INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 379 



staiitly sliatled, very few alg;e, aiul those only of the smallest and sim- 

 plest kinds, such as Ocillatoria^ and Diatoms, are to be found, liut iu 

 these shaded situations many auimals, such as Tubularians and other 

 Hydroids, some Ascidiaus, Bryozoa, &c., delight to dwell. Many of 

 these adherent Jiuimals also live iu abundance on the outermost piles of 

 the wharves, at or just below low-water mark, where they are more or 

 less exposed to the sunlight. 



The auimals that are found among or attached to the seaweeds 

 growing on the piles are, for the most part, identical with those that 

 are to be found in similar situations among the algte on rocks and iu 

 rocky tide-pools. 



Among those that are uearly or quite peculiar to submerged wood-work 

 are several species of '•'■ ship-worms," {Teredo of several species, and the 

 Xyloirya fimhnata,) which are bivalve mollusks ; the wood-eating Lim- 

 noria ; several species of barnacles, which belong to the Crustacea; 

 some of the tubularians, and other hydroids, &.G. 



Of the salt-water Insects two species have been observed on the piles 

 of wharves. One of these is a small, slender, green larva, with a dark, 

 firm head, and sharp jaws. It is the larva of a small, two-winged fly, 

 lirobably identical with the CMronomus oceanicus of Packard. 



On the piles of a wharf at Meuemsha, Dr. Edward Palmer found, iu 

 October, a very interesting insect-larva. It lived in a stout tube com- 

 posed of grains of sand firmly cemented together, and attached by its 

 whole length to the piles ; the single specimen is broken at both ends. 

 The tube is fiatteued, and consists of a central, subcylindrical, tapering 

 portion, or proper tube, which is covered on all sides with a single layer 

 of small grains of sand, ueatly arranged ; along each side of this, and 

 partly covering its upper surface, and to fill the angle between it and 

 the surface to which it was attached, larger grains of sand are cemented. 

 The in-eserved portion of the tube is about three-quarters of an inch 

 long and uearly one-quarter wide, at the larger end, but uot more than 

 half as wide at the small end. The larva is about a third of an inch, 

 long, rather stout, aud has a pair of long, sharp, curved jaws, and three 

 pairs of rather long, hairy legs. It belongs to the Phryganidoe, among 

 the Xeuroptera, aud somewhat resembles some of the well-knowu larva? 

 of the caddis-flies, common in fresh water, which make tubes or cases 

 of various kinds. Dr. Hagen, who has examined this specimen, refers 

 it to the genus Mohoma, of which three North American species are 

 known, but only in the adult state. All the larvie of this genus, known 

 in Europe, live in fresh water, aud no other species of the Phryganida^ 

 has been observed in sea-water, although some live in water that is 

 slightly brackish. 



Of Crustacea the most important species is the Lim )ioria lignorum, 

 (p. 370, Plate VI, fig. 25.) This little creature is grayish iu color, and 

 covered with minute hairs. It has the habit of eating burrows for 

 itself into solid wood to the depth of about half an inch. These bur- 



