112 R. C. PUNNETT. 



Two very large eyes are present on either side. 



As in the other species of the genus the head glands are exceedingly well developed 

 and reach back a little way past the brain. They open into a deep pit lined by modified 

 ectoderm resembling that figured by Burger (Naples Monograph, Taf. 18, fig. 12). 



The only account of the genus Prosadenoporus is that given by Biirger in founding 

 the genus on several species from Amboina (Zeit. f Wiss. Zool. 1890, p. 30). I have there- 

 fore thought it fitting to name this new species in honour of the zoologist to whom our 

 entire previous knowledge of the genus is due. From the account given in this publication 

 it will be seen that the present species differs from the forms there described chiefly in 

 the absence of external markings, the number of proboscis nerves, and in the ventral 

 position of the opening of the canal of the cerebral organ. 



11. Drepanophorus roseus, n. sp. (PI. IV. fig. 7.) 



Localities. Hulule, Maldive Is. From boulder zone. Naifaro, Fadiffolu atoll, Maldive Is. 



Several specimens, most of which were somewhat fragmentary. In three complete specimens 

 the length varied from -50 — 64 mm. and the breadth from 5 — 5'5 mm. after preservation. 

 The posterior and middle portions of the body were exceedingly flattened. Colour in life 

 pink to red. 



The epithelium is high, and contains numbers of elongated unicellular glands with small 

 granules inside (" Stabchenzellen "). It is separated from the circular muscle layer by a 

 thick basement membrane. The relative thickness of the three layers, epithelium, basement 

 membrane, and circular muscle layer, is as 4:3: 2. The longitudinal muscular layer is 

 well marked, being of about the same thickness as the preceding three layers together. A 

 thin diagonal layer occurs between the circular and longitudinal. 



Mouth and proboscis pore open separately into a common depression on the ventral 

 surface near the anterior extremity. The latter opening is the more anteriorly placed. At 

 first without glands the oesophagus begins to shew large deeply staining unicellular glands 

 in the cerebral region. There is a well-marked ventral blind gut passing forward from the 

 junction of oesophagus and intestine. It does not however reach forwards quite two-thirds 

 of the distance between its point of origin and the brain. The intestine is a small round 

 tube whose area in cross-section is not much more than double that of one of the nervous 

 stems at the same level. 



The vascular system conforms to the usual metanemertean arrangement. It contains 

 numbers of large oval corpuscles which render it exceedingly conspicuous in section. The 

 lateral vessels lie just dorsal to the nervous stems, and the commissural vessels which they 

 give off pass directly up between the intestinal diverticula to the median dorsal vessel. 

 Others, however, pass right round the ends of the intestinal diverticula before reaching the 

 median dorsal vessel. 



The proboscis sheath presents the usual basket-like arrangement of its muscle fibres 

 which characterises the genus. The diverticula are long and slender, and pass round the 

 intestinal pouches to reach as far as the nervous stem. The proboscis shews the usual 



