[487] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC 4 . 



ilit,) which it somewhat resembles in form. The color is very 

 it is often bright yellowish greeu, but frequently dark green, brownish 

 green, or brown. 



The Nereis virens (p. 317, PI. XI, figs. 47-49) is very abundant in bur- 

 rows beneath the rocks. The males of this species, six to ten inches or 

 more in length, and of a dark green color, were found at Watch Hill, 

 April 12, in great numbers, swimming about in the pools of water among 

 the rocks, with an undulatory motion, and discharging their milt in large 

 quantities. Various other Annelids burrow or build tubes beneath the 

 stones. A.planaria and Leptoplana folium creep over their lower sur- 

 faces. 



Attached to the stems of Fmus at low-water, several Hydroids may 

 usually be found, but the Sertularia pumila (p.. 327, PI. XXXVII, tig. 

 279) is by far the most abundant. The Obelia geniculata is also very 

 common, attached to Laminaria and other alg3. Various Bryozoa occur 

 attached to stones and to Fucus and other alga?. The Alcyonidium 

 hispidum (p. 312) is one of the most abundant species, and usually in- 

 vests the stems and fronds of Fucus vesiculosus, but also often covers 

 broad surfaces of the rocks. The A. hirsutum is often associated with 

 the preceding species on the rocks; it forms broad, thin, soft crusts, cov- 

 ered with small soft prominences, but is without the spines or bristles 

 seen in the latter. The Zooids are also much smaller. 



The Farrella familiar is is a singular and delicate species, which occurs 

 both on the under side of rocks and on alga3. The body is small, fusi- 

 form, attached by a long and very slender, flexible pedicel. When it 

 surrounds the stems of small algne, the whitish pedicels project outward 

 in all directions, and thus produce the appearance of a delicate chenille- 

 cord. This is a nor them and European species. It was also dredged on 

 Saint George's bank in 1872. 



List of species found on the outer roclcy shores. 



ARTICULATA. 



Crustacea. 



Page. 



Cancer irroratus 486 



Cancer borealis 486 



Pauopeus depressus 312 



Panopeus Sayi $12 



Homarus Arnericanus. 492 



Orchestia agilis 315 



Hyale littoralis 486 



Calliopius Iseviusculus 315 



Gamin a-rus ornatus 486 



(jam mar us aunulatus. . 486 



Page. 



Gammarus marinus 486 



Amphithoe maculata 4*6 



Arnphithoe, sp 4S6 



Caprella, sp 316 



Jrera copiosa . , I >( 



Idotea irrorata 486 



I. phosphorea ... : ^ { > 



Erichsonia filiformis " 1 6 



Balanus balauoides 486 



