1909.] CRUSTACEA OF THE GENUS GENNADAS. 729 



Geiinadas sp. Ecuador. 



Faxon, Mem. Mus. Oomp. Zool. Harvard, xviii. 1895, p. 207, 

 Gennadas sp. Hawaiian Is. 



Rathbim, Bull. U.S. Fish Comm. for 1903 (1906), p. 907, 

 fig. 62. 



It is much to be regretted that so little is known concerning 

 the branchial formulfe of many of the species. At present only- 

 one undoubted species of Amalo2)en(Bus is known — A. elegans 

 Smith, though it is probable that the form described by Smith as 

 valens also belongs to the same genus. Six species, viz., the four 

 described in this paper along with G. scutatus Bouvier and 

 G. carinatus Sraith belong to Gennadas {sensu, stricto). In all the 

 remaining species precise information concerning the branchial 

 formula is lacking. Even those who are not disposed to admit 

 the existence of two distinct genera will recognize the value 

 of the character for splitting the group into workable sections. 



EXPLANATION OF THE PLATES. 



PiATE LXXIII. 

 Gennadas parvus Sp. Bate. 



Fig. 1. Lateral view of the anterior part of the tj'pe specimen. X 10. 



2. Apex of the endopod of the second maxilla. X 65. 



3. Second maxillipede. X Hi. 



4. Antennal scale. X 11. 



5. Mandibular palp. X 24. 



6. Apex of telson. X 26. 



Gennadas intermedius Sp. Bate. 



Fig. 7. Lateral view of the anterior part of the type specimen. X 6. 



8. Mandibular palp. X 5^. 



9. Apex of the endopod of the second maxilla of the type specimen. X 30. 



10. Apex of the endopod of the second maxilla of the second specimen. X 30. 



11. Part of the endopod of the second maxillipede. X 5^. 



12. Apex of the telson. X 26. 



Plate LXXIV. 

 Gennadas houvieri, sp. n. 



Fig. 1. Lateral view of the anterior part of the carapace. X 7^. 



2. Antennal scale. X 8i. 



3. Mandibular palp. X lOj. 



4. Second maxillipede. X 14. 



Gennadas calmani, sp n. 



Fig. 5. Lateral view of the anterior part of the carapace. X og. 



6. Part of the second pereiopod, showing the epipod, podobranch, and two 



arthrobranchs hi situ. X 9. 



7. Part of endopod of second maxillipede. X 6. 



8. Second maxilla. X 65. 



9. Antennal scale. X 4. 



10. Mandibular palp. X 7. 



11. Apex of the telson. X 21^. 



