114 BULLETIN 34, UNITED STATES NATIONAL MUSEUM. 



or sometimes blackish, and the muzzle is rather abruptly shortened. 

 The tail has a fin at its extremity, which extends also well anteriorly on 

 the superior edge. The digits are flattened, and their apices are pro- 

 tected in many specimens by a horny cap of a blackish color. This 

 larva, however, ditfers from that of other species of the genus in other 

 characters of more importance. First, There are no teeth on the splen- 

 nial bone. (Ihavenotexamined very small specimens.) Secondly. The 

 branchia3 have a peculiar shape.* There are no i^rocesses such as exist 

 in all other Urodele larvtie, but the fimbriae arise from the edges of the 

 vertical lamince, which separate the pharyngeal fissures (Fig. 3, p. 3, No. 

 7). The superior part of the lamina is a little more produced than the 

 inferior, so as to form in some specimens, on the third lamina, a short 

 process. This type of external branchiae does not resemble any of 

 those of the perennibranchiate types, where there are always proc- 

 esses which are frequently furnished with more or less numerous rami. 

 Thirdly. The teeth of the larva are stronger than in the adult. They 

 are compressed, double-edged, and acute, having thus a dagger-shape. 

 They can inflict a severe bite. 



As they approach maturity the marbled colors begin to appear. 

 They can probably reproduce without undergoing a metamorphosis, 

 since I have found eggs in the ovaries ready for deposit. 



I observed these larva? in some tributaries of the McCloud Eiver, 

 near Baird, Cal. They swam with great rapidity, darting about and 

 hiding themselves among the fallen leaves that covered the bottom. 1 

 took from the stomach of one of them a larva of its own species of one- 

 third its size. They are common in the mountain streams of northern 

 California™and western Oregon. The skeleton of a large specimen from 

 Salem, Oregon, is figured on Plates 20-21.* The hyoid apparatus of a 

 younger larva is represented on PI. 22, figs. 2-3. 



LINGU^LAPSUS Cope. 



American Naturalist, 1887, x>. 88. 



Otoglossal cartilage free from the basibranchial, and capable of an- 

 teroposterior movement on it, and not forming a ring. Tail cylindric. 



In other respects this genus is identical with Amblystoma. The dif- 

 ference in the otoglossal cartilage is great, and is presented under mod- 

 ifications by two species. This cartilage is drawn backwards by two 

 pubohyal muscles, and forwards by two corresponding geniohyals. 

 (Plate' 22, figs. 10-13.) 



The species of Linguselapsus resemble in the character of their tongue 

 and vomerine teeth the type of G. microstomus and the genus Ohondro- 



* See page 31, antea. 



* The fourth, ceratobrancliial was present in this specimen, but was overlooked by 

 the artist. 



