MARINE GAMMARIDEAJSr AMPHIPODA 



69 



Figure 18. — 'Stenothoidae : a, mandibles, note variations in palp, absence of triturative 



molar; h, accessory flagellum vestigial or absent; c, maxilliped, note obsolescence of outer 



plate [see Amphilochidae]; d, uropod 3, uniramous [see Amphilochidae]; e, coxae 1-4, 



left to right [see Leucothoidae, Anamixidae, Pagetinidae, Phliantidae];/, telson. 



Thaumatelsonidae often have some of the urosomal segments coalesced and the telson 



strongly thickened. Cressidae have the telson fused with pleonite 6, and always have an 



expanded article 2 of pereopod 3, whereas Stenothoidae always have a slender article 2. 



