158 ANNALS OF SCOTTISH NATURAL HISTORY 



CONTRIBUTION TO OUR KNOWLEDGE OF THE 

 HYDROID FAUNA OF THE WEST OF SCOT- 

 LAND. 



BEING AN ACCOUNT OF COLLECTIONS MADE 

 BY SIR JOHN MURRAY, K.C.B., ON S.Y. "MEDUSA." 



By JAMES RITCHIE, M.A., B.Sc., 



The Royal Scottish Museum. 



( Continued from p. 3 4, No. 7 7 , January 1911.) 



Family CAMPANULINID^E. 



38. STEGOPOMA FASTIGIATUM (Alder) (= Calycella fastigiata 

 of Hincks's " History "). 



MULL OF CANTYRE, 49 fms. 

 FIRTH OF LORNE, 20-30 fins. 



39. CALYCELLA SYRINGA (Linn.). 



As Broch J has recently shown, an extraordinary amount of 

 variation takes place in this species, especially as regards the relative 

 proportions of peduncle and hydrotheca. As a rule, however, 

 according to Broch, the length of the former lies between a half and 

 the full length of the hydrotheca. The specimens obtained by Sir 

 John Murray, on examples of Aglaophenia tubitlifera from Loch 

 Lome, 30-110 fms., are exceptional in several respects. The hydro- 

 thecae are themselves longer than is normal ; but, notwithstanding, 

 the length of their peduncles is far out of proportion, for they may 

 be twice as long as the hydrotheca. The hydrothecse, too, are 

 characterised by the presence of many successive margins due to 

 the death and subsequent regeneration of the hydranths, as many as 

 seven being counted in one case. I am of opinion, in view of 

 Broch's researches, that these unusual proportions could well fall 

 within the limits of variability of Calycella syringa, although Hart- 

 laub 2 has created a species, C. gradlis, for specimens with similar 

 habit. The following measurements of the Loch Lome and typical 

 forms give a more accurate idea of the relative sizes : 



1 Hj. Broch, 'Die Hydroiden der arktischen Meere,' in " Fauna Arctica," 

 Band v. Lief, i, 1909, p. 164, Fig. 22. 



2 Cl. Hartlaub, 'Die Hydromedusen Heligolands,' " Wiss. Meeresunters. 

 deutsch. Meere," 1897, p. 451. 



