SIXTEN BOCK, TWO NEW COTYL. GEN. OF POLYCLADS. 29 



Stylochoides Hallez and Leptoteredra Hallez, the reduction 

 being more or less advanced. 



The female apparatus in the median line is very simple. 

 It opens to the exteriör extremely close to the male porus 

 or a very short distance behind it (text fig. 5, Plate 2, 

 fig. 5). Some small variation in this respect may take place 

 as indicated in the figure just referred to in comparison 

 with Plate I, fig, 5, which represents another specimen. The 

 internal part of the vagina, which is placed immediately 

 below the seminal vesicle and above the sueker, is a narrow 

 and short duct eompared with the same part of Chromoplana. 

 The shell-chamber is only slightly dilated and has not that 

 characteristic horisontal widening which is so common in the 

 Cotylea. Accordingly it is more tube-like as in the Acotylea, 

 not sac-like as it generally is in the Cotylea. The course of 

 the vagina differs also from what is typical for the Cotylea. 

 The vagina is not sharply bent and has not the distal part 

 running vertically but piirsues a direot course obliquely 

 ventrally and anteriorly. The characteristic anterior curve 

 of the vagina of the Acotylea which is more feebly ex- 

 pressed in the Cotylea is totally lacking here. 



To the new family, Chromoplanidoe, I give this diagnosis : 

 Small cotylean polyclads with a vivid colour caused by 

 pigment granules. No tentacles, Tivo dusters of cerebral eyes; 

 marginal eyes only at the frontal end of the body. Pharynx 

 large and much folded, situated in the anterior half of the 

 body. Moiith at the middle of the pharyngeal area. Male 

 apparatus directed forivar d and situated close to the pharynx. 

 Penis unarmed with or without penis folds. Seminal vesicle 

 opens into the prostatic vesicle {ivhich can be partly reduced). 

 Ovaries few, situated ventrally and producing large ova. 

 The genus Chromoplana is characterized as follows: 

 Chromoplanids of oval outline. Cerebral dusters of very 

 feiv eyes. Male porus in closest proximity to the mouth. Penis 

 with penis folds. Prostatic vesicle large, pear-shaped. An acces- 

 sory seminal vesicle behind the true vesicula seminalis. Female 

 apparatus of ordinary cotylean type, at a distance behind the 

 male apparatus. Marginal sensorial furroivs. 

 One species from Japan. 



