2 y Q NATURAL HISTORY BULLETIN. 



tips, the presence or absence of a sternal canal for the sexual 

 appendages, or the development of the ridge on the palate. 



The modification of the palatal ridge is an important factor 

 in Dr. Ortmann's division of his section B. of the Xanthini. In 

 this section the family Xanthidse is said to differ from the 

 family Oziidas only in lacking a ridge on the palate, which in 

 the Oziidag is either distinct or indistinct. The fact is, that 

 typical species of Xantho, such as X. hydrophilus Herbst (= 

 X. incisus Leach) have a rudimentary ridge on the palate 

 posteriorly developed as in Enrypanopens. In the three spe- 

 cies of Enrypanopens so-called, herbstii, occidentalism and anier- 

 icanus (species so much alike in general appearance that they 

 are not acknowledged by Dr. Ortmann to be distinct), the 

 palatal ridge is stronger than in Xantho; it is longest in 

 herbstii, of about equal length in occidentalis and americanus, 

 but better developed in the latter than in occidentalis. In E. 

 texanus (family Oziidas Ortmann) the ridge is less developed 

 than in Xantho hydrophilus. 



For the value of spoon-shaped fingers as a generic character, 

 compare Eurypanopetts depressus with E. abbreviatus. 



In order to express the relationships of the various Xantho- 

 Panopean species I believe it is best to divide them according 

 to their form and general appearance into a number of genera, 

 including the ten above mentioned to which I have assigned 

 in nearly every case different limits from those before ascribed 

 to them. The collection of the University Expedition con- 

 tains six of these closely related genera of which three are new. 



Genus Leptodius A. Milne Edwards. 

 Carapace suboval, wider than in Xantho; antero-lateral 

 margin very long, with five well-developed teeth; front and 

 orbits wider than in Xantho; frontal and antero-lateral mar- 

 gins not thickened; palatal ridge absent in typical species; 

 ambulatory legs narrower than in Xantho. Type, L. exaratus 

 (Milne Edwards). 



77. Leptodius floridanus (Gibbes). 

 Tortugas, in gulf weed. 



