74 



T. KOMAT : STUDIES ON TSVO ABERRANT CTENOPHORES 



+ glacial acetic acid 3 parts) was used with preference. The specimens 

 preserved in formalin also were found to retain much of the original 

 condition fairly satisfactorily, and they were observed as total preparations 

 stained with borax-carmine or cut into sections. Sections were always 

 prepared with paraffin method, and stained with Delafield's haemato- 

 xylin and cosin. To find out individuals of small sizes in the body of 

 Salpa, I found it helpful to stain the entire host body with borax- 

 carmine, extract suf^ciently, clarify with clove-oil, and examine with 

 low-power microscope. Even very small specimens were detected 

 without difficulty by this method. 



External Features. 



The parasite is a small transparent and colourless organism. The 

 body is round and disc-like, about equally broad in all directions, 

 distinctly convex on the dorsal side and more or less concave on the 

 ventral. It is generally more convex on the dorsal side than concave 



Text-figure 3. Salpa ftisiformis CuvIEk, hailiourinsj; four inclividiuik of Gaslrodes. 

 p<irasilicum Kordtnicff in various flevcl(jp;ncntal slat^cs a-d. X.v 



nn the ventral, so that the body is thickest in the central part and 

 thinnest in the marginal. It varies in size rather greatly, lluctuating 

 from 0.15 to 3 mm. in diameter, with the height measuring nearly one 

 quarter of the breadth. Small individuals show slight concavity on 

 the ventral side and arc very approxitiiately disc-like; large ones, on 

 the contrary, are generally rather highly vaulted and may even appear 

 hemispherical in form (PI. .S, fig. i). The animal is imbedded always 



