FISHERY BULLETIN; VOL 86, NO 2 



slightly beyond antennal scale. Length articles of 

 these legs in holotype 6 , mm: 



ischium merus carpus propodus dactyl 



Each short dactyl armed with about 4-6 corneous 

 spines on flexor surface, grading from small prox- 

 imally to longest and strongest distally; carpus of 

 each with distodorsal extension projecting as a 

 stop along proximal part of propodal extensor 

 surface; third leg stronger, at least in merus- 

 ischium, than fourth and fifth, but propodus suc- 

 cessively longer from third to fifth; merus of each 

 with ventral spine at 1/3 and 2/3 length; ischium 

 of third, fourth, and fifth leg with 2 spines in line 

 with those on merus. 



Pleopods well developed; first pair with en- 

 dopods about 1/2 length of exopods in both sexes, 

 narrowed into distomesial projection in male (Fig. 

 4k) but evenly tapered in female; appendix mas- 

 culina (Fig. 41) of second pair in male (holotype) 

 armed with 7 slender spines extending beyond 

 level of simple slender appendix interna; en- 

 dopods of third to fifth in male and second to fifth 

 in female with simple slender appendix interna, 

 but that of fifth blunt tipped. 



Uropod (Fig. 3^) with rami subequal in length, 

 lateral ramus slightly exceeding distal end of tel- 

 son, and with movable spine mesial to smaller 

 distolateral tooth, diaeresis sinuous. 



Remarks. — Remarks are given in the account 

 for A. stactophila. 



Etymology. — The name is from the Latin 

 "muria", brine, and "cola", inhabiting, for associ- 

 ation of the species with cold brine seeping from 

 the base of the West Florida Escarpment. 



Alvinocaris stactophila new species 



Figures 5, 6, 7 



Material .—\]SnM 234291, Holotype d, 

 USNM 234292, Allotype 9, USNM 234293, 

 Paratypes, 5 c?, 2 9; north central Gulf of Mexico 

 about 129 km (80 miles) S of Louisiana, 

 27°46.94'N, 9r30.34'W, 534 m, Johnson-Sea- 

 Link Dive 1879, 28 September 1986, Bush Hill 

 hydrocarbon seep. From Linda H. Pequegnat and 



Randall Howard, LGL Ecological Research Asso- 

 ciates, Bryan, TX, supported by partial funding 

 for Minerals Management Service-Northern Gulf 

 of Mexico contract 14-12-0001-30212. 



Measurements in mm. — Holotype 6, postor- 

 bital carapace length 7.0, rostrum 2.7, maximum 

 carapace height 5.3, total length about 25. Allo- 

 type 9 , same 6.8, 2.0, 5.9, 24. Paratype 6 , same 

 4.2, 1.9, 3.2, total length not measured; paratype 

 9, same, 4.9, 2.0, 4.1. 



Description. — Integument thin, shining, mi- 

 nutely punctate. Rostrum (Fig. 5a, b) almost 

 straight, imperceptibly elevated above horizontal 

 in distal half, sharply pointed tip usually reach- 

 ing proximal level of second peduncular article of 

 antennule, but sometimes to proximal part of 

 third peduncular article; dorsal margin raised 

 into thin serrate crest containing 12-17 teeth, 

 strongest in central sector of row, with about 1/2 

 length of crest continued onto carapace; ventral 

 margin less prominent and armed with or 1 

 subterminal tooth; sample tooth formulas 11/1, 

 12/0, 14/1, 17/1; lateral carina broadened proxi- 

 mally and confluent with orbital margin. Cara- 

 pace (Fig. 5a, b) with buttressed acuminate an- 

 tennal spine distinct; pterygostomian spine 

 acuminate and prominent. Prominent anterior 

 antennal carina curving posteroventrally to in- 

 tersect obliquely with carina extending from 

 pterygostomial spine at about midlength of cara- 

 pace, associated groove continuing indistinctly 

 posteriad. 



Abdomen (Fig. 5d) of both male and female 

 broadly arched dorsally, gradually tapering dis- 

 tally, narrowest part of sixth somite less than 1/2 

 (0.44) width of first somite; pleura of 3 anterior 

 somites broadly rounded, that of fourth somite 

 drawn posterolaterally to acuminate spine 

 flanked dorsally by 0-3 much more slender and 

 smaller spines; posterolateral corner of fifth 

 pleuron varying from strongly acuminate to 

 nearly rectangular and flanked dorsally by 2-5 

 spines analogous to those on somite 4; sixth 

 somite with middorsal length about 1.8 that of 

 fifth, broad-based midlateral spine overlapping 

 base of telson, smaller posterolateral spine acute; 

 fourth and fifth somites each with strong, posteri- 

 orly directed spine on sternite. Telson (Fig. 5e) 

 elongate subrectangular, length about 2.8 ante- 

 rior width, 5.2 posterior width, and about 1.7 

 length of sixth somite, not including posterior 

 spines; armed with 5-8 dorsolateral spines of 



272 



