Litocorsa sp. A 

 Figures 29-39, AOa-j 



MATERIAL EXAMINED: 

 Gulf of Mexico BLM-OCS: 



SOFLA 4B-8/81 (1 spec, USNM 86944), 4D-8/81 (3 spec, USNM 86945), 25- 

 11/80 (1 spec, USNM 86946); MAFLA 2208G-6/76 (2 spec, USNM 86941), 

 2209H-8/77 (1 spec, USNM 86943), 2422C-6/76 (13 spec), 2422D-6/76 (2 

 spec), 2422E-6/76 (11 spec), 2423B-7/76 (36 spec), 2423C-7/76 (60 

 spec), 2423D-7/76 (50 spec), 2424C-7/76 (1 spec); STOCS 6/II-3 8/76 

 (1 spec, USNM 86948), 2/III-5 Sp/76 (2 spec, USNM 86949), 4/III-5 F/76 

 (13 spec, USNM 86951), 4/III-4 W/77 (1 spec, USNM 86950), 1/IV-6 W/76 

 (2 spec, USNM 86952); IXTOC S52-6 11/79 (1 spec, USNM 86947). 

 DESCRIPTION: 



Length, Co 25 ram; width, to 0.20 ram. Largest specimen complete with 107 

 setigers. Prostomium with minute median and lateral antennae (Figure 

 29-40a). Eyes apparently absent. Palps fused, with pair of minute 

 palpostyles (Figure 29-40b). Tentacular and dorsal cirri short, digiti- 

 form, similar in length (Figure 29-40c). Parapodia (Figure 29-40d) 

 poorly developed, not set off from body wall. Ventral cirri beginning 

 on setiger 2, slightly smaller than dorsal cirri. Body entirely smooth. 

 Stout notopodial spines beginning on setigers 6-8, accompanied by slen- 

 der notoaciculum (Figure 29-40d). Slender, serrate neurosetae (Figure 

 29-40e) present throughout, accompanied by 1-2 acicular spines. Spines 

 serrate on first 1-3 or 4 setigers (Figure 29-40f), gradually becoming 

 smooth more posteriorly (Figure 29-40g). Pygidiutn (Figure 29-40h) with 

 a pair of smooth, filiform anal cirri. 



REMARKS: Litocorsa sp. A has a glandular organ present dorsally just 

 beneath the integument (Figure 29-40i,j), extending from the palps to 

 about setiger 3. Such an organ has also been reported for L_. stremma 

 Pearson, 1970. The function is unknown, but because the posterior tips 

 are pigmented, it may be photoreceptive. Litocorsa sp. A differs from 

 L. stremma only in possessing minute antennae and palpostyles. Examina- 

 tion of specimens of L_. stremma , loaned by Dr. Pearson, confirms the 

 absence of any head appendages on his specimens. The setal morphology 

 of both species is identical, including the serrate neuropodial spines 

 of the anterior few setigers. 



GULF OF MEXICO BLM-OCS OCCURRENCE: Off Florida and Texas (Figure 29- 

 39); 15-98 in; medium to medium-fine sand, silty fine sand, clayey sand, 

 clayey sandy silt, silty clay. 



29-41 



