Pharynx nuJlus, os anticum ante otoJithum; ocelli 

 dno aut nuJJi; bursa scmi^udis orificio cliitinaceo; corpus Jatum, supra convcxuiiu 

 -idjtus pJanum ; marijincs JcdcraJcs non invertentes. 



m 1. C. subtilis V. Graff. Corpus ovale, antice late rotundatum, postice 

 attenuatum, long. (),") mm, pars tertia anterior sine colore, pars posterior flavida 

 aut flavoviridis; ocelli duo fusco-rubri. 



Habit. : Adria: in fossis salinarum prope Capo dTstria, Trieste (Gkaff). 



Convoluta Oekst. Phari/nx sinq^Jex; os ventirde post otoJitJinm positnm; 

 ocedi ntdJi aut duo; bursa semincdis orificio chitinaceo; penis ci/Jindrnm eJongcdnm 

 (jJandidosum rcfercns; corpusJcdum deprcssum, marjines JcderaJes pJus minusve invoJuhdcs. 



m 1. C. sordida v. Grafp (? C. sordida Metschn.). Corpus depressum 

 planum, lamellosuni, marginibus fere semper involutis; ocelli ad latera otolithi 

 positi; coi'pus pigmentis duobus coloratum, flavo et nigro, hinc modo sordide flavum, 

 modo sordide griseum. 



Habit. : Napoli (v. Gkaff). 



