LUMBRICONEKEIS. 371 



In this group are instances of the somewhat rare endo -parasitism of Polychaeta, 

 indeed, the majority of the examples appear to pertain to it, and, further, they are 

 parasitic on Vermidia of one kind or other, chiefly Polychaeta. Thus the Amphinomids 

 Hipponoe Gaudichandii and H. Mulleri inhabit Lejpas anatifera; and the Ctenophore 

 Gydippe densa, Forsk., is the home of Alciopina parasitica ; whilst Ophvwricola cynips is 

 found in a cleep-sea Ophiuroid (Ophioglypha tumulosa). The Lumbriconereid forms, 

 again, are Oligognathus Bonellix, which haunts the Gephyrean Bonellia ; Hxmatocleptes 

 terrebellidis occurs in a blood-sinus of the gut of Terebellides stroemii; Labrorostratus 

 parasiticus is found in the body-cavity of various Syllicls, viz. : — Odoiitosyllis ctenostoma, 

 Eusyllis moiiilicornis, Syllis prolifera, Pionosyllis lamelligera, and Grubea clavata; and 

 another Lumbriconereid in the same cavity in Marphysa sanguinca. Lastly, Monticelli 

 met with Ophryotrocha puerilis in the body-cavity of Oucumaria Planci at Naples. 



The Lumbrinereids are common in mud, indeed some, such as the red form mentioned 

 by Mr. Crossland, are the only inhabitants of the mud which forms the bottom between 

 the coral reefs in Red Sea harbours. 



Genus LXIII. — Lumbbiconebeis, De Blainville, 1828 (char, emend.). 



Head more or less conical, without tentacles or palpi; a neck-fillet with retractile 

 papillas. Mouth with two lips. Body elongated, distinctly segmented, little tapered 

 anteriorly, but more distinctly so posteriorly, where it terminates in four anal cirri. 

 Two smooth segments behind the head. Maxillge smooth with basal processes; maxillary 

 plates symmetrical, toothed, and with a broad horny ledge. Mandibles connate in the 

 broad middle region anteriorly, and diminishing posteriorly. Foot with a long terminal 

 flap, simple and compound bristles, in the posterior segments (and in the young in all) 

 simple hooks. Body-wall as in the type (see p. 368). The circulation is highly deve- 

 loped, and the vascularity of the feet is characteristic. The segmental organs, repro- 

 duction, and development are all in need of further investigation. 



Kinberg 1 made two divisions of the genus Lumbrico nereis, viz., (1) those having 

 maxilla Illi unidentate, and (2) those with the same part bidentate. 



Ehlers (1868) points out the substitution by Grube of the term Lumbriconereis for 

 Lumbrinereis, Blainville; and amalgamates Scoletoma, Blainville, Zygolobus, Grube, and 

 Eranno, Kinberg, with the genus, whilst Araeoda, Schmarcla, and JSfotocirrus, Schmarda, 

 are also partially connected with it. 



The species range from tide-marks to very great depths, e.g., in the ' Challenger ' to 

 2225 fathoms. 



A form {Liimbricoiiereis) occurs in the fresh waters of Trinite 2 (Trinidad?). 



Gravier 3 mentions Miss F. Buchanan's observations on the regeneration of the 

 anterior region in Lumbriconereis impatiens and in Holla. Regeneration of the tail is 

 more frequent. 



1 ' Ofversigt af-K. vet.-Akad. Forliancll./ 1864, pp. 568 and 569. 



3 Benham, ' Camb. Nat. Hist./ ii, 1897. 



3 < Ann. Sc, nat,, Zool./ 9 C ser., t, ix, p. 136, 1909. 



