24 
THE VOYAGE OF H.M.S. CHALLENGER. 
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* * * * 
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Cirri -with obtuse points. 
Parapodia slit, .... 
Parapodia not slit. 
Body rounded, length of the cirri often 
greater than the breadth of the border, 
Body oval ; cirri somewhat greater than the 
breadth of the marginal border, 
More than ten cirri on each side. 
Cirri as large obtuse flaps, nearly as broad as long. 
Central disk prominent on the ventral side, . 
Central disk not prominent, . . ... 
Cirri normal, lessened at the point 
Body much longer than broad. 
Cirri sharply separated from the border. 
Some pairs of the cirri extraordinarily elongated. 
The first pair alone elongated, .... 
More (five to six) pairs elongated, 
No cirri of an extraordinary length. 
Suckers quite near the border, 
Suckers moved from the border, more than the breadth 
of the suckers, ..... 
Cirri with a large base rising gradually out of the border. 
Intestine much ramified, . 
Intestinal branches not very numerous, . 
Body circular, not, or not much, different in length and breadth. 
On each side not more than twenty cirri. 
Cirri sharply separated from the border, . 
Cirri with a large base, rising gradually out of the border, 
More than twenty cirri on each side. 
Cirri ending in very fine points, .... 
Cirri ending obtusely. 
Suckers round, parapodia feeble and small, 
Suckers oblong, parapodia vigorous and big, 
Suckers are wanting. 
Border irregularly notched ; back smooth, .... 
Border with ten pairs of cirri, back areolated, 
Border with more than twenty cirri, back ribbed, 
With caudal appendages. 
Two caudal appendages existing. 
Caudal appendages without terminal threads, 
Caudal appendages with terminal threads. 
Terminal thread shorter than the base of the caudal appendages, . 
Terminal thread longer than the base of the caudal appendages, 
Four caudal appendages existing. 
Caudal appendages large and flat, with a notched lateral border, 
Caudal appendages round. 
Caudal appendages without terminal threads, 
Caudal appendages with terminal threads, . . . . . 
Six caudal appendages existing. 
Caudal appendages large and flat, without terminal threads, . 
M. wyville-thomsoni. 
M. vastum. 
M. cirriferum. 
M. vernicosum. 
M. dentatum. 
M. cornuhcm. 
M. brachiatum. 
M. dblongum. 
M. caribbeanum. 
M. elongatum. 
M. mcebianum. 
M. irregulare. 
M. dubium. 
M. elegans. 
M. rotundum. 
M. abundans. 
M. folium. 
M. coronatum. 
M. carinatum. 
M. bicaudatum. 
M. jilicauda. 
M. filiferum. 
M. lobatum. 
M. quadricaudatum. 
M. quadrifilum. 
M. Jissum. 
