552 Mr. 0. T. Regan on a remarkable 



laterally or downwards to a certain extent ; its articulation 

 with the priapium is covered by a large rounded shield of 

 thick skin, placed ventrally, but much more developed 

 upwards on the aproctal side. At the posterior end just 

 below the genital opening is articulated another bony spine, 

 which seems to be freely movable outwards and may be 

 termed the ctenactinium ; when at rest this is directed 

 forwards and lies on the aproctal side of the priapium ; it is 

 laterally compressed, is straight, with the distal end some- 

 what curved upwards and ending in a pointed denticulation, 

 and it bears five other somewhat smaller denticulations on 

 its upper edge. 



The skeleton seems to be typically Cyprinodont * ; the 

 vertebra? number about 40 (9 + 31) and there are seven pairs 

 of ribs inserted on transverse processes. The minute pelvic 

 fins of the female are supported by a correspondingly minute 

 pair of pelvic bones. 



In the female (fig. 4, A) the visceral anatomy shows but 

 little departure from the structure seen in carnivorous Fundu- 

 linse, except for modifications due to the anterior position of 

 the vent and of the openings of the urinary and genital ducts. 

 The large air-bladder is placed posteriorly ; the stomach is 

 a simple expansion of the alimentary canal, without ca?ca, 

 and from it the intestine runs straight back on the left side 

 to the air-bladder, turns downward and crosses above the 

 ovary to the right side, and then runs straight downwards 

 and forwards to the anus; the liver is large. The ureters 

 arise close together from the posterior end of the kidney, 

 which seems to be unpaired ; they unite to form a single 

 duct, which runs downwards and forwards below the intestine 

 on the right side of the ovary and across below the latter to 

 the urinary opening. The ovary is unpaired, as in many 

 other Cyprinodonts ; it is a pyriform organ that lies in front 

 of the air-bladder and occupies the whole width of the body ; 

 it narrows anteriorly and opens almost directly to the exte- 

 rior, there being practically no oviduct. 



In the male (fig. 4, B) the unpaired testis is very similar in 

 form to the ovary, but is shorter and deeper and does not extend 

 so far forward ; the vas deferens leaves it anteriorly and imme- 

 diately becomes closely coiled up into a mass that lies in 

 front and to the right side of the testis, and is rather similar 

 in form but less in bulk than the latter ; within this mass 



* In order to investigate the structure I had series of sections made of 

 the anterior half of the body in two specimens (<5 and $ ) ; these were 

 of great assistance in making clear certain features that could not he 

 made out by ordinary dissection. 



