A COr-LECTIOX OF HVDROIDS. 331 



nodes by transvei"se joints. Pinnae alternate, carried on a 

 process of the stem-internode placed rather above the middle. 

 Pinnie divided into regular internodes by transverse nodes. 



Neniatophores : mesial nematophore adnate to about three 

 fourths of the height of the hydrotheca, and then terminating 

 in a free portion which does not extend beyond the level of the 

 hydrotheca margin ; lateral nematophores strong, cylindrical, 

 generally reaching the level of the hydrotheca margin. On 

 the stem at the base of the pinna? there are three cup-shaped 

 nematophores, one on the process, one above, and one below 

 it. The stem below the pinnate portion may bear an ii-regular 

 number of nematophores. 



Nematocysts of mesial nematophore al)out 15"5 jLt in length 

 and 2"5 ju in breadth. 



Diameter of stem below pinnate portion 0'178 mm., thick- 

 ness of perisarc 24"2 /j, diameter in the middle of the 

 pinnate portion 0'152 mm., length of stem-internode O'2o7 

 mm. 



Diameter of hydrocaulus of pinna from the side 0'071 nun., 

 from the front 0*064 mm. ; thickness of perisarc 8 n ; length 

 of internode of pinna 0"241 mm. 



Hydrotheca. — Eather wide ; margin with nine teeth, four 

 lateral, one median ; intra-thecal ridge distinct, situated at 

 about one-quarter of the height of the hydrotheca from the 

 base. 



Measured from the side, height 0"174 mm., width 0'r22 

 mm.; from the front, breadth at the middle 0*110 mm., dia- 

 meter of mouth 0"15-") mm. 



Hydranth. — Tentacles muricated, about 11 or 12. 



Gonosome. — Male corbula short, with about eight pairs of 

 leaflets which are but slightly adherent to one another. The 

 leaflets bear cylindrical nematophores along both edges. The 

 rachis bears tAvo rows of gonangia ; the peduncle carries one 

 hydi'otheca. 



Length of mature corbula about 1"92 mm., depth about 

 0"869 mm., width from above 0'687 mm. 



VOL. 1, PART 3. 24 



