300 PROCEEDINGS OF THE AMERICAN ACADEMY 



PLATE V. 



Cyclopterus lumpus, Lin. 



Fig. 1. Young Lumpus 20"" in length. 



" 2. The same as fig. 1, seen from above. 



" 3. Profile of young Lumpus still older, measuring 34™" in length. 



" 3a. Spiny protuberances along anterior dorsal line of anterior dorsal. 



" 3b. Largest spiny protuberances of lateral line. 



" 3c. Pectorals and ventrals seen from the abdominal side. 



" 4. Same as fig. 3, seen from above. 



PLATE VI. 



PORONOTUS TRIACANTHUS, GUI. 



Fig. 1. Young Butterfish 7™" in length. 

 " 2. Somewhat older stage than fig. 1. 

 " 3. Older stage than fig. 2 ; 9""" in length. 

 " 4. Slightly more advanced than fig. 3 ; 10""° in length. 

 " 5. Young Butterfish having principal characters of the adult, 16™™ in 

 length. 



PLATE Vn. 



MOTELLA ARGENTEA, Rhein. 



Fig. 1. Young, measuring 4™™ in length. 

 " 2. Somewhat older than fig. 1, 5™™ in length, seen in profile. 

 " 3. Same as fig. 2, seen from below to show rays of ventrals. 

 " 4. Young, measuring 7.5"™ in length. 

 " 5. Young, measuring 12"™ in length. 

 " 6. Slightly older than fig. 5, measuring 14.5"™ in length, seen in profile. 



PLATE VIIL 



MOTELLA ARGENTEA, Rhein. 



Fig. 1. View from above of same embryo as Plate VII. fig. 6. 

 " la. Same as fig. 1, seen from above, with its ventrals fully expanded and 



spread out. 

 " 2. Young Motella with small anterior dorsal, measuring 15™" in length. 

 " 3. Considerably older than fig. 2, measuring 34™™ in length. 

 " 4. Young Gadus measurmg 25"'" in length. 

 " 5. Young Cod measuring 28™™ in length. 



PLATE IX. 



Gasterosteus aculeatus, Lin. 



Fig. 1. Young Gasterosteus with prominent ganoid tail fin measuring 7™™ in 

 length. 

 " 2. Older stage, 12"™ in length, in which the embryonic fin lobe has dis- 

 appeared, the tail fin has become symmetrical, and the permanent 

 rays of the dorsal and anal are well developed. 



