28 BULLETIN GO, UNITED STATES NATIONAL MUSEUM. 



SCALPELLUM REGIUM Wyville Thomson. 



Plate III, tigs. 4, 5. 



1877. iScalpeUum rcfjiuin Wyville Thomson, The Voyage of the Challenger. The 

 Atlantic, II, p. 4, fig. 2 ( J ) and p. 7, fig. o ( <? )— Hoek, Challenger Report, 

 VIII, Cirripedia, p. 106, pi. iv, figs. o-5 (type-locality, north latitude 34° 54^, 

 west longitude 56° 38^ 2,850 fathoms; also 35° 29^, 50° 53', 2,750 fathoms). 



ZocaUti/. —Csit. No. 8629, U.S.N.M., Alhatnm Station 2226, east of 

 tke mouth of Chesapeake Bay, north latitude 37'^, west long-itude 71° 

 54', 2,045 fathoms, Globioerina ooze. Seated on a slender gorg-onian 

 stem and on a pebble. 



This is the first record of this species in the west Atlantic. 



The specimens on a gorgonian stem (Plate III, fig-. 4) have a thin, 

 smooth cuticle, nowhere visibly hairy, though velvety to the touch, and 

 the plates of the basal whorl are somewhat hig-her than in the figui-ed 

 type of S. reglam. Plate II, fig-. S, represents a transverse section 

 of the carina. Leng-th of capitiilum 39; of peduncle 20 mm. The 

 rostrum is lanceolate-linear, extending- up between the umbones of 

 the rostral latera. 



Another specimen, attached to a pebble (Plate III, fig-. 5), is covered 

 with a densely pilose cuticle, the pile longer on the peduncle. The 

 plates are as figured for t3'pi(;al S. regium. The two carinal latera are 

 in contact only near the base, for a space of 2.5 mm., while in the other 

 specimen they are in contact for 7 mm. The rostrum is narrowly 

 lanceolate, the rostral latera meeting above it. Length of capitulum 

 35; of peduncle 23 ram. 



The cirri of one of the examples from Station 2226 agree in essential 

 respects with Hoek's description. The branches of the first paii- have 

 8 and 12 segments, those of the anterior ramus being produced later- 

 ally. Cirrus ii has 26 segments in each ramus. The other cirri are 

 longer and equal. The candal appendage (Plate IV, fig. 8) consists of 

 6 segments, spiny at the articulations, terminating in a pencil of long 

 spines. The penis is \Qvy long, and its distal half is quite slender. In 

 Hoek's example there were 4 segments in the caudal appendage, and 

 no penis. 



The mandible (Plate IV, figs. 6, 7) has four teeth, including the 

 lower angle. The space between the upper and second teeth is double 

 that separating the other teeth. The basal tooth or angle is shortly 

 and closely spinose at the edge (fig. 7). The maxilla has a single 

 large spine at the upper angle, the rest of the face being evenly spinose. 

 The edge recedes a little under the large spine. The upper border is 

 shortly hairy. 



Three quite young examples are before me, clearly referable to 

 S. regium or perhaps to the following subspecies, the smallest with 

 the capitulum 8, the largest 10 mm. long. The inframedian latus is 

 narrower and higher than in adult regium^ with the apex curved 



