456 THE DEPTHS OF THE S1U. [CHAP. ix. 



numerous, for species of Asteracanthion, Cribrcllti, 

 Asteriscus, and Ophidiaster- are as abundant as they 

 are at lesser depths ; but as we go clown new species 

 with tesselated mailing on the disk and massive 

 marginal plates seem to be perpetually added. In 

 our own seas some few very characteristic forms, 

 such as Astrogonium phrygianum and Ar chaster 

 andromeda and parellii, are on the verge of the deep 

 water, and are now and then taken at the outer 

 limit of shore dredging, or on fishing-lines ; while in 

 the deep water all along the north and west of Scot 

 land Astrogonium granulare, Archaster tenuispinus, 

 and Astropecten arcticus abound, and the dredge 

 is enriched from time to time with examples of such 

 forms as Archaster bifrons (Fig. 74), A. vexillifer, and 

 Astrogonium tongimanum, MOBIUS. Many additions 

 have been made to the singular little group of which 

 Pter aster may be taken as a type, but I am inclined 



to think that these are to 

 be referred along with most 

 of the characteristic Ophiu- 

 ridans rather to a fauna in 

 habiting median depths, and 

 coming within range of the 

 naturalist's dredge on the 



o 



coast of Scandinavia, than 

 to the abyssal fauna ; and 



FIG. 75 Solaster furcifer, VON DOBEN 



<o ^rSo ) ral aspect * tlie same ma y be said of a 



few other forms, such as 



Solaster furcifer (Fig. 75), and Pedicellaster typicus 

 which, although beyond the 200-fathom line on the 

 coast of Britain, do not appear to have a great 

 range of depth. 



