THE BAENACLES IN THE U. S. NATIONAL MUSEUM. 



95 



Distribution. — Beyond the 400-fathom line, from south of Nan- 

 tucket to off the Delaware Capes, in the branchial cavity of Geryon 

 qulnqucdvnK., at the following stations: 



The capitulum is quite compressed, somewhat triangular, widest 

 near the base, its width about two-thirds the length. The occludent 

 margin is nearl}^ straight, the carinal convex. 



The scutum is calcified in two segments at right angles. The occlu- 

 dent segment is lanceolate; the basal segment is much broader, sub- 

 triangular, nearly two-thirds the length of the occludent segment, its 

 upper margin straight. 



The tergum is quite small, somewhat claw-shaped, the basal margin 

 rounded, the upper portion tapering, hooked towards the occludent 

 margin, with the end acute. 



The carina is moderately curved above, strongly so near the base. 

 It is fully three- fourths the length of the capitulum. The roof is 

 rounded and with the sides is rather wide throughout. The base is 

 forked, the branches straight, extending about to the middle of the 

 peduncle. 



The peduncle is nearly as long as the capitulum, cylindric, and very 

 finely, faintly wrinkled transversely. 



Length of the capitulum 3.5, breadth 2.5 mm. Length of the 

 peduncle 2.5 to 3 mm. 



O. gerijonopJiila is related to 0. mi'dlerl (Coker), but differs con- 

 spicuously and constantly in the shape of the lateral .segment of the 

 scutum, which is invariably short and wide in O. geryonophila., long 

 and slender in 0. lauIlerL It is an abundant species, only known 

 from the gill cavit}^ of the crab Gf/'i/on qi/u^jucde/i.^f, and taken only 

 ill a rather small area ofi' the continental slope east of New Jersey, in 

 435 to 1.0-13 fathoms. (Fig. 32c/, b.) 



OCTOLASMIS MtJLLERI (Coker;. 



1902. Bichelaspis inilUeri Coker. U. S. Fish Commission Bulletin for 1901, pp. 

 401-412 (Beaufort, North Carolina, on CaUinectes sapidus). 



Locality. — Cat. No. 43100, U.S.N.M., Cameron, Louisiana, on gills 

 of CaUinectes sajpidus (Ord). R. P. Cowles. 



