344 GEOLOGICAL SURVEY OF THE TEERITORIES. 



witli the digitate processes as in the European form. Its occurrence, 

 however, in this country and its being an intermediate form between B. 

 vernalis and B. gruhei shows that the genus Euhrancliipus is not suffi- 

 ciently distinct to be regarded as a valid genus. As our description is 

 brief and giv^es only the salient points observed in alcoholic specimens, 

 we reproduce Mr. Forbes's original descriptions, drawn up from living 

 examples: 



"An important character, constant in the large number of both sexes 

 which I have examined, is found in the abdominal segments, which are 

 narrowed in front, with rounded anterior angles, wliile the posterior 

 angles are produced backward, giving a decidedly serrate appearance 

 to the abdominal margin. The last two abdominal segments are closely 

 united and broader than the precediug. 



"The antemiw extend a little beyond the eyes, and terminate in a 

 cluster of about five slender olfactory clubs. The frotital appendages of 

 the male are considerably longer than the claspers, to the front inner 

 base of which they are attached, the line of attachment being parallel 

 to the length of the basal joint. Their form is irregularly oval, the 

 inner edge being regularly convex on its distal three-fourths, and the 

 outer sinuate-convex on basal two- thirds, and slightly concave on ter- 

 minal third. Both margins are pectinate, except near base, v/ith thick 

 blunt teeth, which are longest on the basal half of the outer margin, 

 where they are as long as the undivided part of the appendage is wide. 

 At the middle of this margin the teeth become suddenly shorter. On 

 the inner margin they are longest near the middle, regularly lessening 

 towards each end. The under (posterior) surface of the appendage, as 

 well as the teeth, is set with short spines, each springing from an in- 

 flated base. The claspers of the fiiale are shorter and stouter than in 

 J^. vernalis. The basal joint is saft and inflated and bears a corneous 

 rounded tubercle at its inner base (wanting in vernalis). The second 

 joint is stout and regularly incurved, strongly angulated at its base in 

 front where it is received into the first joint. A long strong tooth, 

 about half as long as the joint, extends backward and a little inward 

 from near its base. The rounded tip of this tooth is thickly set with 

 minute, low, circular elevations, each with a cenrral depression, within 

 which is a disk-like elevation, the whole having the appearance of a 

 minute sucking disk. The tip of the clasper is expanded and flattened 

 within so that the inner (anterior) part has a spatulate form, while the 

 opposite surface rises into a thick prominent ridge, giving to a trans- 

 verse section of the tip the form of the letter T. The anal appendages 

 are linear-lanceolate, as long as the last four segments of the abdomen, 

 and plumosely haired to the base. The ovisac of the female is as broad 

 as long, three lobed behind, with the middle lobe the largest. 



"Length of a full grown male, including anal stylets, 20"""; width, 

 6"^"^; across eyes, 4""' 5 clasper, 4.5'"™; frontal appendage, 5"™ by 3'"'". 

 The largest females were a little more slender than the males." 



Genus STEEPTOOEPHALUS Baird. 



Plate XII; figs. 1-7. 



Streptocephalns Baird, Annals and Mag. Nat, Hist. 2d Ser. XIV, 219. 1854. 

 EcUrobrartehipus Vcrrill, Amer. Joiiru. Sc. slviii, p. 2r)0. 1869. 

 Strepiocephalas Verriil, Proc. Amer. Assoc. Adv. Sc. July, 1870. 



Body rather slender, much more so than in BrancMpus. 2d anten- 

 njE of male 3-jointed, remarkably long and large, tortuous and twisted, 



