454 Surveij of Fishing-Grouiuh, West Coast of Ireland, 1890—1891. 



ojDportunity occurred of examining by night any other species of macruri during 

 the Survey ; but since 31. lacvis also possesses a black, scaleless dej^ression between 

 the pelvic fins, and shows some traces of an internal arrangement similar to that 

 met with in the species before us, it seems possible that this gland-like body may 

 be in some way functional for purposes of illumination. 



The peritoneum is thickly speckled with black ^^igment, but the mouth is 

 white. 



The rectum comes almost jjerpendicularly downwards towards the vent, and 

 the reproductive organs which are situated at the jDosterior extremity of the 

 abdominal cavity send their ducts forwards and downwards. On the left side a 

 long lobe of liver extends the entire length of the abdominal cavity, and bends 

 into a median position jDosteriorly. The riglit lobe of the liver is insignificant, 

 but on this side of the body a fold of the intestine passes backwards. The pyloric 

 coeca are numerous, but not to the same extent as in 31. laevis. The stomach 

 is large and rounded, the duodenum springing from the centre of the inferior 

 surface. 



The viscera completely filled the cavities of the specimens examined ; and in 

 an examjDle of fair size (23-7 cm.) which had the ajopearance of being a mature 

 male, the testes were joined together posteriorly so as to form a single-forked 

 organ. 



The air-bladder is attached laterally to the extremities of the transverse pro- 

 cesses of the dorsal vertebraj. On opening it, along this lateral line of attachment, 

 the cavity is seen to project to a certain extent backwards beyond the abdominal 

 cavity proj^er, to the level of the fifth anal fin-ray. It is wide and capacious in 

 extent. Anteriorly, below the dorsal fin, it becomes constricted, and ends behind 

 the head in a somewhat broad jDoint. A convoluted rete lies on the inner inferior 

 surface near the anterior end. The superior membrane of the bladder is imper- 

 fect, so that a circular space occurs at a point corresponding with the position of a 

 central muscular opening described in 31. laevis (p. 477). A portion of the kidney 

 can be seen passing immediately above this opening. There are two head- 

 kidneys continuous with a single body organ, as described below in the case of 

 M. laevis. 



Skeleton. — The skull is figured by Costa [op. cii, PI. xxxix.) 



Section I. A. — Sub-section 1 (supra), 

 c. Mouth wide and lateral ; dorsal spine serrated. 



