166 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 



NON-MYXOSPORIDIAN. 



1. Psorospermia sciaenae-umbrae Robin, 1853.' PI. 1, figs. 1-4, 



Hist. Nat. des Vcget. Parasites, pp. 314-321, pi. 14, figs. 14, 15; pi. 15. 



Robin defined the species as follows: 



Cellulae ovoideae vel raro sphericse aiit ovoidoo-elougata) ; coriace;B, intus granu- 

 los«, achromaticae, luteo-succineiB vel luteo-fiiscae. Long., mm. 0-027; lat., mm. 

 0-018; sphericiB, mm. 0-017. In stratis (colonise) iudefinitis, vel cylindricis, fila- 

 mentosis, circulatim flexuosis, continuis coliiErentes, raro isolatse. 



JSab. Infra mombrauam mucosam cavi brauchialis iusitam in septo abdomino-bran- 

 cliio sciajnaB-umbra;. 



The species consists of three varieties. The description is Robin's 

 condensed and rearranged. 



Variety 1.— (Robin's plate 15, figs. 2a, h; ia, I; 6.) 



Microsco-pic. — Colls ovoid (27 by 18 ti) or spherical (diameter 17 //), a 

 little flattened on one side, having an amber-yellow tint with a white 

 shining reflex, strougly refriiigent, resembling fat drojis; ovoid cells a 

 little flattened with clearly defined borders and double contoured walls 

 (1 1± thick) rupturable by pressure, cell-contents then escaping. Con- 

 tents clear, yellow, homogeneous, strongly refracting, liquid, in which 

 float 5 to 8 or more, strongl}^ refringent granules, 1 ^i in diameter. Cells 

 not altered by acetic acid or ammonia. 



Macroscopic. — Cells cohering into grayish yellow, flexuous cylinders 

 (colonies) 0-5 mm. in diameter (plate 15, fig. 1) ; length sometimes 1 m. or 

 more. Cylinders convoluted, circular, endless, usually united in pairs 

 by a double or triple delicate transparent connective tissue sheath 

 (fig. 2e, /, </), the whole ibrming a delicate string rolled upon itself, in 

 every direction (pi. 1, fig. la of this paper) into a flattened spherical, 

 lobulated or nonlobulated mass, whose size varies from that of a nutlet 

 to that of a fist. 



Variety 2.— (Robin's plate 15, figs. 2c, d; 4c, d.) 



Microscopic. — Cells ovoid, white, colorless, transparent, with a shining 

 reflex, with more numerous and larger granulations than the other 

 varieties. 



Macroscopic. — Cells united into opaque, milk-white, filameutous, con- 

 tinuous, endless cylinders, either by simple cohesion or by amorphous 

 matter, which latter forms around each cylinder a (hardly perceptible) 

 thin enveloping membrane (plate 14, figs. 2c, d; 4:C, d). These fila- 

 ments are only visible under a lens, being only yV to ^ as thick as the 

 cylinders of the first variety. 



'This species was first described as a constituent part of the body of the host by 

 Robin, iu his paper "Auatomie d'un orgaue ddcouvert sur I'orabre (Sciaina umhra) 

 read to the Soci6t6 plnlomaUqiie Nov. 28, 1846 (Procfes verb. d. la Soc. philomat. Paris, 

 1846, p. 140; also .Jonrn. I'lustitut No. 683, Feb. 3, 1847, Paris, xv, p. 41), Not seen; 

 fide Robin, 1853, p. 314. 



