"LARVAE" OF CHIMERA. 113 



too, the unpaired fins change proportions notably; in the stage shown in plate x, 

 fig. 52, their width is much greater proportionately than at other stages. 



In shape. The shape of the trunk undergoes noteworthy changes. In the 

 stage shown in plate x, fig. 53, it is much longer proportionately than in the earlier 

 and later stages. We note also that the dorsal fin (or rather that portion of it 

 posterior to the first dorsal) changes from continuous to lobate and then again later 

 to a lower and less lobate form, during progressive development. 



In color. Pigmentation appears progressively. In the youngest stage the pig- 

 mented areas are dorsal. In the stage of plate x, fig. 53, pigmentation is more 

 marked on the sides of the body than at any other stage. The sharpness in the 

 coloration of the distal margin of the dorsal fins is most conspicuous in the stage of 

 plate x, fig. 52; also a distinct larval coloration is noticed in the pectoral fin, a well- 

 marked color being present along the anterior margin of this fin and in the anterior 

 portion of its dermal web. Observe also the distinct patch of pigment at the base 

 of the dermal web in plate x, fig. 53. Noteworthy, further, is the progressive 

 increase in the number of pigmentless blotches; few in fig. 51", they become 

 numerous in fig. 53", and small and most numerous in the stage of plate x, fig. 54. 

 Similar changes in coloration affect the region of the eye. 



A late stage in the development of Chimcera colliei may finally be referred to in 

 plate XT. At this age the young fish has attained nearly mature size (i. e., about 

 three-quarters of that of the adult), although it is still distinctly "larval." Its 

 coloration is darker (cf. fig. i), making the small pigmentless spots more con- 

 spicuous. The margins of the fins, on the other hand, are pigmented, and with 

 these we may contrast the fin margins in the adult, figs, i and 2, especially in the 

 latter figure, where we observe that the anterior rim of the paired fins, notably the 

 ventral, are pigmentless. We observe also distinct changes in proportions from 

 the earlier stages; the length of the fish anterior to the anal region is now scarcely 

 more than one-half the total length; in the earlier stage figured it is less than one- 

 third. In the present specimen, a young male, the ventral fins partly uncover the 

 mixipterygia ; the ventrals are small in size, surprisingly so when we consider the 

 length of the entire fish. At this growth period the young of this species occur in 

 schools and sometimes appear in shallow water. * 



In other species similar changes in colors and proportions are probably present 

 in "larval" young. In one species, Chim&ra monstrosa, they are present in even 

 a more marked condition. In a young specimen preserved in the museum of 

 Tromsoe, to which the writer's attention was kindly called by Dr. V. Storm, the 

 coloration was brilliantly marked. Although not larger than the specimen shown 

 in plate x, fig. 53, it had developed dorsals sharply marked with black, pectorals 

 with an ashen blotch and with a white anterior rim, a pattern which has been 

 reproduced from a sketch in the present fig. 91. It is evident, moreover, that 

 in C. monstrosa this stage is of brief duration; for in a second and equally well- 



*The present specimen was taken, together with 22 others, in a water depth of less than 10 feet, near Port Wash- 

 ington, Puget Sound, June, 1896, in a single haul of a herring seine. In this locality Chimaera is rarely taken in 

 shallow seines. The specimens measured from 30 to 40 cm. 



