2(50 



THALASSEMACEyE. 



by which the creature is here designated. Cuvier and 

 Montagu followed up the views indicated by Gaertner, 

 and to the great zoologist of Devon is due the credit of 

 first perceiving the true relations of the Thalassemacea? ; 

 for, speaking of this worm, he says, " I think it might 

 with propriety immediately precede Holothuria.'" Cuvier 

 afterwards held the same view of its position, and Brandt 

 has followed him. Lamarck, Blainville, and others, asso- 

 ciated the Spoon-worms with the true Annelida. After 

 having studied both the British species, in conjunction 

 with Mr. Goodsir, both zoologically and anatomically, and 

 observed one of them under most favourable circum- 

 stances alive, I hold them to be structurally Radiata, 

 and their relation with the worms to be a relation of 

 analogy. 



Montagu considered Gaertner's animal, as figured by 

 Pallas, to be identical with his own, but badly represented. 

 The figure given by Pallas, however, is not a bad one, but 

 very characteristic of the creature when preserved in spirits, 

 as may be seen on comparing it with my drawing, which 

 I made from a preserved specimen taken by Mr. Harvey 

 at Teignmouth, kindly communicated by Mr. Waterhouse. 

 As Montagu observed the creature alive, I prefer giving 

 his account of it, and then adding what information I have 

 gathered additional from an examination of the dead ani- 

 mal. He tells us it is " ovate-oblong in a quiescent state, 

 and rather more than half an inch in length, but sometimes 

 extends to more than an inch, and then changes its form 

 by alternately inflating each end. It is furnished with 

 annulations, which become ridged at the posterior end, 

 where it terminates in a point or nipple ; it has also longi- 

 tudinal stria? that decussate the annulations, giving it a 

 squamous appearance. At the anterior end the margin of 



