PANTHALIS (BRSTBDL 405 



Pruvot and Racovitza's view that the spinning glands are the homologues of the 

 dorsal setigerons glands, forming the material for the tube instead of the dorsal bristles, 

 is not free from doubt. 



Reproduction, — In a large example procured in July, 1868, in Shetland (78 fathoms), 

 a series of large ova occurred in the perivisceral chamber. The embryo must therefore 

 attain considerable size before extrusion. 



Habits. — Like others of the group, Panthalis (Erstedi inhabits a tube of mud, about 

 3J inches long and about 1 J inches in diameter, with loose extensions of mucus at either 

 end, thus concealing the entrances, and for an example of which I am indebted to Prof. 

 Herdman. The estimated internal diameter of the tube is usually about f inch, while the 

 thickness of the walls in the centre is about J inch. The tube is composed of a number 

 of layers of the thread-like secretion interspersed with mud, these layers not being 

 parallel, but curving outwards, since, according to Mr. Arnold Watson, from whose 

 interesting account 1 of the habits of the species the foregoing is taken, rupture of the 

 anterior end frequently takes place. 



The animal crawls along the surface of the ground, can reverse itself in its tube, 

 and can also swim a little in the water. 



The American Euarche tubifex described by Ehlers 3 makes a curiously ringed 

 arrangement of the anterior end of the tube, probably due to the gradual narrowing of 

 the calibre of the tube at this end. 



Kinberg in 1857 described the species thus : — The cephalic lobe with the peduncles 

 equal to a fifth part of the length of the palpi, tentacular cirri longer than the tentacle ; 

 bristles of three kinds, subulate, serrulate, bipennato-penicillate, bearded. No f oot papillse. 



Marenzeller published an excellent account, with good figures, of the bristles, as 

 well as pointed out the functions of the spinning-glands in regard to tube-making. 



Pruvot and Racovitza give two new species of this genus from Banyuls with accurate 

 and beautiful figures, viz. P. Lacazii and P. MarenzellerL After a careful study of the 

 first-mentioned as given in the authors' descriptions and figures, I have doubts as to the 

 need for specific distinction from the British form, though there are a few minor varia- 

 tions, such as the increased size of the so-called branchial papilla in front. It would 

 also appear to be a question whether the French authors have not placed too much 

 weight on the mere curvature of the ventral bristles of their Panthalis Marenzelleri* 

 especially as Kinberg's artist may have had a mounted preparation for illustration, and 

 thus the curves would disappear. The twist or double curvature referred to is present in 

 all the examples of Panthalis CEJrstedi that have come under my observation, and the 

 bristles of the first pair of feet (bearing the tentacular cirri) are likewise present. The 

 comparative length of the tentacle is not always to be relied on, though in young 

 specimens the tentacle seems to be about the same length. The same remarks apply to 

 the median papilla of the proboscis. The absence of the ceratophore is remarkable. 

 The bristles in young forms show the finer characters better than in the adults — in which 



1 Ibid., pp. 170, 183, &c. 



2 < Annelida of the " Blake," ' &c, p. 54, Taf. 12, 13. 



3 " Faune des Annel. de Banyuls," 'Arch. Zool. exper./ 1895, p. 451. 



