INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 507 



The principal localities where we dredged on the bottoms of fine sandy 

 mud are as follows: SO, c, south of Martha's Vineyard, in 21 fathoms; 

 84, &, southwest of Gay Head, in 16 fathoms; 87, a, &, about fifteen 

 miles east of Block Island, in 29 fathoms. At the last locality the tem- 

 perature, on September 14, was G2° P. at the surface, and 59° at the 

 bottom. 



Among the Crustacea none was more abundant on the soft, muddy 

 bottoms than a small species of Ampelisca, which inhabits soft, flabby 

 tubes, covered with fine mud. When taken out of the water these tubes 

 are always collapsed and flat, and they were so abundant in the mud 

 that it was almost impossible to wash it through the sieves, because 

 they soon became completely clogged up with the tubes. When a quan- 

 tity of the mud was left in a bucket of water these Crustacea would 

 come out of the tubes and rise to the surface in large numbers. This 

 species is generally quite pale, or nearly white. Its body is much com- 

 pressed. 



Another variety, or perhaps a distinct species, found with the last, is 

 pale flesh-color, with a row of bright red spots along the middle of the 

 back ; the antennae were specked with red ; eyes bright red ; epimera 

 reticulated with red lines ; and the legs and caudal appendages are 

 more or less marked with red. 



The Unciola irrorata, (p. 340,) Ptilocheirus pinguis, and other Am- 

 phipods, were associated with the precediug species. 



The Diastylis quadrispinosa (Plate III, fig. 13) was very abundant on 

 the soft muddy bottoms, together with other species of Cumacea, not 

 yet identified. It is pale flesh-color, with a reddish purple patch at the 

 posterior part of the carapax, and two small spots of pink. 



The Annelids were very numerous, both on the soft muddy bottoms 

 and in the sandy mud. One of the most conspicuous species is the 

 Aphrodita aculeata, which was common in the soft mud. This is a large, 

 stout Annelid, the largest specimen obtained measuring about 3 inches 

 in length, and about half as much in breadth. It is remarkable for the 

 exceedingly numerous and long setre of many kinds, which cover its sides 

 and back, except along a narrow dorsal space; some of these setce are 

 stout, and nearly an inch long, with sharp points, and barbed near the 

 end, and they curve over the back much like the quills of a porcupine, 

 and are liable to inflict painful wounds, if the creatures are carelessly 

 handled. These setse usually reflect bright, iridescent colors. 



Several other northern European species, found also in the Bay of 

 Pundy and at Saint George's Banks, were also met with. Among these 

 were Lumbriconereis fragilis, Scolecolepis cirrata, Melinna cristata, 

 Terebellides Stroemi, and several more common species. 



The Nephthys ingens (p. 431, Plate XII, figs. 59-60) is a very abundant 

 species on these bottoms and grows to a large size. 



The curious Stemaspis fossor (Plate XIV, fig. 74) is quite common ; 

 and the Trophonia affinis (Plate XIV, fig. 75) was dredged several times. 



