152 PROCEEDINGS OF THE CALIFORNIA 
Dr. Behr described a new weed from Lower California. 
A paper by W. N. Lockington was read as follows: 
List of Echinidze now in the Collection of the California 
Academy of Natural Sciences, May, 1875. 
BY W. N. LOCKINGTON. 
Suborder DESMOSTICHA. 
This suborder includes the regular sea-urchins, that is, those in which the 
poriferous zones are continuous from mouth to apex, both of which are 
central, the apex with ocular, genital, and anal plates. 
Family CIDARID®. 
Interambulacral areas very,wide, with few coronal plates, each bearing a 
single primary perforate tubercle, surrounded by a large scrobicular circle. 
Actinal and abactinal systems large. Ambulacral areas very narrow, com- 
posed of numerous small plates, the pores in single pairs, and the median 
ambulacral spaces set with small flattened papillae. Jaws not so complicated 
as in the Echinide and Diadematide. Teeth in shape of a gauge. Auricles 
made up of independent arches, and taking their origin from the interambu- 
lacral spaces. The spines are large and solid. 
CIDARIS. 
1. ©. Thouarsii. Valenciennes. Panama. Gulf of California. 
Two large specimens from the latter locality, presented by D. E. Hunger- 
ford. This species attains a diameter of about two inches. . 
2. C. metularia, Blainville. Red Sea. Mauritius. East Indies. Sandwich 
Islands. Feejee Islands. 
The specimens in the museum are from A. Garrett, and were collected in 
the Sandwich Islands. This is a very small species, the largest specimen not 
exceeding three-quarters of an inch in diameter. 
Family ARBACIAD A. 
This small family contains Echini without secondary and miliary tubercles; 
with the pores in single pairs; jaws somewhat resembling those of the Cida- 
ride, and the auricles disconnected. The spines are solid, but thinner than 
those of the Cidaridw, and the anal system consists only of four large plates. 
