332 PROCEEDINGS OF THE ACADEMY OF [DeC, 



T. scohinata, from the Loochoo Islands, various East Indian localities, 

 and the Fiiis. 



V 



A section Scutarcopagia, with T. scohinata as type, may be formed 

 for the Arcopagiae having scaly or granose sculpture. 



Tellina exculta hawaiensis n. subsp. 



Honolulu Harbor, Oahu, Bryan. Midway Isl., Mrs. D. Morrison. 

 Ocean Island, Capt. J. H. Brown. 



Differs from typical T. exculta bj^ having the thread-like striae 

 of both valves continuous over the posterior end, not interrupted 

 in front of the posterior ridge and weakened behind it, as in exculta. 

 The posterior end is also a little wider. 



Length 48.3, height 20.3, diam. 10.5 mm. 

 Codakia thaanumi n. sp. PI. XXII, fig. 9. 



Hilo, Hawaii. Type No. 1 15958, A. N. S. P., collected by Mr. 

 D. Thaanum. 



The shell is subcircular, rather convex, the diameter over half 

 the height; white. Sculpture of unequal rounded radial ribs. On 

 the anterior slope these ribs are narrower than their intervals; on 

 the median segment they are decidedly wider; and at the posterior 

 end, they abruptly become much smaller. There are 38 ribs exclu- 

 sive of the fine posterior group. Over all there are fine, obtuse, 

 subregular concentric threads, and a number of impressions denoting 

 growth-arrest. The beaks are moderately prominent. The lunule 

 is cordiform, small, and rather deeply impressed. The interior is 

 white, tinted with sulphur yellow at the adductor scars; the tooth- 

 plate and pallial line straw yellow. It has either very few or rather 

 numerous punctures hi the cavity. Teeth are substantially as in 

 C. punctata (L.). 



Length 53, alt. 52.5, diam. 28.3 mm. 



This handsome clam is somewhat related to C. punctata (L), from 

 which it differs by the greater convexity and by the stronger, nar- 

 rower ribs. It is also relatively higher, with more prominent beaks. 



Some specimens have the whole interior sulphur yellow. 



Explanation of Plates XX, XXI, XXII. 



Plate XX. Ostrea hryani, n. sp. External and internal views of the valves 



of the holotype. 

 Plate XXI. — Fig." 1. Ostrea hanleyana Sowerby. Mokuoloe Island, Kaneohe 

 Bay. 

 Figs. 2, 3. — Ostrea retusa Sowerby. East of Waipio, Oahu. Two views of 



the same specimen, a lower valve growing upon an upper. 

 Figs. 4, 5. — Ostrea sandnchensis Sowerby. Eastern Loch of Pearl Harbor, 

 No. 116680. 



