Deejy-sea and Shallow-ivater Hydrozoa. 5 



loped near the margin, the base much constricted and 

 connected with a distinct but small process of the stem j 

 aperture of thehydrotheca circular. Nematophores extremely- 

 small, elongated, being more than half the length of the 

 hjdrotheca, slightly ringed near the margin, and jointed 

 below to a thicker basal portion which is placed on the proxi- 

 mal side of the base of the hydrotheca. 



The specimens of this species form small branched colonies 

 which are about 30 or 40 millim. in height, and when dried 

 are of an earthy brown colour. They were found growing on 

 the cable and also attached to specimens of Diphasia pinaster. 

 In these dried specimens the delicate nematophores are often 

 found more or less broken away, but the remaining basal 

 portion easily marks their original position on each side of 

 the base of the hydrothecse. 



Family Sertulariidae. 



Diphasia pinaster. 



Sertularia pinaster, Ellis & Solander, Zooph. p. 55, pi, vi. figs. 6 & B. 

 Diphasia pinaster, Hincks, Britisli Hydroid Zoophytes, p. 252, pi. 50. 

 tig. 1. 



Several specimens of this species were obtained. They 

 agree in nearly every particular with the characteristic form 

 of the species, except that the female gonothecse are usually 

 tetraspinous, bearing only the single lower circle of spines, 

 while occasionally on other gonothecse on the same hydrophy- 

 ton two very small spines of the upper circle are also present. 

 In accordance with the position and prominence of the four 

 larger spines, the female gonothecee have when dried a more 

 or less quadrangular shape. The spines on the female gono- 

 thecEe of this species are thus seen to vary from four to eight. 

 The male gonothecse are much smaller, and have the charac- 

 teristic quadrangular shape, with the four angles produced 

 into very prominent spines. 



To this species I have referred, somewhat doubtfully, some 

 other specimens obtained from the Madeira cable off Lisbon, 

 in which the distinct fold at the point of divergence of the 

 superior half of the hydrotheca is scarcely or not at all repre- 

 sented. In other respects, in the characters of the hydrothecEe 

 and in the habit of the hydrophyton, they are closely like the 

 present species. They present a decided approach to the D. 

 coronifera and the D. elegans. No gonothecaj are present on 

 the specimens, and the final position of the form must remain 

 doubtful until the nature of these structures is observed. For 

 the present I distinguish it as 



Diphasia pinaster ^ var. arcuata. 



