REPORT ON THE CRUSTACEA MACRURA. 



ss<» 



the largest. The degree of development shows that as yet the animal is not fully 

 matured, but the parts described are such as are not likely to vary much in form but only 

 in relative proportions. The ecphysis may fall off at a later stage, and the pleopotla 

 increase in size and become ciliated, but the simple condition of the pereiopoda is not 

 likely to alter, nor the form of the gnathopoda to become changed. 



I know of no recognised adult Crustacean that corresponds so nearly with the pre- 

 ceding genus as Procletes, from which it chiefly differs in the number of teeth on the 

 frontal region. 



Hectarthropus, n. gen. 



Carapace short, anteriorly produced to a horizontally smooth straight rostrum. 

 Dorsal crest armed with a single tooth in the median line, orbit not well defined, frontal 

 surface furnished with a supraorbital and two antennal teeth and one at the fronto- 

 lateral angle. 



Pleon long and slender. 



Ophthalmopoda pyriform. 



First pair of antennas biflagellate. 



Second pair of antennae furnished with a long scaphocerite. 



Mandible without a synaphipod. 



Second pair of gnathopoda pediform. 



Pereiopoda simple, six-jointed, the second joint being long, slender, and furnished with 

 a basecphysis. 



Hectarthropus exilis, n. sp. (PI. CXLIV. fig. 2). 



Carapace about one-eighth the length of the animal, produced anteriorly to a smooth, 

 short rostrum ; dorsal crest armed with one small tooth. Orbital region having a long 

 supraorbital tooth ; outer antennal region with a long antennal tooth ; fronto-lateral 

 angle produced to a small tooth, behind which the lateral margin is fringed with small 

 teeth for a short distance. 



Pleon long and slender ; five anterior somites subequal ; sixth as long as the two 

 preceding. 



Telson longer than the sixth somite 



Length, entire, 

 „ of carapace, 

 ,, of rostrum, 

 „ of pleon, . 

 ,, of sixth somite of pleon, 

 ,, of telson, 



(ZOOL. CHALL. EXP. PART LII. — 1888.) 



9 



1-4 



1 



7 



1-5 



1-8 



mm. (0'3 in.). 



Fff 112 



