58 



ZOANTHARIA 



Polythoa (Taeniothoa) a?iguiconia Andres, Le Attinie 1883 532, 1884. p. 317. 



Epizoanthus amcricamis var. Verrill, Report Blake. Bull. Harvard. Coll. 1883—85. PI. 8, fig. 6. 



Polythoa sp. Ridley, 1886. Proc. Roy. Irish Acad. (2) 4. Ser. p. 617. 



Parazoantlms anguicoiims (Norm.) Haddon. Trans. Dubl. Soc. 4 (2) 1891. PI. 58, figs. 34 — 36, PI. 59 figs. 11 — 12. 



Localities: 35° 45' 30" N., 74° 48' W. Verrill 1883— 85. 



40° 01' N., 70°22' W. 98 fm. U. S. F. C. St. 2245. 1 colony of 4 specimens together with the typical 

 Epizoanthus i7icrustatus (americanus). Fig. 19, PI. i. R. M. 



50°57'N., io°46'W. 184 m. Michael Sars Exp. 1910. St. 96. 3 single spec, and 2 small colonies 

 on Ascidians and vSerpula tubes. 



Shetland 1899. i colony. 



Ireland; various specimens from Dublin Museum. 



Formerly known localities: Shetlands. W. and S. W. of Ireland. See Haddon 1891. 



Dimensions: Column 3 — 5 times as high as broad (Norman). Height of column, when 

 fairly expanded (in spirit) 13 mm. The specimens from U. S. F. C. Height of column 07 cm., diameter 

 of capitulum 04 cm. 



Colour: Pinkish-white (Norman); preserved specimens sand-coloured. 



External appearance. This species has been well described by Haddon and Shackletou 

 (1891). Characteristic are the very deep furrows and the coarse ridges between these in the capitular 

 region. The number of furrows and ridges seems to be about 18, as stated by Haddon. 6 of the 

 polyps examined by me had 18 furrows, i had 17 and another 19. On small polyps the capitular 

 furrows are less distinctly seen, but the future appearance of the furrows and ridges may be discerned. 

 Haddon mentions, that the capitular region is swollen, when contracted. This is easily seen on some 

 specimens, on others it is less distinct, as was the case with the specimens from the American coast 

 (fig. 19, PI. 1). The cesophagus as well as the hyposulcus is of moderate length. The incrustations 

 mainly consist of sand-grains but also of foraminifera and sponge-needles. The specimens dredged on 

 the Michael Sars Expedition were very strongly incrusted and foraminifera also occurred in quantities. 



Anatomical description. In 1891 Haddon described the anatomy of this species, but I 

 am able to supplement his description on some points. The fairly numerous nematocysts with 

 greatly twisted thread are almost double as long as broad (length ca. 24 /i, breadth ca. 12 /i). Very 

 seldom large capsules also occur with slightly twisted thread, length 41—48 by 17—22, which are 

 equally broad, rounded in the ends, but .somewhat broader at the one end. In the sphincter region 

 the encircling sinus is weak btit otherwise it is very well-developed aiul has the appearance descril)ed 

 by Haddon. 



The sphincter has the appearance described by Haddon. 



The ectoderm of the tentacles contains numerous spirocysts and some few, ca. 19 « long, thick- 

 walled capsules. The ectodermal musculature is moderately developed. Incrustations are also found 

 in the tentacles. 



The ectoderm of the oesophagus contains numerous thick-walled, narrow capsules with distinct 

 basal part to the spiral thread; these are generally 19/^, sometimes even 24// long. If present at all. 



