Mr. A. Alcock on Indian Dathyhial Fishes. 363 



Uroconger, Kaup. 



24. Uroconger vicitiusj Vaillant. 



Uroconger vicinns, Vaillant, Exp^d. Sci. du * Travailleur ' et du ' Talis- 

 man,' Poiss. p. 80, pi. vi. fig. 1. 



A large female, 25 inches long, witli gravid ovaries, from 

 Station 132, 475 fathoms. 



The stomach in this specimen has a large CEecum, a much 

 constricted pylorus, and a raucous membrane of two entirely 

 different kinds, that in the anterior half being of an almost 

 horny hardness, while that in the posterior half is soft and 

 glandular. 



In vertical longitudinal sections of the stomach-wall, 

 carried through the abrupt line of demarcation between the 

 two differing regions of mucous membrane, examined under 

 the microscope, the following structure is seen : — 



(1) Common to both regions of the stomach : (a) an external 

 thin fibrous coat, one fortieth to one sixth of a millimetre 

 thick, with many longitudinal bundles of muscular fibres and 

 large blood-vessels ; {b) a very compact thin coat of trans- 

 verse muscular fibres, about one eighth of a millimetre thick ; 

 (c) another very compact layer of longitudinal muscular fibres, 

 about one seventh of a millimetre thick ; [d) a very thick 

 (|-1| millimetre) submucous coat made up of a loose mesh- 

 work of branching and anastomosing small-nucleated cells, 

 the meshes being filled with lymphoid cells ; this coat also 

 contains many blood-vessels, which frequently traverse in their 

 course large, compact, sharply-circumscribed nodules of 

 lymphoid tissue, and a great many branching pigment-cells. 



(2) The mucous membrane of the anterior part^ which is 

 about one eighth of a millimetre thick, appears at first like a 

 superficial layer of pure fibrous tissue ; but good sections 

 show that it consists of a stratified epithelium with its con- 

 stituent cells compressed somewhat as in the horny layer of 

 the human epidermis. These compressed (horny) cells,' how- 

 ever, are not flattened into plates to form a smooth surface, 

 but are angularly concreted to form a broken rough surface. 

 Beneath the superficial horny layer are several rows of cells 

 of which the granular protoplasm seems to be fused into a 

 solid mass, leaving only the nuclei distinct ; and beneath this 

 again comes fibrous tissue gradually passing into the loose 

 submucosa. 



(3) The boundary-line between the anterior horny mucosa 

 and the posterior soft mucosa is very abrupt, and in every 

 section there is seen a conspicuous thickening of the sub- 



25* 



