ON THE CLASSIFICATION OF THE MYXOSPORIDIA. 
415 
Habitat: Subcutaneous, on Cyprinodon variegatus , from the Atlantic at Woods 
Holl, Mass., August 20, 1889. 
Myxobolus obesus, sp. nor. 
(Psorosperm of the “ Ablette,” Balbiani, 1883, Journ de Microgr., vn, p. 203, fig. 43.) 
Spore: Very broadly ovate. 
Habitat:, On Alburnus alburnus L. 
Myxobolus cycloides, sp. nov. 
(Psorosperms of Cyprinus rutilus (pars) Miiller, Miiller’s Archiv., 1841, pp. 481, 486, t. 16, f. 4 
d-g.) 
Spore: Subcircular-ovate to broadly rounded-elliptic. 
Habitat : Opercle and pseudobran chiie of Leuciscus rutilus L., from German rivers, 
May and June. 
Myxobolus spheralis sp. nov. 
(Psorosperms of Coregonus fera Claparede, 1874, in Lunel’s Hist. Nat. d. Poissons dubassin du 
L6man, Geneva, pp. 113-4 . ) 
Spore: Untailed; perfectly spherical ; diameter, 9//; containing a single spherical 
very strongly refringent “nucleus” [? vacuole]. 
Habitat : Cysts imbedded by thousands in the branchial mucosa of Coregonus 
fera Jur. 
Myxobolus globosus, sp. nov. 
Cyst: Elongate-elliptic or rod-shaped: length ad max., 0.50 mm. 
Spore: Globose; length, 7 or 8 /.<; breadth, 0 q; thickness, 5 /<; ridge very wide ? 
one-third of thickness; capsular index somewhat more than 0.50. 
Habitat: Branchial lamellae of Erimyzon sucetta Lac. (= Catostomus tuberculatus 
Le Sueur), from Kinston, N. C., Columbia, S. C., and from the tributaries of the Fox 
River, Miss, (collections U. S. National Museum). 
Myxobolus transovalis, sp. nov. 
Spore: Transversely elliptic; length, usually 6, occasionally 7 p ; breadth, 8 p; 
valves separating in sulphuric acid; ridge narrow; capsules 2, equal; capsular index, 
0.50 ; filaments extruded under the influence of glycerine aud of sulphuric acid ; nuclei, 
2, rarely only 1, pericoruual nuclei apparently absent; vacuole probably present. 
Habitat: In hollow of under surface of scales of Phoxinus funduloides from Four 
mile Run (tributary of Potomac River), Carlins, Ya., June 29, 1892. 
Myxobolus merlucii Perugia, 1891. 
Myxosporidium merlucii, Boll. Soientif. Pavia, xm, pp. 22, 24, f. 9-14. 
Myxobolus perlatus, sp. nov. 
(Psorosperms of Acerina cernua Balbiani, 1883, Journ. de Microgr. Paris, vii, pp. 201, 204, fig. 
44.) 
Spore: Wider than long. 
Habitat: On Gymnoceplialus cernua L. 
