414 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Myxobolus unicapsulatus sp. nov. 
(Psorosperm of Labeo niloticns Miiller, Muller’s Archiv., 1841, p. 487, t. 16, f. 5 a-d . ) 
Spore: Of the form and size of Chloromyxum dujardini Thel. ; capsule only 1, 
obliquely directed. 
Habitat: Labeo nilotieus , from the Nile. * 
Myxobolus piriformis Thdlohan, 1892. 
Bull. Soc. philomat. Paris, iv, p. 177. 
Myxobolus inequalis sp. nov. 
(Psorosperms of Pimelodus blochii (Valenc.) Miiller, Miiller’s Archiv., 1841, p. 487, 1. 16, f. 6 a. b.) 
Spore: Length II r; breadth, 7 pr, capsules 2 of unequal size. 
Habitat: On Pimelodus clarias Bloch ( =8ilurus elarias Valenc.), from Guiana 
and Surinam. 
Myxobolus mugilis Perugia, 1891. 
Myxosporidium mugilis, Boll. Scientif. Pavia, xm, pp. 23-4; Myxobolus mugilis Thdlohan, 1892, 
Bull. Soc. philomat. Paris, iv, p. 166. 
Myxobolus oviformis Thdlohan, 1892. 
Bull. Soc. philomat. Paris, iv, p. 177. 
Myxobolus miilleri Biitschli, 1882. 
Bronn’s Thier-Reich, i, t. 38, f. 6-10. 
Myxobolus oblongus sp. nov. 
(Psorosjjerms of Catostomus tuberculatus Miiller, Muller’s Archiv., 1841, pp. 487-90, 1. 16, f. 7-9.) 
Cyst: Bound or elliptic, 1 mm. or less. 
Spore: Spatular or round-oblong; length, 14 to 17 r; greatest breadth and 
greatest thickness at about the junction of the anterior and second fourth of the 
length; breadth, 8.5 yu; thickness, 5 to 6 /t; width of ridge nearly equal to one-third 
of thickness; capsules, 2; nuclei 2, and perhaps* more; vacuole not seen. 
Habitat: Subcutaneous on head of Erimyzon sucetta Lac. (= Catostomus tuber- 
culatus Le Sueur). 
Myxobolus ellipsoides Thdlohan, 1892. 
Bull. Soc. philomat. Paris, iv, p. 177. 
Myxobolus bicostatus sp. nov. 
(Myxosporid ian sporeof branchiae of Tinea vulgaris Biitschli, 1882; Bronn’s Thier-Reich, i, t. 
38, f. 19.) 
Spore: Shell with 2 oblique ribs over the longitudinal axes of the capsules; cap- 
sular index 0.50. t 
Habitat: Branchite of Tinea tinea L. 
Myxobolus lintoni sp. nov. 
(Psorosperms of Cyprinodon variegatm Linton, 1891, Bull. U S. Fish Com. for 1889, ix, pp. 
99-102, t. 35, f. 1-16.) 
Spore: Ovate; length, 13.9 /r; breadth, 11 pr, thickness about 8 pr, shell, valves 
separating rapidly in sulphuric acid (cold, concentrated); capsules, 2, equal; fila- 
ments extruded under influence of sulphuric acid and of iodine water; nuclei ad plur. 
4, 2 of which are the pericornual ; \ vacuole present. 
*The condition of the material being such as not to exclude the possibility of sporoplasmic 
degeneration, these results are not entirely decisive. 
t Capsular index. The ratio of the length of the capsule to the antero-posterior diameter of the 
shell cavity. 
1 Pericornual nuclei. The 2 nuclei ( “ granules” “globules ” ) situated at the antero-lateral angles 
\Cornua ) of the sporoplasm or on the posterior extremities of the capsules. 
