390 PKOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



in front of the dorsal tentacles. Oral and dorsal tentacles nearly equal 

 in length, moderately long, tapered, blunt. The dorsal tentacles appear 

 slightly \Yrinkled transversely. Eyes black, conspicuous, near together, 

 just behind the bases of the dorsal tentacles. Foot narrow, with broad, 

 rounded anterior angles. Head moderately large, its outline nearly 

 semicircular in front, and projecting considerably in advance of tlie 

 bases of the oral tentacles. 



Color variable. In some specimens the nuclei of the dorsal pai^illse 

 and the biliary ducts from them are dark green, the nuclei appearing to 

 belobulated orfloculent; the outer sheath is translucent whitish, with an 

 interruiited streak of ilake-white on the distal half, and with unequal 

 specks and spots of the same scattered over the surface, w^hile on the 

 outer side, near the end, there is a patch of orange ; tip translucent 

 white. In front of tlie bases of the dorsal tentacles there is a dark 

 green patch. Tentacles white. 



In other specimens, taken at the same time, the nuclei of the dorsal 

 papillae were salmon-colored, but the subterminal patch of orange and 

 the streak and specks of flake- white were as in the green variety ; the 

 body was translucent white ; dorsal tentacles white, tinged or faintly 

 reticulated with flake-white ; oral tentacles with a streak of flake-white 

 on the posterior side. 



Odontophore narrow, with a single row of teeth ; these have thirteen 

 sharp denticles, the median one scarcely as long as those next to it ; the 

 anterior border of the tooth is nearly semicircular, with a notch on each 

 side near the outer ends, which run backward, as short processes, some- 

 what enlarged and emarginate at the end. 



Oft' Cape Cod (station 328), in 23 fathoms, among hydroids, September 

 6, 1879. 



This species is nearest allied to Craieiia olivacea (Alder & Hancock), 

 but differs in the form of its teeth, as well as in its coloration. It is also 

 allied to Cratena viridis, of Europe. In case either of the older names 

 {CanoUna and Montagua) be retained for this group, this species should 

 be so named. But both of these names having been jirevaously used 

 for other genera, they should be discarded. 



Cratena gymnota (Couthouy) Verrill & Emerton. 



Montagua Gouldii Verrill, luvcrt. Viuey. Sound, p. 667 (author's copies, p. 373), 

 1873. 



This species, which is common on littoral hydroids, from Massachu- 

 setts Bay to Kew Haven, Conn., is a typical Cratena Bergh* (= Cavo- 

 I'ma Alder & Hancock = Mo7itagua auth.), and is very closely allied to 

 C. aurantiam (A. & H.) of Europe, with which its dentition agrees very 

 nearly, even in minute details. In C. gymnota the coloration, also, is 

 often similar to that of C. aurantiaca, but the dorsal papill* are fewer 



* In tlie excellent work of G. O. Sars this generic name has been, by some oversight, 

 misapi)liecl, in place of Cuthona, to include C. nana, which was the original type of 

 Cuthona Alder & Hancock. 



