450 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



distal ends of the girdle, 0.75 length of body, as compared with 0.5 or less in 

 the two species named. The consequence is that the apical loop of the sulcus. 

 so prominent in these two species, is practically eliminated in P. maxima. It 

 is also striated as are P. violescens and P. striata (figs. 00, 1, 8), thus adding 

 development of siu-face markings and marked expansion of the furrow and 

 sulcus to the other indications of specialization. 



Pouchetia panamensis Kofoid 



Text figure PP, 7 



Pouchetia panamensis Kofoid {1907b), pp. 164, 167, pi. 1, fig. 7. 



DiAGXosis. — A minute sx^ecies with ovoidal body, its length 1.6 transdiam- 

 eters; girdle a descending left spiral, displaced nearly 0.7 transdiameter, and 

 making 1.25 turns; sulcus extends nearly to apex, its torsion nearly 0.5 turn; 

 ocellus subspheroidal with minute central lens; plasma rose pink. Length, Sip-. 

 Pacific, Bay of Panama, October. 



Description. — The body is slightly ovoidal, widest below the equator, its length 1.6 greatest 

 transdiameters. The epicone and hypocone are almost equal, apex hemispherical, antapex more 

 pointed, hypocone somewhat flattened ventrally. The girdle forms a descending right spiral 

 with a very regular descent for 1.25 turns and has total vertical displacement of. about 0.7 

 transdiameter, or 0.43 the total length. The furrow is slightly impressed without marked lips 

 and is relatively very wide, being 0.16 transdiameter in width. The sulcus is about 0.25 the 

 width of the girdle and extends from within 0.12 of the total length of the body from the apex 

 to the posterior end, where it flares out in a terminal pocket. The total torsion of the sulcus to 

 the left is a little less than 0.5 turn. The flagellar pores are at the junctions with the girdle. 

 The anterior flagellum runs the entire length of the girdle ; the length of the longitudinal one 

 is about 0.5 the length of the body. 



The ocellus lies at the left of the junction of the sulcus and the distal end of the girdle. It 

 is a minute body about 0.2 transdiameter in diameter. It consists of a subspheroidal, notched, 

 black melanosome with irregular surface in the left anterior side, of which a very small spherical 

 lens is deeply embedded, so that the melanosome forms a stout crescent about it. The lens as 

 exposed is only about 0.25 the diameter of the melanosome in diameter. The nucleus is also 

 relatively small. It is an ellipsoidal body centrally located below the equator with its major and 

 minor axes respectively 0.40 and 0.24 transdiameter in length. It lies obliquely to tlie main axis. 

 Spherical droplets are scattered in the peripheral plasma. The color is a diffuse rose pink fading 

 out posteriorly and deepest near the anterior end. 



One individual was enclosed in a concentric, trilamellate cyst, the length of which was nearly 

 three times the length of the bod}'. Its surface was gelatinous and was covered with adherent 

 particles of debris. 



DiMEXsioxs. — Length, 34m; transdiameter, 21^^; ocellus, 4m; nucleus, 8m. 



OccuRREXCE. — Several individuals seen in surface collections of plankton 

 made with a No. 20 silk net by the senior author while on the Agassiz Expe- 

 dition to the Eastern Tropical Pacific in 1904—05 in the Bay of Panama, at the 

 ship's anchorage, October 23, 1904, in a .surface temperature of about 27° C. 



CoMPARisoxs. — With the exception of P. parva Lohmann, P. panamensis 

 is the smallest species in the genus. It has the lens reduced t(.) the merest 



