42 TJniversitij of Calif ornia Puhlications in Botany [Vol. 8 



Boring into the shells of oysters and other molliisks. Central to 

 soutliern California. 



Bornet and Flahanlt, Note sur deux nouveaux genres d'algues 

 perforantes, 1888 (p. 2, Ropr.), Sur quelques plantes vivant, 1889, 

 vol. 36, pi. 10, figs. 7-9, and pi. 11 ; Collins, Holden and Setchell, Phyc. 

 Bor.-Amer. (Exsiec.), no. LI. 



In placing this species among our Pacific Coast algae, we do so 

 with some hesitation. The specimens of oyster shells distributed 

 (Phyc. Bor.-Amer., Exsiec, no. LI) as well as others from the same 

 locality at other dates, show definitely a Hyella and some even with 

 young gonidangia, but no such typically well-fruited specimens as is 

 desirable for certainty. Specimens possibly ^ the same have also 

 occurred at San Pedro, California, but unfortunately^ without goni- 

 dangia. This species is, therefore, listed in the hope that further 

 information mav be obtained. 



2. Hyella Littorinae S. and G. 



Plate 3, figs. 19, 20 



Erect filaments numerous, straight, parallel, simple or sparsely 

 branched, 75-85ju, long, 10-14/a diam. ; growth in length by division 

 of apical cell; basal cells of filaments angular, 4-6/a diam., divisions 

 in all planes ; terminal cells of erect filaments cylindrical, 20-30/u. long ; 

 cell contents blue-green, homogeneous ; cell wall or sheath hyaline, 

 homogeneous; 2.5-3.5/x thick; gonidangia unknown. 



Growing on Littorina planaxis Nutt. along high-tide level on rocks. 

 Common along the coast of California, but probably grows wherever 

 this species of Littorina occurs. The type material is from Carmel, 

 Monterey County, California. 



Setchell and Gardner, in Gardner, New Pac. Coast Alg. II, 1918, 

 p. 441, pi. 37, figs. 19, 20 ; Collins, Holden and Setchell, Phyc. Bor.- 

 Amer. (Exsiec), no. 2255. 



Reproduction by gonidia has not been observed in this species, but 

 the vegetative characters are so similar to those of Hyella caespitosa, 

 growing on the shells of oysters and other mollusks as to leave room 

 for little doubt as to its close affinity with that species. Tlie prostrate 

 filaments, characteristic of Hyella caespitosa, have not been observed. 

 Gonidangia may not develop and reproduction may be wholly vege- 

 tative in the same manner as vegetative reproduction is reported to 

 occur in Hyella caespitosa. We base our opinion on the fact that we 



