54 polycemnjE. 



Genus .EGIRES, Loven. 



Teeth, central none, lateral 1717. Body covered with 

 very large tubercles. Tentacles linear, simple, retractile 

 within prominent lohed sheaths ; forehead papillose. Gills 

 arhoriform, placed around the dorsal vent. 



Ex. JE. punctilucens, D'Orbigny, pi. 62, fig. 8. 



The principal differences between this genus and Polycera 

 are the retractile tentacles, and the lobed sheaths at their 

 bases. The branchial plumes are defended by elevated 

 tubercular processes, and the sides are covered with blunt- 

 topped tubercles. The species described are from Norway, 

 France, and the British Islands. 



Species of JEgires. 

 maura, Forbes. punctilucens, D'Orb. 



Genus POLYCERA, Cuvier. 



Body smooth or tuberculated. Tentacles clavate, pectinate, 

 non-retractile, without sheaths ; a frontal veil with simple 

 processes on the head. Gills with two or more lateral 

 appendages. 



Syn. Themisto, OJcen. 



Ex. P. Lessonii, D'Orbigny, pi. 62, fig. 9. 



This genus has clavate, non-retractile, tentacles, and there 

 are no sheaths at the bases ; usually there is an elevated lobed 

 crest on each side of the head, which is continued along the 

 sides of the back as far as the branchial region. The 

 species known are European in their geographical dis- 

 tribution. 



