522 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 99 



undescribed species of Pontonia I found 10 dorsal spinules there. 

 Balss (1925) states the mandible of his Bathypalaemonella zimmeri to 

 be distinctly cleft, though the two processes are placed close together. 

 The lower lacinia of the maxilla in the species of Bathypalaemonella is 

 strongly reduced, forming thereby a transition between the situation 

 as it is in the Palaemonidae and that in Campylonotus. In some 

 species of Palaemonidae a 5-articulated endopod of the second 

 maxilliped m^j be observed. As to points 2, 8, and 9 above, in the 

 Hippolytidae genera are found that have a bifurcated upper anten- 

 nular flagellum (e. g., Lysmata) and some that are very closely related 

 and have the flagellum single (e. g., Hippolysmata) ; there are also 

 Hippolytidae with arthrobranchs (e. g., Ligur) and others (e. g., 

 Barbouria) that lack them, but nevertheless are closely related. In 

 some genera of Hippolytidae some species have and others miss 

 epipods on the pereiopods. In none of the Palaemonidae I examined, 

 however, did I find the palp of the first maxiiliped or the exopod of 

 the third maxiiliped articulated. 



The arguments for a close relationship between the Campylonotidae 

 and the Palaemonidae are the following: 



1 . The shape of the rostrum in Campylonotus (and in a lesser degree 

 also in Bathypalaemonella) is distinctly palaemonoid. 



2. The first maxiiliped has the exopod resembling that of the 

 Palaemonidae and is strongly different from that of the Oplophoridae. 



3. The last joint of the second maxiiliped is inserted alongside the 

 penultimate joint and not at the top of it. 



4. None of the pereiopods bears an exopod. 



5. The second legs are much stronger than the first. 



Especially the last argument seems very strong in my opinion, as 

 the shape and the relationship of the first and second pairs of pereio- 

 pods are of much importance in all the higher groups of Caridea. 

 The character of the presence or absence of exopods is rather variable 

 in the family Atyidae, which belongs to the Oplophoroida. 



In my opinion it is much more reasonable to place the family 

 Campylonotidae in the superfamily Palaemonoida. It then should 

 have to be considered a primitive family in that group. 



This superfamily Palaemonoida must be restricted to the families 

 Campylonotidae, Palaemonidae, and Gnathophyllidae. The families 

 Alpheidae and Hippolytidae, placed by Borradaile (1907) and Balss 

 (1927) in the present superfamily, have to be removed to a separate 

 superfamily. The Palaemonoida then may be defined as: Caridea 

 with the second legs distinctly stronger than the first, with the carpus 

 of the second legs not articulate, without exopods on the pereiopods, 

 with perfect chelae on the first pereiopods, and with the rostrum 

 immovable. 



