20 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 40. 



COMANTHUS (? species). 

 Actinomelra cumingii Brit. Mus. MS. 



Locality. — Mauritius. 



Remarks. — There are two small comasterids in the British Museum 

 from Mauritius, one with thirteen, the other with fourteen arms, 

 which are very close to, if not the same thing as, Comanthus 

 parvicirra. 



Family HIMEROMETMD^. 



Subfamily HIMEROMBTRIN^. 

 Genus AMPHIMETRA A. H. Clark. 



AMPHIMETRA AFRICANA, new species. 



Description. — Centrodorsal, thin-discoidal, broad, the flat polar 

 area being 4 mm. in diameter; cirrus sockets in a single more or less 

 irregular closely crowded marginal row. 



Cirri XXIII, 29-32 (usually 30), 20 mm. to 23 mm. long; first seg- 

 ment short, the following gradually increasing in length to the seventh 

 or eighth, which is about as long as broad ; following similar, after the 

 eleventh or twelfth very gradually decreasing in length so that the 

 terminal segments are about one-third broader than long; tenth or 

 eleventh (usually the latter) and following bearing long and promi- 

 nent dorsal spines which begin abruptly; the cirri do not taper 

 distally. 



Radials entirely concealed; IB^ very short, bandlike, in apposition 

 laterally; IBr 2 short, two and one-half times as broad as long, the 

 lateral edges not so long as those of the IBr x , in apposition; IIBr 4 

 (3 + 4) (eight IIBr series are present; the other arms are broken off 

 before the first syzygy) ; IBr, IIBr, and first brachials in close lateral 

 apposition and sharply flattened against each other; sides of IBr and 

 IIBr series slightly produced ; synarthrial tubercles obsolete. 



Nineteen (? twenty) arms (in the type) apparently about 125 mm. 

 long; first brachial short, slightly wedge shaped, twice as broad as 

 long exteriorly, interiorly united; second brachial slightly larger and 

 more obliquely wedge shaped; third and fourth (syzygial pair) 

 slightly longer interiorly than exteriorly, twice as broad as long 

 interiorly; following four or five brachials oblong, three times as broad 

 as long, then becoming obliquely wedge shaped, twice as broad as 

 long, and gradually less obliquely wedge shaped, after the end of the 

 proximal half of the arm being practically oblong and very short. 



Pj 12.5 mm. long, slender, flagellate distally, with twenty-nine seg- 

 ments, at first twice as broad as long, becoming about as long as 

 broad on the eighth and nearly twice as long as broad terminally; 

 second and following segments with a sharp carinate ridge with the 

 crest parallel to the axis of the pinnule, which gradually becomes less 



