568 Arenicola branchiulis^ ecaudata, and piscatbrum. 



rings separated by an impressed line, their own divisions 

 marked by an elevated band very obvious when the worm con- 

 tracts ; first segment conoid, each of them furnished with a 

 pair of setigerous feet protruding near the band of separation, 

 the first pairs small, gradually enlarged on the other segments ; 

 the seventh pair with a small branchial tuft at its base, and 

 every foot behind this has a similar but larger tuft: branchiae 

 red or purple, arborescent, consisting of several principal 

 branches, which are much divided, the divisions spreading, 

 papillary: bristles yellow, not very numerous, unequal, slightly 

 curved towards the sharp point, smooth : underneath this 

 setigerous foot there is a transverse fold, armed with a series 

 of crotchets shaped like the italic letter,/*; they are few under 

 the first pairs, but become more numerous under the branchial 

 pairs, forming a ridge which meets its opposite on the mesial 

 line : the tail is equal to the rest of the body in length, the 

 segments indistinct, but often constricted at intervals, and 

 sometimes so regularly, that it might almost be described as 

 moniliform. 



Arenicola branchialis has not been noticed as yet on the 

 British coast : it is smaller than the preceding, and, in this 

 respect, as well as in the number of the branchiae, approxi- 

 mates the A. ecaudata, from which I might not have considered 

 it distinct, had any specimen of the latter exhibited any trace 

 of posterior abranchial segments; and the fishermen assure me 

 that the want of a tail is an invariable character. 



Arenicola ecaudata {Jig. 54.) is from 6 in. to 8 in. long, 

 very contractile, minutely granular, of a yellowish-brown, 

 tinted in many places with green and yellow, or sometimes 

 very black, glossed with green : the primary rings seem to be 

 composed of only four intermediate ones : the first fourteen or 

 fifteen pairs of setigerous feet are destitute of branchiae, but to 

 every foot behind these there is appended a dark red arbo- 

 rescent branchial tuft ; in one specimen there were twenty-two 

 pairs, in another twenty-five ; the first few pairs are smaller 

 than those about the middle, whence they again decrease to- 

 wards the tail. In other respects, the structure is similar to 

 that of Arenicola piscatorum. 



The lug-worms burrow in the sand, prefering a station near 

 low-water mark. The hole is about 2 ft. in depth, and the 

 presence of the worm is detected by the spiral rolls of sandy 

 excrement coiled above its aperture ; for these worms twist 

 their " ropes of sand " with an ease which spirits might envy *, 



* " The formation of ropes of sand, according to popular tradition, was 

 a work of such difficulty, that it was assigned by Michael Scot to a number 



