NO. 2 ROST : THE FAMILY ARCIDAE 213 



prominent than the three anterior ones, and does not reach quite across 

 the area covered with ligament. Another specimen, with a length of 15.7 

 mm, has four anterior grooves, but a distinct posterior groove is lacking. 

 One valve is stained with reddish-brown posteriorly and the interior of 

 the umbonal cavity is also reddish-brown. One of the specimens was 

 alive when dredged, but unfortunately it was not preserved in alcohol 

 and the animal was dried up and badly cracked. Though soaking in 

 trisodiumphosphate was tried, a restoration of the animal was impossible. 

 In this specimen a relatively deep byssal cavity seems to be present. The 

 labial palps are short and broad. The gills are elongate and apparently 

 placed more horizontally than in Noetic (Noetia) reverse and Noetia 

 (Eontia) ponderosa, as one would expect from the form of the shell. 

 Occurrence: This species was previously reported only from the type 

 locality, Manzanillo, Mexico, where it was collected at 20 fms by Lowe 

 in 1930. Hertlein and Strong (1943) report it also from Manzanillo, at 

 30 fms in gravelly sand. By the Allan Hancock Foundation, it has been 

 dredged at four stations from Bahia de San Ignacio, Sinaloa, Mexico, to 

 Bahia Honda, Panama. In the California Academy of Sciences, there 

 are specimens from Chamela Bay, Mexico, 15 to 40 fms, and from near 

 Santa Isabel Island, Gulf of California (T. Crocker Expedition, 1932). 

 Distribution: Bahia de San Ignacio, Sinaloa, Mexico, to Bahia Honda, 

 Panama. 



LIST OF MATERIAL OF THE FAMILY ARCIDAE 



PRESERVED IN THE 



ALLAN HANCOCK FOUNDATION COLLECTIONS 



The list of stations under each species is arranged as correctly as 

 possible from north to south, after the records at hand. Place names are 

 given as listed in the Millionth Map of Hispanic America, American 

 Geographical Society. Alternative names for stations occupied by the 

 Velero III from 1931 to 1942 will be found in the Allan Hancock 

 Pacific Expeditions, Volume 1, number 3. The numbers marked BS 

 are mud sample stations taken separately, and alternative names for 

 these will be found in the Allan Hancock Pacific Expeditions, volume 6. 

 Other numbers represent stations at which collections were made by 

 members of the Allan Hancock Foundation staff, or by others. 



The stations lying within a line from Cabo San Lucas, Baja Cali- 

 fornia, and Cabo Corrientes, Jalisco, Mexico, are recorded as from the 

 Gulf of California. 



