TheBlennies: Blenniidag 523 



Zoology, according to Professor Putnam, is "one valve of a 

 pearl-oyster in which a specimen of Fierasfer dubius is beauti- 

 fully inclosed in a pearly covering deposited on it by the 

 oyster." A photograph of a similar specimen is given above. 

 The species found in Holothurians are transparent in texture, 

 with a bright pearly luster. Species living among lava rocks, 

 as Jordanicus umbratilis of the south seas, are mottled black. 

 Since this was written a specimen of this black species has been 

 obtained from a Holothurian in Hilo, Hawaii, by Mr. H. W. 

 Henshaw. 



FIG. 477. Pearlfish, Fierasfer acus (Linnaeus), issuing from a Holothurian. 

 Coast of Italy. (After Emery.) 



The Brotulidae. The Brotulida constitute a large family of 

 fishes, resembling codfishes, but differing in the character of 

 the hypercoracoid, as well as in the form of the tail. The 

 resemblance between the two groups is largely superficial. We 

 may look upon the BrotuUda as degraded blennies, but the 

 GadidcB have an earlier and different origin which has not yet 

 been clearly made out. Most of the BrotuUdce live in deep 

 water and are without common name or economic relations. 

 Two species have been landlocked in cave streams in Cuba, 

 where they have, like other cavefishes, lost their sight, a phenom- 

 enon which richly deserves careful study, and which has been 

 recently investigated by Dr. C. H. Eigenmann. These blind 



