REPORT ON THE AMPHIPODA. 731 



its surface, its lower side cai'ries a brush of long hairs or cylinders, consisting of some 

 seventy rows ; the remaining joints are short, esjaecially the earlier ones ; in a groove on 

 the inner side of the first joint lies the narrow ribbon-like accessory flagellum, consisting 

 of one very long joint and two minute terminal joints, the terminal spines or setae 

 reaching to the end of the first joint of the primary. 



Lower Antennse. — The first three joints very short, the first somewhat inflated, the 

 gland-cone of the second small ; the fourth joint between two and three times as long as 

 broad, three-sided, with several groups of spines along one side ; the fifth joint much 

 longer and thinner than the fourth, three-sided, rather wider at each end than in the 

 middle ; the flagellum longer than that of the upper antennae, shorter than the peduncle, 

 consisting of twenty-five joints, of which the first is the longest. 



The Epistome carinate ; the distal lobes of the upper lip slightly unsymmetrical. In 

 fig. C the upper lip is seen just above the cutting edges of the mandibles, which are in 

 close juxtaposition ; the flagella of the lower antennae, and the terminal portions of those 

 of the upper, are omitted ; the first pair of side-plates are seen in profile. 



Mandibles. — Cutting edge broad, almost straight, but with a little convexity, having 

 a denticle at the upper end (the lower end in fig. C) with a small tooth on the upper 

 margin just behind it ; at the lower end the margin is produced rather into a small tooth- 

 process than a tooth, the lower margin being finely denticulate nearly as far as the base 

 of the secondary plate ; this is found only on one mandible, as far as I could judge on 

 the right, not on the left, mandible ; it lies along the lower side of the principal plate, is 

 much longer than broad, and has the distal edge denticulate with about ten closely set 

 denticles, together with three or four on the lower edge ; the neighbouring tract of the 

 principal plate shows some ciliation ; and beyond this the lower margin runs out to an 

 olstuse angle, apart from which the mandible would have the figure of a parallelogram ; 

 the angle or projection perhaps represents the otherwise absent molar tubercle. In the 

 Plate, figures m.m., the outside surfaces of the mandibles are represented, the right 

 mandible being on the left hand, with the secondary plate seen through the transparent 

 trunk ; the curved depression in the corresponding part of the left mandible is likewise 

 seen through from the inner surface. 



Lower Lip. — The front lobes broad, widely dehiscent, strongly ciliated on the outer 

 margin, less so on the flattened distal margin, and the inner margin smooth ; across each 

 plate from the outer margin to near the centre of the base runs a curved line of short, 

 stiS" bristles, which at either end of the line are very numerous ; the mandibular processes 

 are not flat but form a fold with the hollow inwards, the distal end rounded. 



First Maxilla. — Inner plates very large, the inner margin fringed with about thirty 

 strong plumose setae ; the truncate distal margin of the outer plate is armed with six 

 larger and three smaller spines, variously, but none strongly, denticulate, with numerous 

 spine-like cilia about their bases ; the palp has a few spines at the apex of the indistinctly 



