The Blennies: Blenniide 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. 
Fic. 477.—Pearlfish, Fierasfer acus (Linnus), issuing from a Holothurian. 
Coast of Italy. (After Emery.) 
The Brotulide—The Brotulide 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 Brotulide as degraded blennies, but the 
Gadide have an earlier and different origin which has not yet 
been clearly made out. Most of the Brotulide 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 
