182 RlcJuirdson — Sphseromidai j'wiii Alaskan Waters. 



This genus differs from the genus Ancinus of Mihie Edwards — 



1. In having uropoda with two hranches instead of one. 



2. In having the ahdomen entire and not truncate at the tip. 



8. In tlie proniinent projection of tiie anterior and lateral margins of 

 the head. 



4. In the concealment of the anteiin;e, which are verj- conspicuous in 

 the Ancinus. 



Tecticeps alasceiisis sj). nov. 



Outline of ])ody oval. Surface (jnite smooth, lint covered with little 

 points of depression. 



Head large; twice as long as any one of the thoracic segments. The 

 anterior margin is produced in a way to conceal the antennae, as are also 

 the antero-lateral margins, making the anterior portion of the head in 

 front of the eyes much broader than the posterior portion, and forming 

 very acute antero-lateral angles. This frontal margin forms a very broad 

 obtuse angle with its apex in the median line. On either side of this 

 apex to the antero-lateral angle this portion of the head is somewhat de- 

 pressed. The antennfe are not conspicuous, lying concealed beneath the 

 frontal margin of the liead. The first pair extends 

 Chi:£n^j==>- ^^ ^''^ iwsterior angle of the first thoracic segment ; 

 its flagellum contains ten articles. The second pair 

 reaches the middle of the second segment ; its flagel- 

 lum is twelve-jointed. The eyes are dorsally situ- 

 ated on the i)Osterior half of the liead. 

 Fig. lo.-a, Antenna of rpj^^ thoracic Segments are about equal in length. 



''f 2d iiair X s-^ "^^'^ ^^"^^ *^"^ extends laterally around the posterior 



portion of the head, forming a broad plate at the side 



of the segment. The epimera of all the segments are about twice as broad 



as long, with the exception of those of the fifth segment, which are 



nearly square and very conspicuous. 



The first segment of the abdomen has three suture lines, and its pos- 

 terior margin jirojects down at the sides over the terminal segment. The 

 terminal segment is triangular, and has a very pointed 

 extremity. The uropods differ considerably. The in- 

 ner one is In'oad and tai^ering. and does not reach the tip 

 of the abdomen. The outer one is slender and shar))ly 

 pointed, and extends beyond the abdomen. 



The first pair of legs are subchelate, as are also ,the 



second pair. In the first jiair the propodus is large and 



oval in shape, and bears in the imlma a row of stiff Fig. n.-a, Mandi- 



bristles at regular intervals and pointing obliquel v in the ^^^ ' *' Mandibu- 

 . . , ., ., ■ , e a -1- " ■ i.- lar appendage. 



same direction, wlule a thick row of hue cilia, pointing ^ ^,/ 



^ 5/3- 



ol)liquely in the oi)posite direction, cross these almost at 

 right angles. The dactylus terminates in a single hook, at the base of 

 which two smaller hooks are situated. In the legs of the second pair the 

 propodus is irregular in shape with an indication of a rudimentary 



