NOTE ON A NEW BRITISH ECHIUROID GEPHYREAN. 369 



afterwards to Canon Norman I told him of the specimens, 

 and stated that I thought they were probably pieces of two or 

 three large Bonellia viridis. On looking at the specimens 

 more carefully, however, and on talking the matter over with 

 Professor Lankester, I came to the conclusion that, from the 

 proportions of the body and proboscis (even supposing the 

 latter to be imperfect at the extremity), it was impossible for 

 the species to be a Bonellia, and that it was much more likely 

 to belong to Thalassema, as 1 had at first supposed. The 

 detailed anatomical examination which I have since made 

 proves this latter view to be correct. The specimens belong 

 either to a new species of Thalassema, which comes near 

 T. gig as, M. Miiller, from the Adriatic, or represent a new 

 genus close to Thalassema in the direction of Hamingia. 

 I incline to the former view (see below, p. 381), and shall 

 describe the species asaThalassema. 



Anatomy. 

 The three specimens in my possession are all imperfect. 

 They are certainly pieces of two, and possibly of three distinct 

 worms. I believe they make up between them a complete 

 body, or very nearly so ; there may be a very short piece in 

 the middle of the body missing, but it cannot be much, or of 

 any anatomical importance. Consequently the restoration 

 shown in fig. 4 must be fairly correct. The dimensions and 

 positions in the body of the fragments are as follows : 



A. Anterior half (?) with proboscis (probably incomplete at 

 tip) ; body about 3 cm., proboscis about 9 cm. in length ; 

 preserved in formol (see PI. 27, fig. 1). 



B. Posterior two thirds (?) of the body, measuring about 

 8 cm. in length ; preserved in formol (PI. 27, fig. 2). 



c. Anterior half or more (?) with proboscis (probably com- 

 plete) ; body about 8'5 cm., proboscis about 8 cm. in length; 

 preserved in spirit (PI. 27, fig. 3). 



Possibly A and b may be the two halves of the same speci- 

 cimen, and even if the body be longer than I take it to be, 

 B and together probably represent the whole of it, even if 



