^Ts'Js!^'] PROCEEDINGS OF THE NATIONAL MUSEUM. 171 



(Tl. XXVI, Fig. 56); iii the elevations wbicb giverise to the flutings, how- 

 ever, it has a very delicate structure resembling greatly typical areolar 

 tissue with its connective tissue corpuscles. 



The mouth is large; the stomatoda'um is irregularly ridged longi- 

 tudinally, and the siphonoglyphes are deep and prolonged below the 

 lower level of the stomato<l;eum. 



The mesenteries are arranged in ninety-six pairs, of which only 

 those of the first two cycles, twelve in- all, are i)erfect. These, together 

 with the mesenteries of the third cycle are sterile, the reproductive 

 organs occurring only on the mesenteries of the fourth and fifth cycles. 

 The longitudinal musculature (PI. xxvi, Fig. 55) is fjiirly strong but does 

 not form any distinct pennon upon the surface of the mesentery. The 

 muscle processes show a tendency, especially in the basal portion of the 

 mesentery, to be grouped upon low elevations of the general mesoghea. 

 The parieto-basilar muscle {phni) is well developed and forms a decided 

 projection upon the basal portion of the mesenteries, which portion, 

 where the parieto-basilar occurs, contains a number of cavities, evi- 

 dently developed, as in B, occidua, in connection with the growth of the 

 muscles. 



19. Actinostola pergamentacea, .sp. uov. 



Plate XXVI, Figs. 57 aud 58; Plate xxvii, Figs. 59-63. 



No. 695. Station 2769. Lat. 45° 22' S. ; long. 64° 20' W. Depth 51* fathoms. Five 

 specimens. 



These specimens (PI. xxvi, Fig. 57), which seem to belong to the genus 

 Actinostola, are very much macerated, the tentacles having dissolved 

 into shreds, so that it is impossible to ascertain their shape or struc- 

 ture. The specimens measure o''" in height and 2"" in diameter. 



The base is evidently adherent and larger in diameter than the 

 column. This is almost cylindrical, enlarging somewhat at the margin 

 and limbus. Its walls are smooth, firm, ami parchment-like, being 

 brittle rather than tough, and readily broken. It is pure white in 

 color, the ectoderm, however, being entirely absent. The sphincter 

 PI. xxvii, Fig. 59) resembles in general appearance that of ^l. cxcelsa, but 

 is by no means as strong. None of the specimens show the slightest 

 trace of the margin being infolded over the tentacles, and this is not 

 remarkable, considering the stiffness of the column mesoghiea. 



The tentacles seem to have been numerous, perhaps one hundred 

 and ninety-two, though this is merely an estimate, since they are too 

 badly macerated to allow of a count. Their longitudinal musculature is 

 imbedded in the mesoghea in a luimber of small cavities (PI. xxvii. Fig. 

 00). The disc is roughened by radiating rows of small tubercle-like 

 elevations, and the radial musculature resembles that of the tentacles, 

 though in one specimen the cavities were elongated and separated by 

 narrow trabeculaj of mesoglcea, presenting the appearance shown in 

 PI. XXVI, Fig. 58. 



