2 l6 



Key to the Species of the genus Glyphocrangon A. M.-Edw., known at present'). 



4 



a Antertor moiety of the fourth or lateral crest of the carapace not 

 continuous with the branchiostegal spine. 

 b^ Anterior moiety of the fourth or lateral crest of the carapace 

 produced and expanded at its anterior end into a single huge 

 vertically-compressed spine, that extends far beyond the level 

 of the orbital margin, 

 fj Posterior moiety of the third carapacial crest produced anteriorly 

 into a spine. 

 d^ Spine at the anterior extremity of the posterior moiety of the 

 third carapacial crest large. 

 Rostrum measuring about two-thirds the length of the rest of 

 the carapace in the middle line and about 4-times as long 



as broad aculeata A. M.-Edw. 



(A. Milne-Edwards, in: Annal. Scienc. Natur., Zoologie, 1S81, Art. N" 4, 

 p. 5 and Recueil de Figures de Crustaces nouveaux 011 pcu connus, Avril 

 1883, Plate 38.) 



rt'j Spine at the anterior extremity of the posterior moiety of the 

 third carapacial crest small. 

 Rostrum measuring more than four-fifths the length of the rest of 



the carapace in the middle line and 6-times as long as broad SmitJiii W.-Mas. 

 (A. Alcock, a descript. Catal. Indian Deep-Sea Crust., Calcutta 1901, p. 129.) 

 ^j Posterior moiety of the third carapacial crest not produced ante- 

 riorly into a spine. 

 </j Anterior moiety of the fourth carapacial crest toothed along 

 its posterior half. 

 Behind the anterior pair of rostral spines the rostrum is armed 

 on each side with 3 to 5 smaller marginal spines. Carapace 



and abdomen densely tuberculated alata Paxon 



(VV. Faxon, The Stalk-eyed Crustacea ("Albatross"). Cambridge 1895, p. 137, 

 Plate XXXVII.) 



d„ Anterior moiety of the fourth carapacial crest entire behind 

 the terminal spine. 

 e^ Rostrum with three pairs of lateral spines. 



Hepatic spine long, slender, trending strongly outward. Cara- 

 pace and abdomen sparsely tuberculated loricata Faxon 



(W. Faxon, I.e. p. 140, Plate XXXVIII^/.s-.) 



e^ Rostrum with two pairs of lateral spines. 



l) This key, but especially that of the species of the subgenus Plastocrangon^ is partly taken from J. Wood-Mason's paper, in: 

 Annals Mag. Nat. Hist., Kcbr. 1S91 and from A. Alcock's work ".^ descriptive Catalogue Indian Deep-Sea Crustacea, Calcutta 1901. 



