356 



BULLETIN OF THE UNITED STATES FISH COMMISSION. 



Qonowme. < lonangia in musses, im-rusting the fascicled stem, so closely crowded as to be pressed 

 together, tubular or oblong oval with short bottle-shaped necks. Both sexes found in the same colony. 

 tiuii. Found growing on other hydroids on Nantucket Shoals. (Verrill.) 



Lafoea gracillima (Alder.) Fig. 49. 

 i : tnfonularta graeOKma, <';it. /,<">i>]i. Xorthumb. mid Durluim, p. 39.) 



f. Stem erect, fascicled, often irregularly branched. Pedicels slender, sinuous or 

 apparently twisted. Hydrotheoe very slender, delicate in texture, often slightly curved. 



< iiiiii'snini'. Much like that of L. tltn<>.*i<, and heretofore known as Coppin'm <n-r/n. 



l>ixti i !liiit!ti)i. Reported from the Xew England coast by Professor Verrill. Although not 

 specifically reported from the \Vonds Hole region, it doubtless occurs there, as its distribution is much 

 like that of L. dmnoxii. 



48. Lafrea ihtmosa (Fleming). 49. Laftea graciUima (Alder). 



HALECID^E. 



Trophosome. Hydrothecae alternate, reduced to the form of saucer-shaped hydrophores, usually 

 Itorne on tubular pedicels; margins even, often reduplicated several times, and surrounded by a circlet 

 of bright, bead-like dote. Hydranths large, with conical proboscis, not capable of retracting within 

 the hydrophores. 



Gonosome. Gonangia producing planulse, and usually different in the two sexes, that of the 

 female often being surmounted by a pair of hydranths. 



HALECIUM. 

 The single genus can be identified by the characters given above. 



A'/-// to species of Halccium found in the Woods Hole rrrjinn. 



A. Hydrophores borne on distinct pedicels. 

 . Stein fascicled. 



b. Colony flubellate in form; aperture of female gonangium terminal, but not ^central. Pedicels 



short H. hatecinum. 



b'. Colony dendritic in form. Female gonangia with round lateral apertures. Pedicels short H. beani. 



b". Colony with slender branches. Female gonangia as in H. Italccinum, but with the end emargi- 



nate ff. gractte. 



a'. Stem not fascicled, irregularly branched, annulated II. tenellum, 



A'. Hydrophores sessile, borne directly on broadened shoulder of internodes of stem H. artifulosum. 



