346 PROCEEDINGS OF THE ACADEMY OF 



(6.) That there is reason to suppose that these species are nearly extinct 

 as living organisms ; although to what extent they may have nourished in a 

 previous epoch, and how universally have been diffused, can only be a mat- 

 ter for speculation, until further and more thorough investigations in this, 

 uad other localities, shall have been made. 



References to Plate. 



(1.) Surirella Baileyi, a, V. b, F. V. n. sp. 



(2.) " intermedia, a, V. b, F. V. " 



(3,) " anceps, a, V. b, F, V. " 



(4.) " delicatissima, a, V. b, F. V. " 



(5.) Actinella punctata, nov. gen. a, V. b, F. V. c, group of frustules x 



100 d. 

 (6.) Denticula? or Tryblionella, n. sp. 

 (7.) Amphora intermedia, u. sp. 

 (.8.) Navicula, n. sp. 

 (9.) Mastogloia elegans, n. sp. 

 (10.) Amphiprora pulchra, Var. B. = A. conspicua (Greville). 



These are all magnified about 500 d , excepting Surirella delicatissima, 

 which is amplified to 1000 d. The Figs, from 7 to 10, inclusive, illus- 

 trate a paper on the Diatomaceae of the Delaware River and marine locali- 

 ties adjacent thereto, which will be submitted to the Academy in a short 

 time. 



Synopsis of the species of HOSACKIA. 



BY ASA GRAY. 



1. SYRMATIUM, Vogel. (Drepanolobus, Nutt.) Legume small, subulate 

 or caudately attenuate, often torose, incurved or sickle-shaped, 1-4-seeded. 

 Keel of the corolla not attenuate upwards, mostly obtuse. Claws of the 

 petals slightly exserted or included ; that of the vexillum somewhat distant 

 from the others. Perennial herbs or suffruticose plants, or one species annual. 

 Leaves 3 7-foliolate, with a very short petiole and rhachis. Stipules in the 

 form of small black glands. Flowers small, in sessile or short-peduncled 

 umbels, yellow, or sometimes whitish, often changing to reddish. 



* Shrubby or suffruticose, with rigid slender branches, glabrous or glabrate, 

 the young parts often silky puberulent, with (3 5, commonly 3) small and 

 thick leaflets, somewhat sempervirent. 



1. H. jhkcea, Benth. in Linn. Trans. 17, p. 366. Shrubby, erect, bushy- 

 branched, broom-like, with obovate, oval, or oblong leaflets, and very short 

 peduncled few-flowered umbels ; the calyx-teeth extremely short and blunt I 

 California. The only specimens before me are an original one of Douglas' 

 collection, and those of Dr. Brewer, recently collected in the mountains near 

 San Luis Obispo, in the Geological Survey of California. 



2. H. scor-ARiA, Nutt. (under Drepanolobus), in Torr. & Gray PI. Syrma- 

 tium glabrum, Vogel, inLinnsea, 10 (1836), p. 591. Almost wholly glabrous, 

 shrubby, erect, 2 8 feet high, very bushy-branched and broom-like ; with 

 linear- oblong or barely oblong (obtuse or acute) leaflets, and strictly sess'le 

 Hinbels, which are usually crowded along the flowering branchlets, so as to 

 form a virgate interrupted inflorescence. Teeth of the calyx subulate and 

 acute, varying from one quarter to nearly half the length of the narrow tub*-. 

 California, common from San Francisco to San Diego. 



V&r. DiFFDscB (//. crassi/olia, or Drepanolobus crassifolius, Nutt., 1. c), is a 



[Dec. 



