318 Verrill, JVbtes on Radiata. 



longer, strongly divergent, obtuse at the ends. The posterior inter- 

 ambulacrum and the lateral pair are about equally swollen, within 

 the fasciole, but the former is somewhat inflated beyond it, near the 

 posterior end, which is obliquely truncated, the upper surface project- 

 ing considerably beyond the lower. The anal area is large, elliptical, 

 acute above, and occupies the greater part of the truncated poste- 

 rior end. 



The peripetalous fasciole is nearly transverse anteriorly, but forms 

 two abrupt, angular bends between the anterior and lateral ambula- 

 cra, of which that next to the lateral extends much farther toward 

 the summit. In the rest of its coui'se it agrees very nearly with that 

 of M. grandis as figured by Gray.* The sub-anal fasciole is nearly 

 transverse between the posterior ambulacra ; at a distance from the 

 anal area about equal to the length of the latter, each end bends ob- 

 liquely upward laterally and becomes irregular and gradually disap- 

 pears opposite the sides of the anal area and at some distance from it, 

 without enclosing a sub-anal area. Genital openings four, the two 

 posterior largest and farthest apart. 



Acapulco, Mexico, — A. Agassiz. In exchange from the Museum of 

 Comparative Zoology.f 



I am indebted to the kindness of Mr. A. Agassiz for a typical 

 specimen of this interesting species. It seems to be a true 3feoma. 



Metalia Gray. 



Brissus (subgenus Metalia) Gray, Catalogue of the Recent Echinida of the British 



Museum, p. 51, 1855. 

 Xanfhdbrissus A. Agassiz, Bulletin M C. Z., p. 28, 1863. 



The first division of the genus Brissus, as limited by Dr. Gray, 

 contained only one species, the S. sternalis Ag. This group, to 

 which he applied the name Metalia., he characterized as follows : 

 " Subanal area heart-shaped, edged by a broad subanal fisciole ; the 

 disk radiated, striated, with a series of marginal pores, and with a 

 short fasciole, branched up and edging the sides of the vent ; the 

 hinder part of the peripetalous fasciole slightly bent, but not margined 

 to the hinder edge of the hinder ambulacra ; spines on the side of 

 the ambulacra larger, elono-ate." 



This division appears to be perfectly equivalent to Xanthohrissus 

 A. Agassiz. The type of the latter, M. Garretii (Ag. sp.), from the 

 Kingsmills Islands, is closely allied to M. sternalis, as I have ascer- 

 tained by an examination of typical specimens of the former, belong- 



* Datalogue of the Recent Echinida of the British Museum, Part 1, pi. 5, fig. 2, 1855. 

 f More recently sent by J. Pedersen from La Paz, — Reprint. 



