3(> . BULLETIN GO, UNITED 8TATES NATIONAL MUSEUM. 



faintly marked with arcuate ^-rowth-liiies. The .sides are narrow and 

 concave. T^asal margin a little convex. 



The upper lateral plate is pentagonal, the tergal and scutal margins 

 longer, subequal, the carinal side shorter and about equal to that 

 against the carinal lateral plate. The side opposed to the inf ramedian 

 lateral plate is shortest. The umbo is superior, acute, and terminal. 



The rostrum is small and triangular, the basal margin slightly 

 greater than the height. 



The rostral latus is very narrow, the scutal and basal margins 

 parallel. 



The int'ramedian latus is triangular, the apex curving ventrad, 

 around the end of the rostral lateral plate and between the lower 

 angles of the upper lateral plate and the scutum. 



The carinal latus is irregularly triangular. It projects })ackward 

 beyond the carina. The umbo is recurved and Hares outwards, in 

 the shape of a short subspiral horn. 



The peduncle is short, with about 13 rows of transversely lengthened 

 scales, about 6 in a row. 



Length of the capitulum 12, width 7.7 mm.; length of peduncle 7 

 mm. Length of the carina 11.3, diameter at base 2.2 mm. 



A single example was taken, either at Station <)062 or Station 6063. 

 It was supposed by Mr. Bigelow to be young, but comparison with 

 numerous young examples of the related species of equal size with 

 S. 'portorlcanuiii shows that the Porto Rican form is distinct. It has 

 some resemblance to 8. velutinum Hoek, but compared with 3'oung 

 individuals of equal size, S. portorlcutniui differs markedly b}- the much 

 narrower roof of the carina, which is in width only one-tifth the 

 length. The rostrum is much larger and the inf ramedian and carinal 

 latera are of a different shape. S. peduncnhitiun Hoek, from near 

 New Zealand, is also somewhat similar, but the plates of the lower 

 whorl differ. 



8. 2)oTtoTicanu)ii is allied to 8. trltonis Hoek, but differs in the fol- 

 lowing respects: The occludent margin is straight, not convex; the 

 carinal latera are distinctly wider than high, with outwardly ffaring 

 umbones; the sides of the carina are narrower above; finally, the 

 scutum and upper latus differ somewhat in shape. 



8. h/rsiitma Hock, hi-spidian Sars, riihraDt Hoek, and (itlanticuin 

 Gruvel have more or less rescmlilance to ^S*. p>ortoric(inimi., but all differ 

 in various characters of the valves. (Fig. 8 a-e.) 



SCALPELLUM PORTORICANUM INTONSUM, new subspecies. 



<7o^yj9fs.— Cat. No. 9757, U.S.N.M. 



Type-locality.— Albatross Station No. 2401. north latitude 28° 38' 

 30", west longitude 85° 52' 30", in 142 fathoms. 



There is a series of three individuals taken by the Alhat'wss in the 

 Gulf of Mexico west of Florida. Thev are smaller than the Porto 



