from the North Pacific Ocean. 441 



colony the branches become a little shorter (PI. XVI. fig. 11). 

 The colour is a rather light brown. Each branch divides at 

 a certain distance from its point of attachment at first into 

 two ; and then each half is again subdivided into three, thus 

 forming a complex of six small branches (PL XVI. fig. 12). 

 The hjdrotheca3 are just the same as in Selaginopsis mirabilis^ 

 Verr., with the same two teeth, and the neck projecting 

 strongly outwards, giving an uneven appearance to the sur- 

 face of tlie branches. The branches are uniform through- 

 out their length, equally arranged, and are not divided into 

 internodes as in S. hidentata^ Allm. * The gonangia also 

 are arranged on the whole length of the branches, and not 

 merely upon a single internode (the first or inner one) as in 

 the species just mentioned. The gonangia (PI. XVI. fig. 12 a) 

 differ from those of 8. bidentata in not being curved at the 

 basal part, and in being quite smooth (not ribbed) on the 

 surface. Their form is a little variable ,* and as they are very 

 numerous on the branches and pressed close together, it often 

 happens that they are a little deformed and more or less flat- 

 tened by pressure. 



Lengtli of the entire colony 125 millims., its width 25 ; 

 length of hydrotheca 0*45, its breadth 0"3 ; length of the 

 gonophore 1*3, its breadth 0*7 ; width of a branch 0*8. 



This species is very well distinguished from Selaginopsis 

 mirahilisj Verr., by the general form of the colony, and by the 

 arrangement of the branches on all sides of the stem, as also by 

 the greater number of the series of hydrothecge, which varies 

 from eight to ten, being generally eight or nine, whilst S. 

 mirabilis has constantly only six. From Selaginopsis bidentata j 

 Allm., its nearest relative, it is distinguished by the absence of 

 any special part of the branches destined to bear the gonangia 

 and separated by a trans versejoint, also by the more tufted habit 

 of the whole colony f, by the six branches united in each group, 

 Avhile S. bidentata has only four (which, in fact, causes the 

 less tufted habit of the colony), and, lastly, by the form of the 

 gonangia. The two species are very nearly allied, although 

 it is impossible to unite them under a single one. It would 

 be desirable to know exactly the number of series in which 

 the hydrothecge are arranged in S. bidentata; for Mr. Allman 

 does not state the number. To judge from the figure there 

 seems to be in this respect no difference between the two 

 species. As to the arrangement of the hydrothecge in ^' verti- 

 cils," this term cannot be regarded as correct; for in reality 



* Jouru. Linn. Soc. 1876, vol. xii. p. 273 {Pericladium bidenfatum), 

 pi. XX. fig. 2. 

 t Allman, I. r. fig. ], and my fig. 11, PI. XVI. 



