28 ON A NEW SPECIES OF ENTEROPNEUSTA, 



from its ventro-lateral region to the limiting membrane of the 

 epidermis numerous radial fibres. The trunk coelom represented 

 in the branchial region by the spaces situated laterally to the 

 oesophagus is here considerably reduced and represented by 

 irregular spaces. 



The lateral septa (figs. 22, 23, Is.) are related essentially as in 

 the described Ptychodera species. In the middle of the genital 

 region the septa are of considerable breadth, and pass between 

 the dorsal corner of the gut and the submedian line, which is 

 here situated at about the middle of the internal face of each of 

 the genital wings (fig. 23, Ls.). Anteriorly the point of attach- 

 ment of the septum to the gut gradually passes medianly (fig. 22, 

 As.) until at the level of the last developing gill jDocket it passes 

 over to the skin, to which it is then attached at both ends. In 

 the branchial region the ventral point of attachment of the 

 septum gradually approaches the lateral, which always remains at 

 the submedian line until the two unite. Posteriorly to the 

 middle of the genital region the submedian line gradually passes 

 down from the mid-region of the inner face of the genital wing, 

 and takes a position close to its base, and at the same time the 

 septa are reduced gradually in l^readth and finally end with a free 

 edge in the anterior portion of the hepatic region. The lateral 

 se]3ta thus separate off from the main trunk c(elom two dorsal 

 chambers which anteriorly end blindly in the posterior part of the 

 branchial region, while ^posteriorly they communicate with the 

 main trunk ctelom by their narrow openings. These dorsal 

 chambers Spengel regards as blind-sac-like outgrowths of the 

 trunk ccelom arising in the anterior part of the hepatic region. 



Gonads: The gonads begin in the "genital wings" immediatel}^ 

 l)ehind the posterior rim of the collar and continue for a con- 

 siderable distance into the hepatic region. As distinguished from 

 Pt. miuKta, in which the gonads are simple unbranched sacs, they 

 are in this species, in correspondence with the greatly developed 

 "genital wings," much ])ranched, and are here more complexly 

 branched than is usually the case in /H. clavigera. As in these 

 species, only primary gonads and primary genital pores exist. In 



