REPORT ON THE AMPHIPODA. 635 



Hippomedon geelongi, n. sp. (Ph XL). 



The head narrow, much longer than the very short first perseon -segment, produced 

 into pointed lateral lobes between the upper and lower antennfe. First segment of 

 the pleon with the postero-lateral angles much, second with the same little, rounded ; 

 third with the same acute and bent upwards ; the third segment the longest ; the 

 fourth segment Avith a dorsal depression. 

 No eyes were perceived. 



Upper Antennas. — First joint large and tumid, upper margin distally produced ; 

 the second joint almost embedded in the first ; the second and third both short, 

 narrowing as they approach the flagellum, of which the first joint is large and long, 

 adorned with the usual brush ; of the other joints only two remained, the second 

 bearing a large calceolus, and a row of five cilia near it. The secondary flagellum 

 consists of five joints, furnished with setee. 



Lower Antennae. — Gland-cone rather prominent, third joint not long, still equalling 

 in length the composite first and second ; fourth joint thicker, but scarcely longer than 

 fifth, both furred on the U2:)per margin and carrying feathered cilia on the lower. 

 Flagellum of thirty joints, each apparently except the last furnished with a calceolus 

 and a row of cilia behind it. The calceoli seemed to be rather short-stalked and with 

 the outer rims firmer than usual. 



Mandibles. — The cutting edge not well observed, but probably in near agreement 

 with that of Hippo7nedon hergueleni ; the spine-row of three curved, rather short 

 spines ; the molar tubercle with the dentate crown oval ; the palp set just over the 

 front part of the molar tubercle, its second joint considerably longer than the third, 

 slightly constricted below the middle, this being the place where the muscles in 

 connection with the first joint end, and where those in connection with the third joint 

 begin ; nearer to the apex begins a row of fourteen spines, which increase successively 

 in length as they approach the outer angle of the apex ; the third joint is long, 

 slightly curved, narrowing distally, with two long set« near the beginning of the 

 outer border, and twenty-two pectinate spines along the concave edge ; these slightly 

 diminish in size as they approach the apex, till, close upon it, they rapidly increase. 



Lower Lip. — The front lobes ciliated all round, apically as usual with more 

 fulness ; the mandibular processes narrow and not produced far back. 



First Maxillae. — The inner plate not very long, on the distal portion of its inner 

 margin and the apex carrying a row of seven plumose setae, graduated in size, the first 

 of the row being very slight and the apical one very large ; the proximal part of the 

 margin is furred by the projection of the fine cilia on the surface of the plate ; the 

 outer plate carries distally eleven spines all strongly dentate, the six round the apical 

 border very stout, the five below them on the surface of the plate more slender, not 



