ON THE HYDROIDS OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 



Family Plumulariid.^. 



AglaopheJiia dichotoina (Johns.). Plumularia unilaturalis, n. sp. 



Plumidaria echinulata (Lamk., 1836). Antennularia hartlauhi, n. sp. 



„ magellanica, Hart., 1905. Anteiiiiopsis scotix, n. sp. 



,, ■pinnala, Linn. 



I. GYMNOBLASTEA. 



Family PoDOCORYNli)^. 



Podocoryne earned, 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^. 



Hcdeciun 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 hydrotheca^ 

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

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

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

 some cases set on a " ahort 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 Hartlaub (1905, p. 606, 

 fig. B^ a and b). From within these primary l)asal hydrothecaj arise the tiers 

 which are so common in the species. 



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



(rot. soc. edin. trans., vol. si.v., 523.) 



