- oy _ 
100 AVIAN ENTOZOA—LINTON. 
erythrorhynchus, Yellowstone Lake, August, 1890, an account of which 5 | 
was published by the author in a paper entitled “ A Contribution to — 
the Life-history of Dibothrium cordiceps Leidy.” Bulletin of the U.S. | 
Fish Commission, 1890, Vol. 1x, pp. 337-358, Pl. CXVII-CXIXx. 
The adult stage of D. cordiceps was found in the intestine of Pelecanus _ 
¢ 
Dibothrium exile sp. noy. 
(Pl. vi, Figs. 46-48.) 
Head oblong, tapering both anteriorly and posteriorly; bothria 
elongated, lateral with rather thin lips; neck long and slender; the 
first segments twice as broad as long, this proportion continuing with- 
out much change, except that the breadth increases rather faster than 
the length, until the median region is reached where the segments 
are squarish and even a little longer than broad; the posterior seg- 
ments are rectangular, the length being a little inexcess of the breadth. 
The segments throughout are characterized by considerable regularity 
and distinctness and the strobile by its nearly linear form throughout. 
The single specimen obtained had the following dimensions in alco- 
hol. 
Millimeters. 
1G) y iE Sa enine es Gear os Gece Ceca ericeimnce Sag abso oau Som 153. 00 
IOUT NOPE RES Se aoeaeoes psc poosed aSosoo Cosco as saae 1.50 
Greatest breadth of head= -2- -5-~ +5 .s--ssee >= Ate Ghee JAE . 60 
hii ckiwvesseor Meats. sseere cee yee eter GcogeerasastGocd wou 
Distance from head to first segment....---..------------ 10. (0 
Breadth of neck...--. a sats Deelas eke eae ae oe eerie . 30 
Thicknessiof neck... 2.22.) 5 waa ese eies oe aeere eee .16 
Length of first segments._---------------. = ee 28 
Breadth of rst seo ments... -s0 sae Se see se eens eee 50 
Length of posterior segments... - 5--/. 22> Soca - == eaecer . 85 
Breadth of posterior’semments -—- - << 2. ee coe mone .80 « 
The length of the living specimen was 160 millimeters. 
The genitalia have not yet developed. Careful search was made in_ 
several of the posterior segments which had been stained with borax 
carmine and made transparent in oil of cloves, without revealing any 
genitalia whatever. The interior of the segments is filled for the 
greater part with granular protoplasm. These granules were begin- 
ning to gather into denser masses along the median line rather towards 
the posterior part of the segments. It may be inferred therefore that 
the genital apertures are median in this species, although it can not be 
proved from this specimen. 
Hapirar: Larus Californicus, intestines, Yellowstone Lake Wyo- 
ming, August, 1891. 
EPISION gen. noy. 
(Eziceiwv, a pennant). 
Anterior end of body (head) lamellate, more or less crispate, deflected. 
Body proper, tenieform, segmented, segments not distinct. 
Reproductive apertures lateral (?). 
