MUSEUM OF COMPARATIVE ZOOLOGY. 119 



XIX. Acantkias americanus Storer. Fig. 1, entire side ; 2, half of lower, 3, half 



of upper, and 4, front view of head ; 5, side of tail ; G, section of canal 

 at side of tail. 



XX. Sonuiiosus carcharias Miiller; Garm. Fig. 1, top, and 2, lower view of 



head. 

 XXI. Rhiiia squatina L. ; Dum. Fig. 1, top of head, with tubules ; 2, full 

 length, main tubes ; 3, front, and 4, lower view of head. 

 XXII. Pristiophorus cirratus Lath. ; M. & H. Fig. 1, top, and 2, lower view 

 of head. 



XXIII. Pristis pectinatus Latham. Fig. 1, top, and 2, lower view of anterior 



half of total length. 



XXIV. Hhinobatus planiceps Garman. Fig. 1, top, and 2, lower view. 

 XXV. Syirhina brevirostris Jliiller & Henle. Fig. 1, top, and 2, lower view. 



XXVI. Uraptera agassisli M. & II. Fig. 1, lower, and 2, upper view. 



XXVII. Raia /cevis Mitchill. Upper surface, showing tubes and tubules. 



XXVIII. Raia Icevis. Upper view, showing (1) the hyaline mucous ducts of the 

 " ampullse of Lorenzini," and (2) the main tubes of the canal system. 



XXIX. Raia Icevis. Fig. 1, lower, and 2, upper view of head. 



XXX. Raia ocellata Mitch. Fig. 1, top, and 2, lower view of disk. 



XXXI. Torpedo californica Ayres. Upper view. 



XXXII. Torpedo marmoruta Risso. Upper view. 



XXXIII. Narcine brasiliensis Oif ; Henle. Upper view. 



XXXIV. Potamotrijcjon motoro M. & H. ; Garm. Fig. 1, upper, 2, lower surface. 

 XXXV. Disceus strongi/lopterus Schomh. ; Garm. Fig. 1, upper, 2, lower surface. 



XXXVI. Urolophus halltri Cooper. Upper view. 

 XXXVII. Urolophus halleri. Lower view. 

 XXXVIII. TcEniura lijinma Guv. ; M. & H. Fig. 1, upper, and 2, lower view. 

 XXXIX. Dasijbatus niidus Gthr. ; Garm. Fig. 1, upper, and 2, lower view. 

 XL. Dasi/batus dipterurus Jordan. Fig. 1, lower, and 2, upper view. 

 XLI. Dasybatus tuberculatus La C. : Garm. Lower view. 

 XLII. Dasi/batus tuberxidatus. L^pper view. 

 XLIII. Fig. 1. Pteroplatea hirundo Lowe. Upper view. Fig. 2. Pteroplatea 



viarmorata Cooper. Upper view. 

 XLIV. Pteroplatea valenciennii Dumeril. Upper surface. 

 XLV. Pteroplatea valenciennii. Fig. 1, upper, and 2, lower view. 

 XL VI. Mi/liobatis aquila L. ; Cuv. Upper surface. 

 XLVII. Myliobatis aquila. Fig. 1, lower surface, and 2, side of head. 

 XLVIII. Myliobatis freminvdlii Lesueur. Fig. 1, upper, and 2, lower view. 

 XLIX. Aetobatis narinari ^wp\\. ; M. & II. Fig. 1, upper, and 2, lower surface ; 

 3, lower view of end of pectoral; 4, side and lower view of head; 

 5, tail and hinder part of body. 

 L. Rhinoptera brasiliensis Mtiller. Fig. 1, upper, and 2, lower view of disk ; 

 3, lower side of end of pectoral fin ; 4, side and lower view of head. 

 LI. Rhinoptera jussieui Cuv. ; Gthr. Fig. 1, upper, 2, lower, and 3, side and 



lower view of head. 

 LII. Dicerobatus olfersii ^luller ; Gthr. Fig. 1, upper surface ; 2, side of head. 

 LIlL Dicerobatus oljtrsii. Lower surtace. 



