348 L. MURBACH. 



just above the aboral set of tentacles^ standing at unequal dis- 

 tances apart, and were not more than three in number on any 

 of the individuals observed. The first sign of a budding gono- 

 phore is a slight elevation with a deep pink pigment-spot on 

 the hydranth. Both older and younger stages have a spindle 

 or elongated oval form, which in the mature ones becomes 

 distorted by the growth and aggregation of the sexual products 

 in the ectoderm of the outer wall (fig. l,g'). The general hue 

 of the gonophores is bright pink. In length the older ones 

 equal the part of the hydranth between the two circles of 

 tentacles, but being less contractile may appear longer. 



A narrow neck connects the gonophore with the hydranth, 

 and just at the junction there is a small curved process directed 

 aborally (fig. 1, p-). It is hollow, and appears to belong to the 

 gonophore, its cavity being connected with that leading from 

 the gonophore into the coelenteron of the hydranth. In small 

 specimens these processes are not yet present. Their nature 

 and significance have remained an enigma to me. I do not 

 know of a homologue anywhere among the hydroid polyps. 

 The coelenteron is continued through the gonophore to its tip, 

 where a bit of bright pigment is visible. Active circulation 

 may be observed in gonophores as well as in processes at their 

 proximal ends. 



Asexual Reproduction. 

 My attention was first attracted to the remarkable mode of 

 asexual reproduction by the peculiar appearance of the foot 

 end of a few specimens in a lot of about twenty, taken July 

 26th. One or two constrictions (cf. fig. 2) marked off 

 deeper pink portions of greater diameter. When these seg- 

 ments were freed from the body of the adult they looked not 

 unlike the large planulse of Pennaria, obtained at the time in 

 considerable numbers. Indeed, the same day such a plauula- 

 like body was found in the tow. It was isolated and watched, 

 to determine if it were the detached foot end of Hypolytus 

 or a plauula. It moved about for some time, and then slowly 

 erecting itself, attached by its narrow end (making it at once 



