164 FISHES. CHONDROPT. Ammoccetes- 



number and disposition of the teeth vary according to the age of the indivi- 

 dual. — This species enters the rivers from the sea, in the beginning of the 

 year ; spawns in March or April ; and, about mid-summer, returns again to 

 the ocean. 



The P. Jura, which Dr MacCulloch describes and figures in his " Western 

 Islands," ii. J 86, tab. xxix. fig. 1. probably belongs to this species, with which 

 it agrees in external characters. The differences in the teeth are at present 

 of doubtful value. 



Gen. II. AMMOCCETES. Pride— Maxillary ring with- 

 out teeth. Lips semicircular. 



3. A branchialis. Common Pride. — The two dorsal fins 

 narrow, united with each other and with the tail. 



Lampetra parva fluviatilis, Merr. Pin. 188. Ray, Syn. Pise 36. — Petro- 



myzon branchialis, Linn. Syst. i. 394. Penn. Brit. Zool. iii. 80 E 



Stone Grig In rivers in England. 



This species seldom exceeds 8 inches in length, and a quarter of an inch in 

 diameter. The body is marked by numerous transverse lines, giving it an 

 annulated appearance. Tail lanceolate. — Frequent in the rivers near Ox- 

 ford, and other places of England, lodging ki the mud. 



Gen. III. MYXINE. Hag— A temporal orifice. Mouth 

 round, the margin with eight processes, and a single large 

 tooth in the palate. 



4. M. glutinosa. Glutinous Hag. — Dorsal fin narrow, con- 

 tinued round the tail to the vent. 



Linn. Syst. ii, 1080. Penn. Brit. Zool. iv. p. 39, tab. xx. fl 15 On the 



English coast. 



Length about 8 inches. Body nearly cylindrical, and destitute of eyes or 

 scales. Margin of the tongue, on each side, with a series of pectinated teeth. 

 — This species, which seems to have been confounded with the preceding, by 

 Willoughby and ltay, and which was placed by Linneus among the vermes, in- 

 habits the ocean. It enters the mouths of fish when on the hooks of lines 

 that remain a tide under water, and totally devours the carcase, except skin 

 and bones. The Scarborough fishermen often take it in the robbed fish, on 

 drawing up their lines. It is the Gastrobranchus of Bloch. 



Pristis Autiquorum. The late Dr Walker, in his MS. Adversaria for 1769, 

 p. 41, when noticing some British fishes not in Pennant, adds, in reference 

 to this species, " Found sometimes in Loch Long." I have not met with 

 any other proof of its ever having visited the British shores. 



Gen. IV. SQUALUS. Sail-Fish. — Teeth simple, conical, 

 pointed. The first dorsal fin nearly above the pectorals. 



5. S. maximus. Common Sail-Fish. — Branchial apertures 



extending nearly across the neck, in front of the pectorals. 



Linn. Syst. 400 — Basking Shark, Penn. Brit. Zool. iii. 101. tab. xiii. 

 Home, Phil. Trans. 1809, p. 208 — E, Sun-fish ; G, Cterban ; N, Brug- 

 de.— Common on the west coast. 



