54 CARL BOVALLIUS, AMPHIPODA HYPEKIIDEA. I. 2. THAUMATOPSIDiE. 



with strong, feebly curved spines and intermixed slender, short hairs; at the lower corner 

 there is a stronger spine, twice as long as the preceding. The secondary lamina, or the 

 palp, is half as broad as the stem of the principal lamina, curved, longer than the ma- 

 xillar process; the sharp-pointed apex is crenulated with short, unequal teeth. 



The second pair of maxillce (PI. IV, fig. 7, 8 and 9) consist of a single lamina, 

 the basal portion broad, rounded, the terminal part abruptly narrowed, the outer margin 

 curved, the inner nearly straight, the apex armed with ten to twelve sharp, short teeth. 



The maxillipeds (PI. IV, fig. 10) are well developed, consisting of an almost cubical 

 basal joint articulating with the second larger joint. This second joint carries at the middle 

 of the lower margin a median lobe or inner lamina, broader below than at the base, thick, 

 hollowed, forming a kind of tube; the lower, feebly excavated margin is finely serrated. 

 At the sides of this median lobe the second joint carries as usually two lateral lobes or 

 outer lamina?, they are feebly curved on the outer margins, smooth, the inner margins 

 are strongly denticulated, each with twelve smaller and larger, sharp teeth. 



The perceon has higher and more raised dorsal portions of the segments than in 

 the other species. The articulation between the first and second segment is more distinct 

 than in Thaumatops longipes, and just as perfect as between the second and third seg- 

 ments. The dorsal keel is very sharp, but does not show any spine-like prominences on 

 the first four segments, on the fifth segment there is a blunt prominence at the anterior 

 corner of the keel, on the sixth two sharper prominences, one at the anterior and one at 

 the hinder corner, on the seventh segment there are three such prominences, two anteriorly 

 and one at the hinder corner. The hinder margins of all the segments are fringed with 

 minute spines. From the anterior margin of the third segment runs a sharp ridge over 

 the lower parts of the pera?onal and pleonal segments, ending at the hinder margin of 

 the first ural segment; this ridge is smooth in the third to sixth segment, but feebly 

 spinulous in the seventh, and in the pleon. The pergonal segments are growing rapidly 

 narrower below; the hinder corner of the lower end is produced into a more or less sharp 

 tooth, longest in the first segment. The first two segments reach farther down than the 

 following. The first segment is a little shorter than the second, Avhich is longer than 

 each of the following segments except the seventh. The third to sixth segments are equal 

 in length; the seventh is scarcely longer than the second. The length of the whole pe- 

 rteon is about 48 mm. 



The epimerals are coalesced with the corresponding segments. 



The branchial sacks are fixed to the second to sixth pairs of perasopoda, those of 

 the second and third pairs are very small, those of the fifth and sixth pairs much longer, 

 as long as half the femur of the corresponding pairs. 



The Jirst pair of peraiopoda (PI. IV, fig. 11, 12 and 13) equal a third of the length 

 of the third pair. The femur is considerably shorter than the four following joints to- 

 gether, prismatic; along the front margin it carries eight unequal teeth, on the hinder 

 margin two teeth, the lowest formed by the produced, lower hinder corner of the joint; 

 the inner margin is smooth. The genu is broader than long, the lower hinder corner 

 produced into a strong, curved tooth. The tibia is short, the hinder portion broader, 

 produced, embracing the lower part of the carpus. The carpus is long, longer than the 



