120 G Canadian Arctic Expedition, 1913-1918 



Family HALCAMPID.^ Andres, 1884. 

 IlyanthidcB (pars). Many authors. 



Column usually narrow and much elongated, generally without a definite 

 basal disk or with a very small one; most often the base is pomted, with or with- 

 out a central pore Tentacles usually few (8—24) ; most frequently 12. Mesen- 

 teries few, hexamerous; most often only 6 or 12 pairs; all may be perfect and 

 fertile; those of the second cvcle may be imperfect; sometimes the mesenteries 

 exceed the number of tentacles. Sphincter muscle feeble, diffuse, or lacking. 

 Mesenteries usually haye a strong, often narrow or circumscribed, longitudinal 

 muscle. A conchula may be either well deyeloped oj- lacking. 



Sub-family HALCAMPIN^ Verrill, New name. 



Halcampidffi which lack a conchula and apparently a pore at the aboral 

 end of the body. Scapus sulcated, it may be naked or it may be coyered with 

 a loosely attached epidermal coating consisting mainly of mucous, fine sand, etc. 

 Tentacles usually 12, sometimes 10, 14, 20, or 24; mesenteries 12 to 24; 12 

 usually perfect and fertile. Longitudinal mesenterial muscle strong, restricted. 



Genus Halcampa Gosse. 



Peachia (pars) Gosse, Trans. Linn. Soc, XXI, p. 271, 185.5. 

 Halcampa CiossE, Ann. and Mag. of Nat. Hist., 3rd series, i, p. 418, 1858; 

 Actinologia Brit., p. 246, 1860. Andres, op. cit., p. 100, 1884. 



Column yery contractile, much elongated and slender in expansion, occupj^- 

 ing holes in the earth or among rocks, etc., l)ut able to creep about, adhering 

 by the sides.; in contraction irregularly cylindrical, often with constrictions; 

 column-wall membranous throughout, translucent, with or without adherent 

 sand, etc. Base capable of being enlarged and greatly distended, without a 

 distinct disk, but capable of adhering slightly by its surface to foreign bodies 

 by yery minute sucker-hke organs; apparently imperforate. Tentacles 12, 

 rarely 10, short, in two cycles. Perfect mesenteries, usually 12. They are 

 yery thin next the wall, but near the middle haye a yery strong, longitudinal, 

 muscular thickening, which narrows both aboye and below. The peripheral pores 

 of the mesenteries are large and well defined; six pairs are imperfect. 



Halcampa duodecimcirrata (Sars). 



Edward-sia dvodvcuiicirrala ^L Sars, Nyt. INIag. Nat. Hist., VI, n. 10, p. l42, 

 1851. MoBius and jMeyer, Weig. Arch. f. Naturges., Jahr. 29, b. 1, p. 70, 

 pi. Ill, figs. A, D, 1863. 



Edwardsia farinacea (pars) Verrill, Amer. .Journ. Sci., \o\. ^TI, pi, VIII, fig. 5, 



]S74 (not fig. 4, nor the text). 

 Ilalciiiii]jii fdfiiiacea (/x/rs) Andres, op. cit., 1884, p. 102, 



Plate XXI; Figures 1, 2, 2a. 



Column changealile in form, often nearly cylindrical, at other times swollen 

 ill the middle or posteriorly, ca])able of contracting to less than half its full 

 l''ugth. f 'olumn is usually coyered with scattered, feebly adherent, fine grains 



