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MONOCAULUS PEiXDULUS. 397 



2. MoNOCAULUS PEXDULUS, Agassiz 



CoRVMORPHA TENDULA, — Affossiz, Cont. Nat. Hist. U.S., vol. iv, p. 270, pi. .\xvi, figs. 7 — 17. 

 MoNocAULUS PEXDULUS, — Allinuti, in Aun. Nat. Hist, for May, 18G4. ■" ■!',/>■ 37o, 



TROPHOSOME. — Htdrocaulus attaining a heiglit of four inches, and in its 

 thickest part a diameter of one quarter of an inch, from which part it gradually tapers 

 towards its proximal and distal ends, proximal end emitting filamentary hydrorhizal 

 rootlets. HroROCAULUS marked hy longitudinal hands. Hydranths pendulous. 



GONOSOME. — Peduncles of gostophoues branched. Sporosacs (male) with a 

 thick tentaculiform process projecting from one side of the distal end, and with a 

 band of greatly developed cells over each radiating canal. 



Habilat. — On a sandy or muddy sea bottom. 



Bathy metrical distribution. — Coralline zone ? 



Localities. — Massachusetts Bay, Agassiz aud Stimpson ; Cape Cod, Agassiz. 



The present species is one with regard to whose generic position we are by no means free 

 from uncertainty. Agassiz gives us some beautiful figures of it, but the gonosome is hardly 

 figured in sufBcient detail. It would seem that radiating canals are visible in the gonophores ; 

 it appears pretty certain, however, both from the description and the figures, that the gonophores 

 are as truly adelocodonic as those of Tuhiilaria. 



A short thick tentacle is described as being developed from one side of the distal end of the 

 gonophore ; and it is also stated that there exists " on the outer surface of the bell, over each 

 radiating tube, a narrow longitudinal band of enormously developed cells." It is to be desired 

 that we had more information regarding these bands than what is contained in the remark here 

 quoted. The presence of a voluminous spermatic mass, enveloping the spadix and completely 

 filling the cavity of the sporosac, shows that the male specimens — the only ones described — were 

 mature when examined. 



Mr. Alexander Agassiz, on the other hand, figures (' Proc. Boston Soc. Nat. Hist.,' 1862, 

 and ' Illustrated Catal.,' p. 193) a medusa, Avhich he regards as that of Professor Agassiz's Cory- 

 morpha pendula. It resembles that of a true Corymorjjha, but besides the long solitary tentacle 

 has others in process of development from the margin of the umbrella. Since, however, he states 

 that it was taken in the open sea, and not du'ectly observed to proceed from the trophosome to 

 which he inferentially attributes it, we cannot consider Professor Agassiz's description of the 

 gonophore in his Corymorjjha pendida as superseded by the observation of his son. 



The chitinous pellicle of Monocanlus pendula is described by Professor Agassiz as con- 

 spicuous over the proximal third of the hydrocaulus, though on the remaining two 

 thirds it has either disappeared altogether, or exists only as a mere film. This condition 



