Gatty Marine Laboratory , St. Andrews. '21 



often forms a small s})oul-slia])ecl process. The anterior 

 surface of the cephalic plate is occupied hy the tentacles, 

 wliich are of a pale flesh-colour or oranj^^c with or without 

 red s[)ecks. They arc lonji^, })owerful, and marked here and 

 there with whitish opacities probai)ly from the peritoneal 

 corpuscles, which roll backward and forward in their interior. 

 In some examples they are of a deeper hue than tiiose of 

 Terebella nebulosa, probably from the presence of the reddish 

 specks. These mobile organs are grooved throughout^ and 

 arc sometimes flattened in a spathulatc manner and again 

 contracted and richly crcnate. Under the structureless 

 cuticle is the cellulo-grannlar hypoderm, then follow the fine 

 but tough non-striated muscular fibres, circular and longi- 

 tudinal. In life the slender vermiform tentacles coil and 

 twist in every direction, now showing nodular enlargements 

 and again extending into a uniform thread as before, or 

 actively wriggling as if each were endowed with independent 

 life. Each granular tentacle, when separated from its 

 attachment to the cephalic plate, coik-d itself in sj)asmodic 

 jerks or gently unfolded. By their aid, as in other Tere- 

 bellids, the annelid pulls itself upward on the perpendicular 

 wall of a glass vessel. The tentacles at the ventral angle of 

 the cephalic plate are small and short. 



The body is typical of the Tcrcbcllids — viz., enlarged 

 anteriorly and tapered gently therefrom to the posterior 

 end, where the anus, surrounded by about a dozen pai)illae, 

 is terminal. It is rounded dorsally and more or less rugose 

 or warty in old and large specinjcns anteriorly, rounded also 

 anteriorly on the ventral surface, then flattened and slightly 

 grooved, the groove continuing almost to the posterior end. 

 The segments are distinctly marked throughout, the anterior 

 presenting dorsally four transverse lines, and the longer and 

 narrower posterior segments a larger number. The ventral 

 scutes (glandular thickenings) are well developed, and can be 

 distinguished as such as far back as the thirtieth bristle- 

 bundle. Moreover, a thick glandular coat invests the body 

 laterally — enveloping the tori and the setigcrous processes in 

 each segment. In large examples from the Arctic seas the 

 anterior scutes arc rugose transversely and cut into various 

 folds in each segment. 



The feet are represented by setigcrous processes and tori 

 uneinigeri. The fiist setigcrous process arises dorso-laterally 

 below the second series of branchiie, and the others follow 

 in succession at the posterior part of each segment, the 

 glandular investment of the region passes above it and forms 

 a finished edge dorsally. The succeeding processes gradually 



