266 F. M. Turnlmll — Aviatomy and Habits of JSfereis virens. 



al)le freedom and rapidity, pusliiiig themselves along by means of 

 their aciculse, setse and ligula^, the acicuhe being controlled by 

 special muscles. They hold their tentacular cirri straight out in 

 front of them, as they move, in order to have warning of anything 

 that they may approach. 



The tautog, scnp and other fishes dig them out of the sand and 

 devour them eagerly. But at certain times, especially at night, they 

 leave their burrows, and swim about like eels or snakes, in large num- 

 bers, and at such times fall an easy prey to many kinds of fishes. 

 This habit seems to be connected with the season of reproduction. 

 They were thus observed swimming at the surface in the day time, 

 near Newport, in April, 1 872, by Mr. T. M. Prudden and Mr. T. H. 

 Russell, and several times by Professor Verrill, later in the season. 

 At Watch Hill, R. I., April 12th, 1873, Professor Verrill found great 

 niimbers of the males swimming in the pools among the rocks at low- 

 water, and discharging their milt. The males were also seen swim- 

 ming in the tide-pools and shallow waters at Savin Rock, April, 1875, 

 by Professor D. C Eaton and Mr. Kleeberger. The JVereis virens is 

 abundant at all seasons of the year, in most places along the sandy 

 and muddy shores, both of the sounds and estuaries, burrowing near 

 low-water mark. It occurs all along the coast, from New York to 

 the Arctic Ocean, and is also found on the northern coasts of Europe.* 



The body consists of a large number of rings or segments. This 

 number varies with the size and age of the worm. It may be less than 

 one hundred, or as many as two hundred. The increase in length 

 takes place by the addition of new posterior segments, in advance of 

 the caudal segment. New segments may also be formed when a part 

 of the body is broken oif, and in this way a considerable part of the 

 posterior portion of the body can be completely reproduced. The head 

 (figs. 1 and 17) is very fully developed, being provided with two 

 pairs of eyes and two pairs of antennae. It is attached to the dorsal 

 side of the first segment, wliich is called the buccal or mouth-ring 

 (figs. 1 and 15, d), because it contains the mouth (fig. 15, ni). There 

 are also four feelers, called tentacular cini (fig. 1, ee, ee', e and e'), 

 arising from the buccal ring on each side of the head. 



The abdominal rings (fig. 1, g) follow the buccal ring. Each one 

 of these has a pair of lateral lamelliform appendages (figs. 1 and 1 7, A), 

 used as paddles in swimming and also Serving the purpose of gills. 

 The last segment or ring of the body bears a pair of cirri, similar to 

 the tentacular cirri, and also contains the anal orifice. 



* See, for habits of this and allied species, Professor VerriU's report in First Report 

 of U. S. Commission of Pish and Fisheries, p. 318. 1873. 



