534 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
smaller toward the apex of the proboscis. The anterior part of the body 
was covered with scale-like spines, each with a midrib somewhat like 
that of a small leaf. Length of slender basal hooks, 0.08 mm ; length of 
large median hooks, about 0.13 mm ; length of fusiform proboscis, l mm ; 
length of sheath , 2 mm ; length of dermal spines, 0.036 mm . 
One of the specimens from the u angler” gave the following measure- 
ments while living : Length, 5 mm ; length of proboscis, 0.8 mm ; diameter 
of proboscis at base, 0.28 mm ; near base, at widest part, 0.34 mm j at apex, 
0.22 mm ; length of proboscis sheath, 2 mm ; diameter of inflated part of 
body, compressed, 1.7 mm ; diameter of posterior part, 0.6 mm ; length of 
cylindrical part of body, 1.88 mm ; length of largest hooks, 0.1 mm ; length 
of dermal spines, 0.035 mm ; length of caudal spines, 0.027 mm . 
The shape of the proboscis is similar to that of E. proteus , but the 
median hooks are larger and the extremities of their basal supports 
not forked. There is also a more abrupt transition from the smaller 
basal to the larger median hooks thau is the case in E. proteus. 
These specimens agree closely with E. incrassatus , the principal dif- 
ference being the presence of spines on the body. The spinose epidermis, 
characteristic of many immature forms of Echinorhynchi, seems to be 
frequently lost in the adult, and too much importance, therefore, should 
not be given to it as a specific character, when immature forms alone 
are under consideration. 
Habitat: Lophius piscatorius, peritoneum, July 31, 1885 ; Paralichtliys 
dentatus , July G, and Pomatomus saltatrix, July 26, 1889, Wood’s Holl, 
Massachusetts. 
Echinorhynchus agilis Rudolplii. 
[PI. vii, figs. 70 to 72.] 
U. S. F. C. Rept. 1886, pp. 490-492, pi. v, figs. 1 to 6. 
In the report cited above I have noted the occurrence of this para, 
site in the common eel ( Anguilla rostrata) intestine and in the dusky 
shark (Car char hinus ohscurus ) stomach. 
On October 20, 1886, 1 received from Prof. S. E. Meek, then employed 
in the biological laboratory of Mr. E. G. Blackford, at Fulton Market, 
New York, five specimens of this Echinorhynchus from the intestines 
of the white perch ( Roccus americanus ), associated with E. thecatus. The 
males in this lot are about 6 mm and the females about 8 ram in length. 
Echinorhynchus serrani. 
[Plate vii, figs. 73 to 79.] 
The following description is based on a single immature specimen 
from the peritoneum of the sea bass (Serranus atrarius ) : 
Body linear, gradually attenuate posteriorly, more abruptly atten- 
uate anteriorly. Proboscis with seven or eight hooks visible in single 
spiral on one side, sixteen in longitudinal series. Hooks large, espe- 
