SYNCH^ETAD^E. 127 



lobes are brought forward, and then spasmodically spring back to their ordinary position, 

 when the creature shoots forward with redoubled energy. All its actions display vigour 

 and precision ; and convey the impression of intelligence and will. 



The most interesting fact connected with its history is that it seems to be one of the 

 sources of the phosphoric light which often pervades the waves of the sea. In July, 

 1854, at Tenby, I saw the water within the harbour splendidly luminous. No trace of 

 light, indeed, appeared on the smooth surface, but when this was agitated it blazed. 

 The finest effect was produced by dashing a large stone down from the quay : every spray 

 that splashed up was luminous ; and thus a momentary star of many irregular rays of 

 light was made, some of the lines reaching to fifteen or twenty feet. At the same 

 moment a great circular wave was raised, which took the appearance of a bank, or 

 annular agger, most intensely lustrous, but so transient that the progression of the wave 

 could not be traced ; the light sank into darkness in an instant. The Bristol steamer 

 was just leaving the wharf, and an impatient stroke or two from her paddles illuminated 

 the dark water under her quarter, and the lowest step of the quay stairs was every 

 instant covered with sparks, like diamond dust, by the tiny wavelets that washed over it. 

 On examination, I found specimens of S. Baltica in it; associated, however, with other 

 animalcules, both larger and smaller, which were indubitably luminous, as Noctiluca 

 and Ceratium. 



I first met with this species in July, 1850, in water from the mouth of the Naze, in 

 Essex. Mr. Hood has lately found it in the estuary of the Tay, in Scotland, with many 

 other marine Eotifera ; and has communicated living specimens to me, one of which has 

 contributed to the present description. P.H.G.] 



Length, yj^ to T ^ inch ; width, ^ 7 to 7 | 7 inch. Habitat. Sea-water ; coasts of 

 England, Wales, and Scotland (P.H.G. ; J.H.). 



S. OBLONGA?, Ehrenberg. 

 (PI. XIII. fig. 4.) 



Synchata oblonga (?) . . . . Ehrenberg, Die Infus. 1838, p. 438, Taf. liii. fig. 6. 



[SP. CH. Body ovate or pyriform; head very large; auricles wide; "rotatory 

 clusters six; styles four; crest single, sessile"; toe single, minute, without foot. Lacus- 

 trine. 



A species which I met with in the Watering Pond on Hampstead Heath in 1850, I 

 concluded to be S. oblonga of Ehrenberg, though I could not identify all the characters. 

 But a single specimen occurred, and I have never seen it since, till in November 1885, 

 in a tube dipped from Keeper's Pond, Birmingham, and sent to me by Mr. Bolton, I met 

 with a second example, recently dead, but in fair preservation. 



The front has two minute ridges, each with an edging of short comb-like spines ; 

 outside these are the two knobbed antennae, 011 which I did not detect any brushes of 

 divergent set. A good deal lower, on the slope of the auricle, on one side, was a long 

 stiff bristle, doubtless one of a pair. The auricles are very large, and each is pervaded 

 by a chain of globose bodies, possibly ganglia, which, having passed around the swollen 

 extremity, turns back at least as far as the base of the bristle. A vast mastax exists, 

 whose chief visible feature is a stout incus, whose wide rami appear as diverging lines. 

 A very long, delicate, corrugated oesopliagus leads to a small, globose, sacculate stomach 

 (which recalls the structure common in the Asplanchnat) filled with green food; thence 

 a thick, much-wrinkled intestine passes straight to the extremity, where is a very minute, 

 conical toe, which I could not by any effort divide. A glandular thread runs from the 

 tip to a minute globose vacuole (?) at its base. Three great ova, colourless but turbid, 

 were in the body-cavity, from the appearance of which I should conjecture the animal to be 

 viviparous. Various muscles and nervous (?) threads are shown in the figure. P.H.G.] 



Length, ^ inch ; greatest width, TT <j inch. Habitat. Hampstead ; Birmingham 

 (P.H.G): rare. 



