ad PROCEEDINGS OF THE NATIONAL MUSEUM, 93 
specimens are somewhat fusiform. The anterior region of the body is 
rounded and echinate. The proboscis, especially of the larger speci- 
mens, the spines of the anterior part of the body, and the shape, num- 
ber, and arrangement of the proboscis hooks agree closely with those 
of the first lot. There is, however, a slight difference between the 
larger and the smaller specimens in the shape of the proboscis and 
the number of hooks. In the smaller specimens the proboscis is less 
conical than it is in the larger and there appears to be a less number 
of vertical rows of hooks. ‘The hooks toward the base of the proboscis 
are stouter than those near the apex. 
The testes are oval, and, when not displaced by constrictions in the 
body, lie close together, even slightly overlapping at their contiguous 
ends, near the base of the proboscis sheath. In some cases the anterior 
constriction of the body forced the anterior testis forward beside the 
sheath. 
The prostatic glands appear to be about four in number and are 
elongated and parallel. 
The most characteristic feature of these specimens is the echinate 
posteriorend. This, indeed, appears to be an echinate armature of the 
bursa. These spines are numerous, forty or more having been counted 
in two of the specimens. They are terminal, and, like those on the 
anterior part of the body, appear to be sagittate in some aspects. 
Two specimens from this lot yielded the following measurements : 
mm. | mm 
en rtihitice = smescescenetwce a eeeseen 5. 50 | 2.50 
Diameter, anterior ....... .40 | .35 
Diameter, median......... $Oon| 50 
Diameter, posterior.-....-. ~20°) 20 
Length of proboscis .-....-.-.---- .60 | .60 
Diameter of proboscis at base....) .24 | .15 
Diameter of proboscis at apex....| .18 15 
Length of proboscis sheath. .-..... 70 | . 60 
| The anterior testis in one specimen was 0.3 millimeter in length and 
| 0.17 millimeter in breadth; the posterior testis was 0.28 millimeter in 
|| length and 0.15 millimeter in breadth. 
TREMATODA. 
Holostomum variabile Nitzsch. 
(Pls. v, vi, Figs. 26-29, 30-32.) 
Amphistoma macrocephalum Rudolphi, Entoz., 11, 340; Synopsis, 88, 354, 
Holostomum variabile Nitzsch., Diesing, Syst. Helm.1, pp. 312-313, Revis. d. Myzhelm., 
p. 320; Von Linstow, Trosch. Archiv., p. 187, Compend. Helm., p. 103; Wedl, Sitz- 
unigsb., XXVI, p. 252-253, Pl. 1, 18; Molin, Denkschrift. d. Kais. Akad., X1x, pp. 
194-195, Pl. 1, 6,7; Brandes, Monograph d. Holostomidx Zo6l. Jahrb., 1890, p. 
590, Pl. x11, figs. 1, 8, 9. 
Holostoma macrocephalum Creplin, Dujardin, Helm., pp. 368-369. 
Holostoma macrocephalum (Rud.), Olsson, Bitrag till Skand. Helm., p. 31, 
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