INVERTEBRATE FAUNA OF LABRADOR. 273 



Menipea ternata Busk ' 

 Eare. Straits of Belle Isle, fifty fathoms. Caribou Island, eight fathoms. 



Menipea fruticosa Pack. 1. c. p. 409, PI. I., fig. 3. 



This fine species grows an inch in height, with large wide branches, dividing dichoto- 

 mously The cells are large and long, being attenuated downwards. Above they are 

 truncated with four spines, two upon each side, and invariably with an outer projecting 

 snine when the others are absent. The upper valve is long, oval, and sunken; aperture 

 transversely linear, closed by a square incomplete lid. Cells contiguous, arranged m two 

 alternating rows, with two or three median ones before the origin of the branches. The 

 avicularia have long beaks, and are arranged sparsely at the base of the median cells. 

 Loner vibracula arise near the front of a few lower valves. The ovi-capsules are globose 

 and°smooth It is more nearly allied to M. cirrata of Europe than to any other species, 

 though very distinct. It is a common species, and occurs in Greenland, from whence I 



have a specimen. 



Serupocellaria americana Pack. 1. c. p. 409. 



This species is closely allied to S. scruposa, with specimens of which, collected by Dr. 

 Stimnson on the English coast, I have compared it. With much the same habit, our species 

 is twice as large and much more solid. There are the same relative proportions in the form 

 and size of the cells, but in our species the avicularia are smaller in proportion to the cell, 

 and there is but a single spine surmounting this appendage, the lip of the orifice being 

 unarmed, while in S. scruposa two spines are very constantly present on the inner side of 

 the cell. ' The lids or upper valves, which in my specimens are raised from the coenoeemm 

 by the relaxation of the muscles, are convex, and somewhat rugose, owing to several slight 

 transverse lines. The ovi-cells are smooth and globose. It is not infrequent on the Bank 

 in the Straits of Belle Isle. Belles Amours, eight fathoms ; Square Island, ten to thirty 



fathoms. Common. 



Acamarchis plumosa Busk. 



A. fastigiata (Fabr.) Faun. Gronl. 



Thomas Bay, at a depth of fifteen fathoms, in sand and mud. Rare. 



Caberea Hookeri Bosk. 



Our specimens present some differences from the British specimens in my possession, 

 collected by Dr. Stimpson ; and also from Mr. Busk's figures. It is abundant in Labrador, 

 and on the coast of Maine as far as Casco Bay. Mr. Smitt pronounces our form identical 



with the European. 



Halophila borealia Pack. 1. c. p. 409, PI. I., fig. 4. 



This species agrees well in its generic character with H. Johistonice Gray, from New 

 Zealand, though differing specifically, among other respects, in being multisenal. The 

 coenoecium forms soft and flexible, horn-colored tufts, an inch in height. The cells in 

 mature specimens are arranged in several contiguous series, and are very long, sub-clavate, 

 truncate, widening a little above, with sometimes a slight spine on the outer angle. The 

 aperture is transversely linear and closed by a slightly sinuate lid. The ovi-capsules are 



