LEPIDONOTUS. 273 



Ventral cirrus twice as long as pinna, seta? simple, two anal cirri. Elytra covering 

 dorsum or leaving it bare. Pharynx with a crown of simple papilla?. Jaws horny, not 

 denticulated. He grouped the species chiefly according to the arrangement of the 

 tentacles, the number of the elytra and their structure, with a few additional particulars. 

 The account is thus more detailed than that of 1874. 



Gr. Darboux 1 fils distinguishes in the dorsal cirrus the cirrophore and the cirrostyle. 

 The former is an evagination of the entire musculocutaneous envelope. The cirrostyle 

 is inserted on the cirrophore by a delicate epidermic membrane. A secretion, he says, 

 fills a glandular pocket at the insertion and causes a strain so that rupture ensues. 



Whether as a family or a sub-family the Polynoidas are sufficiently distinguished 

 from the Aproditidse by the shape of the body, the absence of a facial tubercle, the 

 diminished size and the chitinous armature of the proboscis, the reduction in size of the 

 alimentary caeca, and the position of the segmental (nephridial) papilla?. 



They are cosmopolitan forms, yet each area has its characteristic species. Thus in 

 Britain such as Eupolynoe anticostiensis , McL, Melaenis Loveni, Mgrn., and Encranta 

 villosa, Mgrn., are absent, while they are found in more northern latitudes. 



Commensalism is not uncommon in the group ; thus Dr. Baird found Harmothoe 

 cirrata (?) in the tubes of Ghoetopterus, Gattyana cirrosa is common in the tubes of 

 Amphitrite, Polynoe scolopendrina in tubes of Terebella nebulosa. Malmgrenia and Acholoe 

 occur on Echini and starfishes (Astropecten) } and Harmothoe in Euplectellae. Dr. Baird 

 notes that Mr. Lord found at Vancouver's Island a Lepidonotus coiled under the foot of a 

 Fisurella, and another on a starfish. Verrill, 2 again, mentions an orange-red Polynoe 

 which occurs amongst the tentacles of the anemone, Boloeera Tuedide, and another species 

 with a dark purple proboscis and finely spinulose scales is very abundant among the 

 branches of Acanella Normani. Dr. H. J. Johnson adds two species to the forms living 

 as commensals, viz. Polynoe reticulata, in tubes of Amphitrite and Thelepus, and P. gigas 

 in an Amphitrite, both from the Pacific coast of California. 3 



Genus VIII. — Lepidokotus 4 {Leach, 1816), char, emend. 

 Body short, more or less linear. Anterior part of the cephalic lobe produced into 

 the bases of the median and lateral tentacles. Palpi smooth or with papilla? in five 

 longitudinal rows. Three comparatively short alimentary ca?ca directed forwards into the 

 peri-pharyngeal space. Elytra, twelve pairs, covering the dorsum entirely, and occurring 

 in segments bearing feet thus : 1, 3, 4, 6, 8, and so on to 20, 22. Bristles of the superior 

 lobe slender, serrate, shorter than the inferior, which have a smooth portion below the 

 slightly hooked tip, and then a spinulose region beneath. Nerve-trunks in the granular 

 layer of the epiderm, between the powerful oblique muscles. 



1 C. R., 126 (1878), pp. 257-8. 



2 'Albatross' Explorations, 'U.S. Fisheries "Report/ 1885, p. 525. 



3 'Proceed. Calif. Acad. Sc./ 1896, 3rd ser., vol. i, No. 5, p. 170, &c. 



4 Kinberg (op. cit., 1857) gives as a diagnosis of the genus: — "Anterior part of the cephalic 

 lobe produced into the bases of the tentacle and antennas ; pharynx with papillee ; jaws ; elytra 

 covering the dorsum entirely ; body short." Nothing special can be made out of his remarks on the 

 jaws and tentacular cirri. 



