THE VICTORIAN NATURALIST. 93 



only, and unable to indulge in any locomotion beyond crawling 

 on the rocks or weeds of the ocean floor, while all those shells, 

 and other mollusks which I shall describe were captured on the 

 surface ; and an interesting fact may be here noticed — that with 

 the exception of a few varieties, such as the " Physalia," or 

 " Portuguese Man-of-war," the " Porpitae," and the " Janthina," 

 or blue sea snail, which may be captured at any time of the day 

 or night, all these mollusca only rise to the surface for a period 

 of a few hours after sunset, and as a rule they succeed each 

 other at different times in their ascent to the upper air. 

 Another matter of interest may be noticed — viz., that on no single 

 occasion when it was practicable to tow the net did I fail to 

 secure some specimen during those hours, though it might be 

 towing all day without success. 



Let me shortly describe the method and means of capture. 

 The best material for the purpose is a strong mosquito netting, 

 which should be fastened to a semicircular frame of wood, and 

 terminate in two or three pockets about the size of the foot of 

 a sock, rather than in one conical point, as the extreme delicacy 

 of many of the rarer kinds of mollusks renders them liable to 

 injury. It is also necessary to have a long spar or oar projecting 

 from the stern of the ship, and have the net drawn by means of 

 an out-haul from the exremity of the spar, and so avoid towing 

 •exactly in the wake of the ship, where the creatures must 

 necessarily be disturbed and driven down by the body of the 

 ship. When the net has been in the water for a short time, the 

 interesting work of hauling it in and emptying its contents 

 into a bucket of salt water is gone through, and then 

 a careful examination is necessary to ascertain the 

 success of the haul. You will observe small shells flitting 

 and jerking themselves about in the water, or timidly 

 sinking to the bottom. These, and anything that is thought 

 worth the capture, must be taken out of the bucket by means 

 of a small hand-net, and placed in a basin of fresh water, 

 where they rapidly die and sink to the bottom. Next morning 

 each shell must be carefully held in one hand while a jet of 

 fresh water is injected from a syringe held in the other, and 

 this generally will bring out every particle of the fish, and 

 leave the shell clear and pellucid. This system of cleaning the 

 shell I may claim as my invention, never having seen in 

 recorded in any work; and it answers admirably. 



Foremost amongst the creatures caught — not mentioning the 

 ^' Medusae," or jelly fish — I may notice the " Physalia pelagica," 

 or Portuguese man-of-war, which consists of an oblong bladder, 

 with a beak-shaped point at one end, of a deep purple colour, 

 and with a crest or ridge extending along its summit, which 

 can be raised or depressed at will, and has its edge tinted with 

 orange or carmine, with deep blue vein-markings at interval? 



