144 DEVELOPMENT OF PALINDRUS VULGARIS. 



appendages. These tendrils are long, slender, and dichotomous. 

 Their double character commences at the third joint ; for the 

 remainder of their length they are nearly equal, and are covered with 

 strongly marked spines ; their termination is pointed. The caudal 

 extremity is simple, contracted, pointed, and somewhat oval ; on the 

 centre of the rostrum is a dark spot ; the eyes are placed on 

 enormously long and stoutly club-shaped peduncles, which are 

 attached by very narrow and slender points. The pedunculated eyes 

 are about two-thirds as long as the carapace. The contrast between 

 the young of the present species and others is very great. In them 

 the eyes are sessile ; in this enormously pedunculated. In them the 

 limbs are beneath the carapace ; in this they are attached to what, 

 for clearness, I have called the abdominal rings. Instead, therefore, 

 of belonging to the genus Zoe, this would be placed in Phyllosoma 

 of Milne Edwards, as belonging to the Stomapodes." 



Here, then, although it is evident Couch did not know much of 

 the morphology of Crustacea, we have a great improvement on his 

 former description. He evidently means to describe four pairs of 

 biramous appendages ; he mentions the long peduncles of the eyes, 

 and the median eye (dai*k spot he calls it) on the rostrum. In this 

 paper the comparison of the larva of Palinurus with Phyllosoma is 

 made for the first time, although the importance of the comparison 

 remained to be developed by men who understood the structure of 

 Crustaceans better than Couch. In the British Association Report 

 no figures accompany Couch's paper, but it is reprinted in the 

 Natural History Review, vol. iv, 1857, with a plate (pi. xvii). On 

 this plate is given a figure of the Palinurus larva from the ventral 

 aspect. The figure is recognisable, though not very accurate. It 

 gives fairly well the general shape of the body, the eyes, antennae, 

 and four pairs of long thoracic appendages. But the shape of the 

 thorax is incorrect, as also that of the appendages, especially of the 

 exopodites, while the appendages in front of the third maxilliped 

 are entirely wanting from this figure and the rest of the plate. 



In a Report on the Progress of Entomology in the Archiv f. 

 Naturgeschichte, 1858, Gerstacker speaks of the similarity of Couch's 

 figure of the Palinurus larva with Phyllosoma, but does not mention 

 that Couch made the comparison himself. 



Independently of Couch, Gerbe in 1858 made the observation 

 that the newly hatched larva of Palinurus had the characters of the 

 genus Phyllosoma. Gerbe's studies were made at the Laboratory of 

 Concarneau in Brittany, and were briefly described by Coste in the 

 Comptes Rendus of 1858. Coste's publication was not accompanied 

 by figures, but stated that Gerbe would be able, from material sup- 

 plied by the aquaria of Concarneau, to publish at a future time a 



