OF ARTS AND SCIENCES. 303 



PLATE XVm. 



LOPHIUS PISCATORIUS, Lin. 



Fig. 1. Young Lophius showing still greater increase in length and number of 

 anterior dorsal and ventral rays. 

 " 2. Oldest pelagic stage, measuring 30""" in length, seen in profile. 

 " 3. Same seen from above, slightly less magnified. 



PLATE XIX. 



FUNDULUS NIGROFASCIATUS, C. Sf V. 



Fig. 1. Young, measuring 7""" in length. 

 " 2. Same seen from above. 

 " 3. Older than fig. 1 ; dendritic pigment cells more numerous in the upper 



part of the head ; the nearly unbroken lines of chromatophores are 



broken up into separate cells ; the permanent rays of the dorsal and 



anal fins make their appearance. 

 " 4. Crossopterygian stage of pectoral of young Fundulus about in stage of 



fig. 1, from the side. 

 " 5. Same fin seen from above, slightly bent laterally when in motion. 

 " 6. Same fin seen from above, at rest. 



PLATE XX. 



Fundulus nigrofasciatus, C. Sf V. 



Fig. 1. Young measuring llmm Jn length and uniformly covered with dendritic 

 chromatophores, dorsal and anal quite high, well separated from the 

 caudal ; first trace of veiitrals. 



" 2. Young measuring IG"™ in length, body more compact, ventrals quite 

 distinct, anal and dorsal slightly lobed, caudal rounded, pectoral 

 elongated, whole body covered uniformly by closely packed dendritic 

 chromatophores. 



" 3. Young measuring 20""" in length ; although the head is still compara- 

 tively larger than in fig. 4, yet the anterior part of fish has assumed 

 the characteristic sloping outline of the adult. The scales are 

 already well developed in this stage. The pigment cells are com- 

 paratively smaller than in younger stages, and very closely packed 

 over the whole surface, especially on the dorsal side. 



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



