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“Genus Pterocypridina n. gen.
Diagnosis.
Shell. The height of the shell is about 2/3 of the length. The dorsal margin is a little more arched than the ventral. Rostrum is rounded anteriorly and weakly pointed inferiorly. The posterior part of the shell forms a low process or flange with its dorsal corner bent upwards, or a rounded triangular process well set off from the dorsal margin. The shell halves (included the rostrum) have lateral wing- or lobe-like processes. In one species these processes are found both on the rostrum and on the posterior part of the shell, in another only on the posterior part of the shell, in a third only on the rostrum. The surface of the shell is covered either with scales or with ridges and minute grooves.
First Antenna. In the only species (P. alata) of which the male is known the proximal filament of the b- and c-bristles bear at the end a large disk-formed sucker; these filament are the only sucker-bearing filaments. The f- and g-bristles have proximally a dense clothing of very thin, long filaments. The 1st antenna (in both sexes) is characterized by having a short 3rd joint (its length being less than ½ its width) with the dorsal and ventral margins of almost the same length.
Second Antenna. The endopodite is short, unsegmented. The exopodite has short or medium-sized basal spines. The distal 3/4 of the ventral margin of the bristle of the 2nd joint has a row of 6-12 short, blunt spines, otherwise the bristle is bare. The natatory bristles of the 3rd – 4th joints have proximally along the ventral margin a series of short spine-like hairs.
Mandible. Basale has ventrally only one d-bristle, this is very stout and provided with wreaths of long hairs. The two c-bristles are shorter than the height of the joint. On the second endopodite joint the spines of the disto-ventral pair are both pointed, and of about equal size. The number of coarsely pectinate cleaning bristles is very low (1-2), or such bristles are completely lacking. Two of the claws of the end-joint are pectinate proximally.
Maxilla. The exopodite is well-developed with the usual 3 bristles. The 1st endopodite joint has 2 alpha-bristles and 2 beta-bristles, the alpha-bristles are either bare or plumose. The cutting edge forms a large single or bifurcate tooth. The 2nd joint has 3-4 a-bristles, the longest may be pectinate, the others are always bare; 2 or 3 pectinate b-bristles, 3 pectinate c-bristles and 2 or 3 d-bristles.
Fifth Limb. The epipodial appendage has 45-50 bristles; the endites are of the usual pattern. The anterior group of bristles on the 1st joint has 3 or 4 bristles. The main tooth does not differ from that in the other genera. The 2nd exopodite joint has 4 a-bristles with strong teeth and 7 pectinate b’ + b’’-bristles. The inner lobe has one proximal and 1 or 2 terminal bristles; the outer lobe is well developed, either with 2 plumose bristles or with one plumose and one bare bristle. The 4th and 5th joints are completely united with a total of 4 or 5 bristles.
Sixth Limb. This limb could only be described for P. alata and excreta; it is characterized by a large number (6-8) bare bristles at the place of the epipodial appendage. The numbers of bristles on the endites are rather low; on the 4th endite only 3 terminal and 1 medial bristle. The 8-10 bristles of the last exopodite joint are placed in a continuous series along the ventral margin.
Seventh Limb. Each of the two distal groups of cleaning bristles have 5-8 bristles; in P. alata and P. excreta is on each side more proximally one single bristle; in P. birostrata are 8 scattered on each side more proximally. The end-comb consists on each side of 5-11 teeth; the chitinized jaw opposite the comb terminates in 1 or 2 short, curved teeth.
Furca. Each lamella has 5-10 claws, all decreasing gradually in length the more dorsally they are placed; the 2nd, or the 2nd and the 4th, claws are united with the lamella.
The Upper Lip (only known for P. alata and P. excreta) is without larger tusk-like processes.
The Lateral Eyes and the Median Eye are well-developed.
The Frontal Organ is short, pear-shaped, ending in a pointed tip.
Remarks.
The genus Pterocypridina has been established to include three species which are characterized by having lateral processes from the shell (including the rostrum); processes which are not just simple tubercles, ridges or elevations, but formed like wings, keels or lobes. In the genus Cypridinodes rather large tubercles or even low lobes may be found laterally on the shell, but from this genus Pterocypridina is clearly distinguished by a number of characters: its short one-jointed endopodite of the 2nd antenna, the presence of only one d-bristle on the basale of the mandible, its pointed slender tip of the largest alpha-bristle of the maxilla, and the lacking of cleaning bristles between the jaw and the comb of the 7th limb.
The two species P. alata and P. excreta resemble one another closely, and it is natural to unite them in one genus. However, they are still separated from one another : P. alata has the 2nd and 4th claws of furca united with the lamella, P. excreta only the 2nd; P. elate has only 2 bristles on the 9th joint of the exopodite of the 2nd antenna, P. excreta 4 bristles.
The 3rd species P. birostrata is only included in the genus with some doubt, as it in a number of characters differs considerably from the two other species. It is in many characters close to Skogsbergia and Paravargula (due to the defect upper lip in the single specimen available it can not for certain be established to which of the genera it is most closely related). If it did not possess the large well-defined lateral lobe on the rostrum, which is not found in any species of Skogsbergia and Paravargula it could naturally have been included in these one of genera. The only specimen present in the material was rather defect, and therefore the description is not complete. When more specimens (including males) become known, the position of the species within the sub-family can be more definitely settled.”
(Poulsen, 1962, pp.234-235)
