HOLOTIIUIIIANS. 



181 



In the Dendroehirotte the teiitack's aiu tice'-liko or braiichiiiji', ami there are no 

 Cuvieriaii organs. The pharynx has retractur luusi-les. Many <it' the s|iei'ies inhabit 

 ncM'thern regions. Feutactu fvoialosa, the 

 euinnion seu-eueiimber north of Cai)e Cod, 

 and extending through the Aretic regions 

 to Great Britain, is from six inches to a 

 focit in length, of a tan brown i-oicir, and 

 suggests a eiicuinbrr by its shape and the 

 corrugations (if its skin. The ]jliar_\nx is 

 nniscular; the stomach short, with uell- 

 marki'd transvi'rse folds within ; tjie intes- 

 tiiu' several times longer than the botly, 

 and till' respiratory tret' with but one main 

 stem. C'oiniecti'd with the ring-canal are 

 two Poiian vesicles, ricaily two-thirds as 

 long as the body. Tlu' single ovary is 

 made n]i of a mass of long tidies, which 

 are larger than tin' branclu'S of the res- 

 jiiratory tree, and are tangleil up wifli 

 them. The genus ( 'iituniiiria, or 1\ n- 

 tarta, has many sucki'rs in the aml)ul;i- 

 cr.al area, and some forms have tliem also 

 in tiie interamliulacral areas. The body 

 is short and somewhat fi\'e-angic<l, and 

 there .are ten tenta(dcs, of wliich the two 

 lielonging to the odd amludacrum (jf the 

 biviiim are often smaller than the (ithers. 



In ('{ihirJiinix the feet are ranged in three rows upon liie ventral surface, the 

 remaining andiulacra of the back having oidv jiapilhc. The 1 wo central tentacles of 

 the lower surface are smaller than the others. In ^ '. (■"yv^A'^^v, from the Philippines, 

 the ])a]iilhe of the back are very long. 



In I'solus the ventral surface is clearly sejjtirated from the rest, and there are no 

 siK-kers u])on the upper surface. The surface of the body is covered with compara- 

 tively large plates, of whicdi I'sulus roiuplanatas has ft)urtcen to sixteen, in a trans- 

 verse row. '{"his spei-ies and ani.ither occurs in the I'hilipjiines, P. sqiMmatus is found 

 at the Kurile islands, /'. /ilKtiitojuiH and P.fuhricii in the North Atlantic, and 7-". 

 untarrtii'iis in tlie Straits of .Alagellan. 



The female of I's'i/ns tjihijijiijir has tijion the npjier or dorsal stu'face a group of 

 larger tessellateil plates, e.ach carried, like the head of a nmshroom, upon a ]iedicel 

 imbedded in the skin. The spaces left underneath thcs(> tiny vauhs :n-e utilized for 

 the ])rotection of the young, wliieli develop directly into sea-eueuinl)ers. The males 

 have the plates of tlu' back similarly arrangecl, tliouL;li tiiere is no marsupium. 



In 77ii/o/i(\ Thi/Oiiidiimi, and other related genera, tlu' suckers of the entire body 

 are alike, and seldom show traces of arraiigcmciit in rows. T/n/iiiihliinii has five ])airs 

 of large .and live of small t^'ntaclcs. 



Thti<iii(' hriiireti.-i lives just below low tide from Long Island Souml to Florida, atid 

 is very common. In a specimen little more than three inches long the alimentary 

 canal is about seven feet in length, though the oval stomach is less than an inch. The 



■ rn,l,i.-l.j,J-r„H<l„. 



