594 TEREOSPEL CHAP. 
to Reinhardt’ the allied Stegophilus insidiosus, a small colour- 
less Fish, 30 to 40 mm. long, from Brazil and Argentine, lives 
parasitically in the gill-cavity of large Cat-Fishes (Platystoma). 
Dr. F. Silvestri has noticed that it sucks the blood in the 
gills of Platystoma coruscans, a Silurid growing to a length of 
6 feet. 
Fam. 5. Loricariidae——Distinguished from the preceding by 
the sessile ribs and the absence of the transverse processes in the 
praecaudal vertebrae, which have bifid neural spines. The air- 
bladder is always much reduced, and enclosed in a right and a left 
bony capsule formed by the skull and the anterior vertebrae. Gill- 
openings narrow clefts. The mouth is inferior, with more or 
Fic. 359.—Upper view of heads of Chaetostomus cirrhosus, male and female. (Nat. size.) 
less developed circular lips and feeble dentition; it is used as a 
sucker, by which the Fish fixes itself to any hard object with such 
streneth that it cannot be pulled off without great difficulty. 
The teeth are usually slender and bicuspid. The food consists of 
very small prey and more or less putrefied organic substances, 
the intestine being usually extremely elongate and much con- 
voluted. The habits of these Fish are very little known, but the 
fact that the males of many species have the pectoral fins much 
stronger than the females renders it probable that they pair like 
1 Vidensk, Meddel. (Copenhagen), 1858, p. 79. 
