THE SOLENOSTOMID^!. 63 



surface of the bone covered with enamel. The openings of the gills are small, nearly vortical, slits just 

 in front of the pectoral fin. The vent is prominent, the dorsal and anal fins are triangular at the 

 base, and greatly elongated ; they join on to the caudal fin, which is narrow, and not very conspicuous, 

 though it runs the depth of the body. The back and fins are usually almost black, but the belly is a 

 bi-illiant white. Couch mentions that some small specimens have beautiful variations of colour in 

 stripes, with blotches of blue, yellow, and white. The stomach is long and large, the intestine thick, 

 and convoluted into a ball, and there is a large iirinary bladder which communicates with large 

 kidneys by two ducts. The Sun-fish is usually infested with parasites, which are found in the gills 

 and on various parts of the skin. 



The Oblong Sun-fish (Orthagoriscus truncatus) has the height of the body less than one-half its 

 total length. The mouth is about level with the eye ; the smooth skin is divided into small hexagonal 

 scutes. A specimen taken at Plymouth in 1734 weighed 500 Ibs., but it is not often met with of 

 a large size. It lives on worms, sea-shells, crabs, and other marine animals. A young specimen 

 twenty-five inches and a half long had the body twelve inches and a half deep, and the height, from 

 the tip of the dorsal fin to the tip of the anal fin, was twenty-one inches and a half. On this 

 specimen there were wavy vertical stripes both on back and belly ; only on the back they appear as 

 silver streaks on a dusky brown surface, and on the belly as greyish-brown streaks on a surface of 

 silver. It has never been noticed basking in the sun like the Broad Sun-fish. The caudal fin 

 is more distinct in this species, and the dorsal and anal fins form continuations from it. The pectoral 

 fin, which in the Broad Sun-fish is rounded at the extremity, in this species terminates in a point. It 

 is very rarely met with, but has been found in the English Channel, Bristol Channel, and the northern 

 coasts of Scotland, and ranges along the west coast of Africa by Sierra Leone and the Cape Seas, and 

 has been met with in the Pacific. A third species of Sun-fish (Orthagoriscus lanceolatus) is recorded 

 from Mauritius. It differs chiefly from this in having the caudal fin as long as it is deep. 



ORDER IL-LOPHOBRANCHII,* OR FISHES WITH TUFTED GILLS. 



The most remarkable characteristic of this order of fishes is found in the form of the gills, 

 for instead of being pectinated, or shaped like a series of combs, as in other fishes, they consist of 

 small rounded lobes clustered together, so as more to resemble the appearance of minute mulberries, and 

 yet are attached to the branchial arches. These gills are protected by a single large plate, which is 

 the only representative of the operculum. The snout is produced into a tube, and ends in a small 

 toothless mouth. The air-bladder, when present, is simple, without a pneumatic duct connecting it 

 with the oesophagus, though in one species Dr. Giinther has found a band leading from the oeso- 

 phagus to the air-bladder, which probably indicates the former existence of a duct, which has become 

 obliterated. There are only two families in this group, which are named Syngnathidse, comprising the 

 Pipe-fish and the Sea-horses, and the Solenostomidse, which contains only the genus Solenostoma. 



FAMILY I. SOLENOSTOMID^E. 



This family is distinguished by the great width of the openings into the chambers contain- 

 ing the gills, and by possessing two dorsal fins, with firm tmjointed rays in the first fin, while all 

 the other fins pectoral, ventral, anal, and caudal are well developed. These characters easily 

 separate Solenostoma from the Pipe-fishes. Of Solenostoma only three species are known. The genus 

 has a very simple intestine, dilated somewhat, so as to form a stomach, but without any appendages 

 in the pyloric region, so that the function of the pancreatic secretion in assisting digestion must be 

 rendered unnecessary by the nature of the food on which these animals subsist. The air-bladder is 

 absent. The ventral fins, which are opposite the anterior dorsal, are free in the male, but in the female 

 their inner margins are united with the covering of the body, so as to form a large pouch into which 

 the eggs are received to be hatched. The inner walls of this sac are lined with long filaments, which 

 are arranged along the seven ventral rays in series, and are most numerous at the base of the rays. 

 There is a canal in the interior of each filament, which may furnish a secretion for the attachment of 

 the embryo. The largest filaments have a length of half an inch, and are covered with little 

 appendages like mammae. The filaments are most developed in fishes which have already deposited 



* Lophos, a tuft ; branchia, gills. 



