INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 323 



around to the sides, open upward by a free extremity ; they also fre- 

 quently occur in sheltered nooks in the tide-pools. The worm, when un- 

 disturbed, puts out a beautiful wreath of branchiae somewhat resembling- 

 that of the Serpula, but there is no operculum. The branchiae are always 

 beautifully colored, though the colors are quite variable. In one of the 

 commonest styles of coloration, the branchiae are surrounded at base 

 with reddish brown ; above this with a ring of white ; next by a band 

 of reddish brown ; then for the terminal half the color is yellowish gray, 

 with indistinct blotches of brown ; on the outer sides of the branchiae 

 there are one to three dark red eyes. There are ten or more branchiae 

 in each half of the wreath, and they are longer on one side than on the 

 other. 



Another related species, the Sabella microphthalmia Y., also occasionally 

 occurs in the pools and on the under sides of stones, constructing tubes 

 very much like those of the last species. This is a much shorter and 

 stouter worm, with the branchial wreath relatively much larger and 

 nearly half as long as the body. The branchiae are pale yellowish, 

 greenish, or flesh-color, with numerous transverse bands of darker green 

 extending to the pinnae ; on the outer side of the branchiae there are 

 numerous minute eye-like spots of dark brown, arranged in two rows on 

 each. The body is usually dull olive-green. The Fabricia Leidyi V., is 

 another member of this group of worms, but is of very minute size. It 

 constructs delicate, flexible tubes, free toward the end, which usually 

 stands upright. Its tubes may be found in the pools and on the under 

 side of stones. The worm itself is very small, slender, and when un- 

 disturbedj)rotrucles a wreath, composed of six branchiae, to a considera- 

 ble distance above the mouth of the tube. The branchiae have five 

 to seven pinnae on each side, the lowest much ^the longest, so that when 

 expanded they all reach nearly to one level. At the base of the bran- 

 chiae there are two pulsating vesicles, alternating in their beats 5 and 

 just back of these there are two minute brown eye-specks ; two similar 

 eyes exist at the posterior end. Eleven segments of the body bear fas- 

 cicles of setae. Color yellowish white, the blood-vessels red. 



Two or more species of the minute but beautiful worms belonging to 

 the genus SpirorMs are found attached to the fronds of sea- weeds, to 

 shells, stones, &c, especially in the pools. These are related to the 

 Serpula, and like it form solid calcareous tubes, but these are always 

 coiled up in a close spiral, and the coil is attached by one side. The 

 little worms put out an elegant wreath of branchiae, and are furnished 

 with an operculum. Another very interesting and beautifully colored 

 worm, sometimes found under and among the stones, where there is 

 mud, is the Cistenides Gouldii V., (Plate XVII, figs. 87, 87a.) This 

 constructs very remarkable, conical, free tubes, of grains of sand ar- 

 ranged in a single layer, like miniature masonry, and bound together by 

 a water-proof cement. This worm belongs more properly to the muddy 

 and sandy shores and will be mentioned again. 



