96 Arenicolidae 



cephalic region not club-shaped but tapering, and the reticulation of 

 the anterior end are worthless as systematic characters, for they 

 depend largely on the degree of extension, and therefore on the 

 mode of preservation adopted. Girard's specimens, which were from 

 Chelsea, Mass., were examples of A. marina, which species has been 

 recorded from other stations in the same State. 



A. papillosa has been considered already (p. 93). A. tindoria 

 was a light-coloured example of A. marina. It was denned by 

 Leach as having ' : body yellow, inclining to cinereous, beautifully 

 banded with blue ; organs of respiration blood-red, tail greenish." 

 There is in the British Museum Collection a specimen labelled 

 " Arenicola tindoria, Musselborough, Frith of Forth. Mus. Leach," 

 probably the type specimen of this species. It is light brown in 

 colour, and in life was probably similar to that represented in PI. I, 

 Fig. 1, which was also obtained at Musselburgh. 



The small worm described and figured by Claparede as Clymenides 

 sidplmrca or sill/urea was almost certainly a post-larval example 

 of A. marina, as were also undoubtedly the specimens designated 

 C. sulfiLreus by Prof. Mesnil (pp. 75-77). 



Pallas's account and figures of Nereis lumbricoides, and his remark 

 on its use as bait for Gadus and Pleuronectes, show clearly that this 

 worm was A. marina. The description given by Linnaeus of the 

 common " Orin " shows that the lugworm was before him, although 

 he attributed to it twenty pairs of bristles. 



BIONOMICS, VARIETIES, SIZE. Arenicola marina is abundant in 

 northern and western Europe J on numerous beaches, where the sand 

 is not shifting and contains a considerable proportion of the decom- 

 posing organic matter on which these worms feed. They are often 

 very numerous near sewage outfalls, and in other places where a 

 rich diet of decomposing matter is available ; their absence or com- 

 parative fewness in other stretches of sand depends on at least two 

 factors (1) the purity of the sand, that is, the almost total absence 

 of food ; (2) the force of the sea and the constantly shifting character 

 of the sand. A. marina is usually present only in small numbers 

 on sandbanks well out to sea, and on certain beaches where 

 decaying matter is scarce ; its absence from other beaches is accounted 

 for by the second factors named above. Some idea of the abundance 

 of the worms in favourable situations may be obtained by reference 

 to the enumerations of their castings given on p. 99, and by the 

 1 For an account of the distribution, see p. 101. 



