INSTITUTE OF SCIENCE, PHILADELPHIA. 129 



ADDITIONS TO THE FLORIDIAN FAUNA. 



Tropidonotus taxispilotus (?) var Brocki. PI. 17. 



I venture to describe, under the above name, the ophidian figured on 

 plate 17, which agrees in general characters with one of the common forms 

 of southern water-snake (Tropidonotus taxispilotus), but yet differs in 

 certain elements of structure, which, taken by themselves and under 

 absolutely normal conditions, would be considered to be of at least generic 

 value. This peculiarity of structure rests principally in the disposition 

 of the parietal head-shields, which, instead of consisting of the normal 

 triangular pair, meeting in the median line, diverge from one another, 

 leaving in the opened posterior angle or space a parr of accessory minor 

 plates, that might be termed intcr-parietals. The presence of this accessory 

 pair may be due to a want of coalescence in calcification, since even the 

 primary parietals show a disposition to split off into minor plates ; or, at 

 any rate, the presence of the outlines of the ordinary rhomb scales in 

 these plates proves them to be composites in structure. In how far the 

 peculiarly modified parietals, and the presence of the accessory pair, may 

 represent permanent structures, I am unable to say, inasmuch as we 

 obtained but a single individual of the species; but it is interesting to note, 

 as will be observed by a reference to plate 17, that the distinctive feature 

 is accompanied by a slight variation also in the arrangement and disposi- 

 tion of the ventral head-shields as well. Recognizing the multiple 

 character of the head-shields, it becomes a question in how far these may 

 be used as a basis for classification. In the present instance, although I 

 have not been able to discover a parallel case, I feel confident that the 

 characters are not of generic, nor probably of even specific value, and I 

 have, therefore, referred the form in question to Tropidonotus taxispilotus, 

 although separating it as a sub-species or variety. 



Kagle Bay, Lake Okeechobee. 



Ictalurus Okeechobeensis, nov. sp. PI. 18. 

 (Okeechobee Cat.) 



Of the general form and outline of Ictalurus lacnstris, from which it 

 differs principally in color, the relative position of the dorsal fin, and the 

 greater length of the humeral spine. Head broad, depressed, of nearly 

 equal width and length, with the eye nearly central antero-posteriorly ; 

 body moderately stout; dorsal fin nearer to the adipose fin than to the 

 snout (the reverse in /. lacnstris); humeral process moderately acute, 

 covered by skin, about one-half the length (or more) of the pectoral 



