BIGELOW, MEDUSAE AND SIPHONOPHORAE. 381 



the knobs are permanently spherical, or whether, with growth, they 

 assume the oval outline seen in C typa. 



Color. In the two larger specimens (preserved in formalin), the 

 manubrium is pale reddish yellow. But experience has shown that 

 this gives little idea of its color in life. 



The localities of capture, Straits of Florida and N. E. Providence 

 Channel, add a link to the chain of evidence that Calycopsis is a 

 neritic form, though probably the hydroid stage of most of its mem- 

 bers is passed in deep water. Were this not so, we might expect to 

 find Calycopsis generally distributed over the high seas, like most 

 holoplanktonic coelenterates, for the range of the genus extends from 

 the Arctic to the Antarctic, and to all three great oceans. But most 

 of the records so far obtained suggest just the contrary, being near 

 land. Thus C. typa (sens, sir; p. 277) is only known along the con- 

 tinental shelf between Cape Cod and Chesapeake Bay; C. nemato- 

 phora from the Sea of Okhotsk and Bering Sea; C. borchgrevinki from 

 the shores of the Antarctic continent; C. geometrica from Malaysia; 

 C. simulans between the Galapagos Islands and Central America; 

 C. bigelowi from the Gulf of Aden ; C. chuni from the Gulf of Aden and 

 the neighborhood of Cape Gardafui. Calycopsis valdiviae alone, has 

 been taken far from any coast-line, i. c. off Liberia (0° 12' N.; 16° 39' 

 W.), and in the Indian Ocean off Bourbon; its other captures are from 

 the Alguhlas current off South Africa, and near the Cape Verde Islands 

 (Vanhoffen, 1911, 1912a, " S. typa"). 



Heterotiara Maas, 1905. 



The two known species of Heterotiara, H. anonyma Maas (1905), 

 large (15-25 mm. high) but with only 12 tentacles at most, and //. 

 viinor Vanhoffen, small (10 mm. high), but with 20 or more tentacles, 

 have been so fully discussed by Vanhoffen (1911), by Hartlaub (1913) 

 and by me (1913) that no comment would be needed here had not 

 Browne (1916) recently suggested that the specimens from off the coast 

 of Peru referred by me (1909a) to H. anonyma really did not belong to 

 Heterotiara at all but to some other genus. This supposition is based 

 on the absence in these Peruvian specimens, of the terminal tentacular 

 knobs which have since proved to be characteristic both of H. anonyma 

 and //. minor. But since their tentacles were obviously imperfect, and 

 they agree otherwise with several excellent specimens from the north- 

 western Pacific and Bering Sea (1913, p. 25) and with the present 



