I'OLYCILKTA. 267 



Hesione genetta, Grtjbe. (See Grube, 'Ann. Semp.,' 1878, p. 104.) 



One specimen from Chilaw Paar, Station LXIX. 



This species is distinguished from the members of the splendida group by its very 



characteristic and enduring pigmentation. At the junction of the tirst and second 

 setigerous segments there is a broad dark transverse band passing from one side to 

 the other across the convex dorsum. Behind this band the segments are marked by 

 transverse brown spots which are sometimes confluent. The cuticle is highly 

 iridescent ; the body flexed ventrally and the ventro-lateral borders elevated, leaving 

 a median neural groove between them. The prostomium is quadratic ; two frontal 

 notches from which the minute antennae arise ; eyes barely visible. The body is 

 shaped like that of H. reticulata, von Maeenzeller (South Japan), and resembles 

 the body of a caterpillar, as remarked by vox Marenzeller. Length 13 millims., 

 inclusive width 3 millims. 



Irma limicola, n. sp. Plate III., figs. 74 to 76. 



This species is founded upon a single example which occurred in one of the mud- 

 tubes of Loimia montagui from Palk Bay. It is not very well preserved in 

 consequence of having been trapped in such a narrow recess. Its length is 

 20 millims., width 3 millims., with upwards of 50 segments. 



The head is transverse, the eyes widely separated, the anterior and posterior eyes 

 of each couple crescentic and closely approximated. From the frontal border of the 

 prostomium on each side two equal cephalic appendages (antennas and palps) curve 

 backwards, lying over the eyes and sides of the prostomium. The biannulate 

 proboscis is extruded. No tentaculum impar could be observed. Six tentacular 

 cirri are present on each side of the buccal segment, placed in a dorsi-ventral manner, 

 the upper and lower of the group being shorter than the intermediate. 



The dorsal ramus of the parapodium is intimately connate with the cirrophore of 

 the dorsal cirrus into which an acicula extends, and from a slight protuberance on 

 the lower side of the cirrophore a bundle of very fine capillary setae emerges 

 (Plate III., fig. 74). The compound setae of the ventral ramus are numerous, about 

 fifty in each fascicle. They are falcigerous, carrying very long appendices curved at 

 the tip and bidentate, the apical tooth frequently connected with the minor tooth by 

 a limbus. The superior setae of the ventral ramus have appendices about one-half 

 shorter than the average ; the inferior setae, i.e., the most ventrally placed seta?, carry 

 quarter-sized appendices (Plate III., figs. 75 and 76). The relations of the dorsal 

 and ventral cirri and the lip of the parapodium are shown in the figure (Plate III., 

 fig. 74). Repeated examination failed to reveal any trace of a tentaculum impar in 

 Irma limicola. In this respect it approaches the genus Castalia, Sav., as amended 

 by M. Sars ('Christ. Vid. Selsk. Forh.,' 1861, p. 88), but there are no coronary 

 papilke on the proboscis and no jaws. 



2 m 2 



