474 



THE VOYAGE OF H.M.S. CHALLENGER. 



Second pair furnished with a long and sharp-pointed scaphocerite. 



First pair of pereiopoda chelate. 



Pleopoda biramose, ultimate pair unequally branched, shorter than the telson. 



Observations. — From every point of view this genus is truly Macruran, having the three 

 great and original characters of a long pleon with well-developed pleopoda, a large powerful 

 rhipidura, and a well-developed scaphocerite attached to the second pair of antennae. 



On the other hand the carapace is broad and depressed, and a longitudinal angular 

 ridge traverses it from the orbit to the posterior angle ; beyond which on the ventral 

 surface the carapace is bent inwards after the manner in the Brachyura. I have therefore 

 placed this genus here as belonging to the Aberrantia of this division, thereby assuming 

 that eventually it may be shown to be the young of some genus of the Anomura. 



Zoontocaris galatheas, n. sp. (PI. LXXXV. fig. 3). 



Carapace broad, depressed, anteriorly produced to a long rostrum, broad at the base 

 and tapering to the apex ; posterior lateral angle produced to a long and slender 

 pointed process, flanked on each side by a row of teeth that meet beneath its base. 

 Pleon narrow ; fifth somite produced to a tooth on each postero-lateral angle. Telson 

 broad, fiat, and distally produced to two long pointed processes. 



mm. (0-24 in.). 



Habitat. — Off Cape Howe, Australia (Young). 



Numerous specimens were taken but that figured and described appears to be the 

 most advanced. They were associated with Lucifer, Oodeopus, and Gonerielitliys. 



The carapace is short in the median dorsal line, and, measured from the centre of the 

 interorbital space to the posterior margin, it is less than one-fourth of the entire length 

 of the animal. Anteriorly it is produced, unevenly but continuously narrowing from 

 a broad base to the apex, forming a rostrum equal in length to the carapace in the 

 median line. The lateral margins are posteriorly produced to long, pointed, tooth-like 

 processes, and have the margins at their base armed with spine-like teeth that meet 

 beneath the large wing-like processes. The carapace on the dorsal median line recedes 



1 Except when stated otherwise, the measurements are taken in the median line, and the entire length means the 

 length from a point corresponding with the frontal margin of the carapace to the extremity of the telson. 



