202 U.S. NATIONAL MUSEUM BULLETIN 271 



Probably Sphaerophthalmus Spandl is assignable to the Dexamin- 

 idae. See its diagnosis under "Incertae Sedis." 



Key to Subfamilies of Dexaminidae 



1. Mandibular molar large, triturative (fig.84j) Dexamininae 



Mandibular molar evanescent (fig. 85e) Anatylinae 



Key to the Genera of Dexaminidae 



(expanded after Sheard, 1938) 



1 . Palp of maxilliped with three articles (fig. 84d) 2 



Palp of maxilliped with four articles (fig. 84e) 4 



2. Inner lobes of lower lip well developed (fig. 84/i) Dexaminella 



Inner lobes of lower lip vestigial (fig. 84z) 3 



3. Pereopods 1-5: article 4 shorter than articles 5-6 combined (fig. 85n). 



Dexamine 

 Pereopods 1-5: article 4 longer than articles 5-6 combined (fig. 85o). 



Tritaeta 



4. Pereopods 1-5 cheliform (fig. 85p) Polycheria 



Pereopods 1-5 simple 5 



5. Palp of maxilla 1 uniarticulate (fig. 847n) 6 



Palp of maxilla 1 biarticulate (fig. S4l) 9 



6. Inner plates of maxillipeds vestigial, short and bud-like (fig. 84c) 7 



Inner plates of maxillipeds of medium size (fig. 84d) 8 



7. Inner lobes and mandibular lobes of lower lip distinct; palp article 4 of 



maxilliped claw-shaped (fig. 84e) Dexaminoides 



Inner lobes of lower lip coalesced, mandibular lobes obsolescent (fig. 84/) ; 

 palp article 4 of maxilliped stout, blunt (fig. 84c) Dexamonica 



8. Mandibular processes of lower lip absent (fig. Sig) Syndexamine 



Mandibular processes of lower lip present (fig. 84z) Paradexamine 



9. Palp article 2 of maxilla 1 large (fig. 841) ; inner plates of maxillipeds well 



developed (fig. 85z) ; coxa 5 small, coxa 4 not posteriorly excavate. 



Anatylus 



Palp article 2 of maxilla 1 small (fig. 84A;) or large; inner plates of maxillipeds 



vestigial, short and bud-like (fig. 84c) ; coxa 5 larger than anterior coxae, 



coxa 4 posteriorly excavate Guernea 



Genera of Dexaminidae 



Anatylus Bulycheva 



Anatylus Bulycheva, 1955. 



Type-species: A. pavlovskii 'Bulycheva, 1955 (original designation) . 



Mandibular molar evanescent; lower lip bearing inner lobes, man- 

 dibular processes distinct, palp of maxilla 1 biarticulate, article 2 long 

 {Guernea); maxUlipedal palp 4-articulate, inner plates well developed; 

 coxa 4 not excavate posteriorly. Species: 1, boreal N. W. Pacific, 

 littoral. 



285-135 O - 69 - 14 



