384 Transactions. 



showing as rounded structures where they project beyond the margin of 

 the cup. As the disc flattens somewhat, pressing the egg-envefope with its- 

 incipient rays, the envelope is drawn flatter dorsally and ventrally. Against 

 the ventral portion of the envelope the tube-feet are worked with a stamp- 

 ing or pushing movement, much as an infant works with its hands at the 

 mother's breast. Presently the envelope gives way, and the young animal 

 struggles out. The disc soon completes its ventral flattening. Locomotion 

 is efiected by the animal raising itself upon its almost-rigid tube-feet and 

 toddling, as it were, occasionally falling forward. The movements suggest 

 those of a fat puppy making its first real attempt to walk. From under 

 the grooved terminal plate of each arm these extends a blunt, rigid tentacle, 

 capableof being retracted. 



As there is yet no marine laboratory here, and I wished to keep these 

 young animals alive as long as possible, I placed a number in a specially 

 contrived glass cage, which I sank in a rock-pool, concealing it by means 

 of stones. When I visited the pool three weeks later I found that the 

 stones had been lifted out and the cage taken away. 



In the laboratory I was able to keep some alive and under observation 

 for thirty days. The mortality was, however, great, and only two speci- 

 mens reached the stage at which a second pair of tube-feet developed. 



For the photo-micrographs that illustrate this note I am greatly indebted 

 to the kindness of Mr. P. G. Harwood, of Auckland. 



Art. XXXVII. — -On the Gonoducts of the Porcupine-fish (Dicotylichthys- 



jaculiferus Cuvier). 



By H. B. Kirk, M.A., Professor of Biology, Victoria College, Wellington. 

 [Read before the Wellington Philosophical Society, 22nd September, 1915.] 



In the Teleost fishes generally the gonoducts, when distinct ducts are 

 developed, either open together to the exterior, or both open into the base 

 of the iireters or of the combined urinary duct. I have been unable to find 

 a recorded case in which the two gonoducts discharge separately to the 

 exterior, the condition that exists in Dicotylichtys jaculiferKs so far as the 

 male is concerned. 



The mesonephridia are large, and in each the ureter arises from the 

 posterior end, toward the ventral aspect. The two ureters converge as 

 they run backwards, and about 4 cm. before they unite they become closely 

 bound together by connective tissue (removed in the preparation figured). 

 Their union forms the urinary bladder, which discharges by a median open- 

 ing into a shallow urino-genital sinus situated just behind the anus. 



The testes are large, and their ducts are very short indeed. Each has 

 its own opening, difficult to distinguish, into the urino-genital sinus. The 

 two openings are slightly in front (ventrad) of the urinary opening, and 



