DEVELOPMENT OP PALINURUS VULGARIS. 147 



at the Crystal Palace. But no correct figure of it is in existence, 

 nor have its later stages been described. I now proceed to the 

 description of my own observations. 



2. Observations on the Larva of Palinurus vulgaris. 



In July, 1889, a large number of larvae were hatched from a 

 beri'ied crayfish in one of our tanks at the Plymouth Laboratory, and 

 I preserved some hundreds of these, but did not then study them. 

 This year, on the 9th July, when I was working a large net made 

 of mosquito netting at the surface, a little to the north of the Eddy- 

 stone, I obtained a number of Phyllosomes of different sizes and 

 stages. On the 16th I obtained a still larger number in the same 

 net to the south of the Eddystone. Hitherto they have only been 

 very rarely taken on the south coast of England, and then, according 

 to Spence Bate, only solitary specimens. The reason of this seems 

 to be merely that suitable nets have not been used in the right 

 place at the right time of year. These larvse apparently do not 

 occur near shore, for we have never taken them before in our 

 ordinary tow-nets worked within a mile or two of the coast. At 

 any rate it is interesting to find that some hundreds may be taken 

 in about an hour in the neighbourhood of the Eddystone in July, 

 with a net whose meshes are about 2 mm. in diameter, and whose 

 mouth is 8 feet by 6 feet in area. On the two occasions on which 

 I obtained the larvae, I captured them only when towing the net at 

 the surface, not when it was sunk to some depth. 



The newly hatched larva of Palinurus is 3*1 mm. in length from 

 the anterior border of the cephalon to the posterior extremity of 

 the abdomen. The second antenna is almost, but not quite, as long 

 as the first, and neither of them is divided into joints. The thorax 

 is provided with four pairs of very much elongated appendages, 

 namely, the third maxilliped and the first, second, and third ambu- 

 latory limbs or pereiopods. These appendages all have six joints, 

 and from the end of the second joint springs an exopodite consisting 

 of a larger number of short joints, and fringed with long feather-like 

 bristles. The exopodite of the third pereiopod is not completely 

 developed, having slight indications of one or two joints and no 

 bristles. Of the oral appendages, the mandibles and first maxillse 

 are fully developed and functional ; the second maxilla is rather 

 large and foliaceous, and extends away from the median line ; the 

 first maxilliped is not wanting, but rudimentary, being- represented 

 by a simple, small, but distinct conical stump. The second maxilli- 

 ped is a slender six-jointed appendage, not extending beyond the 



