358 



THE VOYAGE OF H.M.S. CHALLENGER. 



The next stage in the progressive life-history of the animals in this genus is that 

 given in the annexed cut (fig. 50), from a drawing by Willemoes Suhm. 

 The following are Suhm's notes attached to his drawing : — 



" Length of rostrum, 



„ carapace, 



„ pleon, 



Entire length, 

 Length of ophthalmopoda, 

 Greatest breadth of carapace, 

 Length of lateral spinous processes, 

 Length of posterior do., 



"Taken 25 August 1875. Lat. 12° 42' N., long. 152° l' W. South of the Sandwich 

 Islands. 



" At the next succeeding moult the great posterior process is divided into two, so 

 that the Zoea has three of these processes on each side, after which the third Amphion- 

 like larva is produced. 



" The points on each side of the abdominal segments project considerably. It is only 

 by destroying the animal that we can get any knowledge of the pereiopoda or their 

 development. 



" After the second moult come the later forms of larva." 



It differs from his previous figure in having a long rostrum, distally serrate at the 

 margins, and dorsally armed at the middle with a long, slender, solitary spine, posterior 

 to which the margins are smooth. The carapace is circular or nearly so; it is furnished 

 external to the orbital angle, on each side of the frontal margin, with a large spinous 

 process. On the lateral margin, in a line with the oral apparatus on each side, is a 

 large spinous process; and in the median line of the posterior margin is a long dorsal 

 spine, armed on each side with two lateral spines and dorsally with two, and having 

 the distal portion laterally serrate. 



The ophthalmopoda are fungiform and the antennas are well developed. 



The first pair of antennae consists of one long and one short joint, distally furnished 

 with three or four long ciliated hairs. 



The second pair is birainose, a basal joint supporting an inner Inarticulate branch 

 which consists of one long and one short joint tipped with three or four long ciliated 

 hairs, and a second multiarticulate branch, that represents the scaphocerite in the adult ; 

 it is smooth on one side and on the other furnished with many long plumose hairs. 



The oral appendages are also present, and the epistoma is armed with a long spine - 

 like tooth that reaches beyond the frontal margin. 



The mandibles are present and the incisive margins are serrate. 



The maxillipedes and gnathopoda are furnished with long plumose hairs. 



