894 



THE VOYAGE OF H.M.S. CHALLENGER. 



Habitat. — April 1876, North Atlantic, surface; probably near the Cape Verde 

 Islands. 



This species resembles Hectarihropus exilis, but may easily be determined by the 

 form of the rostrum and the absence of the dorsal teeth on the posterior margin of the 

 fifth somite of the pleon. 



The carapace is armed on the dorsal crest with three teeth, whence the rostrum, 

 produced to about half the length of the carapace, is slightly depressed and smooth on 

 the upper and lower margins. The orbit is furnished with a supraorbital tooth of 

 moderate size. The frontal margin is anteriorly produced, but is not armed with an 

 antennal tooth as in other species, and the infero-lateral angle is produced to a strong 

 tooth, from which point the margin is smooth. 



The second somite of the pleon is longer than the first, and the third is longer than 

 any except the sixth, which is equal in length to the three preceding. 



The telson is about half the length of the sixth somite and gradually tapers to a 

 sharp point. 



The ophthalmopoda are clavate, and slightly longer than the rostrum. 



The first pair of antennas are biramose, but are not perfect. 



The second pair is also broken, and the scaphocerite is not perfect. 



The oral appendages have not been examined, and all the pereiopoda are broken off 

 at the ischial joint, and all the ecphyses also, excepting those of the second gnathopoda 

 and first pair of pereipoda, these are long and slender. 



The pleopoda are short, biramose, and without cilia. 



The posterior pair is slightly longer than the telson and furnished with a tooth on 

 the outer margin. 



Eretmocai^is, 1 n. gen. 



Carapace about one-fourth the length of the animal, anteriorly produced to a rostrum. 



Pleon having the somites subequal ; sixth a little longer than the fifth. 



Telson subecmal with the sixth somite. 



Ophthalmopoda very long and supported on a long slender pedicle. 



First pair of antennas biflagellate. 



1 ioer/xo;, an oar ; *«fi's, a shrimp. 



