ON THE HYDROIDS OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 523 



Aglauphenia dichotoma (Johns.). 

 Plumularia echinulata (Lamk., 1836). 



„ magellanica, Hart., 1905. 



„ pinnala, Linn. 



Family Plumulariid^e. 



Plumularia unilateralis, n. sp. 

 Antennularia hartlaubi, n. sp. 

 A?ttennopsis scotiss, n. sp. 



I. GYMNOBLASTEA. 



Family Podocorynid^e. 

 Podocoryne carnea, Sars, 1846. 



Encrusting three Gasteropod shells from one locality there occur gymnoblastic 

 colonies which cannot be separated from the above species. The nutritive hydranths 

 bear from. 8 to 15 tentacles, 12 being most common, while the gonophore-bearing 

 individuals possess only 5 or 6. All the hydranths are in a contracted state, some of 

 the larger measuring about 0*8 mm. in height. Short chitinous spines stud the 

 investing crust at irregular intervals. 



The gonophores are borne in threes or fours beneath the tentacles. The medusoid 

 has 8 tentacles, 4 larger and 4 smaller. 



Locality, etc. — On empty shells of Nassa crepidula from Saldanha Bay, Cape 

 Colony. Trawl. 19th May 1904. 



TT. CALYPTOBLASTEA. 



Family Haleciid^e. 

 Haleciun beanii, Johnstone, 1847. 



Two fragments occur, one 4, the other 7 cm. high. The characters of the 

 species are well shown in the specimens ; the polysiphonic stems and branches which 

 distally become monosiphonic ; the pinnate arrangement of the branches ; the extreme 

 delicacy of the ramuli, especially in the distal regions ; the frequent tiers of hydrothecse 

 and the peculiar female slipper-shaped gonothecse, with their openings placed medianly 

 instead of at the extremity. In the present specimens, as in Allman's (1888), only 

 slipper-shaped gonothecse occur. We note, however, that while the hydrothecse are in 

 some cases set on a " short basal offset from the distal end of each indernode " (Allman, 

 1888, p. 12), in the majority of cases the primary hydrotheca arises directly from and 

 lies almost against the distal end of the internode, as figured by Hartlatjb (1905, p. 606, 

 fig. B 3 , a and b). From within these primary basal hydrothecse arise the tiers 

 which are so common in the species. 



Locality, etc.— Fathoms, 56. Date, 1st December 1903. Burdwood Bank. 



