76 A Dredging Excursion. 



A good deal of judgment is required for the regulation of the 

 line : if too long, the dredge will be in danger of getting fast ; 

 if too short, it will only skim the bottom. If the bottom 

 be sandy or muddy, the boat must have pretty good way on 

 her or the dredge will bury itself. If rocky, or composed of 

 boulders, shorten the line, or the strain will break it : but expe- 

 rience is the only teacher ; and the feel of the line soon tells 

 whether the dredge be properly bumping or scraping the 

 bottom. Before lowering the dredge a weight is to be fastened 

 on the line, a fathom or two from the handles, in order to keep 

 the strain as near as possible on the plane of the bottom. 



Sweeping thus along, whatever comes in the way of the 

 dredge is draughted into it, the water escaping through the 

 meshes, and leaving the live desiderata and dead shells in the 

 inside. It is often advisable, especially in dredging over hard 

 and pebbly ground, to have a lining-net inside the dredge- 

 net. This should be made of bunting, and will often secure 

 rare shells, such as Mangelia, Scalaria, etc., which would other- 

 wise have escaped with the rush of water. When a sufficient 

 distance has been traversed, or the straining of the rope seems 

 to render it desirable, the boat is brought to, the dredge and 

 its contents hauled on board and capsized into a sieve of quarter 

 of an inch mesh, or, as we are amateurs, a basket, which will 

 answer our purpose just as well. 



And now begins our real work.- "What," cries Mr. Deli- 

 cate Faintheart, " do you call it delightful and fascinating to 

 poke about in that dirty black mass of mud and stones ? If that 

 be the only way to secure specimens for aquarium or microscope, 

 I beg to decline having anything to do with either," and our 

 fastidious friend returns to his sandwiches : we laugh at him, 

 and set to work all the more vigorously. In the basket we find 

 a portentous mass of dirt, stones, crabs, sea-urchins, oyster 

 shells, etc. ; at once we pounce on them, and our one compa- 

 nion becomes quite excited as he fumbles among the mud, having 

 come across a crab, and finding, when he has worked the mud 

 off his shell covering, that he has discovered the rarer species of 

 Hyas. Hyas coarctatus, or the contracted spider crab, his cara- 

 pace, or shell, is in form somewhat between a fiddle and a lyre ; 

 the first pair of legs half as long again as the body. He is the 

 largest yet met with there, his carapace measuring 1*7 inches by 

 1*1 inches. Put him into water and you will see that those dirty- 

 looking things upon the back are beautiful zoophytes. I have met 

 with this species in Greenland. Crawling over the surface of the 

 stones and mud, I see a long-legged spider crab, with a very 

 small back ; no other Stenorynchus having been found here, you 

 may be pretty sure he is 8 '. phalangium ; the second pair of 

 legs in this crab are almost four times the length of the body, 



