MARINE INVERTEBRATA OF GRAND MANAN. 15 



mark in the summer, at some localities, but these are always small, and never more 

 than half grown. The large individuals, some of which are a foot in diameter, are 

 found only in deep water, chiefly in the laminarian zone. 



S. PAPPOSA, Forbes, 1. c. This species is rare in this region, and small specimens 

 only are found. They usually occur on shelly bottoms in the coralline zone. 



PTERASTER MILITARIS, M. et T., 1. c., 128. This is perhaps the most remarkable of the 

 Asteriadce, presenting, as it does, the singular phenomenon of a web among these 

 lower animals. A soft flexible membrane connects the ambulacral spines, the in- 

 ner rows transversely, the outer longitudinally; also the spines surrounding the 

 mouth, and those surrounding the large anal pore. In one of my specimens, where 

 this anal pore is widely open, the cavity is distinctly seen to divide into five large 

 channels, corresponding to the five interspaces between the rays. These channels 

 pass underneath, and parallel to, the skin, and, from their action in life, I am in- 

 clined to consider their function, at least in part, respiratory. It is perhaps super- 

 fluous to say this, when we know that this function is performed by the whole 

 surface of the skin ; the webs seeming especially qualified for the office. When, 

 however, we place a living Pteraster and a Holothuria in the same jar, and see the 

 same action of inhalation and expulsion of water going on at the anal aperture in 

 each, it is difficult to refrain from considering its object the same in both, especially 

 when they are so closely related zoologically. 



This starfish has hitherto been observed only in Northern Europe, and in Green- 

 land, where it would seem to be rarely found. At Grand Manan, I took three 

 specimens, all of which occurred in the Hake Bay, in 35 fathoms, shelly bottom. 



GONIASTER PHRYGIANA. Asterias phrygiana, Parel. Goniaster equestris, Agass. 

 Astrogonium plirygianum, M. et T., 1. c., 52. A large specimen was taken off Duck I., 

 in the coralline zone. It was bright red above, and bright yellow below, being by 

 far the most elegant of our starfishes. The minute vesicles which protrude from 

 the dorsal pores, are short and tipped with black. The eyes are very dark red in 

 color, and the suckers near them are very long and slender, especially a single one 

 just above each eye. 



CTENODISCUS CRISPATUS, Dub. et Kor., Skand. Echin., 253. This fine starfish is 

 by no means rare in New England, although not yet noticed by our naturalists. 

 At Grand Manan, it occurred on muddy bottoms in fifty and sixty fathoms. 



ECHINUS GRANULATUS, Say, Gould., Inv. Mass. The rocky shores of the islands 

 in this region are covered Avith a zone of EcJiini, extending from the ordinary low- 

 water mark, to a depth of half a fathom. In this zone, these animals are so crowded 

 together that it is impossible in most places to thrust an oar to the bottom without 

 striking some of them. Among them are found several varieties, perhaps species, 

 which an extended investigation only can elucidate. The most common form is of 

 a dark gjeen color, with short blunt spines, the same, in fact, as that found in 

 Mass. Bay, but much larger (three inches in diameter). Among the younger 

 specimens, are found some with very long spines, as in E. virens, Dub. et Kor., 



