KOFOID : NEW SPECIES OF DINOFLAGELLATES. 187 



Girdle narrow, median in the midbody, impressed, without salient ridges, 

 forming a descending right spiral, displaced its own width. Longitudinal 

 furrow extending a short distance on the epitheca where it contains an accces- 

 sory ventral pore and is continued posteriorly on the midbody as a diminish- 

 ing groove nearly to the base of the autapical. 



Thecal wall hyaline, finely porulate, larger pores on apex and antapex. 

 Dorsal wall of apical greatly thickened. 



Length, 275 ^; dorso-veutral diameter, 67 (i. 



Station, 4722. 



This is the type species of Centrodinium. 



Podolampas reticulata, sp. nov. 



Plate 3, Fig. H. 



A large species with the form of P. biceps, but with reticulate fins on the 

 autapical spines. Their fins are very large and broadly rounded, with irregu- 

 larly serrate margins and distal reticulations spreading from the spines. The 

 fins are more decurreut laterally and less pointed than in P. biceps, and the 

 spines 0.5-0.7 as long. The body is a trifle shorter and somewhat more ro- 

 tund anteriorly and less squarish posteriorly. 



Length of body, 80-92 /x; transdiaraeter, 70-75/*. 



Stations, 4638, 4732. 



Oxytoxum challengeroides, sp. nor. 



■Plate 10, Fig. 65. 



A medium-sized species resembling 0. milneri, but shorter, with fine regular 

 polygonal reticulations resembling those of the Cliallengeridae. 



Body elongated, its length 3.7 times the transdiameter, which equals the 

 dorso-ventral at the girdle. Ej^itheca 0.4 of the length of the hypotheca, low 

 conical, flaring at the base, its altitude 1.17 times the transdiameter, tapering 

 quickly into the short straight apical horn, which is displaced ventrally and 

 has an asymmetrically pointed apex, the terminal spinule being on the left 

 margin of the horn. 



Hypotheca conical, with slightly convex sides, tapering without constriction 

 into the pointed antapical, which is also somewhat displaced ventrally. 



Girdle wide, 0.33 of the length from the apex, furrow deeply impressed, with 

 well-defined margins, forming a descending right spiral displaced nearly its own 

 width. Small accessory pore in its posterior margin in the midventral line 

 behind the large flagellar pore. Longitudinal furrow not extended upon the 

 hypotheca, with a tapering lanceolate extension 0.6 of the distance to the apex 

 on the epitheca. 



Plates normal, 5 apicals, pre- and postcingulars, one apical spine. Sutures 

 with narrow bands, thecal wall minutely and subregularly reticulate with small 

 hexagonal polygons, porulate. 



