286 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 3 



two layers; medulla narrow, rather dense of (mostly longitudinally ar- 

 ranged) interlacing cellular filaments about 6 fx diam., the cells 30-65 fi 

 long; reproduction unknown. 



Type: D. 85, dredged in 12-20 meters, outside Guaymas Harbor, 

 Jan. 23, 1940. Herb. AHF no. 34. 



A comparison of this plant with Callymenia angustata shows many 

 features in common : cuneate base of blade and slender stipe region, tex- 

 ture and color, general structure of frond. The small size and early split- 

 ting and progressive laceration of the blades are distinctive features. Lack- 

 ing fertile material, the generic determination must be somewhat tenta- 

 tive, but these similarities certainly suggest relationship with C. angustata, 

 and in association with that species it probably may most readily be recog- 

 nized. It likewise is fairly deep sublittoral in habit. 



Call>Tnenia guaymasensis sp. nov. 

 Plate 68, Fig. 2 



Frondes 5-7 cm. altae, planae, membranaceae, stipite curta, angusta supra 

 discum basalem; laminis flabellato expansis, profunde in segmentis raultis, rotun- 

 datis, superpositis (8-15 mm.) divisis, marginibus integris aut per occasionem pro- 

 liferationibus parvissimis angustis lobiformibus indutis, 60-70 u (inferne usque ad 

 130 |x) crassis; medullis angustissimis, filis rudibus intertextis compositis. 



Fronds 5-7 cm. high, flat, membranaceous, with a short, narrow stipe 

 above the simple disk-holdfast; blades expanding flabellately, deeply di- 

 vided above into many broad, rounded overlapping segments (8-15 mm.), 

 margins entire or occasionally with very small, narrow lobate prolifera- 

 tions; frond 60-70 /x thick, up to 130 /* below by repeated periclinal divi- 

 sion of cortical cells, above, a single-layered cortex of cells 6-7 ju, diam., a 



subcortex of a layer of -1 elliptical cells about twice as large, and a 



very narrow medulla of coarse, loose, cellular filaments about 5 \i. diam.; 

 reproduction unknown. 



Type: D. 49, dredged in 4-6 meters over muddy bottom, Gua>Tnas 

 Bay, Jan. 22, 1940. Herb. AHF no. 35. 



D. h R. 3308, drifting along shore of bay, 4 km. east of Guajmias, 

 Dec. 



This species has essentially the same frond structure as the other two 

 Callymenia species of the Gulf, but here again there is an entirely differ- 

 ent habit by which this plant may be easily distinguished. It is also sub- 

 littoral, inhabiting the mucky bottoms of shallow bays, usually badly over- 

 grown with foraminifera shells and brj^ozoan colonies. Its bright rose 

 color is much like that of the other species. 



