NO. 1 HARTMAN : POLYCHAETOUS ANNELIDS 151 



are apodus; together they are about \y2 times as long as the first setiger- 

 ous segment. 



Parapodia are prominent from the first setiger because of the pro- 

 truding postsetal lobe and spreading fascicle of limbate setae; they con- 

 tinue prominent throughout. The postsetal lobe is at first more or less 

 auricular (pi. 10, fig. 219), becomes gradually less so, but continues 

 about as long (pi. 10, fig. 221) ; in the midregion it elongates rapidly 

 (pi. 10, fig. 223), so that in far posterior segments the lobe comes to be 

 long, erect (pi. 10, fig. 222). The presetal lobe remains inconspicuous 

 throughout. 



Setae in the first 15 segments consist of only simple, bilimbate ones; 

 they form a spreading fascicle of 9 or 10, accompanied with about 3 yel- 

 low acicula. Two simple, hooded hooks are present from parapodium 16, 

 together with 5 or 6 limbate setae; the latter are gradually replaced, so 

 that in a median segment there are only 2 or 3 simple hooks in a para- 

 podium. Acicula in posterior segments number only about 2 in a para- 

 podium. Hooded hooks are as shown in pi. 10, fig. 220. Anal cirri con- 

 sist of 4 short, blunt lobes. 



The proboscidial armature includes maxillae and mandibles. The 

 maxillary carriers are much longer than broad, with lateral incision ; 

 forceps (maxillae I) are simple, terminate in falcate tips; maxilla II has 

 4 subequal teeth on either side; maxillae III and IV have each a single 

 tooth (pi. 10, fig. 217). The mandibles are thin, delicate, yellowish, with 

 long, slender, basal ends and flaring distal end (pi. 10, fig. 218). 



L. bassi belongs to a group in which ( 1 ) anterior segments are pro- 

 vided with only simple, limbate setae, (2) acicula are yellow, and (3) 

 the postsetal lobe comes to elongate posteriorly and is more or less erect. 

 It dififers from nearly related species in that the erect postsetal lobe is 

 developed only in far posterior segments; the maxillary formula is 1-1, 

 4-4, 1-1, 1-1 ; the mandibles have long, free ends, and the general shape 

 is greatly attenuate. 



Some of the individuals in the collection have large, spherical eggs, 

 measuring about 0.25 mm in diameter, indicating their sexual maturity. 



It is a pleasure to dedicate this species to the late Mr. John F. Bass, 

 Jr., founder of the Bass Biological Laboratory of Englewood, Florida, 

 who has greatly encouraged a better understanding of the fauna of south- 

 eastern America, and with whose help the present collection was made. 



Holotype. — AHF no. 46. 



Type locality. — Englewood, Florida; intertidal. 



Distribution. — Southwestern Florida; in sandy shoals. 



