728 PROCEEDINGS OF THE ACADEMY OF [NoV., 



rim of orbit. Mandible rather small, not broad, and each ramus ele- 

 vated inside of mouth. Teeth minute, jaws forming a thin narrow 

 cutting edge. No teeth on vomer and palatines. Tongue far back 

 in mouth, rather small, elongate, free along sides, and miited by median 

 frenum with floor of mouth. Nostrils lateral, in front of eye above. 

 Interorbital space a trifle broader than snout, and flattened. Post- 

 ocular ridge distinct. 



Gill-opening large, carried forward till about under front rim of 

 orbit. Rakers long, slender and numerous on first arch. Filaments 

 numerous, about equal to rakers in length. Pseudobranchia^ large, 

 much longer than filaments. Isthmus long and narrow. Branchi- 

 ostegal membranes united by narrow frenum in front. Lower surface 

 of isthmus with a shallow groove. 



Scales large, thin, cycloid, and not imbricated. Three rows on cheek. 

 Opercles scaled, and top of head posteriorly scaled to eyes. Snout, 

 interorbital space, jaws, and lower hyal region naked. Snout, both 

 above and on sides, together with interorbital space with cavernous 

 bones, ridges connected by soft membranes. This region also fur- 

 nished with pores. Pectoral without flap. Ventrals with rather short 

 scaly flap between their bases, and each with a small short axillary 

 scale. 



Origin of spinous dorsal nearer tip of snout than base of caudal by 

 length of ventral. Spines pungent, slender, third and fourth longest 

 and subequal. Soft dorsal inserted a little behind anal, much nearer 

 origin of ventral or spinous dorsal than base of caudal, and second ray 

 highest. Anal inserted nearer base of caudal than origin of pectoral, 

 and anterior rays highest. Caudal rather small, deeply emarginate. 

 Pectoral broad, level with eye, and reaching over origin of ventral. 

 Ventral reaching under posterior portion of spinous dorsal or half way 

 to origin of anal. Anus well posterior or a little nearer tip of ventral 

 than origin of anal. 



Color in alcohol pale brown, sides of head and trunk more or less pale 

 silvery. Back specked with small dark brown dots. Side with longi- 

 tudinal narrow silvery band about as wide as pupil of eye extending 

 to base of caudal. Fins plain pale brown. Peritoneum black. 



Length (caudal damaged) 4y^g- inches. 



Type of Atherina lacustris Bonaparte, No. 9,953, A. N. S. P. Italy. 

 Bonaparte Cofl. (No. 341). Dr. T. B. Wilson. 



Twenty-one co-types with same data. 



Thirty-eight examples, also from Italy, with the same data except 

 that the lake from which they were taken is not given. (No. 348.) 



