Laguna Warine Laboratorp 21 
instance the similarity in internal structure of the ‘‘bat-fish’’ (4A eto- 
batus californicus) and the ‘‘shovel nose shark’? (Rhinobatus pro- 
ductus), whose viscera are correlated with bottom living habits and 
similarity of food, rather than body structure or form. Other modi- 
fications, on the other hand, such as that shown in the peculiar 
diverticulum or cecal appendage of the stomach in Gymnothorax 
mordax, are not so readily understood, and offer interesting fields 
for speculation. 
In only one family, the Blennide, were enough species obtained 
to allow any comparative study. But in this one alone some remark- 
able modifications are found, as shown in the accompanying figures. 
In this one family several extremes are typified, in regard to both 
form and structure of the visceral organs. The most peculiar of 
these is the great divergence from the comparatively short, compact 
viscera, with the long, coiled alimentary canal in such forms as 
Heterostichus or the Gibbonsias, to the extremely long, drawn out 
viscera and perfectly straight alimentary canal of the eel-like Xerer- 
pes fucorum, That this is not due solely to external form is shown 
by the intermediate visceral structure of NXiphidion rupestre, which 
in body form is extremely long and eel-like, just as is Xererpes 
fucorum. 
Unfortunately only enough has been done to show a few of the 
extremes, and not enough to indicate relationships between genera. 
But even this indicates that a comprehensive study of this large 
and varied group in its entirety could not fail to bring out some 
important and interesting facts in regard, both to individual species 
and to their inter-relationships. 
Family EPTATRETIDAE 
Eptatretus stouti (Lockington). Hagfish. 
Not common. <A few specimens taken on set lines, or brought in 
by fishermen at Laguna. 
Family CARCHARIIDAE 
Mustelus californicus Gill. Dog-shark, Oil-shark. 
Abundant at Newport and common at Laguna. 
Triakis semifasciatus Girard. Little Leopard Sharp. 
Found commonly in the vicinity of Laguna and Newport, but 
never abundant. Taken on set lines close to the shore at Laguna. 
Carcharias laminella Jordan and Gilbert. 
Two specimens seen at Newport are thought to be this species. 
