Systematical Notes. 



19 



CCC 2. The liead is more or less pi'oduc- 

 ed forming a rostrum. Tiic maxillœ 

 are rudimentary. 

 cccc 3. The telsou is coalesced with 

 the last ural segment. The 

 seventh pair of perajopoda are 

 complete, not trausfoi-med. 

 CCCC 4. The telson is free '), not co- 

 alesced witii the last nral 

 segment. The seventh pair 

 of perseopoda are transformed. 



ixth pair of perœopoda is more 

 or less operculiform. 

 CC 3. The seventh pair of perseopoda are complete, 

 not transformed. The mouth-organs are 

 narrow, protruding. 



The seventh pair of perseopoda are reduced. 

 The mouth-organs are short and bi'oad. 



15. OXYCEPHALID^. 



10. XlPHOCEPHALID^. 



C 2. The femur of the 



CC 4. 



17. 



18. 



Parascetjd.«;. 

 eutyphid^. 



name Tryphœnidœ ought to be applied to tlie family thus composed, but as it has been used as a sy- 

 nonym for Lycœiâœ by myself an>l by Stebbing it would make confusion in the synonymy. I therefore 

 prefer to use a family-name derived from the new form given by Stkbbing to the old generic name 

 Phorcus, which was found to be preoccupied. To maintain, as does Stebbing, the family-name Pliorcidce, 

 when the generic name Phorcus is rejected, is not convenient as the family-name must refer to a generic 

 name in use within the family. 



1 have also divided the old family TryphtenidcB into two, Euthamneidœ — comprising the 

 (wo genera Thamyris. Spkxce Bate, (or Brachyscelus, according to Stebbing) and Euthamneus, (the 

 former name Thamneus being thus modihed to avoid confusion) — and Lyeœidœ, Claus, — restricting 

 it to the two genera Lycœa, Dana, and Pseudoîycœa, Claus. Of the old members of the family Try- 

 phœvida:, as it was composed in my paper, which I have just referred to, I have thus placed Tryphœna 

 in the family Phorcoraphidœ; Partilycœa in the Pronoidœ, (this transposition was really done in 1887 

 but owing to a typographical error it stands into »S^'stematical list» with its number from Pronoidœ 

 among the Tryphosnidœ) ; Thamyris and Euthamneus in tlie new family Eutlmmneidœ-, Lycœn und Pseu- 

 doîycœa in the Lycteidœ: and lastly Simorhynchotus in the OxycephalidiB. 



1) A very puzzling exception to this rule is Rhahdosoma hrevicaudatuin, described by Stkbbinô 

 (1. c. p 1612, pi. 208). He says namely that the telson is coalesced with the last ural segment and 

 much shorter than this segment, broadly rounded and pectinate at the apex, but all these statements 

 are strikingly opposed to ray experience which is founded upon the examination of many specimens of the 

 two old species, Xiphocephalus arniatus and X. Whitei. I for my part am much inclined to 

 believe that the single specimen which was the type for the new species proposed by Stebbing, may 

 have been abnormal, perhaps injured. 



