MARINE GAMMARIDEAN AMPHIPODA 295 



hidden by follo^^■ing coxae; rami of uropod 3 lanceolate, outer often 

 2-articiilate, inner occasionally reduced in size, rarely both absent; 

 telson cleft, emarginate or entire, long or shorty rarely absent. 



Gnathopod 2 is an unmistakable mark of this family. Nevertheless, 

 Sebidae have a chelate gnathopod 2 \nth elongate article 3 but they 

 are distinguished from Lysianassidae by the elongate peduncle of 

 antenna 1 and the elongate and uniramous uropod 3. Some talitroideans 

 have a mitten-shaped gnathopod 2 but article 3 is not elongate. Some 

 Stegocephalidae also have long third articles but all of them have a 

 characteristic shape of coxae 1-4, the first acuminate, the second 

 and third narrower than 1, the fourth extremely broad, all four coxae 

 fitting together tightly, forming a ventral semicircle and not over- 

 lapping. Stegocephalid mouthparts are highly characteristic although 

 a few Lysianassidae have mouthparts resembling them. Stegocephalid 

 mandibles usually have some foliaceous parts, rarely occurring in 

 Lysianassidae. Stegocephalid mouthparts are always formed into a 

 conical bundle, rarely occurring in Lysianassidae. Gnathopod 2 is 

 always simple, whereas few Lysianassidae have a completely non- 

 subchelate gnathopod 2. 



Nomenclatural Changes in Lysianassidae 



Alicella scotiae Chilton (1912) is removed to Paralicella. 



Aruga Holmes (1908) is synonymized with Lysianassa. 



Arugella Pirlot (1936) is synonymized with Lysianassa. 



Lakota advtrsicola K. H. Barnard (1925) is removed to Schisturella. 



Lakota rotundatus K. H. Barnard (1925) is removed to Schisturella. 



Lysianassa anomala Nicholls (1938) is removed provisionally to 

 Parambasia. 



Lysianopsis Holmes (1903) is synonymized with Lysianassa. 



[Pronannonyx] Schellenberg (1953) is also synonymized with Lysian- 

 assa. 



Shoemakerella Pirlot (1936) is synonymized with Lysianassa. 



Socarnopsis obesa Chevreux (1927) is removed to Socarnes in view 

 of Hurley's (1963) classification, because uropod 3 has the outer 

 ramus 2-articulate. 



Tryphosites coxalis J. L. Barnard (1962d) is transferred to Tryphosella 

 Bonnier, and is reflected in Key I, triplicut 7 (p. 304). 



Key to the Genera of Lysianassidae 



A basic key partitions the genera into several groups further developed 

 in keys A to Q. This method brings together genera or portions of 

 genera in different places in order to signal their complicated, net-like 



