THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 291 



EXPLANATION OF PLATES. 



All figures copied are either of the same size as, or li times the size of, the figure* 

 from which they were copied; tliiit is, in copying ouly 2 ratios were used, 1:1 aud 

 f :1. The relative sizes of tlie copied and the original figures are in every case 

 indicated by the figures «'«7/iiH the parentheses. All figures outside the parentheses 

 indicate the total amplification from the specimens. For the derivation of any figure, 

 see table, pp. 131-134. 



Plate 1. 



Figs. 1-4. Psorospermxa sciwno'-nmhra; (after Robin, x i). 

 Irt. The convoluted string (cordon enroide). x 1^. 

 lb. Section of fig. la. X li. 



2. Cells of variety 1. X 600. 



3. Cells of variety 2. X 600. 



4. Operculate cells of variety 3. X 600. 



Plate 2. 



Figs. 1-2. ir//(oct/sfi8 8c/ine?(?eH (after Cu^uot. X |). 



1. Gregarine stage, with voluminous nucleus and clinorhombic crystals. 



2a. Spore at the extremity of the tube, showing the truncated distal a»»,. 



rounded proximal extremities, and the sporozoites in course of formation. 

 2b. Fully developed spore containing 8 sporozoites. 

 Fig. 3. Genus incert. sp. 3 (alter Miiller & Retzius. X I). Spores li-om the diseasou 

 air bladder of Gadus murrhua, 



Plate 3. 



Figs. 1-5. Balhianiarileyi (aftei Stiles, x 1). 



1. A portion of the pectoral muscles of Jnas boschas in the condition known as 



"measly duck." 



2. Longitudinal section of parasite (greatly enlarged). 



3. Transverse section (greatly enlarged) : ct, connective tissue cyst with numer- 



ous nuclei; cu, cuticle of the i)ara8ite; m, sections of muscle. 



4. Microtome section ol meshes containiug falciform bodies greatly enlarged. 



5. Falciform bodies: a, stained, showing nucleus aud vacuole; b, unstained. 



Fig. la-m. Gevus incert sp. 4 (after Valentin. X |). 



Irt. The original glol>ular form. 



Ih-d. Difi'erent stages of the unrolling of tl^e tail. 



Ic. A globule in which the separate dark granules appear to be inclosed iu -.ca- 

 rafe peduncles. 



1/. Pe<l uncle ideally enlarged. 



Ifl-m. Various forms of the developi d animal. 

 Figs. 2-8. GenuH incert. sp. 6 (after Schewiakotf. x 1). 



2. Amiebiform stage. X 1500. 



3-5. Eucvstmeut. X l.">00. 



6. Cvst with 6 spores, x 1500. 



7. Cysttliiekly lilled with spores. X 1500. 



8. Plaoiuodo proceeding from the fusion of 3 amcobaj. X 1500. 



