214 AMPHITRITE. 



tongue or scoop between them, forming altogether a remarkable appara- 

 tus, fig. 4. 



The margin of the first segment enlarges as a frill, fig. 2 a. A super- 

 ficial, longitudinal groove traverses the body throughout, and short pen- 

 cils, with a smaller brush at the root, issue in a row from each side of 

 the segments. 



But a minute detail of the external and internal organic structure 

 would exercise the faculties of a skilful anatomist. Nor is it an easy 

 task to explain the nature of parts imperfectly exposed, whose use may 

 be equivocal during life, and which are utterly disfigured or obliterated 

 by death. 



In this animal the branchiae most intimately resemble fleshy feathers. 

 The feather consists of a rib, clothed on each side by numerous active 

 cilia ; and on its back are several prominences, their number depending 

 on its length. The branchiae or feathers, I say, are disposed as two fans, 

 from the flattened, fleshy roots, of which both originate. A groove or 

 channel is so adapted in this fleshy portion, as to receive any foreign 

 matter falling on the rib, and passing downwards, whereby it is transmit- 

 ted to the organ between the two trowels, fig. 4. 



In regard to this particular organ, which originates much higher 

 than the trowels, inclining downwards, so as to share in their operations, 

 it is somewhat of the nature of a long triangular tongue, very thick and 

 broad at the root, but susceptible of dilatation as a scoop, or the sides 

 fold together longitudinally. 



The observer may be very long disappointed of obtaining a view of 

 these organs in the living subject. His search for them in others would 

 be hopeless. 



The Amphitrite ventilabrum is decked with various colours, all of 

 different shade and intensity, distributed in proportion ; according to the 

 specimen, red, green, and purple predominate. The expanded funnel 

 seems environed by so many vivid circles, from the bright spots with which 

 the branchiae are studded. One side of the body is greenish and brown, 

 with a brighter ellipse on each segment. The opposite side is greenish- 



