HOWE AND HOYT: MARINE ALGAE FROM BEAUFORT, N. C. IO7 



subdichotomous or more often lateral, the lateral branches usually 

 without a basal septum, the others with or without one or two 

 septa above the dichotomy; chloroplasts at first orbicular, elliptic, 

 or ovate, 5-7 ix in diameter, later irregularly confluent and fusi- 

 form; sporangia turbinate, broadly obconic-obovoid, broadly 

 pyriform, or pestle-shaped, 1 12-182 ix long (excl. stalk), 104-156 /x 

 broad, mostly about as broad as long, the apex subtruncate, the 

 outline commonly somewhat obdeltoid; pedicel mostly 14-32 /x 

 (rarely 70 m) long, 15-21 /x broad, the pedicel cell usually about 

 18-21 11 high and broad, or sometimes broader than high (10 /x 

 X 21 ju); spores immature. [Plate ii, figures 10-16.] 



Dredged in 133^-14 fathoms of water on reef about 23 miles off 

 shore from Beaufort, North Carolina, Lewis Radcliffe, August 11, 

 1914, in company with Cladophora sp. 



In most of our material of Derbesia tiirhinata the chloroplasts 

 are more or less decolorate and disorganized and they show 

 numerous and conspicuous brownish violet pyrenoids. It is 

 probable that in the younger stages the plant may be of a bright 

 green rather than an olive-green color. Many of the sporangia 

 show no pedicel cell, but such sporangia as a rule are smaller and 

 evidently younger than those that are subtended by a stalk cell 

 and we are inclined to the opinion that this cell is a regular and 

 normal part of the stalk of the mature sporangium. 



Derbesia turbinata seems to be distinguishable from the previ- 

 ously described species of the genus by its turbinate or very 

 broadly pyriform sporangia, the maximum width of which is 

 commonly about the same as their length, though sometimes a 

 little less and sometimes even greater. The pedicel is usually 

 very short, mostly lirVs as long as the sporangium, though, in 

 occasionally occurring pestle-like structures, the length of the 

 pedicel may approach that of the sporangium itself. Among the 

 hitherto described species, Derbesia turbinata is perhaps best 

 compared with D. repens Crouan, known to us only from descrip- 

 tions and the Crouans' published figures. But D. repens is repre- 

 sented as having an obovoid or pyriform sporangium which is 

 twice as long as broad and the enlarged detailed figure of a prac- 

 tically mature sporangium shows no pedicel cell. D. repens is 

 apparently a smaller plant and an epiphyte. 



Derbesia vaucheriaeformis (Harv.) J. Ag. was described from 

 Key West, Florida, from sterile material, but the sporangia borne 



