PART 1 GARTH : PACIFIC OXYRHYNCHA 29 



Abbreviations 



Institutions in which specimens consulted in the preparation of this 

 study are deposited have been abbreviated as follows: 



A.H.F. Allan Hancock Foundation, University of 



Southern California 

 B.M.N.H. British Museum (Natural History) 



C.A.S. California Academy of Sciences 



H.M.S. Hopkins Marine Station, Stanford University 



M.C.Z. Museum of Comparative Zoology, Harvard 



University 

 N.R.S. Naturhistoriska Riksmuseum, Stockholm 



N.Y.Z.S. New York Zoological Society 



R.M.N. H. Rijksmuseum van Natuurlijke Historie, Leiden 



S.D.M.N.H. San Diego Museum of Natural History 

 U.S.N.M. United States National Museum 



Z.M.H. Zoologisches Museum, Hamburg 



Superfamily OXYRHYNCHA 



Oxyrhyncha or Maioidea Alcock, 1895, p. 159, + Hymenosomidae 

 Alcock, 1900, p. 280. Oxyrhyncha Borradaile, 1907, p. 479. Rath- 

 bun, 1925, p. 10. 

 Carapace more or less narrowed in front, and usually produced to 

 form a rostrum ; branchial regions considerably developed, hepatic regions 

 small. Epistome usually large; buccal cavity quadrate, with the anterior 

 margin usually straight. Branchiae almost always nine in number on 

 either side; their efferent channels open at the sides of the endostome or 

 palate. Antennules longitudinally folded. (Alcock) 



Key to the Families of the Superfamily OXYRHYNCHA 



(after Borradaile) 



la. Carapace thin and flat. Chelipeds not long or specially mobile 

 or with fingers bent at an angle with the hand. Male opening 

 sternal. No orbits. Second article of antennal stalk slender, fused 

 with epistome but not with front. No hooked hairs 

 Hymenosomidae 



lb. Carapace not thin and flat. Chelipeds either mobile or powerful, 

 with bent fingers. Male opening coxal 



