318 PLAGIOSTOMATA. 



If inches long, and from this size numbers down to a mere speck. Also nine 

 young, 9^^ inches long each, in the oviduct, some of them so slightly 

 adhering that in a very short time they would have been extruded. Five 

 were males and four females. Mr. Eagle Clarke (Sept. 26th, 1883) observes "the 

 other day, I exam.ined a young Acanthias vulgaris, which along with five others 

 had been taken from the uterine cavity of a female specimen, captured off the 

 Isle of Man about the middle of this month. This embryonic specimen was 9f 

 inches in length, a perfect miniature of the mature iish, and having the pikes well 

 developed. From the anterior half of the belly it was connected by an umbilical 

 cord or tube, 1^ inches long, to an umbilical vesicle or yolk sac, about the size of 

 a pigeon's egg. On the back it was pale blue-gray, spotted, especially above the 

 lateral-liae, with white spots : beneath it was white." Dr. Ball (Proc. Roy. Irish 

 Acad. April 27th, 1846) describes the apparatus by which the mother is defended 

 from laceration from the spines of her young. The spines of the foetus are of as 

 hard and bony a consistence as in adults. 



Uses. — Oil in places (as the Orkneys) is made from the liver, while the skin 

 used to be employed to polish wood, and the garbage makes excellent manure. 

 Mitchell observes that the greater number taken at New York in December were 

 females in a gravid state. Storer says they are so numerous about Cape Cod that 

 they form in the spring and autumn an important fishery for the oil they furnish. 

 They are true scavengers of the sea. 



As food. — This fish is dried and eaten on many parts of our coasts ; it is rather 

 strong tasted, but largely employed by the poor as food in the Hebrides, and sold 

 as Darwin salmon. It is cut open and dried, and is so full of oil that it does not 

 decompose. In the west of England it is a common article of food with the 

 fishermen ; it is used both fresh and salted. Also in Ireland it is consumed in 

 some parts by fishermen. 



Diseases, ^c. — Couch has taken this shark from the stomachs of ling, blue-sharks, 

 and other fishes. In a healthy female example, heavy with young, captured 

 March, 1868, there was seen at the base, and clinging all round the spine of the 

 second dorsal, a healthy growing specimen of the sea-hair coralline, Sertularia 

 operculata (Cornish, Penzance, Zool. 1868, p. 1222). 



In January, 1884, Mr. Dunn sent me from Mevagissey one of these fishes, 

 27 inches long, in which the entrails and flesh vvere entirely consumed, only the skin 

 and skeleton remaining, and numerous isopods, Gonilera cylindracea, which had caused 

 this destruction. It appeared that the dog-fish had been captured in a mullet-net, 

 which had been set to secure some smaller spotted dog-fish, of which as many as a 

 hundred had been netted at one time, but every fish, except the smaller spotted 

 dog-fishes and two picked-dogs, were consumed like the specimen sent to me. 



Habitat. — This species has been recorded from the temperate seas of both the 

 northern and southern hemispheres, but not from the intermediate localities. It is 

 found in abundance all round the British coast, and especially so off' Cornwall, where 

 as many as two thousand have been taken at one time, and that without apparently 

 diminishing the stock. Mr. Saxby remarks of this fish that at Newfoundland, during 

 the last five or .six years, it is thought to have been " cursed away " (Zool. 1871, 

 p 255.3). In the Orkneys and Shetlands very abundant (W. Baikie, Zool. 1853, 

 p. 3846), and Pennant observes that it swarms on the coast of Scotland. Banffshire 

 plentiful (Edward). In March, 1858, the nev?spapers reported a prodigious 

 school of dog-fishes reaching westward to Uig, from whence it extended from 

 twenty to thirty miles seawards, and in an unbroken phalanx eastward 

 to Moray, Banff, and Aberdeen (Tarrell), at which latter place it is termed 

 sea-dog (Sim). Often caught on the deep-sea lines of the fishermen at St. 

 Andrew's (M'Intosh) : Berwickshire, very common (Johnston). Abundant off 

 Yorkshire, and termed sea-dog (Yorkshire Vertebrata) ; also off Norfolk estuary 

 and along the east coast; it is found in numbers at most of the fishing-stations 

 along the south-eastern coast, round to Kent and Sussex (Yarrell). Very 

 common off Devonshire (Parfitt) and Cornwall. Swansea (Dillwyn). 



In Ireland it is found around the coast. 



It attains to at least 4 feet in length off our shores. The one figured is a 

 young specimen, 12 inches long, from the coast of Su,ssex. 



