DEVELOPMENT OE EALlNUEUS VULGAEIS. 143 



tlie adult^ and rather long. The tail is long^ extended, and com- 

 posed of five unequal annulations ; it is generally semi-flexed on the 

 abdomen and hid among the claws. On the four superior rings of 

 the tail are situated four pairs of long slender appendages. They 

 are attached to the rings by joints, similar to those of the true 

 claws. At a short distance from the basal joint these organs 

 branch into two long slender branches, which extend nearly one third 

 as long again as the tail ; hence the posterior part of the body has 

 a very bushy appearance. The termination of the tail is formed of 

 two small fan-shaped expansions, separated by a shallow notch. ^^ 



Couch gives a figure of the larval Palinurus in profile, which is as 

 fictitious as his description. It is evident from the description, that 

 he mistook the thorax of the larva for the abdomen, and regarded the 

 true rudimentary abdomen as the last joint of the ^^tail." In his 

 figure the thorax appears cylindrical instead of flat, and the four 

 long characteristic thoracic limbs of the Phyllosoma are represented ' 

 by four biramous appendages having a filamentous appearance. But 

 the extraordinary thing is that in the figure, as in the description, 

 there are four unbranched appendages in front of the four biramous, 

 attached to the cephalic portion of the larva which Couch mis- 

 took for the cephalothorax. Since, in reality, there is only one 

 elongated articulated appendage in front of the four biramous, 

 namely, the second maxilliped, and as the rest of the oral append- 

 ages are quite small and visible only under a lens, it is extremely 

 difiicult to understand how Couch invented his figure. It is possible 

 that he supposed all the long appendages that he saw, four pairs, to 

 be on one side, those of the other side being invisible ; in this way 

 he may have reached his conclusion that there were eight pairs of 

 limbs in all, four claws on the " body " and four slender appendages 

 on the tail. However this may be, this first description is quite 

 worthless, and there is no reference in it to Phyllosoma. 



In the Report of the same Society for the following year, 1844, 

 there is a second paper on the Metamorphosis of Decapod Crustacea, 

 but all that it contains concerning Palinurus is that the young had 

 been examined again with the same results as before. 



In the Report of the Meeting of the British Association in 1857 

 there is a short paper by R. Q. Couch, entitled On the Embryo State of 

 Palinurus vulgaris. The description of the larva there given is much 

 more correct than that previously published by the same observer. 

 It runs thus : — " The carapace is globular, oval, slightly pointed or 

 produced both at the anterior and posterior margin, and also slightly 

 contracted anteriorly, so as to give the appearance of a rostrum. 

 The abdomen is moderately long, and from four of the six annu- 

 lations of which it is composed arise eight pairs of tendril-like 



NEW SERIES. VOL. II, NO. II. 12 



