148 Prof. Mcintosh's Notes from the 



Fig. 2 [2]. Anterior extremity of the body of Rotifer vulgaris, with the 

 rotatory organ protruded, k, the cephalic end of the animal 

 thrown up upon the back ; iiz, cervical lobe (" respiratory tube " 

 of authors) ; gngl, cephalic ganglion ; ro, rotatory organ. 



Fig. 3 [3]. The anterior end of the body of Rotifer vulgaris, with the 

 rotatory organ retracted. 3 a, from the side ; and 3 b, from 

 above ; tb, tactile setae. The other letters as in figs. 1 and 2. 



Fig. 4 [6]. Production of daughter-nuclei by budding from the primary 

 nucleus in Philodina roseola. 



Fig. 5 [7]. Trypanococcus-vesicleB in the body-cavity of Rotifer, mkrp, 

 mic-ropyloid external aperture. 



Fig. 6 [8 e], A perfect Trt/panococcus-\esic\e produced by growth from 

 the granular layer (=matrix). v, vacuole ; kg, globular body 

 (nucleus). 



Fig. 7 [9]. A vacuole adherent to the nucleus, with motile filaments in 

 the interior (flf). 



Fig. 8a,b,c [11 a, b, c]. Trypanococcus-\e$ic\es with u saccules/' and the 

 formation of vacuoles in the latter. 



XIV. — Notes from the St.-Andrews Marine Laboratory [under 

 the Fishery 'Board for Scotland). By Prof. M'lNTOSH, M.D., 

 LL.D., F.E.S., &c. 



I. On the British Species o/ Cyanea, and the Reproduction 

 o/'Mytilus edulis, L. 



Two species of Cyanea have been familiar to British zoolo- 

 gists, and both are very common at St. Andrews, where Prof. 

 Hackel worked at them in 1879. They are described in the 

 latter author's fine work* as Cyanea cajnllata, Eschscholtz, 

 and Cyanea Lamarel-ii, Peron and Lesueur. The following 

 observations, however, would lead us to believe that the latter 

 is only the young condition of the former. 



On the 12th of June not a single example of Cyanea ap- 

 peared on the surface of St.-Andrews Bay ; but the trawl 

 in a few fathoms' water was laden with the purplish-blue form 

 which Hackel and other authors would call Cyanea La?narckii } 

 Per. and Les. Most of them were of small or moderate size, 

 ranging from 2 or 3 inches in diameter to 6 or 7. The colour 

 was the same in all, though it might vary a little in depth. 

 No trace of any tendency to pass into a brownish tint was 

 visible. The earliest appearance of these Medusae on our 

 shores in numbers seems to have been about the end of May, 

 when they were procured off Aberdeen under similar circum- 

 stances, viz. at a depth of several fathoms ; indeed, invisible 

 from the surface. The sixteen Ephyra-lobes of these and the 

 interrupted concentric striae from the muscles are characteristic. 

 * Syst. Medus. Acraspedae, pp. 528-530. 



