382 KEPORT 0^H>MMI8SI0NER OF FISH AND FISHERIES. 



alive ou the bottoms of vessels, and especially such as liave recently 

 arrived from tbe AYest Indies and other foreign countries. These 

 resemble, in general appearance, L. fascicularis, (Plate VII, fig. 33,) 

 which is a common indigenous species, usually found adhering to floating 

 sea-weeds and other small objects in early summer, in large numbers. 

 It is doubtful whether any of those found ou the bottoms of vessels 

 can be regarded as true natives of this region. The most common of 

 them is L. anatifera; the valves of its shell are bordered with orange. 

 The other common species are L. anserifera and L. pectinata. Species 

 of the curious genus, ConcJioderma, also occur on the bottoms of vessels. 



Among the Crustacea that commonly occur among the ascidians, 

 hydroids, and alga? on the piles of wharves, are Panopeus Sayi, (p. 312,) 

 P. dejrressus, (p. 312, Plate I, fig. 3,) Gammarus ornatus^ (p. 314, Plate IV, 

 fig. 15,) AmpliWioe compta S., (p. 370,) CoropMum cylindricum, (p. 370,) 

 Melita nitida, (p. 311,) Caprella, sp., (p. 316,) and various small Entomos- 

 traca. Ja'ra copiosa (p. 315) often occurs abundantly near high- water 

 mark, on old piles and timber, living in the crevices and cracks, or 

 under loosened bark. 



Of Annelids ver^' few if any species occur that are peculiar to these sit- 

 uations. The Potamilla oculifera (p. 322, Plate XVII, fig. SG) is quite 

 common on the piles of wharves where the water is i>ure. P. microph- 

 fhalma V. (p. 323) also occurs under the same circumstances, and also on 

 the piles in harbors, where the water is brackish. 



The Leprcva rubra V. was found living in tubes among the ascidians 

 on the piles of the wharves. This is a Terebelloid worm, somewhat 

 resembling the Amphitrite or)tata, (Plate XVI, lig. 82,) but is much 

 smaller, and there are fascicles of seta^- on all the segments. There are 

 three pairs of arborescently divided branchiie, which are pedunculated, 

 the last pair being quite small. The body is bright red, the tentacles 

 pale flesh- color. 



The Xicolea simple.v V. (p. 321,) was also found with the last in large 

 numbers, but mostly of small size. Both males and females of Nereis lim- 

 hata,{p. 318, Plate XI, fig. 51, male) were often found among the barnacles 

 and ascidians on the piles of the wharves at Wood's Hole, but the males 

 were the most abundant, while the reverse was the case with those dug 

 out of the sand and gravel on the shores. 



Numerous other Annelids were occasionally met with among the ascid- 

 ians and alga\ Among these were Polycirrus eximius, (p. 320, Plate 

 XVI, fig. 85;.) Podarle ohscura V., (p. 319, Plate XII, fig. 61;) a Phyl 

 lodoce, &G. Two Xemerteans were also common; one of these was an 

 olive-green species, with alight dorsal stripe, belonging probably to the 

 genus Cerebratulus, but it was not carefully studied ; the second was 

 PoUnia glutinosa, (p. 321, Plate XIX, fig 97.) 



Of Gastropod mollusks quite a number of species occur on the piles 

 of wharves, and some of them in great abundance, especially the smaller 

 kinds which live among the hvdroids and conferva?. The most abun- 



