344 THE VOYAGE OF H.M.S. CHALLENGER. 



The first pair of antennas has the first joint broad, excavated on the upper surface, 

 and armed on the outer with a stout stylocerite about half the length of the joint, the 

 outer distal angle of which is rounded and fringed with long ciliated hairs. The second 

 joint is about half the length of the first, and the third is stouter and rather longer than 

 the second ; the flagella are broken short off. 



The second pair of antennas is furnished with a long, slightly curved ancecerite, 

 and with a broad and somewhat tapering scaphocerite, smooth on the outer surface and 

 fringed on the inner with long, ciliated hairs, and reaching as far as the distal extremity 

 of the third joint of the peduncle of the first pair. 



The epistoma projects in the form of a rounded protuberance. 



The mandibles support a long, two-jointed synaphipod of extreme thinness ; the first 

 joint is broad and ovate, and the second narrow and tapering, its extremity reaching as 

 far as the distal border of the first joint of the first pair of antennas. 



The oral appendages are of extreme delicacy and tenuity. 



The first pair of gnathopoda has the meral joint extremely broad and very thin, the 

 margins being thickly fringed with hairs ; the basis supports a long ecphysis, and the 

 coxa carries a podobranchial plume attached to a rudimentary mastigobranchia. 



The second pair of gnathopoda carries a podobranchial plume borne upon a rudi- 

 mentary mastigobranchia attached to the coxa ; the basis carries a long and slender 

 ecphysis ; the ischium and meros articulate, and the latter is enlarged to a broad plate 

 of extreme tenuity; the two succeeding joints are narrow. The dactylos is spatuliform, 

 curved, and terminates in a slender but stiff spine, more like Benthesieymns than 

 Gennadas ; on the outer surface the dactylos is furnished with a small but distinct 

 process or tooth. 



The first pair of pereiopoda is short and slender, but more robust than the second and 

 third, which are successively longer, slighter, and more feeble. The last two pairs are 

 broken off at the ischium. 



The first pair of pleopoda in the typical specimen, which is a male, supports a 

 large and well-developed petasma, which resembles that of Gennadas parvus, as shown 

 on PL LIX., p. The others are all biramose and subecmal. The rhipidura is damaged, 

 but the telson appears to have been more than half the length of the lateral plates. 



Length (male), 45 mm. (175 in.). 



Habitat.— Station 106, August 25, 1873 ; lat. 1° 47' N., long. 24° 2G' W.; off Sierra 

 Leone; depth, 1850 fathoms; bottom, Globigerina ooze; bottom temperature, 3G°"G. 

 One specimen. Trawled. 



A specimen, 24 mm. in length, was taken at the surface between Bermuda and the 

 Azores, in June 1873. 



Station 137, October 23, 1873 ; lat. 35° 59' S., long. 1° 34' E. Surface. One male 

 specimen. Length, 23 mm. (0'9 in.). 



