STHENELAIS. 407 



produced from the median part of the cephalic lobe. Antenna?, when present, arising 

 from the anterior part of the cephalic lobe. Eyes four, occasionally only two or none. 

 Near the base of the tentacle are two fossa? covered with a membrane — perhaps auditory 

 organs. Palpi long, attenuate, smooth. Tentacular cirri furnished with many bristles. 

 Pharynx with f yy yf papilla? and teeth. Dorsal bristles serrate, ventral compound. 

 Elytra and cirri alternate in anterior segments, those of the middle and posterior part 

 furnished with both elytra and cirri. He gives four genera — Sthenelais, n., Sigalion, 

 Aud. and Ed., Leanira, n., Psammolyce, n. He split up the old genus Sigalion into 

 Sthenelais and Sigalion. Sthenelais he characterised as having a cephalic lobe rounded 

 anteriorly, except where marked by the base of the tentacle. Antenna? short, affixed to 

 the base of the tentacle. Dorsal and ventral divisions of the foot of equal length, the 

 former with serrate bristles, the latter with superior subulate-serrate — occasionally 

 bidentate, and with inferior articulate, the apex being bidentate or serrate. Elytra 

 covering the entire dorsum. 



Ehlers, in his ' Annelids of the United States Expeditions ' (1887), follows Grube's 

 arrangement of this group with Kinberg's subdivisions. 



Genus XXIV, — Sthenelais, Kinberg. 



Cephalic lobe rounded anteriorly, with a nuchal collar posteriorly in the prepara- 

 tions. A pair of ctenidia at the base (ceratophore) of the median tentacle ; lateral 

 tentacles fused with the first foot; tentacular cirri more or less separate. Palpi long, 

 subulate and smooth, springing from the ventral surface of the cephalic lobe, but fusing 

 with the first foot. A pair of scoop-shaped ctenidia at the base. Scales covering the 

 dorsum ; fringed. Dorsal and ventral divisions of the foot of equal length. Segmental 

 eminence at the base of each foot, and a ciliated funnel-shaped process on the foot. A 

 well-developed branchial process on every foot, and on the dorsal ridge beneath it three 

 T-shaped ciliated organs. Dorsal bristles long, stiff, finely tapered, and spinous. Upper 

 ventral bristles with simple tips — boldly spinous ; next come compound bristles, at first 

 with a terminal region of three segments, then with one joint, and at the ventral edge 

 with one to four joints — all with bidentate tips. They are arranged in the foot after 

 the outline of a horseshoe (in transverse section). Nerve-cords in a deep area, almond- 

 shaped in section. 



Grube, in the ' Annulata Semperiana,' defines the genus thus : — Body vermiform, 

 segments more or less numerous, alternating. Elytra on the second, fourth, fifth, and 

 on the unequal segments to the twenty-third, the intermediate segments bearing branchia?, 

 the rest furnished with both organs. Scales covering the entire dorsum. One frontal 

 (median) tentacle. Two palpi (his subtentacula). First foot thrown forward with the 

 cephalic lobe, and furnished with bristles and short tentacles. Other feet biramous and 

 with ventral cirri. Superior bristles simple, barbed ; inferior bristles compound or with 

 other kinds. Elytra thin. 1 



1 Vide previous brief description in c Sitz. Schles. Gesell./ 1874. 



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