276 IIYDROIDiE. Part IV. 



is contrary to .all my observations. The meclusoids actually produce a number of 

 hydroids which become attached, but they themselves soon afterwards die. 



SECTION VI 



CORYMOUrilA PKNDULA AG. 



The hydroid. — This Ilydroid is not found along our shores, as are the other 

 Tubularians, but may be obtained by dredging in deeper water, on a sandy or 

 muddy bottom. In some localities it is ([uite i)lentiful. It has been collected 

 in three different places, all within Massachusetts Bay; namely, at Beverly, in Sep- 

 tember, 1847 ; off Nahant, by Mr. Wm. Stimpson, who says that it is very plenty 

 about three quarters of a mile, due east, fi'om East Point; and, within a few days, 

 we have received two living males from Cape Cod. From these last, we have 

 drawn all the details of structure mentioned in this section ; those observed in 

 1847 having died while they were drawing. 



The natural position of this Hydroid is an upright one, with its branching 

 base bui'ied in the sand. The prevalent color is a clear, bright pink. Like the 

 European Corymorpha, our species always appears in single individuals, and never 

 branches. It grows to a height of at least four inches, and the stem has a diameter 

 of one quarter of an inch at the thickest part, and gradually tapers, both upwards 

 and downwards. At the base it tapers to a point, but above it diminishes to 

 about one half its gi-eatest diameter, and then expands into the cup-shaped base 

 of the head. The head, which is more or less pendulous, consists of a cupuliform 

 base (PI. XXVI. Fiys. 8 and 8", i'), from the edge of which arises a single row 

 of uniformly tapering tentacles (t), above which projects a broad proboscidal organ 

 («), the terminal third of which is closely set with moderately long, tapering, 

 indiscriminately arranged tentacles {t^ f). At the base of the proboscis, there are 

 groups of medusa) (d), arranged on branches, in the same manner as in Tubularia 

 proper, and bearing a strong resemblance to those of the latter genus; in fact, 

 with a low magnifying power the male medusiv of Corymorpha could hardly be 

 distinguished from those of Tubularia (PI. XXIV. Fiy. 5, d), but when we study 

 the details of their organism the resemblance ceases. In the younger stages of 

 growth (PI. XXVI. Fiys. 7, 8, and 8"), the coronal tentacles {Fiy. 8", t f f f) are 

 quite unequal in size ; nor does this inequality cease altogether in the full-grown 

 hydroid, but it does not prevail to so great an extent as in the earlier period 

 of development of these organs. The horny sheath is quite conspicuous from 



