Gaily Marine Laboratory, St. Andrews. 33 



new organs in forms or substance." Something like Pan- 

 genesis was thus thouglit oi before Darwin. 



Euchone rubrocincta, Sars, the twelfth form, comes from 

 St. Magnus Bay, Shetland, in 100 fathoms, where it was 

 dredged by Dr. Gwyn Jeffreys. The collar dorsally has a 

 curvature as it approaches the median fissure, whilst ventrally 

 only a spout-like median fold occurs at the rim. The 

 branchiae are 15-16 on each side (twelve, Sars), connected 

 by a web for half their length. The filaments have pinnae 

 which reach the base of the slender filiform tip, M'hich is' 

 often so closely coiled as at first sight to represent a knob. 

 A narrow hypodermic wing is attached to the axis along a 

 considerable area of the pinnate region and to the base of 

 the terminal process. " Five pairs of branched tentacles " 

 (tentacular cirri) " and several unbranched, of which one long 

 ventral pair is attached to the connecting membrane " of 

 the branchiae, " whilst the others are free " (Southern). 

 These organs are in close proximity to the mouth, have an 

 aflFerent and efferent blood-vessel, and are probably of 

 importance in alimentation. The curve of the vessel is just 

 within the hypodermic tip, which is slightly bulbous. The 

 body is about three-quarters of an inch in spirit, of thirty- 

 two or more segments, of which nine to eleven are included 

 in the anal funnel, which has a furrowed process in front 

 and a creuulated margin. It is somewhat rounded, though 

 the ventral surface is more or less flattened, a little tapered 

 in front, and more distinctly diminished in the caudal region. 

 The segments are two-ringed, and a dorsal furrow runs from 

 end to end, for it does not cease when the ordinary groove 

 bends to the right and passes to the ventral surface between 

 the eighth and ninth segments, and is continued to the 

 anal funnel. The anterior scutes are divided by the trans- 

 verse furrow of the segment ; the posterior scutes are cut 

 into four by the deep and broad ventral furrow. 



The anterior bristles are borne on a setigerous process, 

 are pale, and brittle. The first tuft, which arises a little 

 more dorsal than the others and at the base of the collar, 

 consists of a longer and shorter series of finely-tapered 

 bristles with very narrow wings, those on the shorter series 

 being almost invisible. The average anterior tuft has three 

 sets of bristles, the larger having straight shafts, gently 

 tapered and slightly curved tips ; the next series has shorter 

 tips with a distinct inclination backward and broader wings, 

 but still their condition is in contrast with the broad spatu- 

 late tips of the corresponding series in such as Euchone 



Ann. (& Mag. N. Hist. Ser. 8. Vol. xvii. 3 



